Untitled Flashcards Set

Week 6; Spine:
The vertebral column:

• If the 5th lumbar vertebrae fuse with the sacrum, = sacralization

• If the 1st sacrum vertebrae break off and joints the lumbar, = lumbarilization  

• Often called the spinal column or spine

• It consists of approx. 33 vertebrae 

• The vertebral column serves 2 functions 1)support trunk 2)protect the spinal cord

• The main role is to support the trunk and protect spinal cord 

• movements= flexion, extension, lateral flexion, rotation 

- certain movements are a combination of 2 primary movements 

• Intervertebral discs lie between adjacent vertebrae bodies

Spine development:

Fetal: The vertebral column is C-shaped

Newborn: slight flexure present between lumbar and sacral areas (concave curve)

4 years: another concave curve in the cervical region

Adult: thoracic and sacral curvatures represent the remains of the original curve 

• The spine changes its shape due to spinal stability 

• Spine development is consistent with the mobility level 

• Cervical and lumbar concavities are directed posteriorly (lordodic curve)

- allow for a better balance of body weight on the vertebral column 

- Cervical lordodic curve- develops when a child attempts to hold head up 

- Lumbar lordodic curve- develops during standing and walking stages 

Typical Vertebra:

• Vertebral arch= pedicles and laminae 

• Spinous process= midline posterior projection, muscle attachment 

• Body: cylindrical and heavy made of spongy bone and covered by thin layer of cortical bone

• Pedicles (2) on the posterior side, extend posteriorly and connect to laminae 

- form the vertebral arch

• Vertebral foramen: between vertebral arch and body

• Vertebral canal: successive vertebral foramina, where the spinal cord lies 

• Transverse process: project laterally at point of union of pedicle and laminae 

- allow for muscle attachment and articulation with ribs 

Lateral view of typical vertebra:

• Inferior vertebral notch + superior vertebral notch of lower pedicle form intervertebral foramen

- spinal nerve exits from vertebral canal 

• Zygapophyses (z joints): junction of pedicle and lamina

- facets for articulation with vertebrae above and below 

• Spinous process: midline posterior projection from laminae 

- allow attachment of muscles 

Cervical vertebrae:

• Each transverse process has a foramen (transverse foramen)

• Bodies are delicate, greatest diameter is lateral one 

• Superior articular processes face upward and backward 

• Inferior articulation processes face forward and downward

Cervical vertebra:

What features are specific to the vertebrae in the cervical region- transverse foramen; bodies are thin and wide (not supporting much weight); 

• Get increasingly larger gradually

• C7 transition between cervical and thoracic 

Atlas:

• Superior articular facets are concave and articulate with occipital condyles of the skull 

• Inferior articular facets are flatter and articulate with axis 

Axis:

• Dens articulates with the anterior arch of the atlas and is held in position by ligament 

• Dens acts like a pivot around which the atlas rotates 

Superior view of C1:

Thoracic Vertebra:

• Superior and inferior articular facets almost in frontal plane 

• No foramina

• Costal facets articulate with ribs

• Spinous processes are long, slender, directed downward and overlap each other 

Lumbar Vertebra:

• Bodies massive

• Spinous processes are much heavier and broader 

• The height of lamina is less than the body 

• Transverse processes are long and slender 

Thoracic vertebrae vs Lumbar vertebrae:

Sacrum and Coccyx:

• Pelvic sacral foramina (ventral rami of S1-S4 exit)

• Transverse processes articulate with hip

• Median creat: rudimentary spinous processes

• Dorsal sacral foramina (dorsal rami of S1-S4)

• Coccyx: 3 or 4, 1st is usually separate from the rest 

- rudiments of vertebral bodies 

Sacrum and coccyx:

• Vertebral foramen= sacral foramen

• Canal of sacrum= sacral canal

• Sacral hiatus= deficient caudal portion of canal 

Week 6; Vertebral Joints:
Joints of the vertebral column:

• Play a role in weight-bearing and less related to movements

• Vary in size and thickness in different regions

• The structure of the disc is related to the normal curvature of the spine 

• Most superior between C2 and C3, most inferior between L5/S1

• Composed of annulus fibrosis ~ surrounds nucleus pulposus

Annulus Fibrosis and Nucleus Pulposis:

• Each annulus fibrosis inserts into smooth, rounded rims on articular surfaces of vertebral bodies

• Nucleus Pulposis attached to rough articular surface of vertebral bodies 

- More posterior than central ~ high water

- shock absorber for axial forces ~ high elastic

- becomes broader when compressed ~ avascular 

Anterior Longitudional Ligament:

• strong, broad fibrous band which covers and connects anterior aspects of vertebral bodies and intervertebral discs 

• Stretches from sacrum to C1 and occipital bone 

• Fibres are firmly fixed intervertebral discs and periosteum of bodies 

• Maintains stability of joints between vertebral bodies and prevents hyperextension of the spine 

Posterior Longitudional ligament:

• More narrow and weaker than anterior longitudinal ligament

• Runs along the posterior aspect of vertebral bodies within the vertebral canal

• Attached intervertebral discs and posterior edges of vertebral bodies from axis (C2) to sacrum 

• Prevents hyperflexion of spine and posterior protrusion of nucleus pulposus of disc 

Joints of Vertebral Column:

Zygapophyseal (Z) joints:

• Synovial joints between superior and inferior articular processes 

• Permit gliding movements between vertebrae 

• Surrounded by  loose articular capsule attached to articular margins 

• Longer and looser in the cervical region to allow more flexion

• Control flexion, extension, and rotation between adjacent cervical and lumbar vertebrae 

Ligaments of intervertebral joints:

• Ligamenta flava joins laminae of adjacent vertebral arches 

• Extend almost vertically from the lamina above to the lamina below

• Helps preserve normal curvature of spine and straightens it after its been flexed 

- Interspinous ligaments (weak) and supraspinous ligament (strong): join adjacent spinous processes 

- Ligamentum nuchae: (superior aspect of ligaments) triangular median septum between muscles on each side of posterior aspect of neck 

- Intertransverse ligaments: connects adjacent transverse processes 

Suboccipital (Craniovertebral) Joints:

Superior view:

• Between skull and C1= atlano-occipital 

- permit nodding of head

• Between C1 and C2=atlano-axial

- permits rotation of head (skull and C1 rotate about C2) 

• Synovial joints only 

• No intervertebral discs 

• Transverse ligaments of axis: holds dens against the anterior arch of the atlas 

• Cruciform ligament= transverse + vertical ligaments from transverse ligament to occipital bone

• Alar ligament= extends from sides of dens to lateral margins of foramen magnum 

- check rotation and side-to-side movements 

Suboccipital ligaments:

• Transverse ligaments of axis: holds dens against the anterior arch of the atlas 

• Cruciform ligament= transverse + vertical ligaments from transverse ligament to occipital bone

• Alar ligament= extends from sides of dens to lateral margins of foramen magnum 

- check rotation and side-to-side movements 

• Tectorial membrane: superior continuation of posterior longitudinal ligament

- extends from the body of the atlas to the occipital bone

- covers altar and transverse ligaments 

Neck and back muscles:

Extrinsic Back Muscles:

• Superficial: trapezius, latissimus dorsi, levator scapulae and rhomboids 

- produce and control limb movements 

• Intermediate: Serratus posterior (superior/inferior) 

- Proprioceptive rather than motor (provide information to our nervous system in terms of what position at any given time) 

Serratus Posterior Superior/Inferior:

Serratus Posterior Superior:

• Origin- Lower party of ligamentum nuchae and spinous processes of C7-T2/3

• Insertion- 2nd-5th ribs 

• Nerve Innervation- First 3 or 4 intercostal nerves (i.e. ventral rami of spinal nerves)

• Action- Assists in elevating ribs ~ increasing size of thorax 

Serratus Posterior Inferior:

• Origin- T11-L2 spinous processes 

• Insertion- 9th-12th ribs 

• Nerve Innervation- 9th-12th intercostals nerves 

• Action- Draw lower ribs downward to enlarge the thoracic cavity and stabilize ribs against the pull of the diaphragm (during heavy breathing) 

Intrinsic (Deep) Back Muscles:

• Maintain posture

• Control movements of spine

• Extend from pelvis to cranium

• Formed by a number of incompletely separated layers of muscles 

• Distinguished by the direction of fibres and length 

• Long muscles are superficial 

• Intermediate muscles are deep 

• Short muscles lie against vertebrae 

• All muscles are covered by upper limb muscles and attach to spinous processes 

• Muscles of the back work together as large groups 

• Back muscles are built for endurance 

Back Muscles; Superficial layer:

• Extrinsic back muscles on the left + any grey and on the right side, the red is intrinsic back muscles 

• Intrinsic keep the spine erected; trunk from falling down in respect to gravity

Splenius Capitis & Splenius cervicis 

• Most superior of the intrinsic muscles 

Splenius Capitis:

• Origin- lower half of ligamentum nuchea and spinous process of C7 and T1-T3/4

• Insertion- Mastoid process and occipital bone 

• Nerve Innervation-  Both are innervated by dorsal rami of middle and inferior cervical spinal nerves 

• Action- neck extension and lateral rotation of neck

Splenius cervicis:

• Origin- Spinous process of T3-T6

• Insertion- Transverse processes of C1&C2-4

• Nerve Innervation- Both are innervated by dorsal rami of middle and inferior cervical spinal nerves 

• Action- unilateral= rotate head and cervical spine toward the same side ; if they work together Bilateral= assist in extension of head and neck 

Intermediate Layer of Back Muscles:

Erector Spinae:

• Large mass of muscle with origin over the upper sacral and lower lumbar vertebrae 

• Origin- Posterior surface of sacrum, iliac crest and spinous processes of T11-L5

• Nerve innervation- dorsal rami of spinal nerves

• Action- Extends thoracic vertebral column 

Long muscles of back:

Illiocostalis System:

Iliocostalis Lumborum:

• Origin- Iliac crest and sacrum 

• Insertion- slips into lower 6/7 ribs

Iliocostalis Thoracis:

• Origin- upper borders of lower 6/7 ribs (medial to iliocostalis lumborum insertion)

• Insertion- lower borders of upper 6 ribs 

Iliocostalis Cervicis:

• Origin- angles of upper 6 ribs (medial to iliocostalis thoracis insertion)

• Insertion- transverse processes of C4-C6

• Illium is the common origin of the erector spinae muscle group 

Longissimus System:

Longissimus thoracis:

• Origin- common tendon of erector spinae

• Insertion- lower 9 or 10 ribs and adjacent transverse processes 

Longissimus cervicis:

• Origin- Transverse Processes of T1-T4/6

• Insertion- transverse processes of C2-C6

Longissimus capitis:

• Origin- medial to superior end of cervicis

• Insertion- mastoid process (lateral)

Spinalis System:

• Deepest of the Erector spinae muscles 

Spinalis Thoracis:

• Origin- Common tendon and spinous processes of T11-L2

• Insertion- upper thoracic spinous processes

Spinalis cervicis:

• Origin- ligamentum nuchae and spinous process of C7-T1/2 

• Insertion- spinous process of axis (C2) mabe C3 and C4

Spinalis Capitis:

• Not a separate muscle from spinalis cervicis 

• Medial part of semispinalis capitis 

Deep Layer:

• Shortest and closest to vertebrae 

• Transversospinalis group - extend from the transverse processes to the spinalis processes of the vertebrae 

• Smallest of group of muscles 

Semispinalis muscle:

• Deep to the erector spinae 

• Most arise from transverse processes and travel upwards and medially to attach to spinous processes

• Divided into 3 parts: all innervated by cervical and thoracic spinal nerves 

Semispinalis capitis:

• Medial part

• Origin- Transverse processes of T1-T6/7 and articular processes of lower cervical vertebrae

• Insertion- Occipital bone

• Action- extend head work with trapezius 

Semispinalis cervicis:

• Origin- transverse processes of T1-T5/6

• Insertion- Spinous processes of C2-C5 (heaviest on axis)

• Action- Extend spine at cervical region

Semispinalis Thoracis:

• Origin- transverse processes of T7-T12 

• Insertion- Spinous processes of C6-T4

• Action- extend spine (thoracic region)

Multifidus:

• Deep to semispinalis muscles

• Continuous muscles mass (sacrum to cervical) do not extend to skull 

• Very heavy in the lumbar region, thinner in thoracic and thick in upper cervical 

• Origin- Sacrum and transverse processes of lumbar to lower cervical vertebrae

• Insertion- Spinous processes of lumbar vertebrae to C2 

• Action- (bilaterally): extend spine (cervical and thoracic); (unilaterally): rotate spine towards opposite side and lateral flexion 

Rotatores (Rotators):

• Sacrum to C2 

• Shorter muscles than multifidus 

• Short rotators pass from one vertebra to the one above

• Long rotators pass from one vertebra to two above 

• Origin- single transverse process 

• Insertion- single spinous process 

• Action- rotate(unilaterally) and extend spine (bilaterally) 

Quadratus Lumborum:

• Deepest of the muscles- extends to abdominal muscles (deepest of the abdominal muscles) 

• Origin- Posterior iliac crest

• Insertion- Last rib and transverse processes of first through fourth lumbar vertebrae

• Nerve Innervation- Lumbar plexus T12, L1/2/3

• Action- (unilaterally): laterally tilt/elevate the pelvis, laterally flex the vertebral column to the same side, assist to extend the vertebral column (bilaterally): fix the last rib during forced inhalation and exhalation

Muscles of the abdominal wall:

Thoracic and abdominopelvic cavities:

Muscles of the abdominal wall:

• Linea alba- called white line… in later stages of pregnacy turns dark and is called nagra (black line); identifies when the women is going to go into labour 

• 5 paired muscles in anteriolateral wall:

- 2 vertical muscles: contained within the rectus sheath

- 3 flat muscles; anteriorly form strong aponeuroses (layers); close to midline forms rectus sheath 

Aponeuroses:

• Flat muscles make this up 

• Since fibres cross each other it prevents tearing and makes that part of the body strong

3 flat muscles:

External Oblique:

• The most superficial muscle of this group and the largest

• Origin- External surface of 5-12 ribs 

• Insertion- Linea alba, pubic tubercle, and anterior iliac crest 

• Action- assists in torsional rotation of trunk 

• Fleshy part= lateral wall

• Aponeuroses= anterior wall

• Inferior border= Inguinal ligament

• Digastric muscle (helps in digestion) 

Internal Oblique:

• Run in the opposite direction of external obliques 

• The second layer of the lateral wall

• Thin, fans out anteriomedially 

• Origin- thoracolumbar fascia, anterior ⅔ of the iliac crest, and connective tissue lateral 2/3 of the inguinal ligament 

• Insertion- Inferior border of 10-12 ribs, linea alba, and pecten pubis

• Action- compress and support abdominal viscera, flex and rotate trunk 

Transverse abdominis:

• Internal safety belt 

• Closest to visceral organs 

• Origin- internal costal cartilage ribs 7-12, thoracolumbar facia, iliac crest and lateral ⅓ inguinal ligament deep connective tissue 

• Insertion- Linea alba and internal oblique aponeurosis, pubic crest and pectin pubis

• Fibres: transverse, circumferential orientation 

• Compress contents of the abdomen and increase intra-abdominal pressure 

• Most fibers run transversally

• Inferior fibers run parallel to internal oblique

2 vertical muscles:

Rectus Abdominis:

• Where you get your 6 or 8 pack

• Principle vertical muscle 

• Origin- Pubic symphysis and pubic crest

• Insertion- xiphoid process and 5-7 costal cartilage 

• Action-flexes trunk (lumbar) and compress abdominal viscera; stablizes and controls pelvis tilt

• Pairs separated by linea alba 

Pyramidalis:

• Small, insignificant triangular muscle 

• Absent in 20% of population (1 in 5)

• Anterior to the inferior part of rectus abdominis 

• Origin- the anterior surface of pubis and anterior pubic ligament

• Insertion- linea alba

• Action- Tenses linea alba 

Functions and actions of Anteriolateral Abdominal muscles:

• Strong support abdominal wall 

• Support and protect abdominal viscera

• Compress abdominal contents: affects intra-abdominal pressure (opposite to diaphragm) 

• Move trunk 

• Maintain posture 

Bones and joints of the pelvis:

Bones:

Pelvis= hip bones, sacrum, and coccyx

Hip Bone= ilium, ischium and pubis 

Hip Bones:

• Ilium:

- Wing- muscle attachment 

- Iliac crest: gives rise to ab muscles 

- Iliac tuberosity: ligaments across form sacroiliac joint 

- Body extends inferiorly to superior 1/3 of acetabulum

• Ischium:

- Body: forms 1/2 of the lower ⅔ of acetabulum 

- Ramus: forms posterior wall and part of the inferior wall of obturator foramen 

- Ischial tuberosity: when you sit down this is what you sit on 

• Pubis

- Body: junction between superior and inferior rami

- Crest: anterior superior surface of body

- Tubercle: end of crest

Pelvis:

• Pelvis= 2 hip bones + sacrum and coccyx

• Major (false) pelvis= flared wings of ilia (lower boundary for abdomen) 

• Minor (true) pelvis= sacrum, pubes, ischia and lower ilia (inlet and outlet are bridged by the diaphragm muscles)

Hip bone:

Sacrospinous ligament: sacrum and coccyx to ischial spine 

• Converts great sciatic notch into greater sciatic foramen

Sacrotuberous ligament: sacrum and coccyx to ischial tuberocity 

• Converts lesser sciatic notch into lesser sciatic foramen 

Pubic Symphysis Joint:

• Unites two pubes (left and right pubic bones)

• Interpubic disc: attached to symphysis

• Barely moveable but does become moveable during pregnancy

• Resists flattening of the pelvis and the consequent movement of sacroiliac joint 

• Women have large Q angles while men have smaller

Sacroiliac Joint:

• Small joint cavity and ligaments between sacrum and ilium

• Body weight tends to force upper end of sacrum inferior and anterior between ilia 

• Lower end swings posteriorly 

• Ventral/anterior sacroiliac ligament: thin and anterior 

• Dorsal/posterior sacroiliac ligament: strong and blends with interosseous sacroiliac ligament

• Joints posterior and superior cavity 

Femur: Ligaments, movements, and articulations:

Femur:

• Longest bone in the body 

• Head: rounded and articulates with acetabulum to hip joint

• Shaft: continuous with neck 

• Between proximal and distal ends 

• Neck: does not project in the direction of shaft but an angle (~126 deg) of inclination

• Greater Trochanter: projects upwards where neck joins shaft and is in line with shaft 

• Lesser Trochanter: posterior medial side of junction between neck and shaft

• Intertrochanteric crest: connection between two trochanters on the posterior side 

• Linea Aspera: formed by medial and lateral lips 

• Condyles (2): articulate with knee joint, anteriorly with patela, posteriorly form intercondylar fossa 

• Epicondyles (2): muscle attachment 

• Adductor tubercle: projection off medial epicondyle 

• Popliteal surface: posterior, between linea aspera and intercondylar fossa 

Hip Joint and capsule:

• Forms connection between lower limb and pelvic girdle

• Strong and stable multiaxial ball and socket joint

• Most moveable joint in our body 

• Weight is transferred to head and neck of femur during standing 

• Ligament of head: prevents posteriosuperior displacement in infants 

• Acetabular labrum: attaches to edge and makes acetabulum deeper 

• Labrum bridges notch by transverse acetabular ligament 

• Strength is due to shape and ligaments rather than muscles 

• The joint capsule is very strong (lower anteriorly than posteriorly) (ligament attachment to femur in spiral) 

Hip and thigh: ligaments and movements:

Iliofemoral Ligament:

• From ilium below ASIS 

• Covers most of anterior aspect of femur (2 attachments)

• Inverted Y-shaped and called “Y ligament of bigelow” prevents undue extension at joint and keeps posture erect without muscular action 

Pubofemoral Ligament:

• From pubic portion of acetabular brim and anterioinferior aspect of joint

• Prevents excessive abduction of femur

• Prevents hyperextension

Ischiofemoral Ligament:

• Arises from the ischial rim of the acetabulum 

• Covers the lower posterior portion of the joint 

• Travels transversely

• Tightens during extension 

• Make the extended position the most stable one 

Nerves and Blood Supply:

• Innervation of hip: (lumbar plexus) femoral nerve, obturator nerve, accessory obturator nerve

- (sacral plexus) superior gluteal nerve and nerve to quadratus femoris muscle

• Blood supply: (upper end) medial and lateral circumflex femoral arteries, superior gluteal artery and obturator artery 

Pelvic Movements:

• Involve lumbar and hip joint

- upward rotation (posterior tilt)

- downward rotation (anterior tilt) 

- lateral rotation 

- lateral tilting 

Hip Movements:

• Flexion: thigh brought forward and up towards abs

• Extension: thigh moves laterally from midline 

• Adduction: brings limbs together

• Circumduction= flexion, abduction, extension, and adduction

Landmarks:

• Anterior ASIS, pubic tubercle, inguinal ligament, patella, enlarged ends of femur

• Lateral Greater Trochanter

Blood Vessels:

• External iliac artery to femoral artery at inguinal ligament (femoral triangle)

- Primary artery of lower limb

- Popliteal artery above knee

• Deep artery of thigh: largest femoral branch

• Middle circumflex supplies blood to heas and neck of femur 

• Obturator supplies adductor muscles 

• Accompanying veins have same names 

Lumbrosacral Plexus:

Lumbar Plexus:

• Supplies muscles and skin on anterior and medial sides of thigh 

• Supplies skin on medial side of leg and foot

• Made up of nerves from ventral of L1-L3, variable part of L4 and some communication from T12

• Lies on posterior wall of abdomen 

• Origin is embedded in psoas major muscle 

• L1 divided into 2 branches: upper (iliohypogastric and ilioinguinal nerves) inervates lowermost part of abdominal wall 

• Lower joins branch of L2 and forms genitofemoral nerve~ scrotum/labia majora and some skin on upper anterior surface of thigh

• Anterior branches:

- L2-L4 form obturator nerve (medial muscles of thigh)

- L3-L4 form accessory nerve in ~8-10% of plexus 

• Posterior Branches: 

- L2 and L3 ventral rami form lateral cutaneous nerve of thigh 

- L2 and L3 join L4 to form femoral nerve

- L4 divided into 2 parts: 

- 1. Helps form obturator and femoral nerves (if this is not present= prefixed)

- 2. Forms sacral plexus (if this is not present= postfixed)

Sacral Plexus:

• Supplies posterior skin and muscles of thigh

• Supplies muscle of gluteal region

• Gluteal nerves and common fibular are distributed to extensor muscles of gluteal region and of leg 

• Tibial nerve and it sderivativves supply caudal flexor muscles of thigh and flexors of leg and foot 

Anterior Thigh Muscles:

Anterior group: 

• Action- Flexion at hip and extension at knee

• Nerve Innervation- Femoral nerve 

Adductor Group:

• Action- Adduction and flexion of thigh 

• Nevre innervation- obturator nerve 

Posterior group:

• Action- extension at hip and flexion at knee 

• Nerve Innervation- Sciatic Nerve 

Fascia: 

• Deep fascia= fascia lata

• Facia lata- though layer that completely surrounds muscles of the thigh

• Laterally= thick longitudinal fibres form the iliotibial tract 

• IT tract- has 3-pronged origin= (anterior) from tensor fascia lata muscle, (posterior) insertion of gluteus maximus, between the crest of ilium 

- attached to femur by lateral intermuscular septum 

• Distally: reinforces knee capsule and attaches to lateral tibial condyle (anteriolarterally) 

• Posterolaterally: extends over gluteus medius

- continues on both sides of tensor fascia lata and gluteus maximus

- attaches to iliac crest, sacrotuberous ligament and ischial tuberosity

• Anteriomedially: attaches to inguinal ligament and pubis 

- sends medial and lateral intermuscular septa to the femur in lower part of thigh

- help form medial and lateral retinacula 

Anterior thigh muscles:

• Sartorius- most superficial 

• Tensor Fascia Latae

• Quadriceps femoris- made of 4 heads

• Articularis Genus

• Iliopsoas- 2 muscles 

• Psoas Minor 

Sartorius:

• Origin- ASIS

• Insertion- medial surface of shaft of tibia

• Action- Flexion at the hip, flexion at the knee, lateral rotation of thigh, and abduction of thigh

• Nerve Innervation- Femoral nerve

Tensor Fascia Latae:

• Lateral compartment muscle 

• Origin- Iliac crest (posterior to ASIS)

• Insertion- Iliotibial tract

• Nerve innervation- superior gluteal nerve

• Action- assist in flexion of thigh at hip and medially rotates thigh as it flexes

• Works with gluteus medius and minimus in abduction of thigh

Quadriceps femoris:

Rectus Femoris:

• Origin- Anterior Inferior Iliac Spine and ilium above acetabulum

• Insertion- Upon patella and through patellar ligament on to tibial tuberosity 

• Nerve Innervation- femoral nerve 

• Action- extension of leg at knee, only quad to knee, only quad to cross hip joint and so it flexes thigh at hip

Vastus Medialis, Lateralis and Intermedius:

Vastus Medialis:

• Origin- Medial lip of linea aspera (posterior) and lower part of intertrochanteric line (anterior)

Vastus Lateralis:

• Origin- Lateral lip of linea aspera (posterior) and intertrochanteric line (anterior)

Vastus Intermedius:

• Origin- anterior and lateral surface of femur shaft 

All:

• Insertion- patella (pulls through patellar ligament)

• Nerve Innervation- femoral nerve

• Action- Extend leg at knee

Articularis Genus:

• Origin- distal part of anterior femur surface

• Insertion- Upper part of the synovial membrane of knee joint

• Nerve Innervation- nerve to vastus intermedius (femoral nerve)

• Action- Draws synovial membrane upward as leg extends

Iliopsoas:

• Made up of 2 muscles: iliacus and psoas major 

• Same:

• Insertion- lesser trochanter

• Action- strong flexor at hip 

Psoas Major:

• Origin- anteriolateral aspect og lumbar vertebral bodies and transverse processes of lumbar vertebrae 

• Nerve Innervation- L2-L4 ventral rami 

Iliacus:

• Origin- inner surface of ilium 

• Nerve Innervation- femoral nerve 

Psoas Minor:

• Origin- Anteriolateral surface of T12-L1(L2)

• Insertion- Superior sams of pubis

• Nerve Innervation- Lumbar plexus (L1, L2)

• Action- upward rotation of pelvis 

Medial Thigh Muscles:

Medial (Adductor) Muscles:

• Pectineus

• Adductor Longus

• Adductor Brevis

• Adductor Magnus

• Gracilis

• Obturator externus

ALL:

Origin= pubis

A= adduction of thigh

NI= obturator nerve

BS= femoral artery

Pectinus:

• Origin- Superior ramis of pubis

• Insertion- Femur below lesser trochanter

• Nerve Innervation- Femoral (usually) or Obturator

• Action- Flex and adduct thigh at hip

Adductor Longus:

• Origin- Pubic tubericle

• Insertion- Medial lip of linea aspera (between vastus medialis and adductor magnus)

• Nerve Innervation- obturator nerve (anterior branch)

• Action- adducts and flexes thigh

Adductor Brevis:

• Origin- body and inferior ramus of pubis

• Insertion- Lower part of line between lesser trochanter and linea asera (pectineal line) and upper portion of linea aspera 

• Nerve Innervation- Obturator nerve 

• Action- Flex and adduct thigh

Adductor Magnus:

• Origin- Inferior ramus of pubis, ramus of ischium, and ishial tuberosity

• Insertion- Linea aspera (whole length), adductor tubericle (from ischial tuberosity)

• Nerve Innervation- Anterior Oblique fibers: obturator nerve (posterior branch) and straight posterior fibers: sciatic nerve

• Action- Adduct thigh, anterior oblique fibres flex thigh, straight posterior fibres extend thigh

Gracilis:

• Origin- Inferior ramus of pubis and ramus of ischium

• Insertion- medial surface of proximal end of tibia 

• Nerve Innervation- Obturator nerve (anterior branch)

• Action- Adduct thigh and flex leg (medial rotates flexed leg)

Obturator Externus:

• Origin- Outer surface pelvis, around obturator foramen, and obturator membrane

• Insertion- medial side of greater trochanter 

• Nerve Innervation- obturator nerve

• Action- laterally rotate thigh

Femoral Triangle:

• Superior boundary= inguinal ligament

• Medial boundary= the lateral border of adductor longus muscle

• Lateral boundary= sartorius muscle

• Floor= (medial to lateral) adductor lognus, pectineus, and iliopsoas

• Roof= formed by fascia lata 

• Contents (from lateral to medial)= the femoral nerve, the femoral, artery, the femoral vein 

• these structures are also within the femoral triangle: iliopsoas muscle, pectineus muscle, deep inguinal lymph nodes

Adductor (tendinous) Hiatus:

• Gap above adductor tubericle 

• Femoral vessels pass from anterior to posterior and change names to popliteal vessels 

Adductor Canal:

• Heavy fascia between adductor muscles and vastus medialis 

• Deep to sartorius 

• Anterior to adductor muscles

• Contains femoral vessels and branches of femoral nerve 

Nerve Innervation:

Posterior Thigh Muscles:

Posterior Thigh muscles:

• Semitendinosus

• Semimembranosus

• Biceps femoris

Semitendinosus:

• Origin- ischial tuberosity

• Insertion- medial side of tibia, inferior to tibial tuberosity

• Nerve Innervation- tibial part of the sciatic nerve

• Action- extends thigh at hip, flexes leg at knee, and medially rotates flexed leg

• Pes anserinus: tendons of semitendinosus, gracilis and sartorius 

Semimembranosus:

• Origin- lateral aspect of ischial tuberosity

• Insertion- posteriomedial aspect of medial tibial condyle

• Nerve Innervation- tibial part of sciatic nerve

• Action- extends thigh at hip, flexes leg at knee, and medially rotates flexed leg 

Biceps Femoris:

Long head:

• Origin- ischial tuberosity

Short head:

• Origin- linea aspera

Both:

• Insertion- posteriolateral aspect of knee joint onto head of fibula

• Nerve Innervation- sciatic nerve (tibial part to long head and common fibular part to short head) 

Popliteal Fossa:

• Where common fibular and tibial nerves separate 

Upper medial border= semitendinosus and semimembranosus

Upper lateral border= biceps femoris

Lower medial border= medial gastrocnemius

Lower lateral border= lateral gastrocnemius

Movements at the hip:

Movements at the knee:

Gluteal region:

Sacral Plexus:

• Formed by union of ventral rami of L4 and L5 (lumbrosacral trunk) and ventral rami of S1-S3/4

• Sciatic nerve has 2 branches:

1. Anterior Branch: Tibial nerve (L4-S3)

• Other anterior branches: posterior cutaneous (S1-S3)

2. Posterior branch: Common Fibular nerve (L4-S2)

• Other posterior branches: superior gluteal (L4-S1), inferior gluteal (L4-S2)

Gluteal Muscles:

• Gluteus Maximus

• Gluteus Medius 

• Gluteus Minimus

• Piriformis

• Obturator Internus

• Gemelli

• Quadratus femoris 

Gluteus Maximus:

• Origin- Sacrum, dorsal sacroiliac ligaments, small area of ilium and sacrotuberous ligament

• Insertion- Lateral portion of fascia lata, iliotibial tract and gluteal tuberosity

• Nerve Innervation- Inferior gluteal nerve

• Action- powerfully extend thigh, lateral rotation of thigh, abduct thigh, and adduct thigh

Gluteus Medius:

• Origin- major part of upper lateral surface of wing of ilium and covering fascia 

• Insertion- greater trochanter 

• Nerve Innervation- superior gluteal nerve 

• Action- strong abdutor of thigh. (anterior fibres) flex and medial rotation of thigh, (posterior fibres) extend and laterally rotate thigh 

Gluteus Minimus:

• Origin- Lower part of lateral wing of ilium

• Insertion- greater trochanter

• Nerve Innervation- superior gluteal nerve

• Action- strong abductor of thigh, medially rotate thigh, (flexion of thigh) 

Piriformis:

• Origin- pelvic surface of sacrum

• Insertion- inner surface of superior part of greater trochanter

• Nerve Innervation- branches of S1(S2) ventral rami 

• Action- laterally rotate thigh, abductor when flexed 

Obturator Internus:

• Origin- Inner surface of pelvis (obturator membrane and edges of obturator foramen)

• Insertion- medial surface of greater trochanter above fossa 

• Nerve Innervation- nerve to obturator internus

• Action- lateral rotation of thigh, abducts thigh when flexed 

Gemelli (superior and inferior):

• gemellus

Superior:

• Origin- Ischial spine

• Insertion- upper border of obturator internus tendon

• Nerve Innervation- nerve to obturator internus

Inferior:

• Origin- Ischial tuberocity

• Insertion- Lower border of obturator internus tendon

• Nerve Innervation- nerve to quadratus femoris

BOTH:

• Action- Lateral rotation of thigh, abducts thigh when flexed 

Quadratus Femoris:

• Origin- Ischial tuberosity

• Insertion- Posterior surface of femur between greater and lesser trochanter

• Nerve Innervation- Nerve to quadraus femoris

• Action- Lateral rotation of thigh and adducts thigh

Knee Bones:

• Anatomical name= tibiofemoral joint

• Hinge joint

Tibia and Fibula:

Tibia:

• Tibial candles receive weight transfer from femoral conyles

• Articular facet: articulation with fibula head

• Tibial tuberosity- rough part on anterior where patellar ligament attaches 

Fibula:

• Head: slender upper end, articulates with tibia not knee 

Patella:

• Largest sesamoid bone in body

• Triangular: apex on inferior end

• Posteriorly: smooth superior part for articulation with femur

• Inferior portion is rough for tendon attachment

• Interrupts quadriceps tendon to form patellar ligament 

Knee Joint Capsule:

• Anterior replaced by quadriceps on patella, and patellar ligament

• Medial and lateral patellar retinacula: formed by facia lata and expansions of quadriceps tendon

• Posterior oblique popliteal ligament consists of fibres from semimembranosus tendon

• Deep on posteriolateral side: popliteus muscle

• Arcuate popliteal ligament: strengthens upper edge of opening where popliteal muscles exits

Collateral Ligaments:

• (tibial Collateral) medial: from medial epicondyle of femur to medial surface of proximal end of tibia, attaches to medial joint capsule

• (fibular collateral) lateral: from lateral epicondyle of femur to head of fibula, no attachment to joint capsule (lies lateral to it)

• Lie within joint capsule:

• ACL- ascends from anterior area between tibial condyles, runs proximally posteriorly to back of the medial surface of lateral femoral condyle

• PCL- from the posterior intercondylar area, ascends proximally and anteriorly to lateral side of the medial femoral condyle 

• Tense, especially in extreme flexion and extension

• Stabilize knee in all positions

• Prevent anterioposterior displacement of tibia

• Limit rotation of femur on tibia

Joint Cavity:

• Usually continuous with suprapatellar bursa

• Subdivided bu structure lying deep to cavity

• Infrapatellar synovial fold: From posterior surface of patella and attaches to Inner borders of articular surfaces of both femoral and tibial condyles

• Infrapatellar fat pad: between patellar ligament and synovial membrane 

• Between femur and tibia:  divided into medial and lateral Parts separated by cruciate ligaments 

• Prepatellar bursa: between skin and interior lower part of patella and patellar ligament

• Subcutaneous Infrapatellar bursa: between skin and tibial tuberosity 

Anterior Lateral Ligament (ALL):

• Ligament doesn’t change lengths because it prevents side to side rotation

Menisci:

• Outer border attached to synovial and fibrous layers of capsule

•  medial meniscus is anchored by MC:

•  lateral meniscus: slight attachments to weak lateral part of capsule 

- Separated partly by popliteal tendon, no attachment to LCL 

• Anchor to tibia by strong fibrous bands, limit movement

• Deepen in articular surfaces on upper end at tibia

• Allow better adoption of tibial articular surfaces to femoral condyles 

• Facilitate rotation at knee 

• ACL is a very common injury (espically in women field sports)

• Unhappy triad/3= Medial meniscus torn, MCL torn and ACL torn

Tibialis Anterior:

• Origin- Lateral condyle and proximal 2/3 of lateral surface of tibia, deep fascia of leg and interosseous membrane 

• Insertion- medial cuneifrom bone and base of 1st metatarsal

• Nerve Innervation- deep fibular nerve

• Action- strong inverter and dorsiflexor of foot

Extensor Digitorum Longus:

• Origin- Lateral condyle of tibia, proximal 3/4 anterior surface of fibula, interosseous membrane and crural fascia

• Insertion- middle phalanx and two distal slips onto distal phalanx

• Nerve Innervation- deep fibular nerve

Extensor Hallucis Longus:

• Origin- Middle ⅓ anterior surface of fibula and adjacent interosseous membrane

• Insertion- Distal phalanx of big toe

• Nerve Innervation- Deep Fibular nerve 

• Action- Extend big toes (weak dorsiflexor and inverter of foot)

Fibularis Tertius:

• Origin- Fibula

• Insertion- Dorsal surface of base of 5th metatarsal

• Nerve Innervation- Deep Fibular nerve

• Action- everts and dorsiflexes foot 

Lateral Muscles of Leg:

Fibularis Longus:

• Origin- Proximal ⅔ of lateral surface of fibula, surrounding fascia and intermuscular septa

• Insertion- Base of 1st metatarsal

• Nerve Innervation- superficial fibular nerve (branch of either common or deep fibular nerve)

• Action- everts foot, weak plantar flexor

Fibularis Brevis:

• Origin- distal ⅔ of lateral surface of fibula and adjacent intermuscuar septa

• Insertion- dorsal part of base of 5th metatarsal

• Nerve Innervation- superficial fibular nerve

• Action- evert foot, weak plantar flexor 

Tibial Nerve:

• Skin on posterior surface of leg is supplied by branches of tibial and common fibular nerve that come together to form sural nerve 

• sural nerve supplies lateral side of foot

Fibular Nerve:

• saphenous nerve (branch of femoral nerve) supplies medial surface of leg & foot

• common fibular nerve supplies upper anteriolateral surface of leg

• superficial fibular nerve supplies lower anteriolateral surface of leg & foot

Movements of the foot at the ankle:

Some N.B.s:

• Leg has 3 sets of muscles & 3 sets of retinacula

• flexor retinaculum (posteriomedial): b/t medial malleolus & calcaneous

• superior fibular retinaculum (lateral): b/t lateral malleolus & calcaneous

• inferior fibular retinaculum (lateral): attached to both sides of calcaneous

• superior extensor retinaculum (anterior): b/t tibia & fibula above malleoli

• inferior extensor retinaculum (anterior): aka cruciate ligament, “Y-shaped

• Triceps Surae= 2 heads of gastroc + soleus

Posterior Leg Muscles:
Superficial muscles of calf: 

Gastrocnemius:

• Origin- posterior surface of femur (proximal to medial and lateral condyles)

• Insertion- Lower part of projecting portion of calcaneus

• Nerve Innervation- tibial nerve 

• Action- powerful plantar flexor of foot (helps flex leg when not supporting weight)

- resists dorsiflexion during weight bearing and keeps leg in extension 

Soleus:

• Origin- (one head) soleal line across upper 1/3 and posterior surface of tibia and middle 1/3 of medial border (other head) proximal 1/3 of posterior surface of fibula 

• Insertion- anterior surface of calcaneal tendon

• Action- Plantar flexor of foot (and can plantar flex foot with bent knees) 

- during stance prevents dorsiflexion 

Plantaris:

• Origin- lateral epicondyle of femur above lateral gastronemius

• Insertion- calcaneus (anteriomedial to calcaneal tendon)

• Nerve Innervation- Branch of tibial nerve

• Action- flexion of leg at knee and plantar flexion of foot (weak) 

Deep Muscles of the Calf:

Popliteus:

• Origin- Lateral condyle of femur in knee

• Insertion- proximal 1/3 of posterior surface of tibia (proximodedial to soleus tibial origin)

• Nerve Innervation- Branch of tibial nerve 

• Action- Medial rotation of leg on femur (unimportant flexor of leg)

- During standing, prevents forward sliding of femur on tibia when knee is flexed 

Flexor Hallucis Longus:

• Origin- lateral side of middle 1/2 of posterior aspect of fibula 

- tendon is most posteriolateral of tendons near medial maleolus

• Insertion- distal phalanx of big toe 

• Nerve Innervation- tibial nerve

• Action- flexes big toe (weak plantarflexor of foot)

Tibialis Posterior:

• Origin- Proximal 2/3 lateral side of posterior shaft of tibia, proximal 2/3 medial side of posterior shaft of fibula, posterior aspect of interosseous membrane

• Insertion- navicular (can extend to other tarsal bones except talus) and to bases of 2nd-4th metatarsals

• Nerve Innervation- tibial nerve

• Action- adduct front of foot (aids inversion and plantar flexion)

Flexor Digitorum Longus:

• Origin- Middle 1/3 of posterior aspect of tibia 

• Insertion- distal phalanges of 4 lateral digits

• Nerve Innervation- tibial nerve

• Action- flex distal phalanges of four lateral toes, weak plantarflexor, assists with inversion and adduction

Foot Bones:

Review of L.L muscles:

Ankle and foot bones:

Calcaneus:

• Largest bone of foot 

• Articulates above with talus and in front with cuboid

• Posterior aspect forms heel

• Medial surface has large ridge (sustentaculum tali) that supports the talus

Talus:

• Articulates with tibia and fibula above, calcaneus below, and nevicular in front 

• Has a head, neck and body

• Many ligaments attach to this but no muscles 

Navicular:

• Between head of talus and cuneifrom bones

• Tuberosity lies in front and below medial maleous and attaches to tibialis posterior tendon

Cuboid:

• Articulates with anterior end of calcaneous 

• Deep groove on inferior end of fibularis longus attachment 

Cuneiform bones:

• Small wedge shaped bones

• Provide form and maintain transverse arch of foot 

Metatarsal and Phalangeal Bones:

Metatarsals:

• Numered 1-5 from medial to lateral

• Distal end= head

• middle= shaft

• Proximal end= base

• Tubericle on base serves as attachment for fibularis brevis muscle

Phalanges:

• Every toes except big one has 3 phalanges

• Each phalange also has a head, neck and base 

Deep Fascia:

• Tough fibrous layer

• Gives rise to some muscles

• Blends with pweiosteum of subcutaneous part of tibia (whole length)

• Laterally sends 2 septa to fibula providing 3 compartments 

- anterior intermuscular septum separates anterior muscles from lateral ones 

- posterior intermuscular septum separates lateral muscles from posterior ones 

• Transverse crystal septum passes across calf and separates superficial and deep calf muscle groups 

The foot:
Some N.B.s

The leg has 3 sets of muscles and 3 sets of retinacula

• Flexor retinaculum (posteriomedial): between medial malleolus and calcaneous

• Superior fibular retinaculum (lateral): between lateral malleolus and calcaneous 

• Inferior fibular retinaculum (lateral): attached to both sides of calcaeous 

• Superior extensor retinaculum (anterior): between tibia and fibula above malleoli 

• Inferior extensor retinaculum (anterior): aka cruciate ligament, Y-shaped

• Triceps surae= 2 heads of gastroc and soleus 

Dorsal view of foot:

Lateral view of foot:

Medial view of the foot:

The foot:

• All weight is transmitted to talus by leg

• From the talus weight is distributed evenly to:

- posterior/inferiorly to calcaneus 

- anterior/inferiorly to head of metatarsals 

• Arches: curves in plantar surface

Longitudinal arch:

• Higher on medial side than lateral

• Two parts:

- medial (calcaneus ~ medial 3 heads of metatarsals)

- lateral (calcaneus ~ lateral 2 heads of metatarsals) 

Transverse Arch:

• Medial side (highest): head of talus and navicular bone

• Anteriorly: flattens out all metatarsal heads share weight

• Posteriorly: projected lateral/inferior and posterior/inferior 

• Feet together form ½ dome

Ankle (talocrural) joint:

• Maleoli grip trochlea tali between them and ankle (talocrural) joint

• Hinge-type joint

• Joint tightest during dorsiflexion 

• Ligaments control A/P movements 

Medial (deltoid) Ligament:

• Fans out from medial malleolus

• 4 parts: anterior and posterior tibiotalar, tibiocalcaneal and tibionavicular 

• Resists eversion of foot 

• Footflat results when weight is placed on medial side of arch 

Lateral ligaments:

• Fans out from lateral malleolus

• 3 parts: anterior and posterior talofibular ligaments and calcaneofibular ligament

• Control inversion 

Ligaments of the foot:

• Dorsal tarsal ligaments 

- usually thin

• Plantar tarsal ligaments

- support arch

- plantar calcaneonavicular ligament (spring ligament): resists movement of head of talus (helps support arch)

- long plantar ligament: between calcaneous and cuboid (posterior) and lateral 3 metatarsals (anterior) 

Interosseus Tarsal Ligaments:

• Between adjacent tarsal surface

• Talocalcaneal: strong

• Between cuboid and navicular 

• Between cuboid and lateral cuneiform 

• Between cuneifrom 

Intertarsal ligaments:

• Subtalar

- between talus and calcaneus 

- anterior to talocalcaneal interosseus ligament

• Talocalcaneonavicular

- deep to calcaneonnavicular ligament 

• Calcaneocuboid

- lateral to above ligament

• Transverse tarsal

- Calcaneonavicular part of talocalcaneonavicular 

- stretches across foot

- allows inversion/eversion, flexion/extension of forefoot, and change height of arch

• Cuneonavicular 

Muscles of the plantar surface of the foot:

Superficial layer of muscles: 

• Abductor Hallucis

• Flexor Digitorum Brevis

• Abductor Digiti Minimi

Flexor Digitorum Brevis:

• Origin- Medial Process of calcaneus and plantar aponeurosis

• Insertion- Middle phalanges of 2nd-5th toes

• Nerve Innervation- Tibial 

• Action- Flex middle phalanges (IP joint) of 2nd-5th toes 

Abductor Hallucis:

• Origin- Medial process of calcaneus and plantar aponeurosis

• Insertion- proximal phalanx of 1st toe and medial sesamoid bone

• Nerve Innervation- Tibial

• Action- Abduct and Assist flexion of 1st toe (MP joint)

Abductor Digiti Minimi:

• Origin- Lateral process of calcaneus and plantar aponeurosis

• Insertion- Proximal phalanx of 5th toe

• Nerve Innervation- Tibial

• Action- Flex and assist adduction of 5th toe (MP joint)

Second Layer of Muscles:

• Tendon of Flexor Halluscis Longus

• Tendon of flexor digitoum Longus

• Quadratus Plantae

• Lumbricals

Quadratus Plantae:

• Origin- Calcanneus (medial and lateral plantar surface)

• Insertion- Flexor digitorum longus muscle (posterior and lateral)

• Nerve Innervation- Tibial

• Action- assists with flexion of 2nd-5th toes 

Lumbricals:

• Origin- Tendon of flexor digitorum longus

• Insertion- base of proximal phalanges of 2nd-5th toes and extensor digitotum longus tendon

• Nerve Innervation- Tibial

• Action- Flex MP joint and extend IP joints of 2nd-5th toes

Third Layer of muscles:

• Flexor Hallucis Brevis

• Adductor Hallucis

• Flexor Digiti Minimi Brevis 

Flexor Hallucis Brevis:

• Origin- Plantar surface of cuboid and lateral cuneiform

• Insertion- medial and lateral surface of base of proximal phalanx of 1st toe

• Nerve Innervation- Tibial

• Action- flex MP joint of 1st toe

Adductor Hallucis:

• Origin- Oblique head: bases of 2nd-4th metatarsals; Transverse head: plantar ligament  of 3rd-5th MP joints

• Insertion- lateral surface of base of proximal phalanx of 1st toe

• Nerve Innervation- Tibial

• Action- Adduct and assist flexion of 1st tor (maintain transverse arch)

Flexor Digiti minimi brevis:

• Origin- Base of 5th metatarsal

• Insertion- base of proximal phalanx of 5th toe

• Nerve Innervation- tibial

• Action- Flex 5th MP joint 

Deep Layer of Muscles:

• Plantar Interossei

• Dorsal Interossei

Plantar Interossei:

• Origin- Plantar surface of 3rd-5th metatarsal

• Insertion- Medial surface of proximal phalanges of 3rd-5th toes

• Nerve Innervation- Tibial

• Action- Adduct and flex 3rd-5th toes 

Dorsal Interossei:

• Origin- Adjacent surfaces of metatarsals

• Insertion- 1st:medial surface of proximal phalanx of 2nd toes; Rest: lateral surfaces of proximal phalanges of 2nd-4th toes

Muscles on Dorsal Surface of foot:

Extensor Digitorum Brevis: 

• Origin- Dorsal surface of calcaneus

• Insertion- 2nd-4th toes via extensor digitorum longus tendon

• Nerve Innervation- Deep Fibular

• Action- extend MP joints of 2nd-4th toes 

Extensor Hallicus Brevis:

• Origin- Dorsal surface of calcaneus

• Insertion- proximal phalanx of 1st toe

• Nerve Innervation- Deep fibular 

• Action- Extend Mp joint of 1st toe

Head regions Scalp Brain Cranial nerve:

Cranium (skull):

• Composed of a number of separate bones

- United by saw-toothed joints (sutures)

- Sutures ossify during adult life

• Divided into 2 portions:

1. Cranium (neurocranium)- protects the brain

2. Facial skeleton (viscerocranium)

Head Regions:

Scalp:

• Consists of skin and subcutaneous tissue that cover neurocranium 

• Skin- contain sweat and subcutaneous glands and hair follicles

• Connective tissue- forms thick, dense, and highly vascularized subcutaneous layer

• Aponeurosis- serves as attachment for muscles

• Loose areolar tissue- allows free movement of top 3 layers wrt to underlying layer 

• Pericranium- dense layer of connective tissue 

The brain:

• Consists of:

1. Two cerebral hemispheres 

2. Branstem (midbrain, pons, medulla, and diencephalon)

3. Cerebellum 

Brain:

12 Cranial nerves:

CN 1: Olfactory nerve

• Responsible for the sense of smell 

CN 2: Optic nerve 

• responsible for vision (perception)

• Sensory nerve for my eyes

CN 3: Occulomotor nerve 

• Innervates 4/6 eye muscles 

• Visual tracking

• Saccadic eye movements 

• Vergence 

CN 4: Trochlear nerve

• Innervates 1/6 eye muscles 

• Superior oblique muscle

• Hard to look down if it is weak 

CN 5: Trigeminal nerve 

• Sensory information from face

• Ophthalmic

• Maxillary 

• Mandibular

• Works mastication 

• Sensory and motor 

CN 6: Abducents nerve

• Innervates lateral rectus muscle of eye

• Abducts the eye

• Prevents double vision 

• Motor nerve for motion 

CN 7: Facial nerve:

• Facial expression 

• 2/3 of taste sensations 

• Sensory and motor 

CN 8: Vestibulocochlear nerve

• Body balancer 

• Used for the ear, sound sensor 

• 2 branches: vestibular and auditory 

CN 9: Glossopharyngeal nerve:

• Senses taste from the 1/3 back of the tongue 

• Helps you swallow 

CN 10: Vagus nerve

• vagus= wandering

• Innervates internal organs 

• Custard only if dysphagia 

• Sensory and motor 

CN 11: Accessory nerve 

• Innervates muscles of neck (SCM and trapezius)

CN 12: Hypoglossal nerve 

• Innervates 

• Deals with tongue movement