MSK System

how many bones in the axial skeleton?

80

how many bones in the appendicular skeleton?

126

Tubercle/Trochanter/Tuberosity

round bump

Facet

smooth, nearly flat articular surface

Condyle

round articular surface

epicondyle

raised area above a condyle

head

round expansion of end of bone

Ramus

arm like bar of bone

process

long protrusions

Fissure

narrow, slit like opening

Foramina

round/oval opening

meatus

canal-like passageway

sinus

cavity/space within a bone

Fossa

shallow, basin like depression on the surface

Three types of cartilage

• elastic

• fibrocartilage

• hyaline cartilage (most abundant)

Tendons

connect muscle to bone for joint motion

Ligament

connect bone to bone for joint stability

Joints are also referred to as…

articulation or arthrosis

Two classifications of joints

Functional and structural

Synarthrotic

immovable

amphiarthrotic

slightly moveable

Diarthrotic

freely moveable

Fibrous joints

no joint cavity w/ fibrous cartilage

Cartilaginous joints

no joint cavity w/ cartilage

synovial joints

joint cavity and fibrous cartilage

what kind of joints are the coronal sutures?

fibrous joints

All synovial joints are… (type of joint, movement)

diarthrotic

In synovial joints, articular surfaces of bones are covered by…

articular cartilage

Articular cartilage characteristics

• Hyaline cartilage

• lacks perichondrium

• lacks blood supply

Joint stability and mobility relationship

Inversely related. As stability increases, mobility decreases and vice versa.

Skeletal muscle functions

1. joint stability

2. power joint motion

3. maintain postural control

4. assist with force absorption

Muscle tonus muscle contraction

passive partial contraction

reflexive muscle contraction

automatic

concentric muscle contraction

movement with muscle shortening

eccentric muscle contraction

movement with muscle lengthening

isometric muscle contraction

no movement

The neurocranium includes…

the 8 cranial bones

the viscerocranium includes…

the 14 facial bones

Lacrimal sac location

within the lacrimal fossa in the lacrimal bone

Which bone generates turbulence in inhaled air?

inferior nasal concha

Which bone makes up the majority of the hard palate?

maxillary bone

Which bone makes up the posterior portion of the hard palate?

palatine bones

Which bone makes up the lower part of the nasal septum?

vomer

What makes up the temporomandibular joint?

the condylar process articulating with the mandibular fossa.

Which bone does not articulate with any other bone?

hyoid bone

which bone is the site of attachment for the muscles of swallowing and speech?

hyoid bone

How many vertebrae are there?

26

Atlas

C1

Atlas (C1) motion

allows nodding motion for “yes”

The superior articular facets of Atlas (C1) articulate with…

occipital condyles

Axis

C2

Axis (C2) motion

allows shaking motion of “no”

what is the dens part of?

Axis (C2)

The dens projects superiorly into…

the anterior arch of atlas

What has transverse foramina and what passes through them?

Part of cervical vertebrae and vertebral arteries pass through.

The sacrum articulates with….

L5 superiorly and the ilium laterally

Which vertebral curves are concave anteriorly?

thoracic and sacral curves

Which vertebral curves are convex anteriorly?

cervical and lumbar curves

Primary vertebral curvatures

thoracic and sacral curves

nucleus pulposus

inner gelatinous core of intervertebral discs that resists compression.

Annulus fibrosus

a ring of collagen and fibrocartilage in intervertebral discs that resists tension.

The manubrium articulates with….

the clavicle and 1st rib

the body of the sternum articulates with…

the costal cartilages of ribs 2-7

the xiphoid process is a marker for…

the superior limit of liver, central tendon of diaphragm and inferior border of the heart.

Typical ribs

3-9

Atypical ribs

1, 2, and 10-12

What makes the first rib atypical?

broad, horizontal body, single facet and scalene tuberosity

What makes the second rib atypical?

serratus anterior tuberosity

What makes ribs 10-12 atypical?

single facet on head

What makes ribs 11-12 atypical?

short and no neck or tubercle.

Which and what are true ribs

1-7 because they articulate with the sternum via costal cartilage.

Which and what are false ribs

8-10 because they indirectly articulate with the sternum

Which and what are floating ribs?

11-12 because they have no articulation with the sternum.

Costovertebral joints

head of the rib articulates with superior and inferior costal facet and intervertebral disc

Costotransverse joints

tubercle of rib articulates with transverse process of vertebrae.

Costovertebral joint function

joint capsule support

costotransverse joint function

abundant ligament support

pump handle movement

of upper ribs and sternum. Increases the AP dimension

Bucket handle movement

of lower ribs. increases the transverse dimension

sternocleidomastoid proximal attachment

sternum and clavicle

sternocleidomastoid distal attachment

mastoid process of temporal bone

Sternocleidomastoid action

Bilaterally - flexion of the cervical portion of the vertebral column

unilaterally - rotation of the head to the opposite side.

Sternocleidomastoid innervation

spinal accessory nerve (CN XI)

Scalene muscles attachments

transverse processes of cervical vertebrae.

1st & 2nd ribs.

scalene muscles actions

flexion of the neck

elevates the ribs during forced inspiration

Whats between the anterior and middle scalene muscles?

brachial plexus and subclavian artery.

Scalane muscles innervation

anterior rami of cervical spinal nerves

Spenius capitus & cervicis (superficial)

run in superior lateral direction (Spinous process to transverse/mastoid process)

Semispinalis capitus & cervicis (Deep)

run in superior medial direction (transverse process to spinous process/occipital bone)

Spenius capitus & cervicis + semispinalis capitis & cervicis actions

bilaterally - extend head and neck

unilaterally - rotation and lateral flexion of the neck.

Spenius capitus & cervicis + semispinalis capitis & cervicis innervation

posterior rami of spinal nerves

Erector spinae group (lateral to medial)

• iliocostalis

• longissimus

• spinalis

Erector spinae group actions

bilateral - extension of the spine; keep trunk erect

unilateral - lateral flexion of the spine.

erector spinae group innervation

posterior rami of spinal nerves

Intercostal muscles (superficial to deep) + actions

• external intercostal muscles - inspiration

• internal intercostal muscles - expiration

• innermost intercostal muscles - expiration

Intercostal muscles innervation

intercostal nerves

Diaphragm attachments

xiphoid process

lumbar vertebrae

inferior margin of rib cage - central tendon

Diaphragm action

flattens to increase length of thoracic cavity and compresses abdomen.

diaphragm innervation

phrenic nerve

nerve roots of the phrenic nerve

C3, C4, C5