LAB 8

Axial Skeleton

long axis of the body

skull

facial bone

paranasal sinuses

hyoid

The Skull

part of the axial skeleton

most bones in the skull are flat and connected by sutures

Axial Skeleton → The Skull: Cranium

encloses and protects the brain

hearing

equilibrium

frontal

parietal

occipital

temporal

sphenoid

ethmoid

Cranium: Frontal Bone

forehead

frontal sinus

Cranium: Parietal Bones (Sutures)

coronal: parietal meets frontal

sagittal: 2 parietal bones meet at cranial midline

lambdoidal: parietal meets occipital

squamosal: parietal and temporal bones meet at later aspect of skull

USE IMAGES TO STUDY!!!!!!!

Cranium: Occipital Bone

foramen magnum

occipital condyles

Occipital Bone: Foramen Magnum

large hole

inferior part of brain connects to SC

Occipital Bone: Occipital Condyle

rockerlike

articulate with first vertebra of SC

Cranium: Temporal Bones

zygomatic process

external auditory meatus (external ear canal)

styloid process (anchor for muscles of neck and hyoid)

mastoid process (anchor for neck muscles)

Cranium: Sphenoid Bone

butterfly shaped

central body

greater wings

lesser wings

pterygoid processes

Sphenoid: Central Body

sella turcia houses pituitary gland

Sphenoid: Pterygoid Processes

attachment spots

muscles that move the jaw

Cranium: Ethmoid Bone

between the sphenoid and nasal bones

cribriform plates

crista galli

perpendicular plate

ethmoid sinus

superior and middle nasal conchae (turbinates)

Ethmoid bone: Cribriform Plates

sieve-like

olfactory foramina (openings for olfactory nerves)

Ethmoid bone: Crista Galli

attachment site for dura mater

Ethmoid bone: Perpendicular Plate

superior part of nasal septum

Ethmoid bone: Superior and Middle Nasal Conchae

“turbinates”

protrude into nasal cavity

Axial Skeleton → The Skull: Facial Bones

Mandible

Maxillary

Zygomatic

Nasal

Lacrimal

Palatine

Inferior Nasal Conchae

Facial Bones: Mandible

lower jawbone

largest and strongest bone in face

body

rami

mandibular angle

mandibular notch

coronoid process

mandibular condyle

mandibular foramina

mental foramina

Mandible: Body

forms chin

anchors lower teeth

Mandible: Rami

nearly vertical portion of bone

Mandible: Mandibular Angle

body and ramus meet

Mandible: Mandibula Notch

between mandibular condyle and coronoid process

Mandible: Coronoid Process

insertion point for temporalis muscle

elevates lower jaw when chewing

Mandible: Mandibular Condyle

articulates with mandibular fossa

forms TMJ

Mandible: Mandibular Foramina

nerves for teeth sensation

Mandible: Mental Foramina

BV and nerves pass to chin

Facial Bones: Maxillary Bones

upper jaw

alveolar margins: upper teeth

palatine process: forms anterior 2/3 of hard palate

maxillary sinus: orbits to upper teeth (largest paranasal sinus)

Facial Bones: Zygomatic Bones

cheekbones

temporal process of zygomatic bone

Facial Bones: Nasal

nose bridge

Facial Bones: Lacrimal

medial wall of orbit

houses lacrimal sac

Facial Bones: Palatine

completes hard palate

Facial Bones: Inferior Nasal Conchae

curved bones in nasal cavity

Axial Skeleton → The Skull: Paranasal Sinuses

cluster around nasal cavity

lighten skull’

enhance resonance of voice

frontal

ethmoid

sphenoid

maxillary

Axial Skeleton → The Skull: Hyoid Bone

does not articulate directly with other bones

anchors ligaments

horseshoe shape

attachment point for neck muscles (raise and lower larynx for swallowing and speech)

Axial Skeleton: Vertebral Column

spine

Ligaments

Intravertebral Discs

Divisions

Axial Skeleton → Vertebral Column: Ligaments

hold spine in place

Axial Skeleton → Vertebral Column: Intravertebral Discs

cushion like pads

elasticity

compressibility

shock absorption

Axial Skeleton → Vertebral Column: Divisions

1. Cervical (7): neck

2. Thoracic (12): ribs

3. Lumbar (5): lower back

4. Sacral (1-4): pelvis

5. Coccyx: terminal end of vertebral column

Axial Skeleton: General Structure of Vertebrae

body

vertebral arch

spinous process

transverse process

superior and inferior articular process

intravertebral foramina

Axial Skeleton → Structure of Vertebrae: Body

centrum

Axial Skeleton → Structure of Vertebrae: Vertebral Foramen

where SC passes through

Axial Skeleton → Structure of Vertebrae: Spinous process

posterior projection

attached to muscles and ligaments

Axial Skeleton → Structure of Vertebrae: Transverse Process

on either side

attached to muscles and ligaments

Axial Skeleton → Structure of Vertebrae: Intervertebral Foramina

openings between adjacent vertebrae

passage of SC nerves

Axial Skeleton → Vertebral Characteristics: Cervical Vertebrae

C3-C7

body is oval

spinous process is short and projects directly back

vertebral foramen is large and triangular

transverse process contains transverse foramen (vertebral BV to brain)

Cervical Vertebrae: Atlas

C1

has no body or spinous process

ring of bone

articulates with occipital condyles of skull (“yes”)

Cervical Vertebrae: Axis

C2

has body + knoblike dens (odontoid process) = fuses with atlas during embryonic growth

pivot for rotation of atlas (“no”)

Thoracic Vertebrae

T1-T12

body is heart shaped + 2 facets (demifacets) = attaches to head of ribs

spinous process is long and points

vertebral foramen is circular

Lumbar Vertebrae

L1-L5

bodies are massive and kidney shaped

spinous process is short and flat (hatchet)

vertebral foramen is triangular

Sacrum Vertebrae

S1-S5
triangular shape of all 5 vertebrae fused together

articulates superiorly with lumbar vertebrae via superior articulating process

articulates interiorly with coccyx

Coccyx

tailbone

3-5 fused vertebrae

Axial Skeleton: Boney Thorax

Thoracic cage

Sternum

Ribs

Axial Skeleton → Boney Thorax: Sternum

flat bone (6in)

fusion of manubrium, body, xiphoid process

Boney Thorax → Sternum: Manubrium

knot of necktie

articulates with clavicle and first 2 pair of ribs

Boney Thorax → Sternum: Body

bulk of sternum

articulates with 2nd and 7th rib

Boney Thorax → Sternum: Xiphoid Process

inferior end of sternum

plate of hyaline cartilage in youth

cartilage ossifies in adults

attachment point for diaphragm and abdominal muscles

Boney Thorax → Sternum: Ribs

True ribs: 7 pairs directly attached to sternum with hyaline

False ribs: 5 pairs indirectly attached to sternum

Floating ribs: no sternal attachment

Appendicular Skeleton

bones of limbs and girdles

allow movement

pectoral

upper limb

pelvic

lower limb

Appendicular Skeleton: Pectoral

Clavicle

Scapulae

Appendicular Skeleton → Pectoral: Clavicle

Collarbones

sternal end: attaches to sternum

acromial end: articulates with acromion of scapula

Appendicular Skeleton → Pectoral: Scapulae

shoulder blades

triangular flat bones

glenoid cavity

spine

coracoid process

supraspinous fossa

infraspinous fossa

acromion process

Pectoral → Scapulae: Glenoid Cavity

lateral part connects to armpit

Pectoral → Scapulae: Spine

posterior region ends in acromion

Pectoral → Scapulae: Coracoid process

anchors biceps of arm

Pectoral → Scapulae: Acromion process

forms point of shoulder and end of spine

Appendicular Skeleton: Upper Limb

Arm

Forearm

Hand

Appendicular Skeleton → Upper Limb: Arm

Humerus

head

greater and lesser tubercle

intertubercular groove

trochlea

capitulum

medial and lateral epicondyles

coronoid fossa

olecranon fossa

Upper Limb → Arm: Head

fits into glenoid cavity of scapula

Upper Limb → Arm: Greater and Lesser Tubercle

muscle attachment sites

Upper Limb → Arm: Intertubercular Groove

between greater and lesser tubercle

Upper Limb → Arm: Trochlea

pulley-shaped

medial

Upper Limb → Arm: Capitulum

lateral articulating surface

articulates with radius

Upper Limb → Arm: Coronoid Fossa

anterior surface (upper)

allows for movement of ulna

Upper Limb → Arm: Olecranon Fossa

posterior surface (deeper)

allows for movement of ulna

Appendicular Skeleton → Upper Limb: Forearm

ulna: slightly longer, olecranon and coronoid process

radius: attaches to thumb, rotation

Appendicular Skeleton → Upper Limb: Hand

carpus

metacarpus

phalanges

Upper Limb → Hand: Carpus

wrist

8 carpal bones

Upper Limb → Hand: Metacarpus

palm

5 metacarpal bones

lateral to medial

Upper Limb → Hand: Phalanges

fingers

14 long bones

proximal, middle, distal

Appendicular Skeleton: Pelvic Gridle

hip

attaches lower limbs to axial skeleton

formed by pair of coxal bones

Appendicular Skeleton → Pelvic Gridle: Coxal Bone

acetabulum: socket that articulates with head of femur

ilium

ischium

pubis

Pelvic Gridle → Coxal Bone: Ilium

major portion of coxal bone

alae: winglike portion

iliac crest: thickened superior margins of alae

anterior and posterior superior iliac spine

anterior and posterior inferior iliac spines

Pelvic Gridle → Coxal Bone: Ischium

L/arc shaped

body

ischial tuberosity

thickening: bears weight whenever we sit

Pelvic Gridle → Coxal Bone: Pubis

V shaped

body

obturator foramen: BV and nerves pass through

pubic symphysis: fibrocartilage disc attaches 2 pubic bones

pubic arch: differentiate male from female

Pelvic Structure and Childbearing: Female

tilted forward

broad and shallow

bones: less thick, lighter, thinner, smoother

acetabula: smaller and further apart

pubic arch: broad and more rounded (80-90 degrees)

Pelvic Structure and Childbearing: Male

not tilted as much

narrow and deep

bones: thicker, heavier, more prominent

acetabula: larger and closer

pubic arch: acute (50-60 degrees)

Appendicular Skeleton: Lower Limb

Thigh

Leg

Foot

Appendicular Skeleton → Lower Limb: Thigh

femur

largest, longest, strongest bone in body

head

greater and lesser trochanter: attachment spot for muscles

neck

lateral and medial condyles: articulating surfaces

lateral and medial epicondyles: attachment surface for tendons and ligaments

patella: kneecaps and sesamoid bone (enclosed in tendon)

Appendicular Skeleton → Lower Limb: Leg

Tibia (shin)

second largest, strongest bone in body

medial and lateral condyles

medial malleolus: medial bulge of ankle

Appendicular Skeleton → Lower Limb: Fibula

articulates proximally and distally with lateral tibia

head

lateral malleolus (ankle bulge)

Appendicular Skeleton → Lower Limb: Foot

Tarsus

Metatarsus

Phalanges

Lower Limb → Foot: Tarsus

ankle

7 tarsal bones

talus: attaches to tibia and fibula

calcaneus: heel

Lower Limb → Foot: Metatarsus

instep

5 long metatarsal bones

1-5 from medial to lateral

Lower Limb → Foot: Phalanges

toes

14 phalanges

proximal, medial, distal