ARCL 228 - mod 2.2

Foramen

A natural hole in the bone

• nutrient foramen = smaller hole

• Foramen in spine allows vertebrae to connect

Fossa

A flat (sometimes concave) area of bone

• large fossa on scapulae

• Allows attachment points (for muscles, tendons or ligaments to the bone)

Process

Projection of bone

• acts as secure anchor for tendons and muscles

• Cheek bone

Components of the axial skeleton

• the skull

• Vertebrae

• Ribs

• Sacrum

• Components that make up shoulder/hip girdles (scapula, clavicle and collar bone)

Shoulder girdle

Includes clavicle, scapula and humerus

• a. Clavicle - extends from sternum to rib cage

• B. Scapula - on posterior side

Scapula and clavicle create ball/socket joint for the humerus

Muscles hold together shoulder girdles rather than other bones = easier to dislocate

Clavicle

Part of shoulder girdles

• develop through intramembranous ossification

• No diathesis, epiphesis on lateral/medial ends Superior view

• Superior view = flatter side, inferior view = bumps/ridges

Scapulae

Part of shoulder girdle

• Endochondral ossifation

• Includes large fossa

• Coronoid process helps hold head of humerus (ball/socket joint)

• Glenoid Fossa on the top that connects with humerus

The spine (vertebrae)

3 types of vertebrae

• cervical (7)

• Thoracic (12)

• Lumbar (5)

Vertebral body = large body of the vertebrae

Spines process = projection of vertebrae, sometimes can see, but can feel

• includes Foramen = where spinal cord can pass through

Developed by endochondral ossification

Ribs

Developed through Endochondral ossification

• includes 24 ribs (24 total vertebrae)

• Top portion is fused to vertebrae and articulates with breast plate/sternum

Ribs

• shaft (middle area of rib)

• Head (epiphesis of rib)

• Tubercle (small bump before the head)

Pelvis (os cola and sacrum)

Most caudal section of axial skeleton

• made up of 2 Os Coxa and 1 sacrum

Os Coxa

Part of pelvis

• developed with Endochondral ossification

• Has 3 sections - fused together later in life

1. Ilium (top/largest section, feel with hands on hips)

2. Pubis (bottom of pelvis)

3. Ischium (sit bones/but bones)

Acetabulum

• middle area where head of femur sits

• Centre socket

Sacrum

Part of pelvis girdle (with os coxae and femur)

• endochondral ossification

• Similar formation to vertebrae → spinus processes on posterior side

• Immature sacrum isn’t fully fused

• Includes tail bone → very bottom bone