Skeletal System Overview

Biology 2121Chapter 7

Study Guide Notes 1. You are responsible for any bone covered in the lab.– Bone location – General function(s) of bone

2. PP Notes

3. Review/Objective Notes

Introduction

Skeletal System– Axial vs. Appendicular

– Number of Bones

Functions– 1. Support

– 2. Mineral and Lipid storage

– 3. Hematopoiesis

– 4. Protection

– 5. Leverage

Axial Skeleton – The Skull 1. Skull

– 22 facial and cranial bones

2. Cranium – (8) cranial bones – Thin, formed by intermembranous

processes – Protection; attachment site for head and

neck muscles – Encases the brain

2. Bones are held together by ‘sutures’ – Coronal, saggitial, squamous, lambdoid

3. Facial Bones– (14) facial bones– Functions

Vertebral Column

1. (26) bones total – 7 Cervical; 12 Thoracic; 5 Lumbar;

sacrum and coccyx – Curvature

2. Attachments – Longitudinal ligaments– Ligamentum flavum

3. Discs – Gelatinous; collagen and

fibrocartilage – Compressible

4. Structure and Differences – Differences between cervical,

thoracic and lumbar sections

Sacrum and Coccyx 1. Sacrum – (5) fused vertebrae– Sacral foramina

– Sacral nerves; BVs

– Sacral canal – Continuation of vertebral canal

– Forms joint with hip bones (sacroilliac joint)

2. Coccyx – (4) fused vertebrae– Mostly ‘useless’

Thoracic Cage 1. Function– Protects heart, lungs, blood vessels– Supports shoulder girdles, upper

limbs, attachments for muscles

2. Sternum – Attachment site for clavicles

(clavicular notch) – Xiphoid process ossifies around ‘40’ – Hematopoiesis

3. Ribs – (12) pairs; (7)-True; (5)-False; Last

pair – Floating – Joined by costal cartilage

Appendicular Skeleton – Pectoral Girdle 1. Pectoral ‘Shoulder’

– Attach upper limbs to axial skeleton; muscle attachment

2. Clavicles– Articulates with scapulae and sternum – Anchor muscles (deltoid; pectoralis major);

brace arms and shoulder

3. Scapulae – “spade or shovel” – Coracoid process (biceps; coracobrachialis) – Acromioclavicular joint

Upper, Lower Arm - Hand 1. Humerus– Tubercles (rotator cuff muscles);

deltoid tuberosity (deltoid) – Condyles (capitulum and trochlea) – Epicondyles (muscle attachments)

2. Ulna and Radius – Ulna (elbow joint) – Radius (radial tuberosity – biceps)

3. Carpus-Metacarpus-Phalanges – 8-carpal bones

Pelvic (Hip) Girdle1. Os coxae (hip bones)– Form pelvic girdle – Pelvic girdle + sacrum + coccyx = bony

pelvis – Ilium; Ischium and Pubis

2. Male vs. Female – Male: cavity is narrow; deep; less tilt;

heavier – Female: broad cavity; lighter; acetabula

farther apart

3. Female and Childbirth – True pelvis (inlet and outlet) important for

childbirth

Lower Limbs 1. Femur – Largest, longest, strongest bone in

the human body – Trochanters (thigh and buttock

muscles) – Epicondyles – Patella

2. Tibia and Fibula – Tibia: transfers weight of femur to

foot; distal tibia articulates with talus of foot; medial malleolus (ankle)

– Fibula: not weight bearing; muscular attachments

Foot1. Tarsus– (7) tarsal bones– “talus” – ankle bone;

“calcaneous” – heel– Cuboid, navicular and

cuneiform bones

2. Metatarsus and Phalanges– (14) phalanges