BIO 208 CH 8 SKELETON

What bones make up the axial skeleton?

Skull, vertebral column, and rib cage.

What are the two main parts of the skull?

Cranial bones and facial bones.

What is the function of the cranium?

Protects the brain.

What does the frontal bone form?

Forehead and part of the roof of the cranium.

What do the parietal bones form?

Most of the cranial roof and lateral walls.

What do the temporal bones form?

Lateral walls and part of the floor of the cranial cavity.

What does the occipital bone form?

Rear and base of skull; contains foramen magnum.

What is the sphenoid bone known as?

Keystone bone of the skull; connects all other cranial bones.

What does the ethmoid bone form?

Part of the nasal cavity, septum, and medial wall of the orbit.

What are cranial sutures?

Immobile fibrous joints between skull bones.

Why are sutures open at birth?

To allow for rapid brain growth.

What does the coronal suture separate?

Frontal and parietal bones.

What does the sagittal suture separate?

The two parietal bones.

What does the lambdoid suture separate?

Occipital bone from parietal bones.

What does the squamosal suture separate?

Temporal and parietal bones.

What is craniosynostosis?

Premature closure of cranial sutures → can cause developmental issues.

What are the facial bones?

Lacrimal, nasal, inferior nasal conchae, vomer, mandible, zygomatic, and maxilla.

What does the lacrimal bone form?

Part of the medial wall of the orbit (tear duct area).

What does the nasal bone form?

The bridge of the nose.

Where are the inferior nasal conchae located and what do they do?

Inside nasal cavity; create air turbulence.

What does the vomer bone form?

Lower part of the nasal septum.

What is the mandible?

Lower jawbone; supports teeth and muscles for chewing.

What are the zygomatic bones?

Cheekbones.

What are the maxillae?

Upper jaw bones; form upper teeth and facial structure.

What is Treacher Collins Syndrome?

Genetic disorder causing malformation of facial bones; leads to feeding, breathing, and hearing issues.

What is a vertebra?

A single bone of the spine.

What is the function of the vertebral body?

Supports weight.

What passes through the vertebral foramen?

The spinal cord.

What are transverse processes?

Lateral projections on vertebrae for muscle and ligament attachment.

What is the spinous process?

Posterior projection you can feel through the skin.

What are intervertebral discs made of?

Fibrocartilage.

Function of intervertebral discs?

Shock absorption and flexibility for bending.

How many cervical vertebrae are there?

7

What are unique features of cervical vertebrae?

Small size and transverse foramina for vertebral arteries.

What is the name of C1 and its function?

Atlas; supports skull and allows nodding "yes."

What is the name of C2 and its function?

Axis; allows rotation of the head "no."

How many thoracic vertebrae are there?

12

What distinguishes thoracic vertebrae?

Rib articulation points (costal facets).

How many lumbar vertebrae are there?

5

What distinguishes lumbar vertebrae?

Largest bodies; bear most weight.

What is the sacrum?

5 fused vertebrae connecting the spine to the pelvis.

What is the coccyx?

3-4 fused vertebrae; the tailbone.

What are the normal curvatures of the spine?

Cervical, thoracic, lumbar, and sacral.

What is lordosis?

Exaggerated lumbar curve ("swayback").

What is kyphosis?

Exaggerated thoracic curve ("hunchback").

What is scoliosis?

Lateral curvature of the spine.

How many pairs of ribs are there?

12 pairs.

Where do ribs attach posteriorly?

To thoracic vertebrae.

What are true ribs?

Ribs 1-7; attach directly to the sternum via cartilage.

What are false ribs?

Ribs 8-12; attach indirectly or not at all to the sternum.

What are floating ribs?

Ribs 11-12; do not attach anteriorly.

What are the three parts of the sternum?

Manubrium (top), body (middle), xiphoid process (bottom).

What is the hyoid bone and why is it unique?

U-shaped bone in the neck that does not articulate with any other bone.

What are pectus deformities?

Abnormal chest shapes — excavatum (sunken chest), carinatum (protruding chest).

What bones make up the pectoral girdle?

Clavicle and scapula.

What is the function of the pectoral girdle?

Attaches upper limbs to axial skeleton.

What are the ends of the clavicle called?

Sternal end (medial) and acromial end (lateral).

Key features of the scapula (anterior)?

Coracoid process, glenoid fossa, subscapular fossa.

Key features of the scapula (posterior)?

Spine, acromion, supraspinous and infraspinous fossae.

What does the head of the humerus articulate with?

Glenoid cavity of scapula (shoulder joint).

What is the anatomical neck of the humerus?

Location of epiphyseal plate.

What is the surgical neck of the humerus?

Common fracture site below the tubercles.

What are the greater and lesser tubercles?

Sites for muscle attachment.

What does the capitulum of the humerus articulate with?

Head of the radius.

What does the trochlea of the humerus articulate with?

Trochlear notch of the ulna.

What fits into the coronoid fossa of the humerus?

Coronoid process of the ulna (anterior).

What fits into the olecranon fossa of the humerus?

Olecranon of the ulna (posterior).

What is a subluxation of the shoulder?

Partial dislocation of the glenohumeral joint.

Which bone is lateral in the forearm (thumb side)?

Radius.

Which bone is medial in the forearm (pinky side)?

Ulna.

Which end of the radius is proximal?

The head.

Which end of the ulna is proximal?

The olecranon (elbow).

What are the styloid processes?

Distal projections of radius and ulna at the wrist.

What are the carpal bones (wrist bones)?

Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate.

What is the mnemonic for carpal bones?

"Some Lovers Try Positions That They Can't Handle."

What is the most common carpal fracture?

Scaphoid fracture.

Why do scaphoid fractures heal poorly?

Limited blood supply.

How are metacarpals numbered?

I-V starting from the thumb.

How are phalanges arranged?

Proximal, middle, and distal (thumb lacks middle).

What bones make up the os coxae?

Ilium, ischium, and pubis.

What is the acetabulum?

Hip socket formed by all three pelvic bones; articulates with femur head.

What is the sacroiliac joint?

Connection between sacrum and ilium (posterior pelvis).

What is the pubic symphysis?

Fibrocartilage joint connecting the two pubic bones.

How does the female pelvis differ from the male?

Wider, shallower, larger pelvic inlet, and wider pubic arch (>100°).

Why is the female pelvis wider?

To allow for childbirth.

What does the head of the femur articulate with?

Acetabulum of the pelvis.

What is the fovea capitis?

Small pit for ligament attachment in femoral head.

What part of the femur is most commonly fractured?

The neck.

What is the greater trochanter?

Lateral projection used as a landmark for injections.

What is the lesser trochanter?

Medial projection on the proximal femur.

What do the medial and lateral condyles of the femur articulate with?

Tibia (knee joint).

What is the patella?

The kneecap; a sesamoid bone in the quadriceps tendon.

What two bones form the knee joint?

Femur and tibia.

What is the tibial tuberosity?

Anterior bump on tibia for patellar tendon attachment.

Does the fibula articulate with the femur?

No, only with the tibia.

What are the ankle projections called?

Medial malleolus (tibia) and lateral malleolus (fibula).

What are the tarsal bones?

Calcaneus, talus, navicular, medial/intermediate/lateral cuneiforms, and cuboid.

Which tarsal bone is the heel bone?

Calcaneus.

Which tarsal bone articulates with the tibia?

Talus.

How are metatarsals numbered?

I-V from the big toe (medial) to little toe (lateral).