Lecture 2

What is the anatomical position?

What is the anatomical position?

The body stands erect, with palms facing forward, feet parallel and flat on the floor, and arms at the sides.

What does "supine" mean in anatomical terms?

lying face up

Define "medial" in anatomical terms.

Nearer to the midline of the body.

What is the difference between "ipsilateral" and "contralateral"?

Ipsilateral is on the same side, while contralateral is on the opposite side.

What are the three main body planes used in anatomy?

Coronal (frontal), sagittal, and horizontal (transverse).

What is the primary functions of bones?

Support framework, protection, movement, haematopoiesis, mineral homeostasis, and triglyceride storage.

Name the four types of bone cells and their functions.

• Osteogenic cells - bone stem cells.

• Osteoblasts - build bone.

• Osteocytes - maintain bone metabolism.

• Osteoclasts - break down bone matrix.

What is the structural unit of compact bone called?

Osteon

Describe the composition of an osteon.

It includes the Haversian canal, lamellae, canaliculi, and lacunae.

How does spongy bone differ from compact bone in structure?

Spongy bone contains trabeculae and does not have osteons, while compact bone has osteons and is denser.

What is the epiphyseal plate?

A layer of hyaline cartilage in the epiphyses where bone elongation occurs.

What role does the periosteum play?

It surrounds the external surface of bone, provides attachment for ligaments and tendons, and contains osteoblasts and osteoclasts for growth and repair.

What are the two types of bone ossification?

Intramembranous ossification and endochondral ossification.

Name one bone that is classified as short and one as sesamoid.

Short bone: carpals. Sesamoid bone: patella.

What hormone increases blood calcium levels?

Parathyroid hormone.

How does calcitonin affect blood calcium levels?

It decreases blood calcium levels by inhibiting osteoclasts and promoting calcium deposition in bones.

What are the primary components of bone matrix?

Calcium phosphate, other mineral salts, and collagen fibers.