Lecture 2: Bones & Joints

Question 1

How many bones are in the human body?

Answer 1

206

Question 2

What are the general functions of bones?

Answer 2

1. Living tissue
2. Protects organs
3. Supports soft tissues of body
4. Provides mechanical basis for movement
5. Stores calcium and phosphorus
6. Produces new blood cells (in medullary cavity)

Question 3

Trabecular (Spongy) Bone and Compact Bone

Answer 3

Trabecular Bone:
- Porous
- Lightweight
- Found in vertebral bodies, in ends of long bones, within flat bones

Compact Bone:
- aka cortical bone
- Dense and solid
- Found in the walls of bone shaft and on external surface

Question 4

What is the difference between long bones and short bones?

Answer 4

Long Bones
Parts: Epiphysis, metaphysis, diaphysis, and medullary cavity

Examples:
Humerus, femur, metacarpals, phalanges, etc.

Short Bones:
Cuboidal (foot)
Carpals (hand/wrist) and tarsals (feet/ankle)

Question 5

What is the difference flat, irregular, and sesamoid bones?

Answer 5

Flat bones: Serve protective function
Examples: Several bones in the skull, sternum, ribs, scapula

Irregular bones: Bones that do not fit into any other category
Examples: Vertebrae, bones of the face, hyoid

Sesamoid bones: Develop within a tendon
Examples: Patella

Question 6

Tendons connect muscle to ______.
Ligaments connect bone to ______.

Answer 6

Tendons connect muscle to bone.
Ligaments connect bone to bone

Question 7

During bone growth, what is endochondral ossification?

Answer 7

• Bones preceded by cartilage model
• Cartilage is penetrated by blood vessels (nutrient foramen)

Includes:
1. Metaphysis = primary center of
ossification
2. Epiphyseal plate = “growth plate”
3. Epiphysis = secondary center of ossification

Question 8

During bone growth, what is intramembranous ossification?

Answer 8

• Mesenchyme (embryonic tissue) is directly converted into bone