Bones

Question 1

Describe the structure of bones (3 parts).

Answer 1

Epiphysis
- End of the bone
- Surface that forms joints with other bones are covered with a layer of articular cartilage
- Contains red bone marrow
Disphysis
- Long cylindrical portion in the middle
- Lined by periosteum (outside) and endosteum (inner)
- Encloses the medullary marrow cavity which contains yellow bone marrow
Metaphysis
- Contains a layer of hayline cartilage called the epiphyseal growth plate (allows the diaphysis to grow)

Question 2

What are the 4 types of cells in bone tissue?

Answer 2

Osteogenic cells - act as stem cells

Osteoblasts - produce the extracellular matrix

Osteoclasts - breakdown the extracellular matrix

Osteocytes - mature bone cells that maintain metabolism

Question 3

What are the 4 functions of the skeletal system?

Answer 3

Support + protection - bones serve as a structural framework that supports and protects the internal organs

Assists movement - bones serve as attachment sites for skeletal muscles

Produces blood cells - red bone marrow produces red blood cells, white blood cells, and platelets

Stores minerals and lipids - minerals (ex.calcium)in the extracellular matrix of bone tissue can be released into the blood & triglycerides stores in yellow bone marrow can be released into the blood

Question 4

Define the 5 types of bones.

Answer 4

Long bone - greater length than width + mixture of compact (shaft) and spongy bones (ends)

Short bone - nearly equal length and width + spongy bone surrounded by a thin layer of compact bone

Flat bone - composed of two parallel plates of compact bone, enclosing a layer of spongy bone

Irregular bone - “complex” shapes with variable amount of compact and spongy bone

Sesamoid bone - develop with tendons (reduce wear + tear)

Question 5

What are the 20 bone surface markings?

Answer 5

Depression, openings, fissure, foramen, fossa, sulcus, meatus, projections/outgrowths, condyle, facet, head, crest, epicondyle, line, spinous, process, trochanter, tubercle, tuberosity

Question 6

How many bones are in the axial skeleton?

Answer 6

80 bones that lie around the longitudinal axis of the body

Question 7

How many bones are in the appendicular skeleton?

Answer 7

126 bones of the upper/lower limbs and the “girdles” that connect them to the axial skeleton