Chapter 6: Osseous Tissue and Bone Structur

Question 1

Functions of the skeletal system:

Answer 1

Support
Storage of minerals (calcium) and lipids (yellow marrow)
Blood cell production (red marrow)
Protection
Leverage (force of motion)

Question 2

4 types of bone cells:

Answer 2

Osteoblasts
Osteocytes
Osteoprogenitor cells
Osteoclasts

Question 3

Osteoblasts:

Answer 3

Immature bone cells.
Forms Osteoid, but not yet calcified to form bone.
When surrounded by bone, becomes osteocytes.

Question 4

Osteocytes:

Answer 4

Mature bone cells that maintain bone matrix
Do not divide
Connect to each other through cytoplasmic extensions called calniculi.
Help repair damaged bone.

Question 5

Osteoprogenitor cells:

Answer 5

Stem cells that divide to form osteoblasts.
Assist in fracture repair.
Located in endosteum, periosteum, and linings of central canals.

Question 6

Osteoclasts:

Answer 6

Giant multinucleated cells.
Secrete acids and protein-digesting enzymes.
Osteolysis: Dissolve bone matrix and release minerals.

Question 7

4 kinds of hormones for bone growth and maitenence:

Answer 7

Growth horomone and thyroxine
Estrogens and androgens
Calcitonin and parathyroid hormones
Calcitriol

Question 8

Calcium regulation maintained by:

Answer 8

1. Calcitonin
2. Parathyroid Hormone

Effective at bones (stored), digestive tract (absorbed), and kidneys (excreted).

Question 9

Parathyroid Hormone

Answer 9

Produced by parathyroid glands in neck.
Increases calcium blood levels by:
Increasing osteoclasts activity
Increasing intestinal absorption of calcium
Decreased calcium excretion at kidneys

Question 10

Calcitonin Horomone:

Answer 10

Secreted from thyroid gland:
Deceased calcium blood levels by:
Decreasing osteoclasts activity
Decreasing intestinal absorption of calcium
Increasing calcium excretion at kidneys