Bone Tissue

Question 1

Appositional growth

Answer 1

Continual growth in diameter and thickness. Deposition of new tissue on surface.

Note: bone cells, osteocytes are imbedded in calcium matrix so can only deposit more matrix internally

Question 2

Wolf’s law of bone states that the ________ of a bone is determined by the________ placed upon it.

Answer 2

Architecture

mechanical stresses

Question 3

Abnormal ossification of tissues

Examples

Answer 3

Ectopic ossification
Harding of arteries - arteriosclerosis
Calcified mass in soft organs - calculus

Question 4

The process of dissolving bone

Answer 4

Mineral reabsorption

Question 5

Calcium deficiencies- low concentration of calcium in blood

Causes

Answer 5

Hypocalcemia

Excessive excitability of nervous system - tremors

Question 6

Calcium in excess

Results

Answer 6

Hypercalcemia

Depression of nervous system, emotional disturbances, muscle weakness

Question 7

Calcitriol

Answer 7

Form of vitamin D produced by skin - liver - kidney actions

Question 8

Calcitonin is produced in the

Answer 8

Thyroid gland

Question 9

What is secreted when calcium levels are too high

Answer 9

Calcitonin

Question 10

What mechanisms reduce calcium concentration in blood

Answer 10

Osteoclasts activity is reduced

Osteoblasts are stimulated to deposit calcium into bone

Question 11

What hormone is released when calcium levels in blood is too low?

Where is the hormone secreted?

Answer 11

Parathyroid hormone (PTH)

Parathyroid gland

Question 12

Four mechanism to raise calcium in blood -

PTH functions

Answer 12

stimulate osteoblasts to secrete RANKL (which stimulates stem cells to differentiate into osteoclasts) —> raises number of osteoclasts

Promotes calcium reabsorbtion in kidneys (so not pee out)

Promotes calcitriol (body produced vitamin D) synthesis in kidneys

Inhibits collagen synthesis by osteoblasts - prevent deposition of calcium into bone

Question 13

Tractor in which the bone remains in proper position

Answer 13

Non-displaced fracturing

Question 14

Fractured when a bone is shifted

Answer 14

Displaced fracture

Question 15

Bone in broken in multiple places

Answer 15

Comminuted fracture

Question 16

Bone is incompletely broken on one side but bent on the other

Answer 16

Green stick fracture

Question 17

Steps for healing fractures

Answer 17

Formation of hematoma

Formation of soft callus

Conversion to hard callus

Remodelingrrrrrrrrrrr

Question 18

Functions of skeleton (6)

Answer 18

Support, protect, movement, electrolyte balance, acid-base balance, blood formation

Question 19

Intermembranous ossification produces what type of bone

Answer 19

Flat bones and skull bones

Question 20

What embryonic tissue forms the membrane for intermembranous ossification?

Answer 20

Mesenchyme tissue

Question 21

Endocondrial Ossification occurs from what ages

Answer 21

6 week of fetal stage to the 20s

Question 22

In endochondrial ossification what type of cartilage if formed?

Answer 22

Hyaline cartilage

Question 23

Hormones that lower calcium in blood

Answer 23

Calcitonin
Cortisol
Estrogen
Insulin
Testosterone
Thyroid hormone?

Question 24

Hormones that increase calcium in blood

Answer 24

Calcitriol

Parathyroid hormone