Growth and development; calcium homeostasis

Question 1

What is structural growth? (3)

Answer 1

1. net protein synthesis
2. Lengthening of bones
3. Increased number and size of cells

Question 2

In a human, when is the highest growth rate?

Answer 2

During foetal development and just after birth

Question 3

What are the 4 factors that effect growth?

Answer 3

1. Genetic
2. Socioeconomic and nutritional
3. Chronic disease and stress
4. Endocrine hormones (GH)

Question 4

What is growth hormones role and where is it made?

Answer 4

Role in growth and metabolism

Synthesised in the anterior pituitary

Question 5

How is the release of growth hormone controlled? (7)

Answer 5

1. Hypothalamus
2= Growth hormone regulating hormone
2= somatostatin
3. anterior pituitary 
4. Growth hormone (metabolism)
5. Liver and other tissues
6. Somatomedins (growth)

Question 6

What can affect the hypothalamus response?

Answer 6

Stress, sleep, exercise

Decrease in glucose, decrease in FFA, increase in AA

Question 7

What happens to metabolism when stress affects the hypothalamus? (3)

Answer 7

Increase blood glucose
Increase lipolysis
Increase protein synthesis

Question 8

How does growth hormone affect the liver?

Answer 8

Increases gluconeogenesis

Question 9

How does growth hormone affect the muscle? (3)

Answer 9

Increases AA uptake
Increases protein synthesis
Decreases glucose uptake

Question 10

How does growth hormone affect adipose tissue? (2)

Answer 10

Increase lipolysis

Decrease glucose uptake

Question 11

What is an indirect consequence of growth hormones?

Answer 11

Promotes growth

Question 12

What 3 hormones other than GH are important for growth?

Answer 12

Thyroid hormones (CNS)
Insulin 
Sex hormones (muscle, linear and bone)

Question 13

What are the 3 parts of the bone and how do they stop growing?

Answer 13

Epiphysis — shaft (diaphysis) — epiphyseal growth plate

Sex hormones ossify the epiphyseal plates - can no longer elongate

Question 14

What does a deficient pituitary disease cause?

Answer 14

Stunted child growth

Deficiency in adulthood

Question 15

How can you cure a deficient pituitary disease?

Answer 15

recombinant human growth hormone

Question 16

What does a excess pituitary disease cause? (2)

Answer 16

accelerated growth in children

acromegaly

Question 17

What are the symptoms of acromegaly? (5)

Answer 17

Coarsening of facial features
Enlarged hands or feet 
Headaches
Hypertension
Diabetes

Question 18

How can you treat gigantism and acromegaly? (2)

Answer 18

surgery or radiotherapy

Inhibit GH release

Question 19

What are the 3 functions and their locations of calcium homeostasis?

Answer 19

1. Calcified matrix of bone - extracellular matrix
2. Muscle contractions - extracellular fluid
3. Second messenger pathways -intracellular

Question 20

How is the calcium balance regulated? (3)

Answer 20

Parathyroid hormone
Calcitriol - activated vitamin D3
Calcitonin

Question 21

What is the effect of PTH on the kidney, bone and intestines?

Answer 21

Kidney: Increase Ca2+, decrease PO43-
Bone: Release of Ca2+ & PO43-
Intestines: Ca2+ intake increase

Question 22

How does PTH effect with calcitriol?

Answer 22

Joins in the kidney after absorbing vitamin D from sun/fish oil/egg and going through the liver

Question 23

What is the combined effect of PTH and calcitriol?

Answer 23

Cas2+ in plasma increases

Question 24

What is the combined effect of PTH, calcitriol and calcitonin?

Answer 24

Ca2+ in plasma decreases

Question 25

What is osteoporosis?

Answer 25

• Fragile bone with an increased fracture susceptibility

- Bone mass decreases