13.2 Human regulation of growth, development, and metabolism

Question 1

Pituitary gland

Answer 1

Endocrine gland that has two lobe and is about one centimetre in diameter

• controlled by the hypothalamus via releasing hormones and neurons
• releases several tropic hormones

Question 2

posterior pituitary (3)

Answer 2

part of the nervous system

• does not produce any hormones instead it stores and releases the hormones.
• ADH and Oxytocin are produced in the hypothalamus and transferred to the posterior pituitary by neuronal axons

Question 3

Anterior pituitary (3)

Answer 3

Hormone synthesizing gland
- produces six major hormones:
hGH
Prolactin 
TSH
ACTH
FSH
LH
A series of blood vessels called a portal system carries releasing hormones from the hypothalamus to the anterior pituitary (either inhibit or stimulate)

Question 4

hGH (3)

Answer 4

• affects almost every body tissue
• produced by anterior pituitary

protein synthesis
cell division and grow
metabolic breakdown and release of fats stored in fat tissue

Question 5

gigantism

Answer 5

too much hGH during childhood

Question 6

pituitary dwarfism

Answer 6

Insufficicient hGH production during childhood

Question 7

Acromegaly

Answer 7

when someone reaches adulthood and skeletal growth is complete, overproduction of hGH causes this.

• the excess hGH cannot increase in height so the bones and soft tissues of the body widen
• face widens
• ribs thicken
• feet and hand enlarge

Question 8

Thyroid Gland

Answer 8

• produces thyroxine

Question 9

Thyroxine (5)

Answer 9

• made and secreted by thyroid gland
• increase the rate at which the body metabolizes fats, proteins, and carbs for energy (releases stored energy as ATP)
• does not have a specific target organ
• plays important role in the growth and development of children by influencing the organization of various cells into tissues and organs.
• TSH causes the thyroid gland to secrete thyroxine

Question 10

Hypothyroidism (8)

Answer 10

the process where the thyroid produces extremely low quantuties of thyroxine

• stocky
• shorter than average
• tired
• slow pulse rate
• puffy skin
• hair loss
• weight gain

Question 11

Hyperthyroidism/ graves+ treatment (7)

Answer 11

Overproduction of thyroxine

• anxiety
• insomania
• heat intolerance
• an irregular heartbeat
• weightloss

can be treated by medications or removal or irradiation of part of the thyroid

Question 12

TSH (3)

Answer 12

• released by the anterior pituitary
• targets the thyroid gland to secrete thyroxine
• regulated by the negative feedback of thyroxine.

Question 13

Goitre (2)

Answer 13

• an enlargement of the thyroid gland due to relentless stimulation
• caused by insufficient iodine in the diet and thyroxine cannot be made. There will be non signal to stop the secretion of TSH by the anterior pituitary.

Question 14

Calcitonin (3)

Answer 14

• triggered when concentration of calcium in the blood rises too high
• stimulates the uptake of calcium into bones which lower its concentration in the blood
• secreted by the thyroid

Question 15

Parathyroid gland (2)

Answer 15

• four small glands attached to the thyroid

- produce and release a hormone PTH in response to falling concentrations of calcium in the blood

Question 16

PTH

Answer 16

• stimulated when there is a falling concentration of calcium in the blood
• stimulates bone cells to break down bone material and reabsorb calcium into the blood
• stimulates kidney to reabsorb calcium from the urine, activating Vitamin D in the process. Vitamin D in turn, stimulates the absorption of calcium from food in the intestines.