Endocrine System

Question 1

endocrine system

Answer 1

The endocrine system responds more slowly to a stimulus by producing and secreting hormones into the bloodstream to alter the activities of an effector

Question 2

hormone production and secretion

Answer 2

Hormones are secreted by a stimulus, and the stimuli that trigger endocrine glands
Hormonal stimulus - one hormone stimulates the secretion of another
Humoral stimulus - changes in ion or nutrient blood levels, e.g. glucose, Ca2+, Na+, K+.
Neural stimulus - signals from the nervous system

Question 3

hormonal stimulus

Answer 3

hypothalamus secretes a hormone that stimulates the anterior pituitary gland to secrete a hormone that stimulate other endocrine glands to secrete hormones

Question 4

humoral stimulus

Answer 4

low blood ca2+ levels stimulates parathyroid glands to secrete parathyroid hormone

Question 5

neural

Answer 5

preganglionic sympathetic fibres stimulate adrenal medulla to secrete adrenalin and noradrenalin

Question 6

chemical classes of hormones

Answer 6

steroid hormones made from cholesterol
are lipid-soluble
amino acid based hormones amino acids, peptides or proteins
are lipid insoluble

Question 7

hormones alter target cell activity

Answer 7

-control the rate of chemical (metabolic) reactions
-facilitate the transportation of substances into and out of cells
-regulate fluid and electrolyte balance, blood pressure, reproductive functions, development and growth
-maintain homeostasis

Question 8

Hypothalamus-Posterior Pituitary

Answer 8

hypothalamic neurons produce oxytocin and (ADH).
hypothalamic-hypophyseal tract, which transport hormones to the posterior pituitary
When stimulated neuron secrete hormones into bloodstream

Question 9

ADH

Answer 9

blood Na+ levels increase above the normal range, and/or blood volume and blood pressure decrease below the normal range.
targets the kidneys decreases urine output by stimulating the kidneys to return more water back into the blood
also cause the vasoconstriction of arterioles which helps increase blood pressure.

Question 10

Oxytocin

Answer 10

stretching of the uterus during labour and the suckling action of the infant during breastfeeding.
stimulates the contraction of uterine smooth muscle cells during labour and the ejection of milk from the mammary glands during breastfeeding.

Question 11

Hypothalamus-Anterior Pituitary

Answer 11

When stimulated, hypothalamic neurons secrete releasing/inhibiting hormones into the hypophyseal portal system
Hormones travel to the anterior pituitary
hypothalamic hormones stimulate/inhibit secretion of anterior pituitary hormones

Question 12

FSH & LH

Answer 12

(GnRH) stimulates them, they target the male and female gonads

Question 13

prolactin

Answer 13

Prolactin-inhibiting hormone controls the the secretion of PRL, targets the mammary glands and stimulates milk production

Question 14

ACTH

Answer 14

CRH stimulates it, targets the adrenal cortex to secrete the hormone cortisol

Question 15

TSH

Answer 15

TRH stimulates it, targets the thyroid gland to secrete the thyroid hormones

Question 16

GH

Answer 16

GH-RH & GHIH
GH stimulates cells in the liver, skeletal muscles and bones to secrete insulin-like growth factors (IGFs), which stimulate the actions required for growth

Question 17

Thyroid glands

Answer 17

base of the throat- secreted by TSH
increase BMR, body heat, HR and force of contraction by increasing the number of beta-adrenergic receptors on cardiac muscle cells
promotes growth of muscles and bones and nervous system development

Question 18

Calcitonin

Answer 18

Calcitonin is secreted by the parafollicular cells of the thyroid gland when blood Ca2+ levels increase above the normal range.
targets bone, and decreases blood Ca2+ to normal levels by inhibiting the activity of osteoclasts stimulating calcium uptake from the blood into bone

Question 19

Parathyroid Hormone

Answer 19

secreted by the parathyroid glands when blood Ca2+ levels decrease below the normal range. targets bone, kidneys and small intestines, and increases blood Ca2+ to normal levels by stimulating: bone-resorbing osteoclasts, the kidneys to return more Ca2+ to the blood

Question 20

EPO

Answer 20

secreted by the kidneys when blood oxygen levels drop below their normal range, targets the bone marrow and stimulates the production of red blood cells.

Question 21

Cortisol

Answer 21

from the adrenal cortex is stimulated by the anterior pituitary hormone, ACTH. is an important metabolic hormone that helps the body resist stressors by increasing blood glucose, fatty acid and amino acid levels as follows

Question 22

Aldosterone

Answer 22

an increase in blood K+ levels or Angiotensin II. maintains blood K+ and Na+ levels within their normal ranges by stimulating the kidneys to: remove more K+ from the blood return more Na+ back into the blood

Question 23

Adrenaline and Noradrenaline

Answer 23

sympathetic division of the autonomic nervous system. prolong the fight-or-flight response By binding to the alpha (α) or beta (β) adrenergic receptors on target cells, adrenaline and noradrenaline

Question 24

insulin

Answer 24

pancreatic beta cells when blood glucose levels increase above the normal range (4-8mmol/L). decreases blood glucose to normal levels stimulates body cells to uptake glucose from the blood, targets the liver to inhibit the production of glucose from amino acids and glycerol targets the liver and skeletal muscle to inhibit the breakdown of glycogen to glucose

Question 25

Glucagon

Answer 25

pancreatic alpha cells when blood glucose levels decrease below the normal range. increases blood glucose to normal levels by stimulating the liver to breakdown stored glycogen to glucose
produce glucose from amino acids and glycerol
release glucose into the bloodstream

Question 26

Oestrogen

Answer 26

anterior pituitary hormones, FSH & LH.
Oestrogen targets female reproductive organs to promotes their growth and maturation, targets the uterus to regulate the menstrual cycles and promotes the development of female secondary sex characteristics

Question 27

Progesterone

Answer 27

anterior pituitary hormone, LH.
prepares the uterus for pregnancy and helps maintain the pregnancy. Together with oestogen it also regulates the menstrual cycle

Question 28

Testosterone

Answer 28

stimulated by the anterior pituitary hormone, LH
promote their growth and maturation, targets the testes to stimulate sperm production promotes the development of male secondary sex characteristics