Endocrine System

Question 1

What is a hormone?

Answer 1

a chemical that is secreted by an endocrine gland and that affects the functioning of a cell or organ; often carried in the blood

Question 2

What is the difference between an endocrine and exocrine gland?

Answer 2

Exocrine glands: have ducts, secrete onto the body surface or a body cavity, secrete near the site of release, eg: mammary glands, mucuous glands, tear glands, sweat glands)
Endocrine glands: no ducts, secrete into extracellular fluid of the body, release to target cells, travel in the blood, eg: pituitary, pancreas, adrenal cortex

Question 3

Define the endocrine system?

Answer 3

The body system involved in chemical communication to cells

Question 4

Define the process in which steroidal cells have an impact on the cells

Answer 4

lipid soluble, able to pass through phospolipid bi-layer and into the cell, combine with a receptor protein in the cell (such as mitochondria, nucleus etc) to form a hormone receptor compex and activate genes controlling the formation of particular proteins

Question 5

Define the process in in which non steroidal cells have an impact on the cells.

Answer 5

not lipid soluble, attach to protein receptors on the outside of cells, secondary messenger is sent to diffuse through the cell and activate particular enzymes

Question 6

what is the difference between a steroidal and non steroidal hormone?

Answer 6

steroidal: lipid soluble, able to pass through cell membrane and activate receptors
non steroidal: not lipid soluble, have to attach to receptor proteins on the surface of membrane which send secondary messengers to activate enzymes

Question 7

How do hormones produce a desired effect?

Answer 7

• activate certain genes in the nucleus so a particular enzyme or structural protein is produced
• change the shape or structures of an enzyme so that it is turned on or off
• change the rate of production of an enzyme or structural protein by changing the rate of transcription or translation during production

Question 8

Function, target cells: oxytocin

Answer 8

uterus + mammary glands. Stimulates contraction of uterus during childbirth, release of milk from mammary glands (milk let-down reflex)

Question 9

Function, target cells: anti-diuretic hormone

Answer 9

kidneys. Increases water re-absorption so less is lost as urine

Question 10

Function, target cells: growth hormone

Answer 10

most cells. Increases rate of growth of cells and protein synthesis

Question 11

Function, target cells: adrenocorticotropic hormone

Answer 11

adrenal cortex. Stimulates secretions of hormones from adrenal cortex

Question 12

Function, target cells: follicle stimulating hormone

Answer 12

Ovaries, testes. stimulates development of ovarian follicle/sperm.

Question 13

Function, target cells: luitenizing hormone

Answer 13

ovaries, testes. Ovulation and maintenance of corpus luteum, secretion of testosterone

Question 14

Function, target cells: prolactin

Answer 14

mammary glands. Stimulates milk production

Question 15

Function, target cells: thyroid stimulating hormone

Answer 15

thyroid gland. Stimulates secretion of hormones from the thyroid.

Question 16

Secreted from, function, target cells: thyroxine

Answer 16

Secreted from thyroid. Target cells: most. Increases metabolic rate.

Question 17

Secreted from, function, target cells: parathyroid hormone

Answer 17

Secreted from parathyroid. Target cells: bones, kidneys. Increases levels of calcium in the blood

Question 18

Secreted from, function, target cells: thymosins

Answer 18

Secreted from thymus. Target cells: T lymphocytes. Stimulate maturation of T lymphocytes.

Question 19

Secreted from, function, target cells: aldosterone

Answer 19

Secreted from adrenal cortex. Target cells: kidneys. increases reaborption of sodium ions and excretion of potassium ions

Question 20

Secreted from, function, target cells: cortisol

Answer 20

Secreted from adrenal cortex. Target cells: most. Promotes normal metabolism, helps body deal with stress, promote repair of damaged tissue

Question 21

Secreted from, function, target cells: adrenaline and noradrenaline

Answer 21

Secreted from: adrenal medulla. Target cells: most. Prepares body for fight or flight response, reinforces effects of sympathetic nervous system

Question 22

Secreted from, function, target cells: insulin

Answer 22

Secreted from: pancreas. Target cells: most. Lowers blood glucose levels.

Question 23

Secreted from, function, target cells: glucagon

Answer 23

Secreted from: pancreas. Target cells: liver and fat storage tissues. Increases blood glucose levels.

Question 24

Secreted from, function, target cells: androgens

Answer 24

Secreted from: testes. Target cells: many. Stimulates sperm production, growth of skeleton and muscles, male sex characteristics

Question 25

Secreted from, function, target cells: oestrogen

Answer 25

Secreted from: ovaries. Target cells: many. Stimulates development of female characteristics, regulates menstrual cycle

Question 26

Secreted from, function, target cells: progesterone

Answer 26

Secreted from: ovaries. Target cells: uterus and mammary glands. Regulates menstrual cycle and pregnancy, prepares mammary glands for milk secretion