14.1 Hormonal Communication

Question 1

Defintion of a endocrine gland

Answer 1

group of cells which are specialised to secrete hormones directly into the blood stream

Question 2

What is the endocrine system made up of

Answer 2

endocrine glands

Question 3

What are the major endocrine glands

Answer 3

-pituitary gland
-pineal gland
-thymus
-pancreas
-ovary
-testis
-adrenal gland
-thyroid gland

Question 4

What is the function of the pineal gland

Answer 4

produces melatonin which affects reproductive development and daily cycles

Question 5

What is the function of the thymus

Answer 5

produces thymosin which promotes production and maturation of white blood cells

Question 6

What is the function of the pancreas

Answer 6

produces insulin which converts excess glucose into glycogen in the liver, and glucagon which converts glycogen back to glucose

Question 7

What is the function of the ovary

Answer 7

produces oestrogen and progesterone which controls ovulation and secondary sex characteristics, progesterone also prepares the uterus lining for receiving a embryo

Question 8

What is the function of the testis

Answer 8

produce testosterone which controls sperm production and secondary sex characteristics

Question 9

What is the function of the adrenal gland

Answer 9

produces adrenaline which increases HR, breathing rate and raises blood sugar level

Question 10

What is the function of the thyroid gland

Answer 10

produces thyroxine which controls the rate of metabolism and rate that glucose is used up in respiration, promotes growth

Question 11

What is the function of the pituitary gland

Answer 11

-makes several hormones
-close proximity to the hypothalamus ensures hormonal and nervous responses are closely linked and coordinated
-produces growth hormone which control growth of muscles and bones
-produces anti-diuretic hormone which increases reabsorption of water in the kidneys
-gonadotrophins which control development of ovaries and testis

Question 12

What are hormones

Answer 12

chemical messsengers which are secreted and transported directly in the blood for a widespread and long lasting effect

Question 13

What are steroid hormones and their effect on target cells

Answer 13

-lipid-soluble
-diffuse through the cell surface membrane of target cells and bind to receptors which are present in the cytoplasm or nucleus to form a hormone-receptor complex
-hormone-receptor complex acts as a transcription factor which in turn facilitates or inhibits the transcription of a specific gene

Question 14

What is an example of a steroid hormone

Answer 14

oestrogen

Question 15

What are non-steroid hormones and their effect on target cells

Answer 15

-insoluble hormones so hydrophilic
-cannot directly pass through cell surface membrane of target cells
-bind to specific receptors on the cell surface membrane which triggers a cascade of responses within the cell mediated by chemicals called secondary receptors

Question 16

What is an example of a non-steroid hormone

Answer 16

adrenaline

Question 17

What is the difference between hormonal system (H) and nevour system (N) communication

Answer 17

-H transmission by blood system, N transmission by neurones
-H transmission is slow, N transmission is very rapid
-H travels to all parts of the body but only target cells respond, nerve implies travel to specific parts of the body
-H response is slow, widespread and long-lasting. N is localised, rapid and short-lived
-H effect may be permanent and irreversible, N is temporary and reversible
-H communication is by hormones, N communication is by nervous system

Question 18

What is the contrast between endocrine and exocrine glands

Answer 18

-exocrine glands secrete chemicals through ducts in organs or to the surface of the body
-endocrine glands secrete chemicals directly into the bloodstream

Question 19

What is the structure of the adrenal glands

Answer 19

-2 small glands located on the top of each kidney
-3cm in height and 5cm in length
-made up of adrenal cortex and adrenal medulla surrounded by a capsule

Question 20

What is the productions of hormones by the adrenal cortex controlled by?

Answer 20

hormones released by pituitary gland

Question 21

What are the hormones produced by the adrenal cortex

Answer 21

-glucocorticoids
-mineralocorticoids
-androgens

Question 22

What is the function of glucocorticoids

Answer 22

-help regulate metabolism
-regulate blood pressure and cardiovascular function in response to stress
-regulate immune system, suppress inflammatory response
-release is controlled by the hypothalamus

Question 23

What is the function of mineralocorticoids

Answer 23

-aldosterone mainly produced which helps control blood pressure by maintaining balance between salt and water concentrations in the blood and body fluids
-its release is mediated by signals triggered by the kidneys

Question 24

What is the function of androgens

Answer 24

-small amounts of male and female sex hormones are released
-released by the ovaries or testes after puberty
-impact is relatively small

Question 25

When are hormones secreted by the adrenal medulla released

Answer 25

when the sympathetic nervous system is stimulation when the body is stressed

Question 26

What are the hormones secreted by the adrenal medulla

Answer 26

adrenaline noradrenaline

Question 27

What is the function of adrenaline

Answer 27

increases HR sending blood quickly to the muscles and brain. Rapidly raises glucose conc. levels by converting glycogen to glucose in the liver

Question 28

What is the function of noradrenaline

Answer 28

-works with adrenaline in response to stress -increases HR, widens pupils, widens air passages of lungs, narrows blood vessels in non-essential organs

Question 29

What does noradrenaline and adrenaline control?

Answer 29

The SA node

Question 30

Where is adrenaline and noradrenaline produced?

Answer 30

adrenal medulla

Question 31

What are the difference in the effect of adrenaline and noradrenaline?

Answer 31

Adrenaline specifically increases heart rate, noradrenaline increases blood pressure

Question 32

Define exocrine gland?

Answer 32

Secrete chemicals through ducts into organs or to the surface of body

Question 33

Label the major endocrine glands on this diagram

Answer 33

Question 34

What is the function of the adrenal cortex?

Answer 34

-Secretes steroid hormones which are vital to life eg. cortisol, aldosterone

Question 35

What is the function of the adrenal medulla?

Answer 35

-Secretes catecholamine hormones eg. adrenaline, noradrenaline