Hormones

Question 1

What are hormones

Answer 1

-Enable communication between cells
-Secreted by Endocrine glands
-Carried in bloodstream to target specific regions, (other endocrine glands, organs, cells, the brain)

Question 2

Neural & Endocrine communication Similarities

Answer 2

-Produce chemicals stored for later release
-Stimulated to release chemicals
-Some chemicals act as hormones & neurotransmitters
-React with specific receptors

Question 3

Neural & Endocrine communication Differences

Answer 3

-Neural communication is fixed between channels to precise locations; hormonal signalling is more generalised
-Neural messages are very rapid; hormonal communication is slower and prolonged
-Neurotransmitters travel across synapses; Hormones travel through blood
-Some neural communication is voluntary control (muscle etc), hormone release is not

Question 4

Functions of Hormones

Answer 4

-Excite and set things in motion and regulate:
-growth & development
-reproduction
-metabolism
-homeostasis
-control of internal organs

Question 5

Negative Feedback

Answer 5

-Output from a gland is responsible for preventing further release of more hormones

Question 6

Pineal Gland

Answer 6

-Melatonin, crucial for sleep regulation
-Entrainment- matching a physiological event to an environment oscillation e.g. low levels during day, increase at 8pm, peaks at midnight, decrease over night and dip again at daytime

Question 7

Hypothalamus

Answer 7

-located at base of brain
-hypothalamic nuclei make hypothalamic releasing hormones that stimulate/inhibit hormone release from pituitary gland

Question 8

Pituitary Gland

Answer 8

-Tropic hormones, influence release of hormones from other glands
-Anterior, controlled by hypothalamic releasing hormones
-Posterior, controlled by nerve stimulation from hypothalamus

Question 9

Posterior Pituitary Gland - ADH

Answer 9

-Anti-Diuretic Hormone
-Stimulates re-absorption of water by kidneys (conserves water)
-stimulates vasoconstriction (lower BP in response to stress)
-Caffeine, alcohol block vasopressin (ADH)

Question 10

Posterior Pituitary Gland - Oxytocin

Answer 10

-Causes muscle contraction in uterus and stimulates ejection of breast milk
-Elevated levels during sexual arousal
-Levels respond to social stimulation causing anti-stress effects
-Those who feel socially supported have higher levels of oxytocin

Question 11

Anterior Pituitary Gland - Growth Hormone

Answer 11

-Helps with metabolism, fat storage, glucose regulation

Question 12

Anterior Pituitary Gland - Thyroid stimulating hormone

Answer 12

-Stimulates release of thyroxine by thyroid gland
-Regulates metabolic rate - heart/digestive functions

Question 13

Anterior Pituitary Gland - Gonadotrophins

Answer 13

-Sex hormone release
-Luteinizing hormone, increases progesterone and testosterone
-Follicle stimulating hormone, increase oestrogen and sperm

Question 14

Anterior Pituitary Gland - ACTH

Answer 14

Adrenocorticotropic Hormone
stress hormone release

Question 15

Anterior Pituitary Gland - Prolactin

Answer 15

-Promotes tissue development in breasts during pregnancy and stimulates milk production after birth
-Also plays a part in sexual desire potentially

Question 16

Adrenal Gland

Answer 16

-Sits on top of kidneys
-Medulla (inside), responds to nerve stimulation from hypothalamus
-Cortex (outside), responds to ACTH from ant. pit.

Question 17

Adrenal Medulla

Answer 17

-Noradrenaline & Adrenaline
-Increase heart rate
-Constrict peripheral blood vessels
-Glucose release
-Increase blood flow to muscles etc, short term preparation for stress
-Fight/Flight

Question 18

Adrenal Cortex

Answer 18

-Sex hormones, Androgens and Oestrogens
-Mineralocorticoids, Aldosterone, Helps kidneys retain sodium excrete potassium, maintain blood pressure, maintain salt/water balance in body
-Corticosteroids, Mainly cortisol, maintains essential responses during stressful events

Question 19

Pancreas

Answer 19

-Insulin and glucagon
-Low blood sugar and stress, pancreas secretes glucagon and causes liver release glucose
-High blood sugar, release insulin, excess glucose taken by fat cells

Question 20

Testes

Answer 20

-Release androgens
-Secreted in small amounts from adrenal cortex so also produced by women
-Main is testosterone
-production begins during foetal development
-Burst at puberty stimulates secondary male characteristics
Growth & development of male reproductive structures
Increased skeletal & muscle growth
enlargement of larynx & voice change
Increase body hair
sexual drive

Question 21

Ovaries

Answer 21

-Female sex hormones, oestrogens
-also produced by men in small amounts (adrenal cortex)
-Onset of puberty releases
Estradiol, breast development, distribute fat, maturation of uterus & vagina
Progesterone - thickens lining of uterus in pregnancy
Both - stimulate changes in uterus during cycle, sexual behaviour

Question 22

Hormones & Behaviour

Answer 22

-remove source of hormone
-artificially add the hormone
-measure behaviour associated with hormone
castration/ovariectomy should have an effect on sexual behaviour
Somatic intervention