Endocrine System

Question 1

homeostasis

Answer 1

keep a constant internal environment in the body

Question 2

endocrine glands

Answer 2

glands that release secretions directly into the bloodstream which transports it to the target organs so it can perform its function

Question 3

exocrine gland

Answer 3

glands that release their secretions via ducts to a body cavity or the outside
eg.) saliva

Question 4

hormones

Answer 4

• organic compounds which are chemical messengers

- some are proteins, some are steroids

Question 5

which gland secretes hormones

Answer 5

endocrine gland

Question 6

negative feedback

Answer 6

• regulates the secretion of hormone by stimulating or inhibiting
• caused by a deviation from normal levels

Question 7

relationship between hypophysis and hypothalamus

Answer 7

• connected via neurons and posterior lobe
• thalamus produces hormones which are stored in physis
• thalamus controls physis by secreting releasing factors which stimulate physis to produce +/ release hormones

Question 8

hypophysis location

Answer 8

• fits into small bony cavity in cranium

- attached to thalamus by a small stork

Question 9

two lobes of hypophysis

Answer 9

anterior and posterior lobe

Question 10

hormones in anterior lobe

Answer 10

TSH
STH (growth hormone)
FSH
LH
Prolactin

Question 11

STH

Answer 11

growth hormone
promotes growth of the skeleton and muscles by stimulating protein synthesis
undersecretion = dwarfism
oversecretion = gigantism

Question 12

hypo/hypersecretion

Answer 12

hyper = over
hypo = under

Question 13

FSH

Answer 13

stimulates follicle development in the female ovary / produces sperm cells

Question 14

LH

Answer 14

• stimulates female ovulation

- stimulated cells to produce testosterone

Question 15

prolactin

Answer 15

stimulates mammary glands to produce breast milk

Question 16

hormones of posterior lobe

Answer 16

ADH

thyroxin

Question 17

ADH

Answer 17

• produced by hypothalamus
• when water level DEC, ADH release INC
• osmoreceptors detect change

Question 18

ADH function

Answer 18

controls the reabsorption of water by making renal tubule walls more permeable to water

Question 19

thyroid consists of…

Answer 19

two lobes between the larynx and trachea

Question 20

thyroxin function

Answer 20

increases basal metabolic rate
increases breathing/heart rate
essential for functioning of nervous system

Question 21

thyroid disorders

Answer 21

oversecretion = increased metabolic rate, weight loss, increased heart rate

undersecretion = leads to cretinism in children

Question 22

how is thyroxin levels in the blood controlled

Answer 22

kept constant by a negative feedback mechanism between hypophysis and thyroid

Question 23

process of thyroxin negative feedback

Answer 23

as soon as levels drop, hypophysis secretes more TSH increasing the level of thyroxin being secreted. when levels rise above normal, TSH secretion is inhibited

Question 24

TSH

Answer 24

stimulates the thyroid to secrete more thyroxin

Question 25

cells the pancreas is made up of…

Answer 25

exocrine pancreatic

endocrine islets of Langerhans

Question 26

pancreatic cells

Answer 26

secrete pancreatic juice into the pancreatic duct to aid chemical digestion

Question 27

islets of Langerhans

Answer 27

secrete hormones directly into bloodstream

Question 28

insulin

Answer 28

decreases the glucose level

produced by beta cells

Question 29

glucagon

Answer 29

increases glucose level

produced by alpha cells

Question 30

process of glucose levels changing

Answer 30

normal level
level changes
islets detect the change, hormone secreted
stimulates conversion/absorption
glucose is added/removed from blood
normal

Question 31

diabetes mellitus

Answer 31

• disease characterized by high glucose levels in blood

- no cure

Question 32

symptoms of diabetes

Answer 32

frequent urination
++ hunger
++ thirst
weight loss

Question 33

type 1 diabetes

Answer 33

the loss of beta cells in the pancreas, less insulin produced
- special diets, injections

Question 34

type 2 diabetes

Answer 34

insulin is produced but the body cannot use it effectively

• obesity, age
• medication + exercise

Question 35

adrenal glands structure

Answer 35

located at the top of each kidney; has an outer cortex and inner medulla

Question 36

hormones of adrenal cortex

Answer 36

aldosterone = regulates amount of sodium in the body

= increases sodium absorption

Question 37

hormones of adrenal medulla

Answer 37

adrenalin = secreted during stressful situations / fight or flight hormone
= prepares the body for action in emergencies

Question 38

effects of adrenalin on body

Answer 38

• accelerates/strengthens heart rate
• inc blood pressure
• inc rate and depth of breathing
• dilates pupil
• inc sweat productionq

Question 39

gonads

Answer 39

ovaries in women (in scrotum)

testes in men (on either side of uterus)

Question 40

testosterone

Answer 40

• secreted by Leydig cells
• resp for 2ndary male characteristics
• helps w the development of sex organs
• helps w maturation + quality of sperm

Question 41

oestrogen

Answer 41

• secreted by developing follicles
• resp for 2ndary female characteristics
• helps w development of sex organs
• inhibits secretion of FSH