hormones

Question 1

what is a hormone?

Answer 1

is a chemical substance profuced in minutr quantites by an endocrine gland.
it is transported in the blood to specific target organs where it exerts its effects. After the hormone has performed its functions, it is destroyed by the liver n excreted thru the kidneys

Question 2

what is a gland?

Answer 2

its a cell or tissue tht secretes chemical substance for use in the body or to the external envo

Question 3

exocrine glands

Answer 3

a gland w a “tube” called duct tht allows chemical substances to b secreted out of the body or into a region of the body
eg salivary gland, pancreas, liver, sweat gland and mammary gland

Question 4

endocrine gland

Answer 4

a ductless gland tht secretes hormones directly into bloodstream
eg pituitary gland, adrenal gland, pancreas, ovaries and testes

Question 5

why is the pancreas unique?

Answer 5

it acts as an endocrine gland whn secreting hormones such as insulin n glucagon directly into bloodstream
it acts as an exocrine gland whn it produces pancreatic juice which is carried to the duodenum by the pancreatic DUCT

Question 6

insulin

Answer 6

whn u hv a diet of high carbs tht r digested into glucose:
increased blood glucose level(bgl)
causes pancreas to secrete insulin into bloodstream
transported to liver
stimulates liver cells to conv excess glucose to glycogen which is stored in the liver
stimulates muscle cells to absorb the excess glucose as well
thus decreasing bgl BACK TO NORM

Question 7

glucagon

Answer 7

whn u hv a diet of low carbs/fasting:
decreased blood glucose level(bgl)
causes pancreas to secrete glucagon into bloodstream
transported to liver
stimulate liver cells to conv stored glycogen into glucose
thus increasing bgl BACK TO NORM

Question 8

wht happens whn thrs a lack of secretion of insulin?

Answer 8

1. glucose appears in urine:
   bcos glucose is not stored n is lost in urine n cannot b absorbed back fast enough
   lead to diabetes Mellitus
2. ketones r excreted in urine:
   w/o glucose, the body begins to oxidise fats to release energy which results in the production of ketones n is excreted in urine
   which is a condition called ketonuria

Question 9

wht happens whn thrs over-secretion of insulin?

Answer 9

1. cause bgl to decrease rapidly to an ABNORMAL LEVEL
   HYPOGLYCAEMIA -> results in a condition called SHOCK tht causes onw to faint n also lead to coma & death:)
2. liver releases less glucose:
   excess insulin causes tissue cells to absorb 2much glucose frm blood

Question 10

wht is diabetes mellitus?

Answer 10

its a disease in which the body is unable to control its bgl so the blood glucose conc rises abv norm n the kidneys r unable to completely reabsorb all the glucose excreted in urine since such a large quanity of glucose is filtering at glomerulus n kidney tubules so not able to reabsorb fast enough n clearing ur bladder by urinating will not change the rate of filtration of glucose

Question 11

what is insulin resistance?

Answer 11

body not responding well to insulin so pancreas has to produce more insulin in order to get same amt of glucose into cells n so overtime the pancreas gets exhausted n insulin production decreases

Question 12

adrenaline

Answer 12

secreted by adrenal glands in response to stress, fear, anxiety n excitement
allows body to respond quickly to sudden demands for energy
however, the effects of adrenaline is short-lived

Question 13

fight or flight (my cg b behind her cancerous desk)

Answer 13

1. increased breathing rate-> increase the rate of o2 uptake by lungs
2. increased brkdown of storage glycogen to glucose-> boost bgl (in liver)
3. increase heart rate n bp-> speed up blood circulation do more o2 n glucose can b carried quickly to muscle cells
4. increased rate of resp/metabolism to release more energy-> for contraction of muscles n so tht more energy can b released during tissue resp, n more o2 n glucose can b transported to muscle cells
5. constrictions of arterioles in skin-> allow more blood for muscles
6. pupils diate-> enhance vision
7. constricts arterioles to gut-> decrease digestive activities so tht more blood is channeled to muscles
   fear/stress/anxiety:
   activates hypothalamus(via sensory neuron)
   transmits nerve impulses to spinal cord(via relay neurone in cns)
   transmits nerve impulses to adrenal glands which is the effector via motor neurone
   secretes adrenaline which is thn transported by bloodstream to target organ