hormones

Question 1

define the term hormone

Answer 1

-chemical substance, produced by the gland, carried by the blood, that alters the activity of more than one specific target organs in an organism, it influences growth, development and activity of an organism

Question 2

how are hormones produced

Answer 2

-hormones are produced by the ductless glands
-enter bloodstream to be transported to the body
-reaches other parts of the body where they exert their effect

Question 3

different glands and their function

Answer 3

-pituitary gland secrete number of hormones, control the function of other glands, secretes antidiuretic drug
-hypothalamus secretes ADH
-thyroid gland secretes thyroxine
-adrenal gland secretes adrenaline to prepare body for flight or fight
-pancreas, IoL secrete insulin or glucagon

Question 4

how does insulin regulate blood glucose concentration

Answer 4

-make cell membrane to glucose more permeable, increasing rate of glucose uptake by cells
-stimulate liver and muscle cells to convert the glucose into glycogen
-increase oxidation of glucose during tissue respiration
-over insulin causes shock, coma and death

Question 5

what is diabetes mellitus

Answer 5

-condition where body does not secrete enough insulin to regulate sugar concentration
-blood glucose concentration reaches a level that exceeds kidney’s ability to reabsorb glucose and glucose is excreted in urine
-since muscle cells do not have reserve for glycogen, body becomes weak and person loses weight
-body oxidises fats instead of glucose for energy and this produces poisonous substance ketones
-ketonuria is when large amount of ketone is in urine

Question 6

properties of type 2 diabetes

Answer 6

-occurs later in life
-known as late-onset diabetes
-occurs when target cells such as muscle cells do not respond well to insulin
-treatment is by control of diatery intake, exercise and lifestyle changes

Question 7

signs of diabetes

Answer 7

-high blood glucose concentration
-presence of glucose after a meal
-healing of wound is long and difficult

Question 8

effects of glucagon

Answer 8

-targets the liver and increases blood glucose concentration
-stimulates conversion of glycogen into glucose
-fats and amino acids into glucose
-lactic acid into glucose

Question 9

how does adrenal medulla responds to stimuli

Answer 9

-during anger, stress and anxiety
-hypothalamus stimulated and nerve impulses are sent to the spinal chord
-nerve impulses leave spinal chord to adrenal medulla
-adrenal medulla stimulated producing adrenaline
-adrenaline carried by blood to target organs in body, bring short term responses that prepare body for fight or flight

Question 10

effects of adrenaline

Answer 10

-constrict arterioles to channel more blood to muscles
-dilate pupils to enhance vision
-increases rate of blood coagulation
-increases blood glucose concentration by speeding up rate of conversion of glycogen to glucose in liver and muscles
-increase heartbeat and blood pressure
-contract hair muscles causing goose pimples
-increases rate and depth of ventilation
-increase metabolic rate, more energy released