animal responses - nervous responses.

Question 1

in what ways does the brain activate the appropriate effetor via ?

Answer 1

• nervous impulses via autonomic nervous system to involuntary muscles
• nervous impulses via somatic nervous system to voluntary muscle.
• release of hormones from pituitary and somatic hormones.

Question 2

what is meant by the fight or flight response?

Answer 2

• the response made by body when put under stress.
• sensory neurone detect stimuli + send nervous impulse to hypothalamus -> activate hormonal system ( hyp stimulates pituitary to releases ATCH which causes cortex to release STEROID hormones ) + sympathetic nervous system which trigger release of Adrenaline from adrenal medulla of adrenal gland.

Question 3

F/F physiological changes + responses

Answer 3

intestines -> reduce peristalsis
pupils dilate -> increase amount of light + thus increase field of vision.
heart rate + blood pressure increase -> to increase flow of oxygenated blood around body
increase glycogenolysis -> more O2 for respiration of muscle/ skeletal muscles
erector pilli muscles contract -> hair stands up straight to make animal look bigger than it is.
metabolic rate increases -> moblises nutrients needed for respiration
arterioles in digestive system constrict (ie gut) whilst arterioles to liver, muscles heart etc dilate diverting bllod flow.

Question 4

what are the 3 TYPES of hormones released from the adrenal cortex?

Answer 4

• mineralcorticoids (eg aldesterone)
• glucocorticoids (eg cortisol)
• androgens

Question 5

how do glucocorticoids help in fight or flight response

Answer 5

• can increase glucose levels ie in glycogeolysis for increase ATP levels in respiration
• helps to regulate metabolism by controlling how the body converts FATS , CARBS + PROTIENS to energy .

Question 6

how are mineralcorticoids involved in flight or fight response

Answer 6

• help to maintain K+ and Na+ conc in blood to help to maintain blood pressure.

Question 7

why is it important that when u excercise/times of stress your heart rate increases.

Answer 7

• to provide extra OXYGEN for the increased rate of respiration.

Question 8

GM insulin > pig cow insulin from slaughtered meat

Answer 8

• less likley to trigger immune respse toproduve an allergic reaction
• inslin produced in larger quantities
• production costs are much cheaper
• less chance of infection with pig prions.
• no objection from religious groups

Question 9

benefits of using stem cells as treatment for diabetes type 2

Answer 9

+ can supply unending source of stem cell bc they divide by mitosis quickly + undifferentiated
+ no need for insulin injections

Question 10

negatives of using stem cells as treatment for diabetes type 2

Answer 10

• rejection problems still occur
• moral objection to the ending of a embryo life
• ability to control growth + differentiation is limited in stem cells -> could result in developement of tumours.

Question 11

suggest what happens to the proteins on the surface of the membrane pf B cells to stimulate autoimmune response.

Answer 11

• they undergo a conformational change of 3D shape due to mutation
  thus they are recognised as foreign.

Question 12

why are acinar cells shaped in a particular way

Answer 12

• to form ducts for secretion

Question 13

describe some of the similarities in the action of a plant + animal hormones in cell signalling ( 4)

Answer 13

• hormones bind to receptors
• to cause a cascade of enzyme reactions.
• hormones are needed in small quantities to have HUGE effects.
• may involve the interaction of >1 hormone.