a hormone secreted from the adrenal cortex
b ductless gland
c cell whose metabolism is altered by the binding of a hormone
d coordinated response of an animal to a threat stimulus
Fight or flight response
e neurotransmitter released by sympathetic neurones with similar effects to the hormone adrenaline
2 Describe the difference between:
a the roles of insulin and glucagon
Insulin promotes absorption of glucose by cells but glucagon causes glucose to be released from cells Insulin causes glucose to be converted to glycogen but glucagon causes glycogen to be hydrolysed to glucose Insulin affects, liver and muscle/all body cells, but glucagon acts on liver only
2 Describe the difference betweenb type 1 and type 2 diabetes mellitus
1 (usually), starts in childhood/juvenile-onset, but 2 starts, later in life/middle age 1 requires insulin treatment but 2 may be controlled by diet 1 due to autoimmune attack on β cells but 2 due to decline in responsiveness (of target cells) to insulin or β cells do not produce enough insulin
2 Describe the difference betweenc hormonal and neuronal communication.
Hormonal slow versus neuronal fast Hormonal chemical communication versus neuronal electrical Hormonal ‘message’ carried in blood versus neuronal by neurones Hormonal long-lasting effects versus neuronal short-term effects Hormonal widespread effects versus neuronal localised effect
c i State two advantages of treating type 1 diabetes by using insulin that has been produced by genetically modified bacteria rather than insulin that has been extracted from pigs.
Idea of plentiful/dependable, supply cheap Not cruel to pigs/more ethical No religious objections/can be used by vegetarians Reliable, quality/standard (exact match to) human insulin/no allergic reaction
ii A potential treatment for type 1 diabetes is the use of stem cells. State an advantage of this form of treatment compared to treatment using insulin.
(has the potential to) cure/do more than manage, the condition Long term effect/permanent/no need for repeated treatments
. iii Adrenaline affects a range of target tissues in the body. Suggest how the adrenaline molecules can cause different effects in different target tissues.
Different tissues have different (types of adrenaline) receptors (causing) cAMP concentration to increase or decrease Second messenger (may be) different cAMP/second messenger, activates, different/other, enzymes/enzyme reactions (in different target cells)
b Outline the hormonal and nervous mechanisms involved in the control of heart rate.
Adrenalin(e) increases, heart rate/stroke volume/cardiac output Cardiovascular centre in medulla oblongata idea of nervous connection to, SAN/sinoatrial node (which) controls frequency of waves of, excitation/depolarisation Vagus/parasympathetic, nerve decreases heart rate Accelerator/sympathetic, nerve increases heart rate High blood pressure detected by, stretch receptors/baroreceptors Low blood pH/increased levels of blood CO2, detected by chemoreceptors (receptors) in, aorta/carotid sinus/carotid arteries