Unit 2 Topic 1 - Homeostasis

Question 1

RECALL that homeostasis involves a stimulus-response model in which change in the condition of the external or internal environment is detected and appropriate responses occur via negative feedback (2.1.1)

Question 2

RECOGNISE that sensory receptors (chemo, thermos, mechano, photo, noci)
detect stimuli and can be classified by the type of stimulus (2.1.2)

Question 3

RECALL that effectors are either muscles (which contract in response to neural
stimuli) or glands (which produce secretions)
(2.1.3)

Question 4

INTERPRET feedback control diagrams for either nervous or hormonal systems (i.e. recognise stimulus, receptors, control centre, effector and communication pathways)
(2.1.4)

Question 5

UNDERSTAND that metabolism describes all of the chemical reactions involved in sustaining life and is either catabolic or anabolic (2.1.5)

Question 6

EXPLAIN why changes in metabolic activity alter the optimum conditions for
catalytic activity of enzymes (with reference to tolerance limits).
(2.1.6)

Question 7

IDENTIFY cells that transport nerve impulses from sensory receptors to neurons to effectors (2.1.7)

Question 8

DISCRIMINATE between a sensory neurone and a motor neurone (consider
dendrites, soma, body, axon, myelin sheath, nodes of Ranvier, axon terminal
and synapse)
(2.1.8)

Question 9

EXPLAIN the process of the passage of a nerve impulse in terms of transmission
of an action potential (conduction within neuron) and synaptic transmission
(communication between neurones). Refer to neurotransmitters, receptors,
synaptic cleft, vesicles, postsynaptic and presynaptic neurones and signal
transduction (2.1.9)

Question 10

RECALL that hormones are chemical messengers (produced mostly in endocrine glands) that relay messages to cells displaying specific receptors for each hormone via the circulatory or lymphatic system (2.1.10)

Question 11

RECOGNISE how a cell’s sensitivity to a specific hormone is directly related to the number of receptors it displays for that hormone (an increase in receptors =
upregulation, a decrease = downregulation)
(2.1.11)

Question 12

DESCRIBE how receptor binding activates a signal transduction mechanism and alters cellular activity (results in an increase or decrease in normal processes).
(2.1.12)