Homeostasis, temp control, booze + fags

Question 1

Define homeostasis

Answer 1

self-regulatory process by which biological systems maintain stability while adjusting to changing external conditions

Question 2

Response to increase in temperature

Answer 2

• increase in temperature caused by stimulus
• increase in temperature detected by thermoreceptors in skin (peripheral - external temp) + hypothalamus (core temp)
• thermoreceptors send signals to thermoregulatory control centre in hypothalamus
• control centre sends signal to effectors (muscles + glands)
• stimulate sweat glands + vasodilation of blood vessels near skin surface + shunt blood to skin
• cause temperature to reduce
• cycle is continuous

Question 3

Response to decrease in temperature

Answer 3

• decrease in temperature caused by stimulus
• decrease in temperature detected by thermoreceptors in skin (peripheral - external temp) + hypothalamus (core temp)
• thermoreceptors send signals to thermoregulatory control centre in hypothalamus
• control centre sends signal to effectors (muscles + glands)
• shivering, erector pili contraction (hairs stand up), increase in metabolism, vasoconstriction (blood to key organs, away from peripheries)
• cause temperature to increase
• cycle is continuous

Question 4

What type of loop is temperature control?

Answer 4

Negative feedback loop

maintain a variable between set parameters

Question 5

What type of process is temperature control?

Answer 5

Autonomic process (involuntary)
[but can have behavioural responses eg. put on a jumper]

Question 6

Describe a fever

Answer 6

cytokines can increase temperature set level which produces a hostile environment for pathogens

• temperature set point raised in hypothalamus due to cytokine release
• body’s core temperature not at new set level, so body is essentially ‘cold’
• effectors then carry out actions to increase heat production in order to reach new temperature set level

Question 7

4Cs of addiction

Answer 7

cravings, loss of control, continued use despite harm, compulsion

Question 8

Define sensitisation

Answer 8

dopamine receptors are more responsive/sensitive to dopamine

Question 9

Define incentive sensitisation

Answer 9

wanting more and more increases with greater exposure to the drug (eg. nicotine)

Question 10

Describe abnormal sensitisation

Answer 10

wanting more drugs/substance/behaviour but the pleasure derived from it is diminishing (eg. heroin)

Question 11

Define cross-sensitisation

Answer 11

taking one drug might increase the urge to take others (eg. nicotine leading to illegal drug-taking)

Question 12

Define desensitisation and what it generally leads to

Answer 12

continual dopamine over-stimulation:

• reduction in number of dopamine receptors
• reduced sensitivity to dopamine
• reduced dopamine production

Question 13

Define tolerance

Answer 13

person no longer responds to a drug in the way they did at first (more needed for desired effect - due to fewer receptors)