Biopsychology - The Nervous system & The Endocrine system

Question 1

Briefly discuss the fight or flight response (8 marks)

Answer 1

The fight or flight response is caused by an acute stress. this is a sudden stressful trigger in the environment. For example, a lion jumping out the bushes would be an acute stress. this acute stress causes the amygdala to send a distress signal to the hypothalamus, which signals the Autonomic Nervous System to signal the Sympathetic Nervous System which stimulates to Adrenal gland to secrete the hormone adrenaline, which causes physical changes in the body e.g. pupil dilation to let more light in or faster heart rate because more blood is being pumped around the body

• One weakness of the fight or flight response is that it does not accurately explain the stress response in females. this is because the ‘tend and befriend’ approach may be used instead, meaning a ‘female’ is more likely to tend to her offspring to befriend the danger than fight or flee.
• This is a weakness because it means the fight or flight response is limited as it cannot be generalised to everyone, as it does not apply to females. This makes it less credible.
• However some may argue this response is not beneficial for survival so any female that did this would die, meaning this behaviour would not carry on.
• Despite this, the fight or flight response cannot be generalised to everyone because it doesn’t take into account this response.
• Thus decreasing its external validity
• Another weakness of the fight or flight response is that behaviour is not limited to these responses and people may freeze instead
• This is when a person stops and becomes hypervigilant.
• This is a weakness because it shows that the fight or flight response is limited, which shows that it is incomplete.
• This decreases its validity, as it is not a complete explanation of what happens, which means it is less likely to be used and trusted

Question 2

hypothalmus

Answer 2

action - this is connected to the pituitary gland and it stimulates and controls the release of hormones from the pituitary gland

Question 3

pituitary gland

Answer 3

hormones - oxytocin thyroid stimulation hormone (TSH), ACTH

action - the ‘Master gland’ as it controls all other glands, for example, TSH signals action in the thyroid. ACTH signals action in the adrenal gland

Question 4

thyroid gland

Answer 4

hormones - thyroxine

action - primarily involved with the regulation of metabolism, such as the conversion of food into energy for the muscles

Question 5

parathyroid gland

Answer 5

hormone - parathormone

action - PTH essentially acts to increase the concentration of calcium in the blood from kidneys and bone

Question 6

pancreas

Answer 6

hormone - insulin

action - promotes the absorption of glucose from the blood into fat, liver and skeletal muscle cells

Question 7

adrenal glands

Answer 7

hormones - adrenaline & noradrenaline

action - responsible for reacting to threat via the fight or flight response

Question 8

ovaries (female)

Answer 8

hormones - oestrogen and progesterone

action - responsible for the development and regulation of the female reproduction system and secondary sex characteristics

Question 9

testes (male)

Answer 9

hormone - testosterone

action - a key role in the development of male reproductive system such as the testes and prostate, as well as promoting secondary sexual characteristics, such as increased muscle and bone mass, and the growth of body hair

Question 10

pineal gland

Answer 10

hormones - melatonin

action - regulates the Sleep-wake cycle

Question 11

nervous system structure

Answer 11

central nervous system (processes, interprets, stores information; issues order to muscles, glands, organs)
> brain
> spinal cord (bridge between brain and peripheral nerves)

peripheral nervous system (transmits information to and from the CNS)
> somatic nervous system (controls skeletal muscles)
> autonomic nervous system (regulates glands, blood, vessels, internal organs)
» sympathetic nervous system (mobilizes body for action, energy output)
» parasympathetic nervous system (conserves energy, maintains quiet state)

Question 12

SNS

Answer 12

Somatic Nervous System
part of the PNS that is concerned with the interaction of the outside world. it controls the voluntary movement of skeletal muscles. (i.e. the biceps; moving an arm, typing on a keyboard). it also consists of the nerves that carry messages to the eyes, ears, skeletal muscles and the skin to give the CNS experience of its environment

Question 13

ANS

Answer 13

autonomic nervous system

part of the PNS that controls involuntary (without conscious control) movement from non-skeletal muscles, for example, the ‘smooth muscles’ that control the intestines, digestion, bladder, pupil size and cardiac muscles (the heart)

Question 14

differences between the SNS and ANS

Answer 14

SNS functions include posture and movement; ANS functions include secretion and control of metabolism (converting food into energy)

SNS - in vertebrates - includes excitatory neurotransmitters
ANS - in vertebrates has both excitatory & inhibitory neurotransmitters (we’ll consider these types of neurotransmitters later when we look at synaptic transmission)

Question 15

sympathetic nervous system

Answer 15

activated in situations requiring arousal and energy. when we feel threatened or under stress, the sympathetic branch of the ANS is activated which starts the instinctive reaction of ‘fight or flight’, aiding survival. it produces increased heart and respiratory (breathing) rate, increasing blood flow to the muscles and pupil dilation (bigger pupils)

Question 16

parasympathetic nervous system

Answer 16

activated soon after the threat of danger has passed. this has the opposite effect of the SNS and allows for the body to return to homeostasis (balance). here the person’s heart and respiraotry rate decrease to normal levels and blood flow decreases. the pupils return to normal size. this system is vital for the individual to conserve energy and not become exhausted

Question 17

ao1

Answer 17

The fight or flight response is caused by an acute stress. this is a sudden stressful trigger in the environment. For example, a lion jumping out the bushes would be an acute stress. this acute stress causes the amygdala to send a distress signal to the hypothalamus, which signals the Autonomic Nervous System to signal the Sympathetic Nervous System which stimulates to Adrenal gland to secrete the hormone adrenaline, which causes physical changes in the body e.g. pupil dilation to let more light in or faster heart rate because more blood is being pumped around the body

Question 18

ao3

Answer 18

• One weakness of the fight or flight response is that it does not accurately explain the stress response in females.
• This is because Taylor et al found that the ‘tend and befriend’ approach may be used instead, meaning a ‘female’ is more likely to tend to her offspring to befriend the danger than fight or flee.
• This is a weakness because it means the fight or flight response is limited as it cannot be generalised to everyone, as it does not apply to females. This makes it less credible.
• However some may argue this response is not beneficial for survival so any female that did this would die, meaning this behaviour would not carry on.
• Despite this, the fight or flight response cannot be generalised to everyone because it doesn’t take into account this response.
• Thus decreasing its external validity
• Another weakness of the fight or flight response is that behaviour is not limited to these responses
• Gilroy et al found that before the fight or flight response, the body freezes, this is when a person stops and becomes hypervigilant.
• This is a weakness because it shows that the fight or flight response is limited, which shows that it is incomplete.
• This decreases its validity, as it is not a complete explanation of what happens, which means it is less likely to be used and trusted

this behaviour has negative repercussions on human biological functioning and is detrimental to modern society
- The fight/flight response no longer proves to be a useful survival mechanism
- Modern life situations no longer require an intense biological response, and this can negatively affect our health
= long term stress can lead to physical illness
= fight or flight no longer holds practical applications for humans