Biopsychology

Question 1

What is the human nervous system made up of ?

Answer 1

• The central nervous system (CNS)
• The peripheral nervous system (PNS)

Question 2

What is the central nervous system made up of?

Answer 2

• the brain: centre of all concious awareness
• the spinal cord: responsible for reflex actions and passing messages from the brain and PNS.

Question 3

What is the role of the central nervous system?

Answer 3

• Controls behaviour.
• Regulates physiological processes.
• Coordinates incoming sensory information and sends motor commands.

Question 4

What is the function of the PNS?

and what is it divided into

Answer 4

• transmits messages throughout the whole body from the brain and also relays messages back to the brain.
• The somatic nervous system (SNS) + The autonomic nervous system (ANS)

Question 5

What is the function of the somatic nervous system?

Answer 5

• Controls voluntary movements (e.g., walking, picking things up)
• transmits and receives messages from the senses
• Sends messages from the CNS to skeletal muscles, thorugh motor neurones ( effectors)

Question 6

what is the function of the autonomic nervous system?

AND ITS DIVISIONS

Answer 6

• Controls involuntary bodily functions (e.g., heart rate, digestion, breathing).
• Sympathetic Nervous System
• Parasympathetic Nervous System

Question 7

What is the function of the sympathetic nervous system?

Answer 7

• Activates the fight or flight response.
• Increases heart rate, dilates pupils, inhibits digestion, etc.
• enables a fast, automatic response to a possible threat or dangerous situation (

Question 8

What is the parasympathetic nervous system?

Answer 8

• rest and digest’ system
• Slows heart rate, stimulates digestion, conserves energy.
• returns body to homeostasis

Question 9

What is homeostasis?

Answer 9

• process by which the body maintains a stable internal environment
• maintained by the PARASYMPATHETIC

Question 10

What is the endocrine system?

Answer 10

• A network of glands that works alongside the nervous system to regulate bodily functions.
• Acts by releasing hormones into the bloodstream

Question 11

What are hormones?

Answer 11

• Chemicals secreted by glands into the bloodstream that affect target organs.
• act more slowly than neurotransmitters.

Question 12

Give examples of glands, hormones and their function

Answer 12

pituitary gland: controls release of hormones from other glands from hypothalumus.
pineal gland: releases melatonin , which modulates sleep pattern.
thyroid gland: releases thyroxine , which regulates metabolism basal rate.
Adrenal gland: releases adrenaline and cortisol regulates fight or flight response
Ovaries/Testes: releases oestrogen/testosterone regulates sexual development and behaviour

Question 13

What is the fight or flight response?

Answer 13

• is an evolutionary survival mechanism which prepares the body and mind for extreme action in response to a threat.
• such as fighting for our life or escaping a threat.
• The body returns to homeostasis (maintenance of bodily conditions) after the threat has passed.

Question 14

Describe the biological process of the fight or flight process

Answer 14

1. A stressor is perceived → amygdala (part of the brain) is activated.
2. Amygdala sends a signal to the hypothalamus.
3. Hypothalamus activates the sympathetic branch of the autonomic nervous system.
4. Sympathetic nerves stimulate the adrenal medulla (part of the adrenal gland).
5. The adrenal gland releases adrenaline (and noradrenaline) into the bloodstream.

HPA AXIS

Question 15

Describe the physiological changes of adrenaline.

Answer 15

– increase heart rate
– constricts blood vessels, increasing rate of blood flow and raising blood pressure
– diverts blood away from the skin, kidneys and digestive system
– increases blood to brain and skeletal muscle
– increases respiration and sweating

Question 16

Evaluate the fight or flight response

Answer 16

• Human behaviour is not limited to only two responses
  Gray suggests that the first response to a danger is to avoid it altogether, which is demonstrated by a “freeze” response. During the freeze response, humans are hyper-vigilant while they appraise the situation to decide the best course of action.
• This suggests that the fight-or-flight explanation of behaviour is limited and doesn’t fully explain the complex cognitive and biological factors that underpin the human responses to stress/danger
• Modern humans face psychological, not just physical threats. Constant activation can lead to stress-related illnesses.
• Useful survival mechanism in early humans.
• Supported by biological evidence, like measurable increases in heart rate and cortisol.
• Taylor et al. (2000) suggested women are more likely to show a tend-and-befriend response than fight or flight.

Question 17

Describe structure and function of a neuron (6)

Answer 17

• Neurons enable communication within the nervous system, through the transmission of electrical signals.
• The cell body (soma) contains the genetic material
• Branch-like dendrites extend from the cell body
• Dendrites can carry functional information towards the cell body and receive information from other neurons
• Axons carry messages away from the cell body
• Axons can be myelinated (containing a myelin sheath) to increase the speed of nerve transmission
• Terminal boutons are at the end of axons, these make synaptic connections with other cells
• Axon terminals contain neurotransmitters

Question 18

Explain how sensory, relay and motor neurons function (6)

Answer 18

• Sensory neurons receptors detect stimuli and Carry messages from the sensory receptors (e.g., skin, eyes) to the central nervous system (CNS), using sensory neurones.
• Relay neurons carry nerve impulses within the central nervous system. from and to the sensory and motor neurones. The brain or spinal cold analyses the situation and formulates a response. Relay sends this to motor neurones.
• Motor neurons send messages to the muscles or effectors – here the message from the brain instructs either contraction or relaxation ( dependent on situation)

Question 19

Give the process of synaptic transmission (6)

Answer 19

1. An electrical impulse (action potential) travels down the axon of the presynaptic neuron.
2. It reaches the axon terminal, triggering vesicles to release neurotransmitters into the synaptic cleft.
3. Neurotransmitters cross the gap and bind to receptor sites on the postsynaptic neuron.
4. If the charge inside the postsynaptic neuron passes a threshold, a new nerve impulse forms and the message is passed on.
5. The neurotransmitters detach from the receptors and return to the presynaptic cell via transport proteins, this process is called reuptake.

Question 20

Outline how excitation and inhibition are involved in synaptic transmission (4)

Answer 20

• Neurotransmitters can be excitatory or inhibitory
• If the neurotransmitter is excitatory then the postsynaptic neuron is more likely to fire an impulse
• If the neurotransmitter is inhibitory then the postsynaptic neuron is less likely to fire an impulse
• The excitatory and inhibitory influences are summed,
• if the net effect on the postsynaptic neuron is inhibitory, the neuron will be less likely to ‘fire’ and if the net effect is excitatory, the neurons will be more likely to fire

Question 21

Explain why neurons can only transmit information in one direction at a synapse.(3)

Answer 21

• Diffusion of the neurotransmitters means they can only go from high to low concentration, so can only travel from the presynaptic to the postsynaptic membrane.
• The synaptic vesicles containing the neurotransmitter are only present on / released the presynaptic membrane
• The receptors for the neurotransmitters are only present on the postsynaptic membrane