Biopsychology - Nervous/Neuron/Synaptic/Endocrine/F+F

Question 1

What are the two sub-systems of the nervous system?

Answer 1

• CNS (Central Nervous System)
• PNS (Peripheral Nervous System)

Question 2

What is the Central Nervous System?

Answer 2

• made up of brain and spinal cord
• brain is the centre of all conscious awareness
  
  • cerebral cortex (brain’s outer layer) is highly developed
• spinal cord is responsible for reflex actions
  
  • passes messages to and from the brain and connects nerves to the PNS

Question 3

What is the Peripheral Nervous System?

Answer 3

• transmits messages, via millions of neurons to and from the CNS
  
  • ANS (Autonomic Nervous System) = governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal, and stress responses
  • SNS (Somatic Nervous System) = controls muscle movement and receives information from sensory receptors

Question 4

What is the function of the spinal cord?

Answer 4

• relays info between the brain and the rest of the body
• allows brain to monitor/regulate bodily processes
• contains circuits of nerve cells that allow for simple reflexes

Question 5

What is the function of the brain?

Answer 5

• cerebrum:
  
  • frontal, temporal, parietal, and occipital lobe
  • split into two cerebral hemispheres (communicate via corpus callosum)
• cerebellum:
  
  • controls motor skills/balance and coordinates the muscles to allow for precise movements
• diencephalon:
  
  • divided into 4 sections: thalamus, hypothalamus, epithalamus, and subthalamus
  • involved in crucial bodily functions (e.g. coordinating with endocrine system)
• brain stem:
  
  • regulates automatic functions needed for living (breathing, heartbeat, swallowing)
  • allows for impulses to pass between brain and spinal cord

Question 6

What is the function of the somatic nervous system?

Answer 6

• made up of 12 pairs of cranial nerves/31 pairs of spinal nerves
• sensory neurons -> CNS -> motor neurons
  
  • also involved in reflex actions (without CNS)
• facilitates communication between the CNS and outside world (carries sensory info and provides muscle responses)

Question 7

What is the function of the autonomic nervous system?

Answer 7

• regulates involuntary actions such as heartbeats, digesting food, etc.
  
  • ANS control centre is found in the brain stem
• plays important role in homeostasis (maintains internal processes)
• it has two parts:
  
  • sympathetic nervous system
  • parasympathetic nervous system

Question 8

What is the function of the sympathetic nervous system?

Answer 8

• involved in processes that help deal with emergencies (fight or flight)
  
  • neurons from SNS travel to most organs to prepare body for rapid action
  • e.g. releases stored energy, dilates pupils, inhibits digestion

Question 9

What is the parasympathetic nervous system?

Answer 9

• relaxes the individual after emergency has passed
  
  • slows down heart rate, reduces blood pressure
• returns body to normal resting state

Question 10

What is the structure of a neuron?

Answer 10

• dendrite
  
  • carry nerve impulses
• cell body (nucleus)
  
  • contains genetic material of the cell
• axon
  
  • carries nerve impulses away from the cell body
• myelin sheath
  
  • fatty layer that protects axon and speeds up electrical transmission of impulse
• node of ranvier
  
  • gaps within the myelin sheath which helps speed up transmission (jumps along axon)
• schwann cell
• axon terminal
  
  • communicate with next neuron in the chain across a synapse

Question 11

What is the sensory neuron?

Answer 11

• found in receptors and carry nerve impulses to the spinal cord/brain
  
  • some stop at the spinal cord for a reflex action

Question 12

What is the relay neuron?

Answer 12

• found between sensory input and motor output (in the brain and spinal cord)

Question 13

What is the motor neuron?

Answer 13

• found in CNS and controls muscle movements
• they release neurotransmitters that bind to muscle receptors

Question 14

What are the similarities/differences between neurons?

Answer 14

• sensory:
  
  • cell body in the middle of axon
• relay:
  
  • no myelin sheath
• motor:
  
  • large cell body/dendrites

Question 15

What is synaptic transmission?

Answer 15

• process by which neighbouring neurons communicate with each other (send chemical messages across gap)
  
  • nerve impulse passes from the presynaptic neuron to the postsynaptic neuron

Question 16

What is the process of synaptic transmission?

Answer 16

• neuron in resting state:
  
  • inside of cell = -vely charged
• neuron activated by stimulus:
  
  • inside of cell = +vely charged
  • causes action potential (creates electrical impulse)
  • this is electric transmission
• once AP arrives at axon terminal, it needs to cross the synapse (end of pre/postsynaptic neuron)
  
  • synaptic cleft = physical gap between the two neurons
• synaptic vesicle = sacs on axon terminal
  
  • contain neurotransmitters that help to transfer AP
  • as AP reaches vesicles, exocytosis takes place
  • released NTs diffuse across the synaptic gap and binds to specialised receptors on postsynaptic neuron
• re-uptake = NR taken up again by the presynaptic neuron (stored for later release)

Question 17

What are excitatory neurotransmitters?

Answer 17

• NTs that are likely to increase chances of activating/carrying out behaviour
• e.g. adrenaline, dopamine

Question 18

What are inhibitory neurotransmitters?

Answer 18

• NTs responsible for calming the mind/body (induce sleep/filter out unnecessary excitatory signals)
• e.g. serotonin, GABA

Question 19

What is excitatory post-synaptic potential?

Answer 19

• where the excitatory NT binds to a postsynaptic receptor causing an electrical charge in the membrane
  
  • cell is more likely to fire

Question 20

What is inhibitory post-synaptic transmission?

Answer 20

• where the inhibitory NT binds to a postsynaptic receptor
  
  • cell is less likely to fire

Question 21

What is summation?

Answer 21

• net result of whether or not the cell will fire (cell can receive both EPSPs and IPSPs)
• spatial summation:
  
  • large no. of EPSPs are generated at many different synapses on same postsynaptic neuron
• temporal summation:
  
  • large no. of EPSPs generated at the same synapse by series of high freq. APs by presynaptic neuron

Question 22

What is the endocrine system?

Answer 22

• network of glands across the body that secrete hormones
• blood vessels are used to transmit info
• works alongside the nervous system to control vital bodily functions
  
  • acts much slower than the nervous system but has much long lasting effects
  • hormones enter bloodstream and affect any cell that has a receptor for that hormone

Question 23

What are the main glands/hormones of the endocrine system?

Answer 23

• thyroid:
  
  • thyroxine
  • regulates metabolic rate and protein synthesis
• adrenal medulla:
  
  • adrenaline
  • fight or flight response
• adrenal cortex:
  
  • cortisol = further release of stored glucose
  • mineralocorticoids = regulate water balance of the body
• testes:
  
  • testosterone
  • development of male secondary sexual characteristics
• ovaries:
  
  • oestrogen
  • regulates female reproductive system
• pineal:
  
  • melatonin
  • regulation or arousal, biological rhythms, sleep-wake cycle

Question 24

What are the anterior pituitary gland hormones?

Answer 24

• adrenocortical trophic hormone (ACTH):
  
  • adrenal cortex
  • key component in stress response
• thyroid stim. hormone (TSH):
  
  • thyroid
  • stim. release of thyroxine
• prolactin:
  
  • mammary
  • stim. milk production/release
• follicle stim. hormone (FSH):
  
  • ovaries/testes
  • stim. release of ovarian follicles
• growth hormone:
  
  • cell growth
• melanocyte stim. hormone (MSH):
  
  • stim. production/release of of melanin in skin/hair

Question 25

What are the posterior pituitary gland hormones?

Answer 25

- antidiuretic hormone (ADH): - regulates water balance of the body - oxytocin: - promotes uterine contractions in childbirth

Question 26

What is the fight or flight response?

Answer 26

- when a person experiences a threatening situation, their heart beats faster, breathing is more quicker and muscles tense

Question 27

What happens to the brain during the fight or flight response?

Answer 27

- amygdala: - associates sensory signals with emotions associated with F or F - hypothalamus: - amygdala sends distress signal here - communicates with the body through the sympathetic nervous system

Question 28

How does the SNS prepare for the F+F response?

Answer 28

- response to acute stressors: - prepares for rapid F or F - adrenaline is released into bloodstream - heart beats faster - pushes blood to the muscles, heart and other vital organs, blood pressure increases - faster breathing - increases oxygen intake - blood sugar/fats released - supplies energy to parts of the body associated with F or F

Question 29

How does the PNS respond to the F+F response?

Answer 29

- when the threat has passed, PN branch of ANS dampens down stress response - slows down heartbeat - reduces blood pressure

Question 30

What are the strengths/weaknesses of F+F?

Answer 30

- strength: - makes sense from evolutionary pov (helps individual to survive, F or F would have been more useful back in the day) - weaknesses: - reaction is not limited to F or F, freeze can also be involved - Gray (1988) suggests first response to danger is to avoid confrontation altogether - typically a male response - females adopt a 'tend and befriend' response in stressful situations - Taylor (2000) = women are more likely to protect their offspring and form alliances with other women - Von Dawans (2012) = even males can tend/befriend (9/11) - modern day life rarely requires intense biological responses - stressors of modern day life can repeatedly activate the F or F which can -vely affect our health - suggests that F or F is a *maladaptive* response in modern day life