Biopsychology Flashcards
1
Q
What does the CNS comprise of?
A
- brain
- spinal chord
2
Q
What is the function of the spinal chord? - what does this allow?
A
To relay information between the brain and the rest of the bod.
This allows the brain to regulate and monitor bodily processes such as digestion and breathing and to coordinate bodily movements
3
Q
What does the spinal chord contain?
A
Circuits of nerve cells that enable us to perform some simple reflexes (e.g. pulling your hand away from something hot)
4
Q
What would happen if your spinal chord is damaged?
A
Areas supplied by spinal nerves below the damaged site will be cut off from the brain and will stop functioning
5
Q
What are the four min areas of the brain?
A
- cerebrum
- diancephalon
- cerebellum
- brain stem
6
Q
What is the Cerebrum?
A
- The largest part of the brain
- it is further divided into 4 lobes
7
Q
Describe the functions of 2 lobes in the Cerebrum
A
- The frontal lobe is involved in thought and production of speech
- The occipital lobe (at the back of the cerebrum) is involved in processing visual images
8
Q
The Cerebrum is split into two halves, what are these called?
A
Cerebral hemispheres
9
Q
How do cerebral hemispheres communicate with others?
A
Through the corpus Callosum
10
Q
What does the Cerebellum do?
A
Controlls a persons monitor skills and balance, coordinating the muscles to allow precise movements.
11
Q
Where does the Cerebellum sit?
A
Beneath the back of the cerebrum
12
Q
What may abnormalities in the Cerebellum result in?
A
Speech and motor problems and epilepsy
13
Q
Where does the diacephalon lie?
A
Beneath the cerebrum and on top of the brain
14
Q
What are the two important structures within the diacephalon?
A
- the thalamus
- the hypothalamus
15
Q
What does the thalamus do?
A
-It acts as a relay station for nerve impulses coming from the senses, routing them to appropriate part of the brain where they can be processed.
16
Q
What does the hypothalamus do?
A
- Regulation of body temperature, hunger and thirst
- Acts as a link between the endocrine system and the nervous system, controlling the release of hormones from the pituitary gland
17
Q
What does the brain stem do?
A
Regulates the automatic functions that are essential for life such as breathing, heartbeat and swallowing
18
Q
What neurons pass through the brain stem?
A
Motor and sensory neurons, these allow impulses to pass between the brain and the spinal chord
19
Q
What are the two main processes of the CNS?
A
- the control of behaviour
- the regulation of the body’s psychological processes
20
Q
What is the peripheral nervous system?
A
All the nerves outside the CNS
21
Q
What is the function of the peripheral nervous system?
A
To relay nerve impulses from the CNS to the rest of the body and from the body back to the CNS
22
Q
What are the two main divisions of the peripheral nervous stem?
A
- The autonomic nervous system
- The somatic nervous system
23
Q
What is the somatic nervous system made up of?
A
- 12 pairs of cranial nerves (nerves that emerge directly from the underside of the brain)
- 31 pairs of spinal nerves (nerves that emerge from the spinal chord)
24
Q
What do sensory neurons do?
A
Relay messages to the CNS
25
What do motor neurons do?
Relay neurons from the CNS to other areas of the body
26
How does the somatic system allow reflex actions to occur quickly?
It is involved in reflex actions without the involvement of the CNS
27
What does the autonomic nervous system do?
- actions without conscious awareness
| e. g your heart beats and your intestines digest food without you being consciously aware of this happening
28
Why is the autonomic nervous system necessary?
Because if you had to think about vital bodily functions such as heartbeat and digestion they would not work as well
29
What are the two parts of the ANS?
- The sympathetic
| - The parasympathetic
30
What are the neurotransmitters used by the parasympathetic division?
Acetylcholine which has inhibiting effects
31
What are the neurotransmitters used by the sympathetic division?
Noradrenaline which has stimulating effects
32
What is the sympathetic nervous system primarily involved in?
Responses that help us to deal with emergencies (fight or flight) such as increasing heart rate and blood pressure and dilating blood vessels in the muscles
33
Give some examples on the effects of SNS activation in the body
- Increased pupil size lets in more light for better vision
- Increase in heart rate allows for greater blood flow to skeletal muscles
- Glycogen stored in the liver converted to glucose for energy
- Bronchial tubes in lungs dilate for greater oxygen intake
- sweat glands stimulated to produce more sweat
- adrenal medulla stimulated to release adrenaline
34
What does the parasympathetic nervous stem do?
-relaxes someone once the emergency has passed (after the SNS has pushed an individual into action due do an emergency)
35
Give examples of the effects of PNS activation in the body
- PNS slows the heartbeat down and reduces blood pressure
- Digestion (which is inhibited when SNS is aroused) begins under PNS influence
- because the PNS is involved with energy conservation and digestion it is sometimes referred to as the bodys rest and digest system
36
What are neuron cells?
Cells that are specialised to carry neural information throughout the body
37
What are the three types of neuron cells?
- sensory neurons
- relay neurons
- motor neurons
38
What do dendrites typically consist of?
- a cell body
- dendrites
- an axon
39
What is the control centre of a neuron?
The cell body
40
What is the insulating layer that forms around the axon?
The Myelin sheath
41
What happens if the myelin sheath is damaged?
Impulses slow down as the myelin sheath allows nerve impulses to travel more rapidly along the axon.
42
What do sensory neurons do?
Carry nerve impulses from sensory receptors (e.g to the receptors for vision, taste, touch) to the spinal chord and brain.
43
How do sensory neurons function?
- they convert information from these sensory receptors (e.g the receptors for vision, taste, touch) into nerve impulses
- when these impulses reach the brain, they are translated into sensations, for example visual input, pain etc. so the organism can react appropriately
44
How can reflex actions occur quickly when sensory neurons are involved?
Because not all sensory information travels as far as the brain, with some neurons terminating in the spinal chord
-therefore you do not have the delay of sending impulses to the brain.
45
What do relay neurons do?
- most neurons are neither sensory or motor, but lie somewhere between the sensory input and motor output
- relay neurons allow sensory and motor neurons to communicate with eachother
- they lie wholly within the brain and spinal chord
46
What do motor neurons do?
Form synapses with muscles and control their contractions
47
Where are motor neurons located?
-the neurons are located in the CNS and project their axons outside the CNS and directly or indirectly control muscles
48
How do motor neurons form synapses with muscles and control their contractions?
- When stimulated the motor neuron releases neurotransmitters that bind to receptors on the muscle and triggers a response which might lead to muscle movement .
- When the axon of a motor neuron fires, the muscle with which it has formed synapses with contracts
49
What does the strength of muscle contraction depend on?
-the rate of firing of the axons of motor neurons that control it
50
What is muscle relaxation caused by?
The inhibition of a motor neuron
51
Describe synaptic transmission
- once an action or potentials arrived at the terminal button the end of an axon, it needs to be transferred to another neuron or tissue
- to do this it must cross a gap between the presynaptic neuron and postsynaptic neuron
- the physical gap between the pre- and postsynaptic gap is known as the synaptic gap
- at the end of the axon of the nerve cell are a number of sacs known as synaptic vesicles
- these vesicles contain chemical messengers that assist in the transfer of the impulse, the neurotransmitters
- as the action potential reaches the synaptic vesicles, it causes them to release their contents through a process known as exocytosis
- the released neurotransmitter diffuses across the gap between the pre- and postsynaptic cell, where it binds to specialised receptors on the surface of the cell that recognise it and are activated by that certain neurotransmitter
- once they have been activated, the receptor molecules produce either excitatory or inhibitory effects on the postsynaptic neuron
52
What is re uptake?
| -how does it work as a sort of 're-cycling programme'
- Where the whole process of synaptic transmission are terminated at most synapses
- As the neurotransmitter is taken up by the pre-synaptic neuron, where it is stored and made available for later
53
What determines the length of the effect in synaptic transmission?
-what happens when it is quicker at being taken back?
- How quickly the presynaptic neuron takes back the neurotransmitter from the synaptic cleft
- the shorter the effects on the postsynaptic neuron
54
How can some antidepressant drugs prolong the action of a neurotransmitter in synaptic transmission?
By inhibiting this re-uptake process, leaving the neurotransmitter in the synapse for longer
55
How can neurotransmitters be 'turned off' after they have stimulated the post synaptic neuron?
Through the action of the enzymes produced by the body, which makes the enzymes ineffective
56
What are neurotransmitters?
The chemical messengers that carry signals across the synaptic gap to the receptor site on the post-synaptic cell
57
What are the two ways that neurotransmitters can be classified in terms of their actions?
- inhibitory
| - excitatory
58
Give 2 examples of excitatory neurotransmitters
- acetylcholine
| - noradrenaline
59
What are the effects of excitatory neurotransmitters?
- 'on switches'
| - increase the likelihood that an excitatory signal is sent to the post-synaptic cell which is then more likely to fire
60
Give 2 examples of inhibitory neurotransmitters
- seratonin
| - GABA
61
What are the effects of inhibitory neurotransmitters?
- 'off switches'
| - decrease the likely hood of that neuron firing
62
What are inhibitory neurotransmitters generally responsible for?
- calming the mind and body
- inducing sleep
- filtering out unnecessary excitatory signals
63
How do excitatory neurotransmitters make it more likely that the postsynaptic cell fires?
The excitatory neurotransmitter binds with a post-synaptic receptor to cause an electric change in the membrane of that cell, resulting in an excitatory post-synaptic potential, meaning that the post synaptic cell is more likely to fire
64
How do inhibitory neurotransmitters make it less likely that the postsynaptic cell fires?
An inhibitory neurotransmitter binding with a post-synaptic receptor results in inhibitory post-synaptic potential, making it less likely that the cell will fire
65
What happens if a nerve cell receives both ESP's and ISP's at the same time?
The likelihood of a cell firing is determined by adding up the excitatory and inhibitory synaptic input
66
What calculation determines wether or not the cell fires?
Summation
67
What are the 2 ways the strength of an ESP can be increased?
Spatial summation- a large number of ESP's are generated at many different synapses on the same postsynaptic neuron at the same time
Temporal summation- a large number of ESP's are generated at synapse by a series of high frequency action potentials on the pre-synaptic neuron.
68
What is the rate at which a particular cell fires determined by?
What goes on at the synapses
- if excitatory synapses are more active, the cell fires at a high rate
- if inhibitory synapses are more active, the cell fires at a much lower rate, if at all
69
What is the endocrine system?
Special groups of cells within the endocrine system whose function it is to produce and secrete hormones
70
What does the endocrine system use to deliver hormones to their target sites in the body?
Blood vessels
71
What are the 5 main parts of the endocrine system?
- Hypothalamus
- Testis
- Ovary
- Adrenal glands
- Pituary gland
72
What is the function of the hypothalamus?
Brain region controlling the pituitary gland
73
What is the function of the Pituitary gland?
Secretes many different hormones, some of which affect other glands
74
What is the function of the adrenal glands?
Help trigger the fight or flight response
75
What is the function of the ovary?
Secretes female sex hormones
76
What is the function of the testes?
Secretes male sex hormones
77
What do endocrine glands do?
Produce and secrete hormones, chemical substances that regulate the activity of cell or organs in the body
78
What are the major glands of the endocrine system?
- the pituary gland
- adrenal gland
- reproductive organs (ovaries and testes)
79
Give an example of how the endocrine system is regulated by feedback
- a signal is sent from the hypothalamus to the pituitary gland in the form of a 'releasing hormone'
- this causes the pituitary gland to secrete a stimulating hormone into the bloodstream
- this hormone then signals the target gland (e.g the adrenal gland) to secrete it's hormone
- as levels of this hormone rises in the bloodstream, the hypothalamus shuts down secretion of the releasing hormone and the pituitary gland shuts down secretion of the stimulating hormone
- this slows down secretion of the target glands hormone, resulting in stable concentrations of hormones circulating in the bloodstream
80
What are hormones?
Chemicals that circulate the bloodstream and are carried to target sites throughout the body
81
Why do target cells respond to a particular hormone?
because they have receptors for that hormone
82
What results in a physiological reaction in the target cell?
when enough receptor sites are stimulated by hormones
83
What is critical for normal functioning?
| -what can this result in?
The timing of hormone release
| -too much or too little can result in dysfunction of bodily systems
84
What can lead to Cushings syndrome?
| -what are the characteristics of Cushings?
- A high level of Cortisol
| - High blood pressure and depression
85
What is the most common cause of excess Cortisol?
A tumour in the pituitary gland which makes too much of a hormone called adrenocorticotrophic hormone which stimulates the adrenal glands to make too much cortisol
86
What is the main function of the pituitary gland?
To produce hormones whose primary function is to influence the release of hormones from other glands and so regulating many of the body's functions
87
What controls the pituitary gland?
The hypothalamus, a region of the brain just above the pituitary gland
88
Describe negative feedback in the pituitary gland?
- As the 'master gland' the pituitary produces hormones that travel in the bloodstream to their specific target
- these hormones either directly cause changes in physiological processes in the body or stimulate other glands to produce hormones
- high levels of hormones produced in other endocrine glands can stop the hypothalamus and pituitary releasing more of their more of their own hormones.
- this prevents hormones from rising too high
89
What are the two main parts of the pituitary gland?
1. )The anterior (front)
| 2. )Posterior (back)
90
What hormones does the anterior produce?
| -what does it stimulate the adrenal glands to produce?
ACTH- a response to stress
| -Cortisol
91
What two hormones does the anterior pituitary produce important in the control of reproductive functioning and sexual characteristics?
1. ) Luteinising horomone
2. )Follicle stimulating hormone
- in females these hormones stimulate the ovaries to produce oestrogen and progesterone
- in males they stimulate the testes to produce testosternone and sperm
92
What hormone does the posterior pituitary release?
| -what does this hormone do?
- Oxytocin
| - stimulates the contraction of the uterus during childbirth, and is important for mother-infant bonding
93
What are the two distinct parts of the adrenal glands?
- Adrenal cortex (the outer part)
| - Adrenal medulla (inner region)
94
What is the main distinction between the adrenal cortex and the adrenal medulla?
The hormones released by the adrenal cortex are necessary for life, those released by the adrenal medulla are not
95
What hormones are released by the adrenal cortex?
- what does this regulate and support?
- what does the adrenal cortex also produce?
Cortisol
- cardiovascular and anti-inflammatory functions
- aldosterone which is responsible for maintaining blood volume and blood pressure
96
What increases cortisol production?
Stress
97
What happens if cortisol production is low?
The individual has low blood pressure, poor immune function and an inability to deal with stress
98
What hormones does the adrenal medulla produce?
- adrenaline
| - noradrenaline
99
What do the hormones noradrenaline and adrenaline do?
| -how?
Prepare the body for fight or flight
Adrenaline helps the body respond to a stressful situation, for example increasing heart rate and blood flow to the muscles and brain helping them with the conversion of glycogen to glucose to provide energy. Noradrenaline constricts the blood vessels causing blood pressure to increase
100
What are ovaries responsible for?
-the production of eggs and the hormone oestrogen and progesterone
101
What is progesterone (important in the post ovulation phase of the menstrual cycle) important for?
Heightened sensitivity to social cues that indicate the presence of social oppurtunity (e.g recruiting allies) or threat (e.g from outsiders) that would be significant in the case of pregnancy
102
What is the main hormone produced by the testes?
Testosterone
103
What does testosterone cause?
The main growth of male characteristics such as growth of facial hair, deepening of the voice and the growth spurt that takes place during puberty
- sex drive
- sperm production
- maintenance of muscle strength
104
What is testosterone production controlled by?
| -how?
The hypothalamus and the pituitary gland
-the hypothalamus instructs the pituitary gland on how much testosterone to produce, and the pituitary gland passes this message on to the testes
105
What does the amygalda do?
Associates sensory signals with emotions such as anger or fear and sends a distress signal to the hypothalamus
106
What does the hypothalamus do?
In response to continued threat, It releases CRH into the bloodstream
107
What does the pituitary gland do?
Releases ACTH into the bloodstream and therefore to its target sites
108
What does the SNS do?
Prepares the body for the rapid action associated with fight or flight
109
What does the PNS do?
Dampens down the stress response when the threat has passed
110
What does the adrenal medulla do?
Releases adrenaline into the bloodstream causing physiological changes such as increased heart rate and release of blood sugar
111
What does the adrenal cortex do?
Releases stress hormones including cortisol, in response to stress
112
How does the feedback system work?
Cortisol levels are monitored so that CRH and ACTH production is prohibited if cortisol levels are too high
113
How do the amygalda and the hypothalamus work in the fight or flight response to stress?
- when an individual is faced with a threat, the amygalda is mobilised
- the amygalda associates sensory signals (hear, smell) with emotions associated with fight or flight (fear, anger)
- the amygalda then sends a distress signal to the hypothalamus, which functions like a command centre in the brain, communicating with the rest of the body through the sympathetic nervous system
114
What are the body's two major systems in response to stress?
1. ) Acute (sudden) such as personal attack
| 2. )Chronic (ongoing) stressors such as a stressful job
115
What are the two main responses to acute (sudden) stressors?
1. ) The sympathetic nervous system
| 2. )Adrenaline
116
What happens when the sympathetic nervous system is triggered in response to acute (sudden) stress?
It begins the body ready for rapid action necessary for fight or flight. The SNS sends a signal through the body for the rapid action necessary for fight or flight. The SNS sends a signal through the adrenal medulla, which responds by releasing the hormone adrenaline into the bloodstream
117
What happens when adrenaline circulates the body as a response to acute (sudden) stressors?
It causes a number of physiological changes. The heart beats faster ,pushing blood to the muscles, heart and other vital organs, and blood pressure increases. Breathing becomes more rapid in order to take in as much oxygen as possible with each breath. Adrenaline also triggers the release of blood sugar (glucose) and fats which flood into the bloodstream, supplying energy to parts of the body associated with the fight or flight response
118
What is the response to chronic (ongoing) stressors?
If the brain continues to perceive something as threatening, the second system kicks in. As the initial surge of adrenaline subsides the hypothalamus activates a stress response system called the HPA axis
119
What does the HPA axis consist of?
- the hypothalamus
- the pituitary gland
- the adrenal gland
120
'H'- the hypothalamus- how does it work in response to chronic (ongoing) stressors?
- The HPA axis relies on a series of hormonal signals to keep the SNS working.
- In response to continued threat, the hypothalamus releases a chemical messenger, corticotrophin-releasing-hormone (CRH), which is released into the bloodstream in response to the stressor
121
'P'- the pituitary gland-how does it work in response to chronic (ongoing) stressors?
- On arrival at the pituitary gland, CRH causes the pituitary gland to produce adrenocorticotrophic hormone (ACTH).
- From the pituitary, ACTH is transported in the bloodstream in response to the stressors to its target sites in the adrenal glands
122
'A'-the adrenal glands-how does it work in response to chronic (ongoing) stressors?
- ACTH stimulates the adrenal cortex to release various stress related hormones, including cortisol.
- Cortisol is responsible for several effects in the body that are important in the fight or flight response.
- Some positive (e.g burst of energy and lower sensitivity to pain)
- Some negative (e.g impaired cognitive performance and a lowered immune response)
123
Feedback-how does it work in response to chronic (ongoing) stress?
- efficient at regulating itself.
- both hypothalamus and pituitary gland have special receptors that monitor circulating cortisol levels
- if these rise above normal they initiate a reduction in CRH and ACTH levels, thus bringing cortisol levels back to normal
124
Evaluation of fight or flight: the 'tend and befriend response'
- Taylor et al suggests that for females behavioural responses to stress are more characterised by a pattern of trend and befriend than fight or flight
- this involves protecting themselves and their young through nurturing behaviours (tending) and forming protective alliances with other women (befriending)
- women may have a completely different system for coping with stress because their responses evolved in the context of being a primary caregiver for children
- Fleeing too readily at any sign of danger would put a females offspring at risk
- Studies using rats suggest there may be a physiological response to stress that inhibits flight- the release of the hormone oxycotin, this increases relaxation, reduces fearfulness and decreases the stress responses characteristic of the fight-or-flight-response
125
Evaluation of fight or flight response: fight or flight does not tell the whole story
- Gray argues that the first phase of reaction to a threat is not to fight or flee, but to avoid confrontation
- He suggests that prior to responding with attacking or running away, most animals (inc. humans) typically display the 'freeze response'
- the initial freeze response is essentially a 'stop, listen and listen' response, where the animal is hyper-viligant, alert to the slightest sign of danger.
- The adaptive advantages to this response of this response for humans are that 'freezing' focuses attention and makes them look for new information in order to make the best response for that particular threat
126
Evaluation of fight or flight: Negative consequences of the fight or flight response
- the physiological responses associated with fight or flight may be adaptive for stress response that requires energetic behavioural responses
- However the stressors of modern life rarely require such a level of physical activity
- The problem for modern humans arises when the stress response is repeatedly activated (e.g the increased blood pressure that is characterised by SNS activation can lead to physical damage in blood vessels and eventually to heart disease
- Similarly, although cortisol may assist the body in fighting a viral infection or healing damaged tissue, too much cortisol suppresses the immune response, shutting down the very process that fights infection
127
Evaluation of fight or flight: Positive rather than 'fight or flight behaviours'
- Von Dawans et al challenge the classic view that under stress men respond only with 'fight or flight' wheras women are more prone to 'tend and befriend'
- Von Dawans et al's study found that acute stress can actually lead to actually lead to greater and cooperative behaviour even in men
- this could explain the human connection that happens during times of crisis such as the 9/11 terrorist attacks in new york
- one reason why stress may lead to greater cooperative behaviour is because human beings are fundamentally social animals and it is the protective nature of human nature that has allowed out species to thrive
128
Evaluation of fight or flight: A genetic basis to sex differences in the fight or flight response
- Lee and Harley have found evidence of a genetic basis for gender differences in the fight-or-flight response
- The SRY gene found exclusively on the male Y chromosome, directs male development, promoting aggression and resulting in the fight or flight response to stress
- this suggests that the SRY gene may prime males to respond to stress in this way by the release of stress hormone, such as adrenaline and through increased blood flow to organs involved in the fight or flight response
- the absence of the SRY gene in females (who do not have a Y chromosome) together with the action of oestrogen and oxytocin may prevent this response to stress
