Biopsychology Flashcards
Describe the divisions of the human nervous system.
Human nervous system —> Central Nervous system (CNS) & Peripheral nervous system (PNS)
CNS —> Brain & Spinal cord
PNS —> Somatic & Autonomic (ANS)
ANS —> Sympathetic & Parasympathetic
State the two main functions of the CNS
The control of behaviour and the regulation of the body’s physiological processes
State the main function of the spinal cord
To relay information between the brain and the rest of the body
State the four main areas of the brain
1) Cerebrum (cerebral cortex is the outer layer of this)
2) Cerebellum
3) Diencephalon (thalamus & hypothalamus)
4) Brain stem
What are the four lobes of the cerebrum?
1) Frontal lobe
2) Occipital lobe
3) Parietal lobe
4) Temporal lobe
What does the frontal lobe of the cerebrum do?
Thought and the production of speech
What does the occipital lobe of the cerebrum do?
Processing of visual images
What does the cerebellum do?
Motor skills, balance & muscle co-ordinations
What are the two main structures in the diencephalon?
The thalamus and the hypothalamus
What does the thalamus do?
Relay station for nerve impulses coming from the senses, routing them to the appropriate part of the brain where they can be processed
What does the hypothalamus do?
1) Regulation of body temperature, hunger and thirst
2) Acts as the link between the endocrine system and the nervous system, controlling the release of hormones from the pituitary gland.
What does the brain stem do?
Regulation of automatic functions e.g. breathing, heartbeat and swallowing.
Motor and sensory neurons travel through the brain stem, allowing impulses to pass between the brain and the spinal cord.
Describe the somatic nervous system (SNS)
The part of the PNS responsible for carrying sensory and motor information to and from the central nervous system
Also involved in reflex actions with the involvement of the CNS
Describe the ANS
Governs the brain’s involuntary activities (e.g. stress, heartbeat) and is self-regulating (i.e. autonomous
it is divided into the sympathetic branch (fight or flight) and parasympathetic branch (rest and digest)
Which neurotransmitter does the sympathetic division of the ANS mainly use?
Noradrenaline - it has stimulating effects
What neurotransmitter does the parasympathetic division of the ANS mainly use?
Acetylcholine - it has inhibiting effects
Describe the sympathetic division of the ANS
It is primarily involved in responses that help us to deal with emergencies such as fight or flight.
It slows down bodily processes that are less important in emergencies, such as digestion and urination - does the opposite of the parasympathetic branch.
Describe the main points of the parasympathetic branch of the ANS
It relaxes the body once an emergency has passed. It slows heartbeat down and reduces blood pressure.
Basically does the opposite to the sympathetic branch of the ANS
What structure joins the two hemispheres of the brain?
The corpus callosum
What does the parietal lobe do?
Processing of sensory information
State the two types of ridges in the brain
Gyrus = Top Sulki = Bottom
Why is extreme cortical folding important?
It allows a large sa:vol ratio to allow for better processing.
Describe/draw the main structures of a neuron
Dendrites = At the end of the neurone
Cell body = Like the cytoplasm of the main end
Soma = The nucleus of the neuron
Myelin sheath = A fatty insulating layer that surrounds the axon
Nodes of ranvier = Gaps in between the myelin sheaths
Axon = the long bit where action potentials travel
Schwann cell = Wrap around the axon, producing the myelin sheath
Axon terminal = The other end of the neuron
State the three types of neurone
1) Sensory
2) Motor
3) Relay
How does the myelin sheath speed up impulses?
The action potential jumps from each node of ranvier to node of ranvier. This is called ‘saltatory conduction’
Describe a synapse
Presynaptic neurone and post synaptic neurone
Synaptic vesicles found in presynaptic terminal button
Synaptic gap/cleft
Acetylcholine and noradrenaline are known as excitatory or inhibitory in their actions?
Excitatory
Neurotransmitters such as serotonin and GABA are known as…
Inhibitory neurotransmitters
What do inhibitory neurotransmitters do?
What do excitatory neurotransmitters do?
Inhibitory = Decrease the likelihood of that neurotransmitter firing. Generally responsible for calming the mind and body, inducing sleep, and filtering out unnecessary exhibitory signals.
Exhibitory = Increase the likelihood of that neurotransmitter firing
What do EPSP and IPSP mean?
EPSP = Excitatory post-synaptic potential IPSP = Inhibitory post-synaptic potential
How do EPSP’s and IPSP’s occur?
An excitatory neurotransmitter binding with a post-synaptic receptor causes an electrical change in the membrane of that cell, resulting in an EPSP, meaning the post-synaptic cell is more likely to fire.
An inhibitory neurotransmitter binding with a post-synaptic receptor result in an IPSP, making it less likely the cell is to fire.
The likelihood of a cell firing is determined by…
The summation of excitatory and inhibitory synaptic input
What are the two ways the strength of an EPSP can be increased?
1) Spatial summation
2) Temporal summation
Describe spatial summation
A large number of EPSP’s are generated at many different synapses on the same post-synaptic neurone at the same time
Describe temporal summation
A large number of EPSP’s are generated at the same synapse by a series of high-frequency action potentials on the pre-synaptic neurone.
Define ‘target cell’
Cells with receptors that ‘unlock’ with a certain hormone
What are the effects of too much cortisol?
Too much cortisol can a to high blood pressure and depression
Which gland is called the ‘master gland’ and why?
The pituitary - because it controls many other endocrine glands
The Pituitary gland is split into two parts, what are these called?
The anterior and posterior lobe
What does the anterior lobe of the pituitary gland release and what do these hormones do?
ACTH = Response to stress, stimulates adrenal cortex
LH and FSH = The menstrual cycle
What does the posterior lobe of the pituitary gland secrete and what do these hormones do?
Oxytocin = Comfort & happiness.
ADH = Important in water regulation (osmoregulation)
Also stimulates uterus contraction
What are the two parts of the adrenal gland called?
1) The adrenal cortex
2) The adrenal medulla
What is adrenaline important for?
The ‘fight or flight’ response
What do the ovaries secrete?
Progesterone and oestrogen
What do the testes produce?
Testosterone
What is the HPA axis?
Describes the sequence of bodily activity in response to stress that involves the hypothalamus, pituitary and adrenal cortex
What is the difference between acute and chronic stressors?
Acute stressors = sudden, like a personal attack
Chronic stressors = ongoing, like a stressful job
Outline the difference between stress and stressors
Stress = A physical or psychological response to a stressor.
Stressors = internal or external factors that bring on stress. They can be acute (short-term) or chronic (ongoing)
Explain the body’s response to short-term, acute stressors.
SNS is triggered –> sends a signal to the adrenal medulla –> responds by secreting adrenaline into the bloodstream.
Explain the body’s response to adrenaline
1) Heart beats faster - blood pressure increases
2) Breathing becomes more rapid to take in more oxygen
3) Blood-glucose levels rise