6 - Biopsychology (AS-Level) Flashcards
The Nervous System The Endocrine System Neurons and Synapses The 'Fight or Flight' Response
What are the subdivisions of the human nervous system?
Human NS → Peripheral NS + Central NS
Peripheral NS → Autonomic NS + Somatic NS
Autonomic NS → Sympathetic NS + Parasympathetic NS
What are the 2 sub-divisions of the central nervous system (CNS)?
Brain and spinal chord
What is the function of the CNS?
Controls behaviour, bodily processes and muscles
What is the function of the PNS?
Relays messages to/from CNS
What are the 2 sub-divisions of the peripheral nervous system (PNS)?
Somatic and autonomic NS
What is the function of the somatic NS?
- Carries sensory information from the world to the brain
- Provides muscle responses
What is the function of the autonomic NS?
It controls involuntary/unconscious actions
What is the function of the sympathetic NS?
Involved in triggering responses to help us deal with emergencies (‘Fight or Flight’ response)
What is the function of the parasympathetic NS?
Controls bodily functions when a person is at rest
What are the 4 lobes of the cerebrum?
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
What is the function of the frontal lobe?
Used for higher-order functions (eg. planning and logic)
What is the function of the parietal lobe?
- Integrates information from different senses
- Important for spatial navigation
What is the function of the occipital lobe?
Processes visual information
What is the function of the temporal lobe?
Processes auditory information
What is the function of the cerebellum?
Controls motor skills, balance and coordinating the muscles to allow precise movements
What are the 2 parts of the diencephalon?
Thalamus and hypothalamus
What is the function of the thalamus?
Acts as a relay station for nerve impulses coming from senses and directing them to the appropriate part of the brain to be processed
What is the function of the hypothalamus?
- Regulates body temperature, hunger and thirst
- Controls the release of hormones from the pituitary gland
- Links the endocrine and nervous system together
What is the function of the brain stem?
- Controls automatic functions (eg. heartbeat, breathing and swallowing
- Connects the brain and spinal cord, allowing impulses to travel between them via motor and sensory neurons
What is the endocrine system?
A network of glands throughout the body that manufacture and secrete hormones
What are some glands in the ES?
- Pituitary gland
- Adrenal gland
- Hypothalamus
- Thymus
- Pancreas
- Thyroid and parathyroid
- Pineal
- Reproductive organs
What are hormones?
Chemical messengers that travel through the bloodstream and are carried to target sites throughout the body
What kind of cells respond to particular hormones? Why?
Target cells - they have receptors for their respective hormone
How is the ES regulated?
The ES is regulated by negative feedback
1) A signal prompts the ES to produce a hormone
2) The hormone is released in response to the stimulus and/or signals
3) As levels rise int he bloodstream, a second signals slows down the secretion of that hormone
4) This results in in stable concentration of hormones circulating in the bloodstream
What does the hypothalamus control and what controls it?
- It controls many bodily functions
- It is controlled by the hypothalamus
What is the function of the pituitary gland?
- Produces hormones that control the release of hormones from other glands
- Regulates many bodily functions
What is the function of the adrenal glands?
- Supports bodily functions (eg. cardiovascular and anti-inflammatory functions)
- Causes physiological changes associated with arousal
- Prepares the body for the ‘Fight or Flight’ response
What are the parts that make up each adrenal gland?
Adrenal cortex and adrenal medulla
What does the adrenal cortex produce?
Cortisol
What does the adrenal medulla produce?
Adrenaline and noradrenaline
What do the ovaries do?
Produce:
- eggs
- oestrogen
- progesterone
What do the testes do?
Produce sperm and testosterone
What does summation mean?
The adding up of excitatory and inhibitory postsynaptic potentials
Draw/describe a summation graph
EPSP → IPSP → EPSP → IPSP → EPSP - stimulus at threshold → depolarisation → action potential → repolarisation → refractory period → resting state
What does a neuron do?
They carry information in action potentials (electrical impulses)
What are the 3 main types of neurons?
- Sensory neuron
- Relay neuron
- Motor neuron
What is the function of a sensory neuron?
Receives information from stimuli
What is the function of a relay neuron?
Transmits information from sensory neurons to motor neurons
What is the function of a motor neuron?
Control muscle movement to respond to stimuli
What is synaptic transmission?
The communication between neurons at synapses via neurotransmitters
What are the 8 components of a neuron?
- Axon terminal
- Axon (schwann cells, nodes of Ranvier, myelin sheath)
- Cell body (nucleus)
- Dendrites
Describe the process of synaptic transmission
1) Action potential/neurotransmitter (NT) arrives at axon terminal
2) NT is packed into vesicles
3) Vesicles fuse with cell membrane of the presynaptic terminal
4) NT diffuses across the synapse
5) NT binds to the postsynaptic receptors
6) Excess NT is broken down or recycled by reuptake channels
What are 2 types of postsynaptic potential?
- Excitatory PSP
- Inhibitory PSP
What is excitatory postsynaptic potential?
When an excitatory neurotransmitter binds to the postsynaptic receptor which results in EPSP, making it more likely that the cell will fire an action potential
What is inhibitory postsynaptic potential?
When an inhibitory neurotransmitter binds to the postsynaptic receptor which results in IPSP, making it less likely that the cell will fire an action potential
What are 2 types of summation?
- Temporal summation
- Spatial summation
What is temporal summation?
The quick firing of one presynaptic neuron
What is spatial summation?
Lots of small signals happening at different synapses
How does the body initially deal with stress?
Acute/chronic stressor → amygdala → hypothalamus → autonomic NS → sympathetic NS → response
How does the body respond to acute stressors?
Sympathetic NS → adrenal cortex → cortisol → parasympathetic NS
Sympathetic NS → adrenal medulla → adrenaline parasympathetic NS
