Biopsychology L1 - 4 Flashcards
What are the 2 main functions of the nervous system?
- Collect, process + respond to info in environment
- Coordinate working of different organs and cells in the body
What 2 sub-systems does the nervous system consist of?
- Central Nervous System
- Peripheral Nervous System
What 2 parts is the central nervous system made up of?
- Brain
- Spinal cord
What are the three parts of the brain and what are the main divisions of these?
Parts of brain:
- Hindbrain
- Midbrain
- Forebrain
4 divisions:
- Cerebrum
- Cerebellum
- Diancephalon
- Brain stem
3 Features of cerebrum:
- Largest part
- 4 lobes: frontal, temporal, parietal, occipital
- Divided into 2 cerebral hemispheres
Purpose of cerebellum:
Controls motor skills and balance
2 Features of diancephalon:
- 4 main structures: thalamus, hypothalamus, epithalamus, subthalamus
- Regulates circadian rhythm
Purpose of brain stem:
Regulates automatic functions
What does spinal cord transmit info to and from?
To and from brain
What does PNS transmit info to and from and and what can it be sub-divided into?
- Transmits messages via neurons to and from CNS
Subdivided into: - Autonomic Nervous System
- Somatic Nervous System
3 Features of SNS:
- Transmits messages from receptor cells to CNS
- Also receives messages from CNS (spinal cord) for muscle movement
- Both sensory and motor neurons
4 Features of ANS:
- Automatic and unconscious
- 2 parts: sympathetic and parasympathetic
- Only consists of motor pathways
2 Features of sympathetic nervous system:
- Increases activity and is activated when a person is stressed
- Uses noradrenaline which stimulates
2 Features of parasympathetic nervous system:
- Returns body to resting state after flight and fight
- Uses acetylcholine which inhibits
Differences between brain and spinal cord:
Brain - Conscious awareness
Spinal cord - Simple reflex responses
Differences between somatic and autonomic nervous system:
- Autonomic has 2 subdivisions, whereas somatic only has 1
- Autonomic only has motor pathways whereas somatic has this and sensory ones
6 Parts of neuron:
- Cell body
- Dendrites
- Axon
- Myelin sheath (sensory + motor)
- Axon terminals
- Nodes of Ranvier
What does the cell body include?
Nucleus, which consist of genetic material
What are dendrites?
- Branch-like structures hanging out from cell body
- Receives signals from other neurons/sensory receptors
What is the axon?
- Long slender fibre
- Carries impulses w/ action potential away from cell body down to axon terminals
What is myelin sheath?
Covers axon, protects it and speeds up electrical transmission of impulse
What are nodes of Ranvier and why is it there?
- Gaps between myelin sheath
- Speed up transmission by forcing it to jump across axons
What does the axon terminal do and through what process?
- Connects every neuron to each other
- Synaptic transmission
3 types of neurons:
1) Sensory
2) Motor
3) Relay
3 Features of sensory neurons:
- Found in receptors
- Carry impulses from PNS to CNS
- Quick reflex actions go to spinal cord rather than brain
3 Features of motor neurons:
- Found in CNS
- Control muscle movements
- Release neurotransmitters that bind to muscle receptors triggering response
2 Features of relay neurons:
- Found in CNS
- Allow motor and sensory neurons to communicate
Synaptic transmission:
Neighbouring neurons communicate w/ each other by sending chemical messages across synapse
Presynaptic neuron:
Neuron before synapse
Postsynaptic neuron:
Neuron after synapse
Process of synaptic transmission:
1) When neuron is activated by stimulus, inside of cell goes from negative to positively charged for split second, creating action potential for electric transmission
2) After reaching axon terminal, synaptic vesicles on it release their contents
3) Neurotransmitters diffuse across synaptic cleft + binds to receptors on next dendrites
What is the process where vesicles release their contents called?
Exocytosis
What are the synaptic vesicles and what do they contain?
Number of sacs containing neurotransmitters
What is the synaptic cleft?
Physical gap between pre-synaptic and post-synaptic neuron
What happens in re-uptake?
- Effects of synaptic transmission are terminated by this process
- Taken up again by pre-synaptic neuron + stored for later release
What are neurotransmitters?
Chemical messengers that communicate via cerebral fluid
What can neurotransmitters be classed as and what are each generally responsible for?
- Inhibitory –> Calm mind + body
- Excitatory –> Increases chances to activate behaviour
Examples of excitatory and inhibitory neurotransmitters:
Excitatory: adrenaline, dopamine
Inhibitory: serotonin, GABA
What is excitatory post-synaptic potential (EPSP) and what does it lead to?
- When an excitatory neurotransmitter binds to post-synaptic receptor causing electrical charge in post-synaptic neuron’s membrane
- Means post-synaptic cell is more likely to fire
What is inhibitory post-synaptic potential (IPSP) and what does it lead to?
- When an inhibitory neurotransmitter binds to post-synaptic receptor
- Means post-synaptic cell is less likely to fire
What is summation?
Net result of calculation of excitatory and inhibitory synaptic input to determine firing of cell
What is the endocrine system?
Network of glands across body secreting hormones
Is the endocrine system faster/slower than the nervous system and why is this the case?
- Slower
- Travels through bloodstream rather than electrical impulses
What are the 7 main glands?
1) Pituitary
2) Thyroid
3) Adrenal medulla
4) Adrenal cortex
5) Testes
6) Ovaries
7) Pineal
What is the pituitary gland often known as, why and what can it be divided into?
- Master gland
- Controls release of hormones from all other endocrine glands
- Anterior & Posterior pituitary gland
What does the hypothalamus do?
Controls release of hormones from pituitary gland
What hormone does thyroid gland release and what are the effects?
- Thyroxine
- Regulates body’s metabolic rate and protein synthesis
What hormone does adrenal medulla release and what are the effects?
- Adrenaline + noradrenaline
- Fight or flight response
What hormone does adrenal cortex release and what are the effects?
- Glucocorticoids eg. cortisol –> release of stored glucose + fats
- Mineralcorticoids –> regulate water balance + sodium reabsorption
What hormone do testes release and what are the effects?
- Androgens, mainly testosterone
- Development of male secondary sexual characteristics
- Promotes muscle mass
What hormone do ovaries release and what are the effects?
- Oestrogens, mainly oestradiol
- Regulates female reproductive system
What hormone does pineal gland release and what are the effects?
- Melatonin
- Regulation of sleep-wake cycle, arousal
Which hormones are released in anterior and posterior pituitary gland and what are each responsible for?
Anterior:
- ACTH –> adrenal cortex, release of glucorticoids
- TSH –> thyroid, release of thyroxine
- Prolactin –> mammary glands, milk production
- FSH –> ovaries + testes, release of follicles + sperm
- Growth hormone –> cell growth
- MSH –> skin + hair, melanin
Posterior:
- ADH –> regulates water balance
- Oxytocin –> promotes uterine contractions
