Biopsychology Flashcards
What is the definition of the nervous system?
The nervous system is a specialised network of cells that enables communication within the body.
What two things do the CNS compose off?
The brain and the spinal cord
What is the job of the brain?
The brain is the centre of all conscious awareness, controlling thought, perception and voluntary movements.
What is the job of the spinal cord?
The spinal cord relays information between the brain and the rest of the body and is responsible for reflex actions
What is the job of the peripheral nervous system?
The peripheral nervous system transmits messages to and from the central nervous system (CNS) to the rest of the body through nerves
What is the peripheral nervous system (PNS) divided into?
The somatic and autonomic nervous systems
What is the job of the somatic nervous system?
The somatic nervous system governs voluntary movements and transmits sensory information from the body/sense receptors to the CNS and from this to effectors to produce voluntary movements.
Which nervous system integrates the brain with the outside world?
Somatic Nervous System
What is the job of the autonomic nervous system (ANS)?
The ANS manages involuntary processes (heart rate and digestion). It is responsible for transmitting information to and from internal bodily organs
Which nervous system works alongside the endocrine system?
The autonomic nervous system
What is the autonomic nervous system divided into?
- Sympathetic Nervous System
- Parasympathetic Nervous System
What is the job of the sympathetic nervous system?
Activates the ‘fight or flight’ response in the body
What is the job of the parasympathetic nervous system?
Promotes the ‘rest and digest’ response in the body
What are the ten structures within the neuron?
- Cell Body (Soma)
- Nucleus
- Cell Membrane
- Dendrites
- Axon Hillock
- Axon
- Myelin Sheath
- Schwann Cells
- Nodes of Ranvier
- Axon Terminal
What is the function of the cell body (soma)?
This contains the nucleus
What is the function of the nucleus?
The nucleus controls the neuron’s activities and provides energy
What is the function of the cell membrane?
Regulates substance movement
What is the function of the dendrites?
The dendrites are branch-like structures that receive electrical signals from other neurons
What is the function of the axon hillock?
Controls the initiation of the electrical signal in the neuron
What is the function of the axon?
The axon is a long fibre that transmits electrical signals (action potentials) away from the cell body
What is the function of the myelin sheath?
The myelin sheath is a fatty layer that insulates the axon, increasing the speed of signal transmission
What do Schwann Cells?
The Schwann cells create the myelin sheath
What is the function of the nodes of ranvier?
The nodes of ranvier are gaps in the myelin sheath where the action potential ‘jumps’ from node to node, increasing the speed of transmission
What is the function of the axon terminal?
This is the endpoint of he neuron where signals are transmitted to the next cell via synaptic transmission
What three types of neurons make up the reflex arc?
- Sensory
- Relay
- Motor
What is the function of a sensory neuron?
Sensory neurons carry information from sensory organs to the CNS.
What is the length of the sensory neurons axons and dendrites?
- Long dendrites
- Short axons
Which type of neuron allows us to feel heat and pressure?
Sensory Neurons
What is the function of the relay neurons (interneurons)?
They connect sensory and motor neurons to keep communication with the CNS.
Which type of neuron is only found in the CNS?
Relay Neurons (Interneurons)
What is the length of the dendrites and axons in relay neurons?
- Short Dendrites
- Short Axon
Which type of neuron normally lacks a myelin sheath and why?
Relay Neurons often lack a myelin sheath as speed is less critical for short-distance transmission
What is the function of a motor neuron?
Motor neurons transmit signals from the CNS to effectors such as muscles and glands. This enables responses like movement of the secretion of hormones (adrenaline from the adrenal glands in fight-or-flight).
What is the length of the dendrites and axons in motor neurons?
- Short dendrites
- Long axons
Which type of neuron has cell bodies located in the CNS, with its axons forming the PNS?
Motor Neurons
What is the definition of synaptic transmission?
Synaptic transmission is the process by which one neuron communicates with another
Describe the process of synaptic transmission (5 steps)
- Action Potential reaches axon terminal
- This triggers vesicles to release their neurotransmitters across the synapse via diffusion (makes signal chemical)
- Chemical then locks into special receptor sites which are only found on the membrane of the post synaptic neuron (back to electrical signal)
- Stimulation of the postsynaptic reception by neurotransmitters results in either excitation (depolarisation) or inhibition (hyper polarisation) of the postsynaptic membrane via summation
- Vesicles are replenished with new and reused neurotransmitters
What is meant by inhibition (hyper polarisation)?
If the total/net effect on the post synaptic neuron is inhibitory, then the neuron is less likely to fire
What is meant by excitation (depolarisation)?
If the total/net effect is excitatory, the neuron will be more likely to fire
What happens to excess neurotransmitters?
Either:
- Enzymes are released to break them down
- Excess neurotransmitters are reabsorbed
What is the definition of the endocrine system?
A network of glands that secrete hormones into the bloodstream to regulate physiological processes
Which works faster between the endocrine and nervous system?
The Nervous System
What are glands?
Glands are specialised organs in the body that secrete substances such as hormones, enzymes or other fluids.
What is the job of the thyroid gland?
To produce thyroxine
What does thyroxine do?
- Affects cells in the heart (heart rate)
- Impacts metabolic rate (which affects growth rate)
What is hypothyroidism and what are the symptoms?
Hypothyroidism is when you do not have enough thyroxine. The symptoms are:
- Depression
- Slow Movement
- Slow Thought
- Weight Gain
- Tiredness
What is hyperthyroidism and what are the symptoms?
Hyperthyroidism is when you have too much thyroxine. The symptoms are:
- Nervousness
- Anxiety
- Hyperactivity
- Weight Loss
- Insomnia