Paper 2: 6. Biopsychology Flashcards
1) What is the nervous system?
The nervous system is a specialised network of cells in the human body and is our primary internal communication system.
2) What are the two main functions of the nervous system?
- To collect, process and respond to information in the environment.
- To co-ordinate the working different organs and cells in the body.
3) What are the two sub systems in the nervous system?
- The Central Nervous System - The Brain & Spinal Cord are responsible for passing messages to and from the brain and connects nerves to the peripheral nervous system.
- The Peripheral Nervous System - Nerves
4) Describe the brain’s function in the Central Nervous System.
The brain is the centre of all conscious awareness. It receives and processes sensory information. The brain’s outer layer is called the cerebral cortex which is responsible for higher mental functions and it distinguishes us from other animals. The brain is divided into two hemispheres (L & R).
5) Describe the spinal cord’s function in the Central Nervous System.
The spinal cord is an extension of the brain. It is responsible for reflex actions such as pulling your hand away from a hot plate.
6) Describe the Periphernal Nervous System
Transmits messages via millions of neurons to and from the CNS. There’s two parts - the somatic nervous system and the autonomic nervous system.
7) Describe the Central Nervous System.
This is responsible for passing messages to and from the brain and connects nerves to the periphiral nervous system.
8) What is the Autonomic Nervous System?
This controls vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress response.
9) What are the two branches of the Autonomic Nervous System?
- Sympathetic branch
2. Parasympathetic branch
10) Describe the sympathetic branch.
This increases your heart rate, increases blood pressure, inhibits digestion, inhibits saliva production and pupils become dilated.
11) Describe the parasympathetic branch
This tries to bring the heart rate down, decrease the blood pressure back to normal, stimulates digestion, stimulates saliva production, and constricts pupils.
12) What is the difference between the somatic nervous system and the autonomic nervous system?
The somatic nervous system deals with voluntary actions and functions (ie picking up a pen) whereas the autonomic nervous system deals with involuntary actions and functions (accidentally dropping a pen).
Inhibitory means the message isn’t likely to be passed on to the next neurone (autonomic), whilst excitatory is likely to pass on the message to the next neurone (somatic)
18) What are the three types of neurones?
Motor neurons
Sensory neurons
Relay neurons
19) Discuss motor neurons. (5 marks)
- Motor neurons are nerve cells that process and transmit messages through electrical and chemical signals.
- They’re located in the CNS and directly or indirectly control muscles.
- This is because motor neurones form synapses with muscles and release neurotransmitters into the synapse that binds to muscle receptors.
- This then triggers muscle movement.
- The strength of the muscle contraction depends on the rate of firing with the axons of the motor neurons.
20) Discuss sensory neurons
- Sensory neurons carry nerve impulses from sensory receptors (ie for vision, taste etc) to the spinal cord and the brain.
- These sensory receptors are found in various locations in the body (eyes, tongue) and convert information from the sensory receptors into nerve impulses.
- Sensory impulses convert information from these sensory impulses into nerve impulses.
- When these impulses reach the brain, they’re translated into sensations. This allows an appropriate reaction.
- Some sensory information travels all the way to the brain or down the spinal cord for quick reflex actions.
21) Discuss relay neurons
- Relay neurons connect the Central Nervous System to effectors and glands.
- They have short dendrites and long axons.
- They allow sensory and motor neurones to communicate with each other.
- These relay neurons can only be found within the brain and spinal cord.
22) What does the cell body include? (in relay, motor or sensory neurons)
- Nucleus
- Dendrites
- Axon
- Myelin Sheath
- Nodes of Ranvier
23) What is the function of the nucleus?
Holds the genetic material of the cell.
24) What are dendrites?
Branch like structures that protrude from the cell body. These carry nerve impulses from neigbouring neurons towards the cell body.
25) What is the axon?
Carries the impulses away from the cell body down the length of the neuron.
26) What is the myelin sheath?
A fatty sheath that protects the axon and speeds up the electrical transmission of the impulse.
27) What are the nodes of ravnier?
The gaps in the myelin sheath which speeds up the electrical transmission by forcing impulses to jump across the gaps.
28) What are terminal buttons? (pronounced boo-tons)
At the end of the axon and comunicating with the next neuron in a synapse.
29) Describe an electrical transmission
- When a neuron in a resting style, the inside of the cell is negatively charged compared to the outside.
- When a neuron is activated by a stimulus, the inside of the cell now becomes positively charged for a split second causing an action to occur.
- This creates an electrical impulse that travels down the axon towards the end of the neuron.
30) Describe a chemical transmission.
- Signals between neurons are transmitted chemically across the synapse.
- When the electrical impulse reaches the Presynaptic terminal it triggers the release of a neurotransmitter from tiny sacs called the synaptic vesicles.
31) What is a neurotransmitter?
A neurotransmitter is a chemical messagethat spread across the synapse to the next neuron in the chain.
32) What happens at the synapse?
- A neurotransmitter crosses the gap and binds to the post synaptic receptor site of the next neuron.
- `The chemical message is then converted back into an electrical impulse and the transmission process starts again in the new neuron.