Biological Approach Flashcards
What is the nervous system?
A specialised and complex network of cells in the human body.
What is the central nervous system made up of?
Brain and spinal cord.
Our primary internal communication system has two main functions, which are they?
- Collects, processes and responds to information in the environment.
- Co-ordinates the working of different organs and cells in the body.
What two main subsystems is the nervous system divided into?
- The central nervous system.
- The peripheral nervous system.
What is the structure of the spinal cord?
A tube-like extension of the brain, connected to the brain via the brain stem.
What is the spinal cord responsible for?
Reflex actions
What two near-symmetrical hemispheres is the brain divided into?
Corpus collosum
What is the cerebal cortex?
The outer layer of the brain.
What does contra-lateral do?
- It’s the brain’s control of the body.
- The left hemisphere controls activity of the right side of the body the right hemisphere controls activity on the left side.
What is the structure of the cerebal cortex?
It is about 3mm thick and covers the ‘inner’ parts of the brain.
The various areas and parts of the brain are often divided into what?
- Cortical( belonging to the cortex)
- Subcortical (below the cortex)
What are the subcortical structures?
- Thamalus
- Hypothalamus
- Hippocampus
- Cerebellum
- Corpus callosum
What is the thamalus?
- receives information from various senses and passes it on to the appropriate areas of the cortex for higher- level processing.
What is the hypothalamus?
- Sits below the thamalus. Controls motivational behaviours such as hunger, thirst and sex.
- Has a role in stress response though it’s control of ‘flight or flight’
- Maintains balance of bodily functions such as temperatures (homeostasis) and regulates activity of hormones.
What is the hippocampus?
Part of the limbic system- important in the organisation and storage of new memories.
What is the cerebellum?
- Means ‘little brain’. It coordinates posture, balance and movement.
- It does this by receiving and integrating information from the spinal cord.
What is the corpus callosum?
- Dense collection of nerve cells physically connects the two hemispheres below the cerebal cortex.
- It allows communication between hemipshere.
What does localisation mean?
Certain areas of the brain are responsible for specific functions and behaviours.
How many lobes is the cerebral cortex of both hemispheres subdivided into?
four
What are the four lobes of the cerebral cortex?
- Frontal cortex
- Parietal lobes
- Occipital lobes
- Temporal lobes
What are the frontal lobes?
- Located right at the front of the brain, makes up about 40% of the cerebral cortex in humans.
- Control high- level cognitive functions such as thinking, planning, problem solving and decision- making.
- Also, contain the motor cortex, which controls voluntary movements on the opposite side of the body.
What are the parietal lobes?
- Contains the somatosensory cortex.
- Processes sensory information from the skin (touch, temperature, pressure)
What are the occipital lobes?
- Located at the back of the brain.
- Contains visual cortex.
- Deals with visual information.
- Everything we see to the right of out field of vision (from both left and right eye) is initially processed by the left visual cortex before being shared (via corpus collosum) with the right visual cortex and vice versa.
What are the temporal lobes?
- Contains auditory cortex.
- Deals with sound information mainly from the opposite ear.
- Process location, volume, pitch of sounds. Has a role in understanding language.
Is it true or false that Broca’s area and Wernicke’s area both language areas of the brain?
True
What is the Broca’s area?
Responsible for speech production- damage to this area causes ‘Broca’s aphasia’ which is slow, laborious speech lacking in fluency.
What is the Wernicke’s area?
Responsible for understanding language- damage to this area means difficulty understanding language and producing fluent but meaningless speech (‘Wernicke’s aphasia’).
A neuron is a nerve cell, true or false?
True
What do neurons do?
Carry “messages” or signals electrically or chemically.
What are the different parts of a neuron called?
- Dendrites
- Cell body
- Cell nucleus
- Axon
- Myelin sheath
- Nodes of Ranvier
- Terminal buttons
- Vesicles
What are dendrites?
Branch- like structures which carry impulses from neighbouring neurons towards the cell body.
What is a cell body?
Includes a nucleus.
What is a cell nucleus?
Contains the genetic material of the cell.
What is the axon?
Tube- like structure that carries the impulses away from the cell body down the length of the neuron.
What is the myelin sheath?
A fatty layer which covers the axon- it protects the axon and speeds up electrical impulses.
What is the Nodes of Ranvier?
Gaps in one myelin sheath- allow increase in speed of impulse by forcing the impulse to ‘jump’ across the gaps.
What are the terminal buttons?
At the end of the axon- involved in communication across the synapse.
What are the vesicles?
These are found at the terminal buttons and contain neurotransmitters ( brain chemicals).
What is the synaptic transmission?
A chemical process using biochemical substances called neurotransmitters. The synaptic transmission process starts with an action potential- the electrical impulse by which the message is passed down the axon of the neuron- which triggers the release of neurotransmitters from tiny sacs called vesicles.
How are signals within a neuron transmitted?
Electrically
How are signals between neurons transmitted?
Chemically.
What is the process of synaptic transmission in 4 steps?
- When the action potential reaches the presynamic terminal button, it triggers the release of neurotransmitters from tiny sacs called vesicles. (electrical impulses).
- Those neurotransmitters (chemicals) then diffuse across the synapse (chemical message)
- Neurotransmitters then fit into matching receptor sites on the post synaptic neurone (where the signal is converted back into an electrical signal)
- Neurotransmitters that remain in the synapse are reabsorbed into the presynaptic neuron (reuptake) which means they can be used again.
What are neurotransmitters?
The chemical messengers that act between the neurons in the brain.
What does noradrenaline affect?
- Flight or flight response
- Sleeping, dreaming
- Learning
- Attention
- Emotion, especially mood control
What does dopamine affect?
- Posture and control of movement
- Dependency behaviour- addiction
- Cognitive functions
- Emotion
What does serotonin affect?
- Mood control, happiness and good mood
- Sleep, wakefulness
- Regulates body temperature
What does acetylcholine affect?
- Stimulates muscle contraction and key function in motor control and movement
- Expressions of some emotions (e.g.) anger and sexuality.
What does GABA affect?
- Gamma-AminoButyric Acid
- An inhibitor that blocks messages rather than taking message on.
- It calms nerves that are firing so producing feelings of relaxation. Low levels are associated with anxiety.
What are recreational drugs?
Drugs that are used in the absence of medical grounds but are taken by users for personal enjoyment.
What are examples of recreational drugs?
Caffeine, nicotine, alcohol, cannabis, LSD, cocaine, heroin.