B6 Brain and Mind Summary
- Created by: Farhana
- Created on: 04-01-13 15:21
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- Neurones
- Sensory neurones
- They carry impulses from the receptors to the CNS
- Receptors are cells that detect stimuli e.g. taste receptors on the tongue
- They carry impulses from the receptors to the CNS
- Motor neurones
- They carry impulses from the CNS to the effectors
- Effectors are all muscles and hormones excreting cells found in glands
- CNS is the processing centre that coordinates a response. It is the brain and the spinal cord
- They carry impulses from the receptors to the CNS
- Receptors are cells that detect stimuli e.g. taste receptors on the tongue
- A reflex arc goes through the CNS- the spinal cord or the unconscious part of the brain
- Reflexes are involuntary responses
- A stimulus detected by receptors, impulse sent alond sensory neurones to CNS. In CNS, sens. neurones pass onto relay neurone. Relay neurone pass impulse to motor neurone. Motor neurone to effector
- Simple reflexes improve the chance of survival e.g. sea anemones- tentacles, molluscs- close shells
- Humans have simple reflexes e.g. contract eye allowing in less light. Dropping a hot object. Knee jerk. Newborn baby reflexes, suckling, grasping, stepping
- Reflex responses can be modified by the brain- response overridden by a neurone btween brain & motor neurone of reflex arc
- Reflex responses can be learned- conditioned reflex
- Animals learn to produce a sam reflex response to a sceondary stimulus
- Pavlov's dog learnt to respond to sound of bell(sec stim)- salivating, expecting food, conditioned
- Conditioned reflex can increase chances of survival, e.g. birds eating bright coloured insects-poisonous
- Animals learn to produce a sam reflex response to a sceondary stimulus
- Reflexes are involuntary responses
- The environment can affect brain development and learning
- The brain of a newborn baby is partly deveopled & most neurone connections are not yet formed
- Connections form when child experiences new things, neurone connects to other neurones, creating new pathways
- More exp.s repeated- strengthens pathways- more likely to transmit impulse than others
- There are definate stages in development of child's brain- some pathways need to be strengthened at partic. age or too late e.g. feral children
- Connections form when child experiences new things, neurone connects to other neurones, creating new pathways
- Complex animals adaptable cos of variety of potential pathways
- Simpler animals less flexible nervous systems- behav. more predictable, less adaptable
- The brain of a newborn baby is partly deveopled & most neurone connections are not yet formed
- Cerebral cortex outer part of brain controls intelligence, memory, language and consciousness
- To study the brain methods:
- 1. Studying patients with brain damage, back part damaged, blind= vision
- 2. Electrically stimulating the brain- tiny electrode into tissue w/ electricity. Observ what stim-ing diff parts do
- 3. MRI scans- machiene gioces detailed pic of brain's tructure- fibnd out what parts active when doing things
- They carry impulses from the receptors to the CNS
- They carry impulses from the CNS to the effectors
- Transmit information around the body as electrical impulses
- Electrical impulses pass along the axon of the nerve cells
- Axons are made of the nerve cell's cytoplasm into a long fibre, surrounded by cell membrane
- Axons are surrounded by fatty sheath- acts as insulator, shield neurones from nearby neurones, speeds up electrical impulse
- Axons are made of the nerve cell's cytoplasm into a long fibre, surrounded by cell membrane
- Electrical impulses pass along the axon of the nerve cells
- The gap between 2 neurones- a synapse
- When electrical impulse reaches end of neurone, triggers release of transmitter chems. in the synapse
- The transmitter chems. diffuse across gap & bind to receptor molecules
- Only specific chems. can bind to receptor molecules on neurone- trigger new electr. impulse in next nuerone
- The transmitter chems. diffuse across gap & bind to receptor molecules
- Some drugs e.g. ecstasy, blocks sites in brain's synapses
- Serotonin removed- concentration increases = mood-enhancing effects
- Serotonin though to affect things like pain, agression & appetite- determine's person's mood
- Serotonin removed- concentration increases = mood-enhancing effects
- When electrical impulse reaches end of neurone, triggers release of transmitter chems. in the synapse
- Sensory neurones
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