Nervous System Flashcards
What are the five sense organs?
Skin (integumental system), ears, nose, eyes, tongue
What are the five senses?
Touch, taste, smell, sight, hearing
What is found in the sense organs?
Receptors that relay information through neurones detecting stimulus
What is a neurone?
A nerve cell
What does CNS stand for
Central nervous system
What does PNS stand for
Peripheral nervous system
What two organs are part of the central nervous system?
The brain and spinal chord (has to be spinal chord not spine)
What is the peripheral nervous system?
The portion of the nervous system located outside of the brain and spinal chord
What is the role of the central nervous system?
To coordinate the nervous system
What two systems does the peripheral nervous system consist of?
Systematic and autonomic
What is the systematic nervous system?
The body
What is the autonomic nervous system ?
Automatic (how the heart beats ect, myogenic muscle)
List the main processes of the nervous system (from stimulus to effector)
Stimulus, receptor, central nervous system, effector
What is the iris reflex ?
The size of the pupil changing in bright or dim light
What are the stimulus’s in the iris reflex?
Decrease of light or increase of light
What is the receptor In the iris reflex?
Retina
What is the coordinator in the iris reflex?
Brain
What is the effector in the iris reflex?
Iris
Why does the pupil constrict in bright light?
To stop damage to the eyes in bright light
Why does the pupil dilate in dim light ?
To see better in dim light
What is the patella T reflex ?
A sudden kicking movement in the lower leg in response to forcefull stimulus
What is the stimulus in the patella T reflex ?
Exhorted force
What is the receptor in the patella T reflex ?
The muscle running along the thigh (quads)
What is the coordinator in the patella T reflex ?
Spinal chord
What is the effector in the patella T reflex ?
Quads
What is the patella T reflex important ?
To stop the muscle over stretching
What are the names of the three neurones?
Motor neurone, sensory neurone and interneurones (you only need to know about the motor neurone)
It’s all the key parts of the motor neurone
Dendrites, nucleus, membrane, cytoplasm, axon, mylen sheeth (aka the Schwann cell), nodes of ranvier and motor end plate (try drawing and labelling the motor neurone)
What is the synapse?
A gap between two nerve cells
How do chemicals cross the synapse ?
Diffusion
What is the general name for the chemicals that cross the synapse ?
Neurotransmitters
Where do the chemicals that cross the synapse go to ?
Specific receptors on the postsynaptic membrane
What are all the steps that occur when an impulse arrives (there are 11)
- Impulse arrives at the end of sensory neurone. Na+ enters the axon.
- Calcium channels in the presynaptic membrane open allowing calcium ions to diffuse
into the synaptic end bulb - Ca2+ ions cause vesicles containing acetylcholine to fuse with the presynaptic
membrane. - Neurotransmitter is released into the synapse.
- Acetylcholine diffuses across the synapse.
- Acetylcholine binds to the receptor proteins on post synaptic membrane -
Complementary shape. - Causes sodium channels to open on post synaptic membrane. Sodium ions enter
relay neurone. - Impulse generated at next Node of Ranvier.
- Acetylcholinesterase breaks down acetylcholine (into acetyl and choline) which leaves
the receptor protein. - Acetyl and choline diffuse across the synapse.
11.Acetyl and choline reabsorbed into the presynaptic knob and condense to form
acetylcholine.
Define exocytosis
When cells move materials from within a cell to extra cellular fluid
Define endocytosis
The process where cells absorb external material by engulfing it with the cell membrane
