Nervous System Flashcards
Identify Division of Central Nervous system
- CNS split into two parts brain and spinal cord
- 🧠 recieves info and processes from senses eg visual cortex process visual info initiates response such as emotion/movement/higher mental functioning DM
- spinal cord sends messages to and from brain through relay neurones controls reflex response
moving 🤚🏼 from hot plate 🔥
Describe role of PNS (peripheral nervous system)
- sends and receives messages from CNS two 2 parts of 🧠
- ANS - controls INVOLUNTARY RESPONSES
- example breathing/controls smooth/ cardiac muscle and glands
> control centre are located in 🧠
How is ANS further divided
- sympathetic branch - fight/flight
- parasympathetic branch - conserve energy and restore body
What is the role of Somatic Nervous System
- SNS - controls voluntary movements
such as skeletal muscles 💀💪🏼
- SNS carries commands from motor cortex to the senses
What is the nervous system?
nervous system is a network of cells and is our primary internal communication system
What is the function of nervous system (2)
- To collect, process and respond to information in the environment ( our senses)
- To co-ordinate the working of different organs and cells in the body
Outline structure of CNS (4)
- Divided into brain and spinal cord
- Brain is responsible for higher mental processes eg decisions, 👂 , / generates emotion😁 and
thoughts 💭 etc. - Brain receives and processes information from the
senses - Spinal cord sends information to and from the brain + connects nerves to the PNS
- Spinal cord controls reflex actions such as moving hand away from hot plate
Describe and outline structure of first three parts of neurone strut
- Dendrites - NT’s receptors are found
once receptor + NT bind causes new electrical impulse to occur - Cell body - includes genetic material of cell
- Axon - sends nerve impulse through neurone to transmit messages to next neurone
Describe and outline last 3 parts of neurone structure
- Myelin sheath - protects axon and helps speed up transmission of message
- Nodes of Ranvier - speeds up transmissions jumps across gaps
- Terminal button - end of neurone send info to next neurone via release NT’s
What is the function and structure of sensory neurone?
- sends info from senses > 🧠 via PNS
> receptors found in 👁👂👅 - long dendrites + short axons
What is function and structure of relay neurone?
- relay neurones carry nerve impulses bw neurones allowing sensory and motor neurones t communicate
- involves in analysing sensations from these neurones + deciding how to respond
- > NO MYELIN SHEATH
SHORT AXON
SHORT DENDRITE
what is function and structure of motor neurone?
- sends info via long axons from CNS 🧠 > effects > muscles/glands
- Long axons short dendrites
What is the location of sensory neurone
- PNS in clusters known as ganglia
What is location of relay neurone
🧠 and 👁 visual system
What is a NT?
- chemical messages within 🧠 that can have effect on next neurone
- effect could be excitatory/inhibitory
What is the function/role of NT?
- Transmit info from one neurone to another so I performs an action
> eg movement has emotional response
Where does process of Synaptic Transmission begin
First 3 marks
- Action potentials travel down pre-synaptic neurone
- causes NT’s (chemicals) only stored in VESICLES to be moves to membrane of pre-synaptic neurone and fuse w it releasing NT in synapse
- NT’s diffuse across synapse from high > low conc
Where does Synaptic Transmission end
Final 3 marks
- NT’s attach to specific receptors only present post-synaptic neurone
like 🔑 > 🔒 - ⚡️💬 continue in post - synaptic neurone and next neurone ready to fire impulse depending on NT is excitatory/inhibatory
- NT’s recycled in pre-synaptic neurone (reuptake)
Explain why NT’s only travel in one direction at a synapse
- NT’s stored in vesicles ONLY LOCATED PRE-SYNAPTIC
NEURONE to be released in synaptic cleft/gap - NT’s diffuse across synapse and bind to specific receptor sites only present on POST SYNAPTIC NEURONE
- Diffusion can only happen from high > low conc
> therefore only travel from pre-synaptic to post synaptic
Briefly outline how excitation and inhibitory is involved in synaptic transmission (4)
- NT excitatory/inhibitory - no mark
- if NT excitory then post-synaptic neurone more likely to fire ⚡️impulse
- if NT inhibitory then post synaptic neurone less likely to fire
- if two neurones synapse at same at same post-synaptic neurone then summation occurs
Define term excitation and give eg of NT (3)
- makes a neurone more likely to fire and ⬆️🧠 activity CNS
- noradrenaline - increases alertness/arousal
Define term inhibitory NT an give example (3)
- makes neurone less likely to fire and ⬇️🧠 in CNS
- serotonin - keeps mood stable + released to initiate sleep
Define summation
- occurs when excitatory inhibitory influenced are added together
- Overall effect mainly inhibitory - charged inhibits likeliness neurone will fire an impulse
- overall effect mainly excitatory/+ charged fire impulse down post synaptic neurone
what happens when inhibitory signal from one neurone is more stronger than another neurone?
Next neurone will not fire
Zapurain acts as inhibitory NT
Explain how it might affect process of synaptic transmission
- binds to post-synaptic receptors > post synaptic cell becomes negatively charged
- this prevents/reduces liklihood post - synaptic cell will fire
- ⬇️🧠 in CNS therefore reducing feeling of pain
- excitatory + inhibitory influences added together
if overall effect is mainly - zarupain ⬇️ liklihoodness neurone will fire an impulse down post-synaptic neurone
