Nervous System

Question 1

Identify Division of Central Nervous system

Answer 1

1. CNS split into two parts brain and spinal cord
2. 🧠 recieves info and processes from senses eg visual cortex process visual info initiates response such as emotion/movement/higher mental functioning DM
3. spinal cord sends messages to and from brain through relay neurones controls reflex response

moving 🤚🏼 from hot plate 🔥

Question 2

Describe role of PNS (peripheral nervous system)

Answer 2

1. sends and receives messages from CNS two 2 parts of 🧠
2. ANS - controls INVOLUNTARY RESPONSES
3. example breathing/controls smooth/ cardiac muscle and glands

> control centre are located in 🧠

Question 3

How is ANS further divided

Answer 3

1. sympathetic branch - fight/flight
2. parasympathetic branch - conserve energy and restore body

Question 4

What is the role of Somatic Nervous System

Answer 4

1. SNS - controls voluntary movements

such as skeletal muscles 💀💪🏼

2. SNS carries commands from motor cortex to the senses

Question 5

What is the nervous system?

Answer 5

nervous system is a network of cells and is our primary internal communication system

Question 6

What is the function of nervous system (2)

Answer 6

1. To collect, process and respond to information in the environment ( our senses)
2. To co-ordinate the working of different organs and cells in the body

Question 7

Outline structure of CNS (4)

Answer 7

1. Divided into brain and spinal cord
2. Brain is responsible for higher mental processes eg decisions, 👂 , / generates emotion😁 and
   thoughts 💭 etc.
3. Brain receives and processes information from the
   senses
4. Spinal cord sends information to and from the brain + connects nerves to the PNS
5. Spinal cord controls reflex actions such as moving hand away from hot plate

Question 8

Describe and outline structure of first three parts of neurone strut

Answer 8

1. Dendrites - NT’s receptors are found
   once receptor + NT bind causes new electrical impulse to occur
2. Cell body - includes genetic material of cell
3. Axon - sends nerve impulse through neurone to transmit messages to next neurone

Question 9

Describe and outline last 3 parts of neurone structure

Answer 9

4. Myelin sheath - protects axon and helps speed up transmission of message
5. Nodes of Ranvier - speeds up transmissions jumps across gaps
6. Terminal button - end of neurone send info to next neurone via release NT’s

Question 10

What is the function and structure of sensory neurone?

Answer 10

1. sends info from senses > 🧠 via PNS
   > receptors found in 👁👂👅
2. long dendrites + short axons

Question 11

What is function and structure of relay neurone?

Answer 11

1. relay neurones carry nerve impulses bw neurones allowing sensory and motor neurones t communicate
2. involves in analysing sensations from these neurones + deciding how to respond
3. > NO MYELIN SHEATH
   SHORT AXON
   SHORT DENDRITE

Question 12

what is function and structure of motor neurone?

Answer 12

1. sends info via long axons from CNS 🧠 > effects > muscles/glands
2. Long axons short dendrites

Question 13

What is the location of sensory neurone

Answer 13

1. PNS in clusters known as ganglia

Question 14

What is location of relay neurone

Answer 14

🧠 and 👁 visual system

Question 15

What is a NT?

Answer 15

1. chemical messages within 🧠 that can have effect on next neurone
2. effect could be excitatory/inhibitory

Question 16

What is the function/role of NT?

Answer 16

1. Transmit info from one neurone to another so I performs an action
   > eg movement has emotional response

Question 17

Where does process of Synaptic Transmission begin

First 3 marks

Answer 17

1. Action potentials travel down pre-synaptic neurone
2. 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
3. NT’s diffuse across synapse from high > low conc

Question 18

Where does Synaptic Transmission end

Final 3 marks

Answer 18

4. NT’s attach to specific receptors only present post-synaptic neurone
   like 🔑 > 🔒
5. ⚡️💬 continue in post - synaptic neurone and next neurone ready to fire impulse depending on NT is excitatory/inhibatory
6. NT’s recycled in pre-synaptic neurone (reuptake)

Question 19

Explain why NT’s only travel in one direction at a synapse

Answer 19

1. NT’s stored in vesicles ONLY LOCATED PRE-SYNAPTIC
   NEURONE to be released in synaptic cleft/gap
2. NT’s diffuse across synapse and bind to specific receptor sites only present on POST SYNAPTIC NEURONE
3. Diffusion can only happen from high > low conc

> therefore only travel from pre-synaptic to post synaptic

Question 20

Briefly outline how excitation and inhibitory is involved in synaptic transmission (4)

Answer 20

1. NT excitatory/inhibitory - no mark
2. if NT excitory then post-synaptic neurone more likely to fire ⚡️impulse
3. if NT inhibitory then post synaptic neurone less likely to fire
4. if two neurones synapse at same at same post-synaptic neurone then summation occurs

Question 21

Define term excitation and give eg of NT (3)

Answer 21

1. makes a neurone more likely to fire and ⬆️🧠 activity CNS
2. noradrenaline - increases alertness/arousal

Question 22

Define term inhibitory NT an give example (3)

Answer 22

1. makes neurone less likely to fire and ⬇️🧠 in CNS
2. serotonin - keeps mood stable + released to initiate sleep

Question 23

Define summation

Answer 23

1. occurs when excitatory inhibitory influenced are added together
2. Overall effect mainly inhibitory - charged inhibits likeliness neurone will fire an impulse
3. overall effect mainly excitatory/+ charged fire impulse down post synaptic neurone

Question 24

what happens when inhibitory signal from one neurone is more stronger than another neurone?

Answer 24

Next neurone will not fire

Question 25

Zapurain acts as inhibitory NT Explain how it might affect process of synaptic transmission

Answer 25

1. binds to post-synaptic receptors > post synaptic cell becomes negatively charged 2. this prevents/reduces liklihood post - synaptic cell will fire 3. ⬇️🧠 in CNS therefore reducing feeling of pain 4. excitatory + inhibitory influences added together if overall effect is mainly - zarupain ⬇️ liklihoodness neurone will fire an impulse down post-synaptic neurone