Nervous System - Introduction

Question 1

Types of neurone

Answer 1

Sensory - receive sense info from receptor cell

Relay - connect sense + motor - part of CNS - sends response to motor

Motor - sends response to effector

Question 2

Structure of motor neurone

Answer 2

Cell body - contain nucleus, dendrite
Dendrite - receive neurotransmitter - other neurone
Nucleus - cell activity

Axon hillock - only allow action potential - ion concentration threshold reach - prevent stimulation from small things (dust)

Axon- allow action potential across neuron
Node of Ranvier - allow exchange of ions for action potential
Myelin sheath - insulate neurone - speed up reaction - provide skips for impulse to jump (can’t go through fat layer)
Schwann cell - produce myelin sheath

Axon terminal - end - release signal to neurone or effector

Question 3

Diagram of motor neurone

Answer 3

https://resource.download.wjec.co.uk/vtc/2020-21/el20-21_1-20/motor-neuron.jpg

Question 4

Structure of spinal cord

Answer 4

-Vertebra: bone of the spine (star shape on dorsal side - spread out pressure if it) - give structure to arrange neurone

-Meninges: membrane around spinal cord - protect spinal cord - infection

Dorsal root - contain sensory neurone, root on backside (dorsal) of spine

Dorsal ganglion - swelling in root for cell body for sensory neurone

Ventral root (front) - motor neurone

White matter - contain myelinated neurone

Grey matter (closer to central canal) - contains nuclei, cell body of relay + motor neuron + unmyelinated neurone

Central canal - contains nuclei cerebrospinal fluid

Question 5

Diagram of spinal cord

Answer 5

https://resource.download.wjec.co.uk/vtc/2020-21/el20-21_1-20/nervous-system-structure.jpg

Question 6

Reflex arc

Answer 6

-fast, auto response - protect body from harmful stimuli

1)sensory neurone send message - CNS relay neurone

2)relay send response - motor neurone

3)motor to effects for response

Question 7

Simple nervous system (hydra)

Answer 7

-one type of neurone connected like net - nerve net
- no specialised - so impulse go random

-sensory receptors detect limited amount of stimuli
-low effector number = movement limited

-neurones unmyelinated - slow
-degree of response dependent - on stimulus strength + receptors stimulated

Question 8

Mammalian nervous system (me)

Answer 8

• Specialised neurone with direct pathways
  -CNS + PNS

-more effectors + more receptors for more stimuli

Question 9

Diagram of nerve net in hydra

Answer 9

https://i0.wp.com/www.zoologytalks.com/wp-content/uploads/2021/12/0-2.png?fit=486%2C646&ssl=1

Question 10

Comparison of nervous + endocrine system

Answer 10

Nervous
+quick response
-last shirt

Endocrine
+last longer
-short response