The brain and nervous system part 2

Question 1

What is the middle cord of the spine made up of

Answer 1

Made up of neurones and other cells (grey matter)

Question 2

What is the outside of the spinal cord made up of

Answer 2

Made up of the fibres (white matter) that carry info up and down the cord.

Question 3

What sensory information goes into the spinal cord

Answer 3

1.proprioception, pain and temp

Question 4

describe and locate the motor neurones

Answer 4

Motor neurones are located in the ventral spinal cord, and make direct contact onto the muscles. Stim of these neurones causes movement.

Question 5

What is a motor pool

Answer 5

A motor pool is all the neurones that innervate a single muscle.

Question 6

size of the innervation of muscles …

Answer 6

muscles capable of fine movements are innervated by more neurones

Question 7

Describe the lateral descending system

Answer 7

The lateral descending system is made up of the corticospinal and rubrospinal tracts. The fibres in the lateral system connect to the motor neurones in the ventral horn, which influences lateral musculature.

Question 8

What do corticospinal fibres influence

Answer 8

Influence movement of every part of the body, particularly important for finger use.

Question 9

Describe the medial system

Answer 9

The vestibulospinal and reticulospinal tract make up the medial system. fibres connect motor neurones in the medial part of the ventral horn influencing the medial musculature

Question 10

Functions of the medial system

Answer 10

Medial systems are involved in the control of balance and posture, and these functions happen with little conscious control.

Question 11

Function of the dorsal column pathway

Answer 11

Carries sensory information from the joint and skin about fine touch, vibration and position from the skin and joints.

Question 12

Function of the spinaothalamic pathway

Answer 12

It conveys pain and temperature

Question 13

Where do cell bodies of incoming sensory neurons lie and how is it different to motor neurons

Answer 13

They lie outside the the spine in a series of ganglion called the dorsal root ganglion, unlike motor neurons of which the cell bodies lie in the ventral horn

Question 14

Describe the spinal nerves

Answer 14

There are 31 pairs of spinal nerves, and the size of the nerves will be different depending on the size of the muscles.

Question 15

what are dermatomes

Answer 15

An area of the skin supplied by nerves from a single spinal root

Question 16

What are motor pools made up of

Answer 16

motor units

Question 17

Where in the body are spinal enlargements

Answer 17

the arms and legs particularly the hands and feet.

Question 18

What 3 things make up a spinal segment

Answer 18

1.dorsal horn
2.ventral horn
3.intermiediate zone

Question 19

dorsal horn functions

Answer 19

Contains sensory neurones which receive sensory info and sends this to the brain

Question 20

ventral horn function

Answer 20

Contains neurones that sends info directly to the muscles

Question 21

Intermediate zone function

Answer 21

Contains interneurones that integrate information

Question 22

What is rate coding in the motor system

Answer 22

Motor neurones use a rate coding system to signal the amount of force exerted by a muscle. The maximum contraction is called a tetanic contraction

Question 23

what is the size principle in rate coding in the motor system

Answer 23

Size principle is with the increasing strength of input onto the neurones, smaller motor neurons are recruited before the larger ones.

Question 24

What is the vestibular system

Answer 24

System that provides the sense of balance and spatial orientation coordinating movement with balance

Question 25

What is the reticulospinal tract

Answer 25

It is a set of interconnected nuclei located in the brainstem, and play a role in maintaining tone balance and posture

Question 26

Basal ganglia function

Answer 26

movement regulation, habbit formation, skill learning

Question 27

Describe the primary motor cortex

Answer 27

Neurons have a simple relationship to movement e.g. force, direction and speed

Question 28

Describe the pre motor cortex

Answer 28

Neurones have a more complex relationship with movement e.g. planning movement, spatial guidance of movement, sensory guidance of movement.

Question 29

Describe the function of the primary sensory cortex

Answer 29

1.heat, pain, vibration
2.Proprioception
3.kinesthesia- the ability to reckognise joint movement

Question 30

What is the corticospinal tract

Answer 30

The most important tract in the body for the precise control of limbs

Question 31

function of spinal cord, medulla, cerebellum, basal ganglia, cortex

Answer 31

1.spinal cord-simple reflexes
2.medulla complex reflexes
3.cerebellum-coordinated movement
4.basal ganglia-programmed movement.
5.cortex-complex concious movements