nervous system pt 2

Question 1

brain and spinal cord make up 2 types of tissue

Answer 1

• grey matter
• white matter

Question 2

white and grey matter

Answer 2

grey matter consists of unmyelinated neurons, neuron cell bodies, and glial cells

white matter is made up of myelinated neurons and glial cells

the myelin has a high fat content, which results in white matters white colour

Question 3

protection of the brain

Answer 3

cranium

ventricular system

meninges

blood brain barrier

Question 4

Cranium

Answer 4

Bony tough outer shell to protect the soft tissue of the brain

protection from physical damage

Question 5

Meninges

Answer 5

protective membrane layers around the brain and spinal cord

1. Dura Mater
   2.Arachnoid mater
2. Pia mater

can become inflamed - known as meningitis

Question 6

Epidural Space

Answer 6

a useful administration point for delivery of local anaesthetics or analgesics

Question 7

Meninges

Answer 7

Epidural space - space filled with fat and many blood vessels

Dura mater - first of the meninges membranes. Made from tough fibrous tissue

Subdural Space - a virtue space that can become enlarged with any trauma or haemorrhage.

Arachnoid Mater - second of the meninges membranes. Very delicate layer that is avascular.

Subarachnoid Space - this space is filled with cerebral spinal fluid

Pia Mater - the third meninges layer. It is a highly vascular layer covering the brain and spinal cord.

Question 8

Ventricular System

Answer 8

A series of interconnecting canals and cavities/ventricles found inside the brain and spinal cord

These ventricles are filled with cerebro - spinal fluid

the network of capillaries known as the choroid plexus produces CSF

Question 9

Cerebrospinal fluid

Answer 9

surrounds the brain and spinal cord

protects and supplies nutrients

CSF protects the CNS from damage of sudden movements

Question 10

what can occur when CSF is unable to leave the cranium

Answer 10

Hydrocephalus

Question 11

Syringomyelia

Answer 11

King Charles cavalliers are prone to this condition, which is caused from a partial blockage in the flow of CSF from the brain.

Question 12

Blood Brain Barrier

Answer 12

Modification of Neuroglial tissue that connects and supports all the neurons

creating an almsot impermeable layer to protect the brain from harmful substances

Blocks toxins e.g. urea and certain drugs, but allows oxygen, sodium and potassium ions and glucose to pass through rapidly.

Question 13

The Brain

Answer 13

the brain controls and coordinates all the activities of the normal body

• Forebrain
  -Midbrain
  -Hindbrain

The brain major parts are the cerebrum, cerebellum, diencephalon and brain stem

Question 14

Forebrain: THE Diencephalon

Answer 14

Passageway between brainstem and cerebrum

contains the-

Thalamus - processes information from the sense organs and relays the information to the cerebral cortex

Hypothalamus - Link between nervous and endocrine system - creates hormones stored in the pituitary gland

epithalamus - contains the pineal gland secretes melatonin

Question 15

Spinal Cord

Answer 15

The tissue is arranged in a long cylinder

The grey matter forms the inner layer, and the white matter forms the outer layer

Question 16

Spinal Cord

Answer 16

The spinal cord exits the skull via the foramen magnum a large opening in the base of the skull

Travels down the vertebral column in the vertebral foramen of each vertebra

The spinal cord terminates in a series of fine nerves known as the cauda equina

Question 17

Cauda equina

Answer 17

the end of the spinal cord is referred to as the cauda equina due to its similarity to a horse’s tail

Question 18

Cerebrum, Cerebellum, Brainstem

Answer 18

cerebrum - the largest part of the brain and controls the skeletal muscle functions

cerebellum - plays a role in motor movement regulation and balance control

brainstem - connects the brain to the spinal cord controls your breathing and your heart brate

Question 19

Peripheral nervous system

Answer 19

Cranial Nerves - off the brain

Spinal Nerves - off the spine

Question 20

which cranial nerve runs all the way down the body and is important for parasympathetic function

Answer 20

Vagus nerve

Question 21

Spinal Nerves

Answer 21

spinal cord passes through the vertebral canal

Each vertebral junction gives off a pair of spinal nerves

exit through intervertebral foramen

both containing an afferent and efferent nerve

Question 22

Paraplegia

Answer 22

a common cause of paraplegia or paraparesis ( weakening of hind legs) is disk compression of the spinal cord. this is referred to as intervertebral disc disease.

Question 23

Ventral slot surgery

Answer 23

for dogs who have intravertebral disc disease of the cervical spine sometimes require a ventral slot

A complication of this surgery is bradycardia secondary to stimulation of the 10th cranial nerve

Question 24

Spinal Cord

Answer 24

At each intervertebral joint, a pair of nerves exits the spinal cord

each nerve contains afferent (sensory) and efferent (motor) neurons

The central canal contains CSF

Question 25

Important peripheral nerves

Answer 25

pelvic limb

femoral, saphenous, sciatic and tibial nerves

• supplied from the nerves of the lumbosacral plexus

Question 26

Important peripheral nerves

Answer 26

Thoracic limb

Radial, Meidan and Ulna nerves

-supplied by the brachial plexus that lies above the axilla and just below the spinal cord.

Question 27

‘Routine’ nerve pathways

Answer 27

nerve pulses follow this order

• sensory receptor
  -sensory nerve
  -integration in the spinal cord and brain
• motor nerve
• response

Question 28

Spinal reflexes

Answer 28

spinal reflexes do not involve the brain

can create immediate unconscious responses

reflec arcs are the pathways the nerves take to bring about the reflex action

sensory organ - spinal cord (interneurons) motor function

Question 29

Reflex arcs

Answer 29

reflexes happen unconsciously whenever something sharp/hot etc is touched

sensory neurons detect pain, temperature, pressure and if something harmful is detected

an impulse passes from the receptor in the skin to the sensory (afferent) neuron to the spinal cord

Motor (efferent) neurons cause a muscle to contract and pull the body part at risk of injury away from the heart or sharp object

Question 30

Autonomic nervous system

Answer 30

made up of visceral nerves.

supplies cardiac muscle, smooth muscle, organs and glands

Sympathetic - fight or flight e.g. adrenalin, noradrenalin

parasympathetic - rest and digest e.g. acetylcholine