Anatomy 1 100

What are the two main divisions of the nervous system

Central nervous system

Peripheral nervous system

what makes up the CNS

Brain

Spinal cord

what makes up the PNS

Cranial nerves 12 pairs

Spinal nerves 31 pairs

Example of a cranial nerve

The vagus nerve

Is the vagus nerve a spinal or cranial Nerve

Cranial nerve

What is the autonomic nervous system

A division of the PNS

What is the function of the autonomic nervous system

Provides unconscious regulation of

Smooth muscle

Cardiac muscle

Glands

What organs or systems does the autonomic nervous system affect

Smooth muscle

Cardiac muscle

Glands

The autonomic nervous system is split into two sections what are they

Sympathetic

Parasympathetic

what does the sympathetic nervous system do

Prepares the body for physical activity

what does the parasympathetic nervous system do

Regulates resting functions

What are the two types of cells mentioned

Neurons / nerve cells

Glial / Neurological cells

what do Neurons do

Transmit electrical impulse (action potential)

what does Glial cells do

Support and protect neurons

Name and explain the three parts of the neuron (what do they do or contain)

Cell body : nucleus

Dendrites : short branched process receives impulses

Axon : long process impulse leaves

what do dendrites do

They receive impulses

what do axons do

A single long process through which the impulse leaves the cell body

What can Glial cells not do

They cannot transmit action potentials

What are the three main types of Glia cells and where are they found

Astrocytes - CNS

Oligodendrocytes - CNS

Schwann cells - PNS

what is the function of Astrocytes

Star shaped cells that form the blood brain barrier

They form a sheath around blood vessels

Regulate what reaches neurons from blood

It’s a selective barrier

Allows nutrients to + fat soluble substances to pass

what areas are Astrocytes absent

Vomiting centre and hypothalamus

What do Oligodendrocytes do

Form myelin sheaths around axons in CNS

what do Schwann cells do

Wrap around portion of axon to form myelin sheaths

Wrap around many times

Where are myelinated axons found

White matter

what is the myelin in white matter like

Fatty layer

Insulates axon

Speeds electrical impulses

Where are unmyelinated axons found

Grey matter

what is the myelin like in Grey matter

Not wrapped around axon

What are the 3 types of Neurons / Nerve cells

Sensory (afferent) Neurons

Motor (efferent ) Neurons

Interneurons ( association) Neurons

How do sensory neurons carry information

They carry information from the body towards CNS

From the body to the spinal cord or brain

how are the receptors of sensory neurons connected

Body receptors are connected to spinal cord and brain

how many processes or axons does the cell body of a sensory neuron have

One single process / axon but split into two branches

PNS branch - goes to the body and connects to receptors

CNS - goes to the spinal cord and sends signals to the brain

where are the sensory neurons cell bodies located

Posterior (dorsal) root ganglion

what areas the two axon branches in sensory neurons

PNS

CNS

what is the posterior (dorsal) root ganglion where is it located and what system is it part of

It’s a collection of neuron cell bodies located on the posterior root of a spinal nerve

Part of the PNS system

How do motor neurons send information

Carries signals from the CNS to muscles and glands

What are motor neurons made up of

One axon and many dendrites

motor neurons cell body location

Anterior (ventral) horn of the spinal cord / grey matter

what is the main function of motor neurons

It produces movement

Axons travel from the CNS to skeletal muscle

What is the function of interneurons / association neurons

pass signals from one neuron to another through CNS pathways;

most are entirely within CNS

What is a nerve

A bundle of axons located in the peripheral nervous system (PNS)

What is a tract

A bundle of axons located in the central nervous system (CNS)

Where are nerves found

In the peripheral nervous system (outside the brain and spinal cord)

Where are tracts found

In the central nervous system (brain and spinal cord)

The brain and spinal cord are protected by three connective tissue layers what are they

Pia matter:

innermost , thin and delicate, directly adhered to the surface of the brain and spinal cord

Arachnoid matter:

Middle, wispy and thin

Dura matter:

Outermost layer

Tough fibrous sleeve

discuss the epidural space

Between the dura and bone

Contains fat and blood vessels

what does the dura matter cover

Brain and spinal cord to level S2

2nd sacral vertebra

Discuss the subdural space

Separates dura and underlying membrane (arachnoid matter)

Small amount of fluid

discuss subarachnoid space

Space between pia and arachnoid matter

Ends at S2 sacral vertebra

Contains csf

where is csf produced and what does it protect

Produced in brain and protects brain and spinal cord

how many ventricles are in the brain

4

how does CSF enter the central canal of spinal cord and the subarachnoid space

Through openings in the fourth ventricle

explain circulation of CSF

It’s secreted from blood vessels in walls of ventricles

Circulates around brain and spinal cord in subarachnoid space

Returns to bloodstream via a vein above the brain

what are the four type of arteries mentioned in the brain

Right and left inter carotid

Right and left vertebral arteries

Where is Grey matter found in the brain

Outer surface (cortex) and inner nuclei

where is white matter found in the brain

Deeper surface

Where is grey matter found in the spinal cord

Deeper H shaped

Where is white matter found in the spinal cord

Outer surface