Chapter 5- The Central Nervous System Flashcards
What protects the CNS
- Bone
- Membranes called meninges
- Cerebrospinal fluid (CSF)
What bone protects the brain
- Outter most protective layer
- Cranium, spinal cord runs through an opening in the vertebrae called the vertebral canal
What is the connective tissue protecting the CNS
- Meninges
- Cover entire CNS
- Outter layer is tough and fibrous
- Middle layer is a loose mesh of fibres
- Inner layer is far more delicate, contains blood vessels which stick close to the surface of the CNS
Cerebrospinal fluid (CSF)
- Protects , supports and transports
- Occupies the space between middle and inner layer of meninges
- circulates through cavities in the brain and canal in the Centre of spinal cord
- Clear watery fluid
- Contains glucose, protein, urea, salt
- Acts as a shock absorber
- Supports the brain, it suspends the cranium and floated in the fluid
- Formed in the blood and circulates the CNS
The cerebrum
- Largest part of the brain
- Divided into the left and right hemisphere, cereberal hemispheres
- Subdivisions: frontal, temporal, occipital, perietal
- Has folds/ convolutions
- Cerberal cortext: gray matter on the surface
What is the cerebral cortxt
Grey matter that forms a layers 2-4 mm think on the outside of the cerebrum
Advantages of folds on the cerebral cortex
- increases surface areas
- As it is gray matter it can contain many more nerve cells than if it wasn’t folded
What is the difference between a Sulci and a fissure?
Shallow Dow folds in the cerebral cortext
Fissures are deep folds
When are the functions of the cerebral core text
- Higher order mental activities
- Thinking, reasoning, learning, memory
- Consciously aware of the input from sensory organs which initiate and control voluntary muscle contractions
Name the three areas of the cerebral cortex and their function
- Sensory: interpret impulses from receptors
- Motor: consciously control motor movement
Association: process intellectual and emotional responses
Describe the location of the corpus callosum
- At the base of the longitudinal fissure that divides the cerebrum into two hemispheres
- underneath cerebrum
Why is the corpus callosum white ?
- It is made up of myelinated fibres which link the 2 hemispheres
What is the function of the corpus callosum
- The nerve fibres of the corpus callosum allow the two sides of the cerebrum to communicate with each other
- Impulses are sent from one cerebral hemisphere to the other
Where is the cerebellum
- Underneath and at the back of the cerebrum
What is the main function of the cerebellum
- receives impulses from the inner ear and receptors in voluntary muscles
- Uses info to control posture, balance and fine movements of voluntary muscles
Location of the hypothalamus
- Middle of the brain
- Under cerebrum
- Above pituitary gland
Functions of the hypothalamus
- Regulation of blood pressure
- Body temp
- Dilation of pupils
- Secretions of hormones
- Coordination of the endocrine system
- Food and water intake
What is the medial oblongata
- Part of the brain joined to the spinal cord
- Approx. 3cm long
- Extends upwards from the point where the spinal cord enters the skull
Centres contained within the medulla oblongata
- Cardiac centre: regulate heat rate and force
- Respiratory centre: regulate rate and depth of breathing
- Vasomotor centre: regulates diameter of blood vessels
Location of gray matter in the spinal cord
- centre of the cord
- seen in a cross section
- Has a H shape
