The Central Nervous System (CNS)

What is the CNS

The control centre of the body

- Two main components: brain and spinal cord

- Processes and coordinates all bodily functions

- Protected by bones and meninges (specialized membranes)

What is the CNS composed of?

Myelinated neurons (white matter) and Unmyelinated neurons (grey matter)

- Spinal cord: white matter outside; grey matter inside

- Brain: grey matter outside; white matter inside

What protects the brain?

Skull (cranium), meninges, and cerebrospinal fluid (CSF)

What protects the spinal cord?

Vertebral column, meninges, and cerebrospinal fluid (CSF)

What are the three layers of meninges?

Dura mater (outer), arachnoid mater (middle), and pia mater (inner)

What is the purpose of cerebrospinal fluid?

Provides cushioning and transports nutrients to the CNS from the blood

What are the three main reigons of the brain?

Forebrain, cerebellum, and brain stem

What is part of the forebrain?

Cerebrum: Larget part of the brain

Thalamus: Sensory relay station

Hypothalamus: Homeostasis control

Pineal gland: Melatonin production

Pituitary gland: Hormone control

How is the cerebrum divided?

Right and left hemispheres connected by a bridge of neurons called the corpus callosum

What are the four lobes of the cerebrum?

Frontal: Movement, reasoning

Parietal: Sensation, spatial awareness

Temporal: Hearing, memory

Occipital: Vision

What are the cerebral functions?

- Controls higher-order thinking

- Manages voluntary movements

- Processes sensory information

- Houses lanuage centres

- Regulates emotional responses

- Stores memories

Where is the cerebellum located and what is its function?

It is located in the back of the brain and its primary functions are:

- Balance coordination

- Posture maintenance

- Fine motor control

- Movement timing

(Contains more neurons than the rest of the brain combined)

How many parts are there to the brain stem and what are they?

Three main parts:

- Midbrain

- Pons

- Medulla oblongata

What does the brain stem control?

Vital functions:

- Breathing

- Heart rate

- Blood pressure

- Sleep cycles

What is the structure of the spinal cord?

- Extends from brain stem to lower back

- 31 pairs of spinal nerves

- Grey matter (butterfly shaped): contrains neuron cell bodies

- White matter: contains axon tracts

- Central canal: contrains CSF

What are the functons of the spinal cord?

- Information highway to/from brain

- Reflex centre

- Movement control

What are common conditions that affect the CNS?

Multiple sclerosis, Alzheimer's, Parkinson's, Epilepsy, and spinal cord injuries

What can be done to protect the CNS and its health?

Exercise, nutrition, sleep, mental stimulaton, avoid harmful substances, and protective gear during activities