8.3: The Central Nervous System

Meninges
Cerebellum
Medulla Oblongata
Pons
Midbrain
Thalamus
Hypothalamus
Cerebrum
Blood-brain barrier
Cerebrospinal Fluid
Corpus Callosum
Occipital lobes
Temporal lobes
Parietal Lobes
Frontal lobes
The Central Nervous System
Structural & Functional unit for entire nervous system
Neural integration & processing
Receives info, evaluates & ships off a response
Has both myelinated (white matter) & unmyelinated (grey matter) neurons
CNS
Line of neurons going from back to skull through the backbone
Link between brain & peripheral nervous system
Reflex centre
Made of white & grey matter
Surrounded by cerebrospinal fluid
If spinal cord is damaged, paralysis occurs
Spinal Cord
Contains over 100 billion (1 000 000 000 000) neurons
Divided into 3 main regions
Surrounded by skull & meninges, a membrane
Meninges stop direct circulation of blood into brain, blocking toxins
Cerebrospinal fluid transports hormones, blood cells & nutrients
shock absorber
The Brain

Cerebellum
unconscious movements - posture, reflexes body movement
conscious movements - motor skills
Receives information from proprioceptors within skeletal muscles & body joints
Medulla Oblongata
Reflexes
Automatic body functions such as heart rate, swallowing, breathing, coughing
Pons
Relay between left & right halves of brain
Hindbrain
Processing information from sensory neurons in eyes, ears & nose
Relaying visual & auditory stimuli between hind & forebrain
Eye & skeletal muscle movement
Midbrain
Thalamus: Relay station
connects fore & hind brain
connects sensory systems other than smell & cerebellum
Hypothalamus
Homeostasis & behaviour
controls blood pressure, heart rate, body temperature, thirst & hunger & emotions
links nervous & endocrine systems with pituitary gland
releases hormones
Cerebrum
Largest part of the brain
Divided in half into two hemispheres
Higher thought, memory, consciousness, language
Forebrain
Covered in cerebral cortex, or grey matter, where thinking & feeling occur
hemispheres linked with corpus callosum
transmits messages
Made of 4 lobes
Occipital Lobe
Receive & analyze visual information
If damaged, sight remains but not recognition of what is being seen
Temporal Lobe
Processing of visual information & auditory reception
understanding of speech & visual & verbal memories
Parietal lobes
Sensory information from skin
Information about body's position & orientation in space
Frontal lobes
Integrate from other parts of the brain
Reasoning, critical thinking, memories, personality, language, precise motor movement
Cerebrum