Central Nervous System (CNS)
Responsible in sending, receiving and interpreting informations ftom all parts of the body
Response in external stimuli and monitors coordinates fuction of internal organ
Consists of brain and spinal cord
Brain made in 3 main parts which are
Cerebrum, Cerebellum and Medulla Oblongata
Cerebrum (Largest part in brain) consists of frontal, parietal, temporal and occipital lobes
Cerebellum helps to balance and coordinate voluntary muscle actions
Brain Stem connects brain with spinal cord and discompose the midbrain pons and medulla oblongata
Spinal Cord long about 45 cm, slender cylinder (2cm in diameter) of nerve tissue that extends from brain stem
located in vertebral folamen
Made up of 31 segments : 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccyx
Physiology of CNS
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Neurons that receive information from our sensory organs (e.g. eye, skin) and transmit this input to the central nervous system (CNS) are called afferent neurons
Neurons that send impulses from the central nervous system to your limbs and organs are called efferent neurons.
Function of Neurons in the Nervous System
Structure of the Neurons
Cell Body (known as the Soma) is a houses of cell nucteus
Dendrites
- Tree like branches extend off the soma
- Detect both chemical and electrical stimuli
Axon
- Longest extension from the Soma
- Up to a meter in length
- Serves as primary communication pipeline from one end of neuron to the other neurons
Myelin Sheaths
- Sections of fatty tissue
- Protect the axon
- Speed up Signal conduction
Nodes of Ranver
- Aid in signal conduction
- Allow nutrients and waste to enter and leave the axon
Nerve Cell Network
Message transmission happens at the Synapse (synaptic cleft)
In this area chemical and electrical neurotransmitter are released and picked up the dendrites of other nerve cell
