The Nervous System

1. The Nervous System The body control centre

2. Functions of the Nervous System • Receives, stores & interpret information e.g. from eyes & ears • Controls activities of all body systems to maintain homeostasis within the body Homeo = combining form meaning the same • Controls all muscle movements including speech

3. Divisions of Nervous System 1. Central Nervous System (CNS) • Brain • Spinal cord

4. Divisions of the Nervous System cont’d 2. Peripheral Nervous System (PNS) • These nerves branch out from the CNS to all parts of body • There are: 12 pairs of cranial nerves 31 pairs of spinal nerves

5. Peripheral Nervous System Nerves of PNS function in a voluntary Manner Peripheral nerves carry impulses from receptors in skin, eyes, ears nose to CNS. • These peripheral nerves are called sensory or afferent nerves Peripheral nerves also carry impulses from CNS to body organs • These nerves are called motor or efferent nerves

6. Division of the Nervous System cont’d 3. Autonomic System (ANS) • Nerves carry involuntary impulses to smooth muscle, cardiac muscle & some glands

7. Divisions of Nervous System Central Nervous System Peripheral Nervous System Afferent (sensory) neurons from organs muscles & glands Efferent (Motor) neurons to Muscle & glands Autonomic Nervous System

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9. Neurons and their Function • Specialised cells of the Nervous System • Cells responsible for transmission of nerve impulses

10. What does a neuron look like? Network of nerves or neurons pg1

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12. The Brain • Cerebrum – large brain • Cerebellum – Little brain

14. Cerebral Vascular Accident (CVA) • Is a result of disruption to blood supply (i.e. ischaemia) to part of the brain • Ischaemia to cerebrum can cause brain cells to die and is known as an infarct • Paralysis and loss of speech can occur because cells of the cerebrum control many body movements • Severity depends on what part of the brain is affected

15. Cerebral Cortex • Is the outer layer of cerebrum • Contains motor and sensory areas • Responsible for consciousness and intelligence

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18. Other parts of brain

19. CRANIUM CEREBRUM PONS CEREBELLUM MEDULLA OBLONGATA THE BRAIN Thalamus Hypothalamus

20. Spinal Cord • Extends from the medulla oblongata to the second lumbar vertebra • Carries nerves that affect limbs &lower parts of body • Is the pathway for impulses to & from brain • Inner section composed of grey matter • Outer section composed of white matter

21. Meninges What are the layers surrounding brain & spinal Cord? • Dura mater – outer membrane contains channels for blood to enter brain tissue. Subdural space is below the dura & contains blood vessels • Arachnoid membrane – next layer. Subarachnoid space contains cerebrospinal fluid (CSF) • Pia mater – layer closest to brain

22. Rachiocentesis • Procedure to take sample of CSF from spinal cord fro testing • Also known as a lumbar puncture or spinal tap Act 4

23. Conditions of Nervous System

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26. Conditions & Terms