1. ANATOMY AND PHYSIOLOGY
Chapter 8 The Nervous System

2. The Nervous System
The Nervous System is the major controlling and communicating system in the body

3. The means of communication is
The Nervous System
The means of communication is
Electrical impulses
Which causes immediate responses

4. Monitor changes occurring inside and outside the body
3 major Functions of the Nervous System
Monitor changes occurring inside and outside the body
These changes are called stimuli and the gathered info is called sensory input

5. This is called integration
3 major Functions of the Nervous System
Process and interpret sensory input and make decisions about what should be done.
This is called integration

6. The response is called motor output
3 major Functions of the Nervous System
Effect a response by activating muscles or glands.
The response is called motor output

7. Works along with the endocrine system
3 major Functions of the Nervous System
So……
sensory input
integration
motor output
Works along with the endocrine system

8. The Nervous System 2 Classifications: CNS Central Nervous System
Made of brain and spinal cord

9. The Nervous System 2 Classifications: PNS Peripheral Nervous System
Made of nerves (spinal and cranial)

10. Nerve Tissue
2 kinds:
1. Supporting Cells

11. Nerve Tissue
2 kinds:
2. Neurons

12. Nerve Tissue Neuroglia Supporting cells in the CNS
Support, insulate, and protect neurons
Not able to transmit impulses
Never lose ability to divide so most brain tumors are gliomas. Tumors are formed by neuroglia

13. Nerve Tissue Neuroglia 1. Astrocytes Star shaped Cling to neurons
Form a barrier btw neurons and capillaries
Protect neurons from harmful substances in the blood
Pick up excess ions and neurotransmitters

14. Nerve Tissue Neuroglia 2. Microglia
Phagocytes that dispose of dead brain cells and bacteria

15. Nerve Tissue Neuroglia 3. Oligodendrocytes
Produce insulating covering called myelin sheath

17. Nerve Tissue Supporting cells in the PNS Schwann cells
Form the myelin sheath around nerve fibers in the PNS

18. Nerve Tissue Supporting cells in the PNS 2. Satellite cells
Protective, cushioning cells

19. NEURONS Nerve Cells Made of: Cell body Axon Dendrite
Transmit nerve impulses (messages)
Made of:
Cell body
Axon
Dendrite

20. Cell body - Center of cell. Contains the nucleus
NEURONS
Nerve Cells
Cell body Center of cell. Contains the nucleus
Process or fibers extend from the cell body

21. Axon - conducts impulse away from the cell body
NEURONS
Nerve Cells
Axon conducts impulse away from the cell body
Only one per neuron

22. Dendrite - conducts impulse toward the cell body
NEURONS
Nerve Cells
Dendrite conducts impulse toward the cell body
100s per neuron

23. 1.
dendrites 2.
nucleus 3.
Cell body 4.
Myelin sheath 5.
axon

24. Synapse junction between 2 neurons.
Nerve Cells
Synapse junction between 2 neurons.
The 2 neurons never actually touch

25. Myelin white fatty covering on the axon.
NEURONS
Nerve Cells
Myelin white fatty covering on the axon.
They protect and insulate
Also increase the rate of nerve impulse transmission

26. NEURONS
Nerve Cells
Myelin if the myelin sheath is destroyed as in multiple sclerosis, the person loses the ability to control their muscles.

27. NEURONS Myelin of the CNS Nerve Cells myelinated fibers
White matter
Gray matter
myelinated fibers
unmyelinated fibers

28. Afferent or Efferent NEURONS Classification
Functional classification groups are according to the direction the nerve impulse is traveling
Afferent or
Efferent

30. Afferent Efferent NEURONS Classification
Sensory. Carries impulse from organs to CNS
Afferent
Efferent
Motor. Carries impulse from CNS to muscles, glands.

31. Irritability Conductivity Properties of Nerve Impulses
Ability to respond to a stimuli
Ability to transmit impulses to other neurons, muscles, glands

32. NA K pump Properties of Nerve Impulses depolarization repolarization
Electro-chemical event.
Na ion enters cell
K ion leaves the cell causing a resting state.
depolarization
repolarization
NA K pump

33. NA K pump acetycholine Properties of Nerve Impulses Active transport
Neurons release neurotransmitters to influence other neurons.
This opens a specific ion channel
Neurotransmitter?
acetycholine

34. Reflex Autonomic Somatic
A reflex is a rapid predictable response to a stimulus
Autonomic
Somatic
Regulates activities of smooth muscles, the heart and glands.
Stimulates skeletal muscles

35. Reflex Autonomic Somatic Salivary reflex Pupillary reflex
Patellar reflex
Sucking reflex

36. Reflex Normal reflexes indicate normal nervous system functions
Plantar reflex (Babinski) The normal reflex is toe flexion. If the toes extend and separate, this is an abnormal finding called a positive Babinski's sign.

37. Neural Tube Ventricles Central Nervous System CNS
How nervous system 1st appears in embryo
Chambers. We have 4

38. Neural Tube
Deficiency of Folic acid = neural tube birth defects

39. Also called B9 Folic Acid
Leafy vegetables such as spinach and turnip greens dried beans and peas, fortified cereal products,sunflower seeds and certain other fruits and vegatables are rich sources of folate. Some breakfast cereals are fortified with 25% to 100% of the recommended dietary allowance (RDA) for folic acid.