1. Nervous Tissue and Brain
Ch. 10 Nervous system:
Nervous Tissue and Brain

2. Function of Relays messages (motor)
Monitors changes in body systems (sensory)
Responds to stimuli (sensory)
Maintain homeostasis (sensory)
Integrative – information is brought to CNS info is put together

3. Central Nervous system
Includes brain and spinal cord
Control center, coordinate body activities

4. Peripheral Nervous sys.
Nerves that carry messages to and from the central nervous system

5. Cells of the Nervous System
Neuroganglia – glial cells, nerve glue
Supports, protect and nourish the neurons

6. 2. Neurons Parts of : Cell body Dendrites – receive impulse
Axon – carries impulse away
Myelin sheath- white fatty material
Schwann cells (pns)
Neurilemma (outdside the sheath)
Nodes of Ranvier

7. Types of Neurons
Sensory neurons (afferent) – carries impulse to brain and spinal cord.

8. Types of Neurons
Motor neurons (efferent) – away from brain and spinal cord.

9. Types of Neurons
Interneurons or association neurons – relay impulses from sensory to motor neurons.

10. White matter vs Gray Matter
White because of myelin
Gray matter
Cell bodies, interneurons, nonmyelinated fibers
Nuclei – clusters of cells in CNS
Ganglia – cell cluster in PNS

11. The Nerve Impulse Action potential – steps in the nerve impulse
3 stages of : polarization, depolarization, repolarization

12. Step 1: Polarization Resting state of a neuron
Sodium/possium pump – sodium ions out of cells and potassium ions into cells

13. Polarization continued
Inside of the cell is – charged
Outside of cell is + charged
Due to sodium-potassium pump
2 K+ ions go in as 3 Ca++ go out

14. Step 2: Depolarization Due to stimulation
Inside of the neuron becomes + charged.
Na+ rushes into the cell

16. Step 3: repolarization Return to resting state
Due to the pumping out of K+.
Na+ blocked
Inside of cell negative
Continues to synapse

17. Synapse

18. Brain: structure and function
4 main parts of the brain:
Cerebrum
Diencephalon
Brain stem
Cerebellum

19. Cerebrum Largest part of the brain
Corpus collosum - Right and left hemispheres
Cerebral cortex – gray matter covering the cerebrum
                    

20. Cerebrum Continued
Function of cerebral cortex – learning, reasoning, language, memory
Markings of: gyri (elevations) and sulci (grooves)

21. Diencephalon Thalamus – Hypothalamus -
Relay station for sensory fibers between cerebrum and lower brain.
Hypothalamus -
Body Temperature
Emotions
Hunger
Thirst
Circadian Rhythms

22. Cerebellum
Coordinatin of voluntary muscle movements
Muscle tone

23. Brain Stem Midbrain-relay station, hearing, vision
Pons – relay station, breathing rate
Medulla Oblongata – relay center, heart rate, blood pressure, respiration

24. Ventricles

25. Protection Bone Meninges – 3 layers of connective tissue
Cerebrospinal fluid –
Blood brain barrier – cells associated with blood vessels that supply the brain with blood.

26. Aging Brain
Enlargement of the ventricular system: the volume of the ventricles
Widening of sulci (the grooves) on the surface of the brain.
Reduced brain weight and brain volume: loss of neurons.
Neurological disorders: Alzheimer's disease, Parkinson's disease and stroke are more common in the elderly.