1. The central and peripheral system
Nervous system
The central and peripheral system

2. A few terms Nerve fiber (single neuron) – an axon extension
Nerve – peripheral system: group of many nerve fibers traveling together to the same location
Pathway/tract – group of nerve fibers in the CNS
Ganglia – group of cell bodies in PNS
Nuclei – group of cell bodies in CNS
Gray matter – made primarily of cell bodies
White matter – primarily myelinated fibers

3. Subdivisions of the brain
Cerebrum
Diencephalon
Brain stem includes the midbrain, pons & medulla oblongata
cerebellum

4. Cerebral ventricles Four interconnected fluid filled cavities

5. Cerebrum
Plays a role in perception, movement, reasoning, learning, and memory
Most complex integrating system of brain
Incoming information is processed and made into meaningful ideas
Fine tunes skeletal muscle movements

6. Diencephalon - Thalamus
Thalamus – a group of large nuclei that integrates information coming in from the senses before they are sent onto the cerebrum.
Plays a role in awareness and focused attention & skeletal coordination.

7. Diencephalon - Hypothalamus
Control center for neural and endocrine coordination. In charge of homeostasis.
Regulates pituitary gland
Regulates water balance, eating, drinking, reproduction, body temperature, circadian rhythms
Plays role in behaviors, emotional behavior & control of autonomic nervous system

8. Lymbic system
Interconnected group of brain tissues that include the diencephalon and parts of the cerebrum
Plays essentional role in learning, emotional experience and behavior, visceral and endocrine functions
Mostly controlled by hypothalamus

9. Cerebellum Coordinates movements, controls posture and balance.
Receives information from muscles, joints, skin & viscera

10. Brainstem
Contains all the nerve fibers that pass between the brain and spinal cord
Reticular formation – control of cardiovascular and respiratory system, regulation of sleep, wakefulness and focus attention

11. Spinal cord Gray matter surrounded by white matter
Afferent enter on the dorsal side, efferent on the ventral side

12. Peripheral nerves 43 pairs of nerves 12 are cranial & 31 are spinal
Afferent neurons (primary afferents) are the first cells to enter the CNS & bring information from the senses and organ systems into the CNS.

13. Somatic vs autonomic innervation
McGraw Hill, Human Physiology, Vander, Sherman, & Luciano

14. Subdivisions of the efferent neurons
Because there are many possible responses as a result of the firing of the efferent neurons (move left arm up, breathe faster, digest slower, cross legs) it is broken into divisions.
Somatic nervous system – controls conscious movements
Autonomic nervous system – responses that occur w/o our conscious awareness

15. Somatic nervous system
The efferent nerves that enter skeletal muscle tissue.
Cell bodies are located in groups in the brainstem or spinal cord.
long axon travels from CNS directly to skeletal muscle with no other synapse
Release ACh
Impulses along these nerves only cause contraction of skeletal muscle.
Also called motor neurons

16. Innervation of left arm

17. Autonomic nervous system
Efferent nerves that travel from the CNS to cardiac & smooth muscle, glands and digestive tissues.
Has two neurons. One that travels from CNS to peripheral synapse & the second that leads from the synapse to the target cells/organ.
Primarily ACh is released at the synapse
Can excite or inhibit tissue

18. Divisions of autonomic system

19. Sympathetic
Originate from the cervical, thoracic & lumbar region of spinal cord
Ganglia close to CNS
Many of the neurons act on the same tissue
Acts as a single unit producing a coordinated response
Norepinephrine is the major transmitter at the effector/target cell
Responsible for “fight or flight” response

20. Parasympathetic
Originate from the brain stem and sacral region spinal cord
Ganglia are just out side of the target organ or in the target tissue itself
Nerves are mostly independent
Finely tune to specific needs of body
ACh is the major neurotransmitter at the effector cell
Responsible for homeostatic function “rest or digest”

21. Adrenal medulla Special ganglion in the sympathetic nervous system
Does not have axons
Releases substances into the blood, thus called horomones
Hormones released travel through blood to target organs

22. Peripheral neurotransmitters
McGraw Hill, Human Physiology, Vander, Sherman, & Luciano