1. 12.1 – Structure of the Nervous System

2. Nervous System:
a high-speed communication system which delivers information to and from the brain and spinal cord and all over the body.

3. In any nervous system, there are 4 main components:
sensors: gather information from the external environment (sense organs)
conductors: carry information from sensors to modulators or from modulators to effectors (nerves)
modulators: interpret sensory information and send information to effectors (brain, spinal cord)
effectors: part of the body that responds because of information from a modulator (muscles, glands)

4. In any nervous system, there are 4 main components:
sensors:
conductors:
modulators:
effectors:

5. The Human Nervous System
Two main components of the human nervous system:
central nervous system (CNS): the brain and spinal cord
peripheral nervous system (PNS): the nerves that enter and leave the brain and spinal cord

6. CNS receives sensory information and initiates control
protected by several things:
skull – hard casing that protects the brain
vertebrae – protects spinal cord
meninges – three protective membranes surrounding the brain and spinal cord. They are filled with cerebrospinal fluid to help cushion.
Ventricles (cavities) in the brain which are filled with cerebrospinal fluid
grey matter: brownish-grey nerve tissue consisting of mainly cell bodies within the brain and spinal cord
white matter: the white nerve tissue of the brain and spinal cord, consisting of mostly myelinated neurons.

7. CNS Protection
Meninges

8. PNS 2 parts
autonomic nervous system: the part of the nervous system that relays information to the internal organs that are not under the conscious control of the individual. This system is made up of the sympathetic and the parasympathetic nervous systems.
sympathetic: speeds up muscle activity and activates in times of stress; “fight or flight response” ex. Increases heart rate, breathing rate, nervousness
parasympathetic: the network of nerves that counteract the sympathetic nervous system to slow down heart rate and relax muscles
somatic nervous system: the part of the nervous system that relays information to and from skin and skeletal muscles that are under conscious control of the individual

10. The Brain
Parts of the Brain (see Fig , p. 399)

11. Cerebrum
largest part of the brain; cerebral cortex folded to increase surface area
responsible for complex behavior and intelligence; also interprets sensory inputs and initiates motor response
cerebral cortex divided into 4 lobes:
frontal lobe – contains primary motor area, premotor area, Bronca’s area (motor speech), and pre-frontal area (association)
temporal lobe – located at sides of head contains auditory association area, primary auditory area, and sensory speech (Wernche’s area)
parietal lobe – located near top of brain contains primary somatosensory area, somatosensory association area and primary taste area
occipital lobe – located at back of cerebrum contains primary visual area and visual association area
cerebral cortex divided into two hemispheres, right and left. The cortex consists of grey matter and the two hemispheres are connected by a structure called the corpus callosum, a layer of white matter which transmits between the two hemispheres really quickly.

12. Cerebellum
the part of brain that is responsible for muscle coordination
contains 50% of the brain’s neurons but only takes up 10% of the space

13. Midbrain
a short segment of the brainstem (midbrain, pons and medulla oblongata) between the cerebellum and pons; particularly involved in sight and hearing

14. Pons
contains bundles of axons traveling between the cerebellum and the rest of the CNS
functions with the medulla oblongata to regulate breathing rate and has reflex centers involved in head movement

15. Medulla Oblongata attaches to the spinal cord at the base of the brain
involved in several important processes:
- controlling heart rate - vomiting
- adjusting blood pressure - hiccupping
- controlling breathing - swallowing

16. Thalamus
sensory relay center of the brain that governs the flow of information from all other parts of the nervous system

17. Hypothalamus
The part of the brain that acts as the main control centre for the autonomic nervous system, reestablishes homeostasis, and controls the endocrine hormone system

18. Review
Can you name & locate the 4 lobes?

19. Review
Which lobe might be damaged if you have hearing difficulties?

20. Review
Which lobe might be damaged if you have sight problems?

21. Review What is #37? What is #36 What is #32
What are these 3 collectively called?

22. Review
Which part is the control center for the autonomic nervous system?
Which part of the brain is active when you gag on a chicken bone?

23. Review Which part of the brain is well developed in athletes?
What is #10 composed of?

24. Review
Which part of the brain stem is NOT labeled

25. Review
You make up a question I can ask on the quiz.