1. Chapter 7
The Nervous System

2. Organization of the Nervous System
Central Nervous System
Referred to CNS
Brain and Spinal cord
Integrative control center
Peripheral Nervous System
Referred to PNS
Nerves that extend outside the brain and spinal cord to the body’s extremities
Communicates between the CNS and the rest of the body

3. Regions of the Brain Cerebrum Diencephalon Cerebellum Midbrain *
Pons *
Medulla Oblongata *
* Found in Brain Stem

4. Cerebral Hemispheres (Cerebrum)
Largest part of brain
Include more than half of the brain mass
Controls higher mental functions; conscious mind; MAKES US HUMAN
Allows us to sense, to communicate, to remember, and to understand, and initiate voluntary movements.
Outer layer of cerebrum (cerebral cortex) is made of gray matter
- Folded surface increases surface area
- Elevated ridges (gyri)
- Shallow depressions (sulci)
- Deep Grooves (fissures)

5. Cortex Roadmap Gyri - ridges Sulci – shallow grooves
Fissures – deep groves

6. Lobes of the Cerebrum Surface lobes of the cerebrum Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe

8. Sensory and Motor Areas of the Cerebral Cortex

9. Specialized Areas of the Cerebrum

10. Layers of the Cerebrum Gray matter Outer layer
Composed mostly of neuron cell bodies
Includes regions of the brain involved in muscle control, sensory perceptions, like seeing and hearing, memory, emotions and speech

11. Layers of the Cerebrum White matter
Contains mainly long, myelinated axons
Involved in the relay of sensory information from the rest of the body to the cerebral cortex
Figure 7.13a

12. Diencephalon Sits on top of the brain stem
Enclosed by the cerebral hemispheres; well-hidden brain region
Made of three parts
Thalamus
Hypothalamus
Epithalamus

13. Thalamus The relay station for sensory impulses (switchboard)
Transfers impulses to the correct part of the cerebrum for interpretation
All incoming impulses get sorted here first and identified as pleasant or non-pleasant

14. Hypothalamus Under the thalamus
Contains brain stem and controls organs by maintaining homeostasis
Important autonomic nervous system center
Helps regulate body temperature
Controls water balance
Regulates metabolism
An important part of the limbic system (emotions)
The pituitary gland is attached to the hypothalamus

15. Hypothalamus An important part of the limbic system (emotions)
The pituitary gland is attached to the hypothalamus which secretes hormones to maintain homeostasis

16. Epithalamus Makes the cerebrospinal fluid
Helps to regulate the sleep/wake cycle by releasing hormones like melatonin
Controls some parts of emotions and mood
Epithalamus

17. Brain Stem Attaches to the spinal cord; primitive “rat brain”
Controls automatic behaviors necessary for survival (breathing)
Parts of the brain stem each about an inch long
Midbrain
Pons
Medulla oblongata

18. Midbrain
Smallest region of the brain that sort of works as a relay station for auditory and visual information.
Also controls eye movements, like blinking

19. Pons The bulging center part of the brain stem
Mostly composed of fiber tracts which relay messages to the brain
Includes control of breathing

20. Medulla Oblongata The lowest part of the brain stem
Merges into the spinal cord
Includes important fiber tracts relaying messages
Contains important control centers
Heart rate control
Blood pressure regulation
Breathing
Swallowing
Vomiting

21. Cerebellum
contains ~70% of all the brain's neurons; yet is only 10% of the volume of the brain!
contributes to precise timing of skeletal muscle activity (i.e. walking, running or standing on your hands)
controls our balance and equilibrium
Doesn’t function well under influence of alcohol
Works like ‘auto pilot’ – monitors body position and amount of tension in body parts

22. Cerebellum and other brain parts