1. And Brain Organization
The Nervous System
And Brain Organization

2. Central Nervous System
Consists of the brain and spinal cord
The brain is the central “computer” of the nervous system
The spinal cord is the “cable” that is used to communicate to the rest of the body

3. Peripheral Nervous System
All the parts of the nervous system outside of the brain and spinal cord
Two major divisions
Somatic system – the muscles and sense organs (voluntary behavior)
Autonomic system – the internal organs and glands (involuntary behavior)

4. Autonomic Nervous System
Two divisions
Sympathetic branch – arouses the body
Prepares the body for fight or flight
Parasympathetic branch – quiets the body or brings it back to normal

5. Central Nervous System Peripheral Nervous System
Brain
Spinal Cord
Autonomic System
Somatic System
Sympathetic System
Parasympathetic System

6. Brain Organization
Cerebrum – two large hemispheres that cover the upper part of the brain
Cerebral cortex – the outer layer of the cerebrum
made up of wrinkled gray matter that contains nerve cell bodies

7. Brain Organization cont’d…
Cerebral hemispheres – right and left halves of the cerebrum
Corpus callosum – bundle of fibers connecting the hemispheres
Cut in a ‘split-brain’ operation
Spatial neglect – when a person pays no attention to the left side of visual space after damage to the right hemisphere

8. Lobes of the Cerebral Cortex
Lobes – areas on the cortex defined by major fissures or functions
Occipital lobe – vision
Parietal lobe – bodily sensations (touch, temperature, pressure)

9. Lobes of the Cerebral Cortex
Temporal lobes – language (on the left only) and hearing
Frontal lobes – motor control, speech, abstract thought
Association cortex – all areas of the cerebral cortex not primarily sensory or motor in function – complex skills like language, memory, recognition, and problem solving

10. Parietal lobe
Frontal
lobe
Occipital
lobe
Temporal
lobe
Cerebellum

11. Association Cortex
Broca’s area – language area – grammar and pronunciation – left frontal lobe
Aphasia – speech disturbance related to brain damage
Wernicke’s area – language comprehension – left temporal lobe
Agnosia – inability to identify seen objects

13. Subcortex
Subcortex - all brain structures below the cerebral hemispheres
Divided into three parts
Brainstem (or hindbrain)
Midbrain
Forebrain

14. The Brainstem Also known as the hindbrain Lowest portions of the brain
Contains the cerebellum, medulla and pons

15. Cerebellum – controls posture, muscle tone and coordination – stores memories related to skills and habits
Medulla – connects brain to spinal cord – controls vital life functions such as heart rate, breathing, swallowing, etc.
Pons – bridge between medulla and other structures – influences sleep and arousal

16. The Midbrain
Small region, located above spinal cord, but below the forebrain
Coordinates simple muscle movements with sensory information
Reticular formation – network of fibers and cell bodies throughout the hindbrain – associated with attention, alertness and some reflexes

17. The Forebrain Contains the thalamus and hypothalamus
Thalamus – located on top of brain stem – relays sensory information to the cerebral cortex
Hypothalamus – controls metabolic functions including body temp, libido, hunger, thirst, and the endocrine system

19. The Limbic System
Contains hypothalamus, parts of the thalamus, amygdala, and hippocampus
Large role in producing emotion and motivated behavior
Amygdala – associated with fear responses
Hippocampus – associated with storing memories (lies in the temporal lobe)