NERVOUS SYSTEM:. The Brain. Brain Factoids…. 100 billion neurons Weighs 3 pounds Gray and white matter Cerebrum = 85% of total mass of brain. 4 main areas of brain. Brain stem Cerebellum Diencephalon Cerebrum 2 halves (hemispheres 4 lobes Highly- wrinked part = cerebral cortex.
NERVOUSSYSTEM: The Brain
Brain Factoids… • 100 billion neurons • Weighs 3 pounds • Gray and white matter • Cerebrum = 85% of total mass of brain
4 main areas of brain • Brain stem • Cerebellum • Diencephalon • Cerebrum • 2 halves (hemispheres • 4 lobes • Highly-wrinked part = cerebral cortex
CEREBRAL CORTEX • Sensory perception • Willed movements • Consciousness • Memory • Subcortical= • subconscious
1. Frontal Lobe • Associated with • Reasoning • Planning • Parts of speech • Movement • Emotions • Problem solving • Personality You are who you are because of this lobe. This area determines personality and emotions. It's also involved in controlling judgment, impulses, sexual behavior, language and movement.
2. Temporal Lobe • Associated with • Perception and recognition of auditory stimuli • Memory • Speech This region controls your hearing and the ability to recognize words. It can also affect memory. Damage to the left side of this lobe can cause problems remembering what people said. Damage to the right side might stop you from recalling music or pictures.
Damage to… • Broca’s Area>> expressive aphasia • Know what you want to say, but can’t get the words out properly • Yes... ah... Monday... er... Dad and Peter H... (his own name), and Dad.... er... hospital... and ah... Wednesday... Wednesday, nine o'clock... and oh... Thursday... ten o'clock, ah doctors... two... an' doctors... and er... teeth... yah. • Wernicke’s Area:>> receptive aphasia • No problem getting the words out, but the sentences don’t make sense • “I called my mother on the television and did not understand the door. It was too breakfast, but they came from far to near. My mother is not too old for me to be young.”
3. Parietal Lobe • Associated with • Movement • Orientation • Recognition • Perception of stimuli This region of the brain helps people understand what they see and feel. It also controls how they understand and process information about the environment around them, such as distance and position of objects.
4. Occipital Lobe • Associated with • visual processing Call this the visual center. This area determines if you understand what you're looking at. Damage to the occipital lobe could cause hallucinations, make objects appear larger or smaller then they are or make the colors look abnormal.
Check out brain lobe function • Brain video: The work of neurons
CORPUS CALLOSUM • Broad band of white matter • Contains axons that connect the right and left cerebral hemispheres
Brain Stem & Associated Structures • Cerebellum • Brainstem • Midbrain • Pons • Medulla Oblongata • Spinal Cord
CEREBELLUM • Regulates muscle coordination • Maintains equilibrium • Stores movement patterns • Posture
BRAINSTEM • Relay Station • Connects brain to the spinal cord • Runs from the thalamus to the spinal cord • Composed of 3 parts • Midbrain • Pons • Medulla Oblongata • Life center- controls • breathing • heart rate • blood pressure
A. Midbrain • Superior portion of the brainstem • Contains relays for visual and auditory impulses 1. Midbrain 2. Cerebellum 3. Pons 4. Medulla oblongata 5. Inferior colliculus 6. Superior medullary velum 7. Fourth ventricle
B. Pons • Middle portion of the brainstem • Is a conduction pathway from body to thalamus/cerebrum/ cerebellum • Regulates respiration
C. Medulla Oblongata • Inferior portion of the brainstem that controls • Cardiac function • Respiratory function • Vasomotor centers
SPINAL CORD • Carries messages to and from the brain and the rest of the body • Mediates reflexes
Two-neuron reflex arc: Impulse from sensory neuron • dendrite cell body in dorsal root ganglion, near SC (Ganglion: group of hundreds of nerve cell bodies located in the PNS.) • axon synapse • To motor neuron • dendrite cell body (in gray matter of SC) • axonwhich runs through the ventral root of a spinal nerve • To effector
Limbic System & Associated Structures • Limbic System • Hippocampus • Amygdala • Thalamus • Hypothalamus • Pituitary Gland • Pineal Gland thalamus pineal gland
LIMBIC SYSTEM: emotional brain • Hippocampus • Amygdala • Thalamus • Hypothalamus
A. Hippocampus • Plays a role in long term memory
B. Amygdala • Plays a key role in processing emotion • Linked to • fear response • pleasure
C. Thalamus • Sensory relay station from various areas of the body to the cerebral cortex • Involved with • emotion • alerting mechanisms • arousal mechanisms
D. Hypothalamus • Maintains Homeostasis • Releases hormones to the pituitary gland • Regulates • body temperature • water balance • sleep-wake cycle • sexual arousal • aggression/pleasure • eating/drinking
Pituitary Gland • Releases sex and growth hormones • Stimulates lactation • Stimulates uterine contractions • Regulates urine output
Pineal Gland • Involved in the body’s sleep/wake cycle