Transcript nervous sys notes - Solon City Schools

NERVOUS SYSTEM
ANATOMY & PHYSIOLOGY
PARTS OF THE BRAIN
• Frontal lobe- conscious thought, behavior, emotion, planning, personality,
organizing, problem solving, most uniquely human of all brain structure. Front
of brain
• Parietal: integrations of sensory information, perception, arithmetic, spelling,
manipulation. Middle top of brain
• Temporal: smell, sound, processing of complex stimuli
(faces/senses/memory/understanding language). Temple region
PARTS OF THE BRAIN
• Occipital: sense of sight. Back of brain
• Cerebellum: little brain, balance, coordination, muscular movement, timing,
body position
• Brain stem: pons and medulla oblongata, relays signals between brain and
spinal cord, heart rate, breathing rate, blood pressure
• Hypothalamus:
integration center for autonomic NS, controls endocrine
system, body temperature, water balance, sleep-wake pattern, food intake,
behavioral responses with emotion
FUNCTIONS
• Sensory: Monitor internal and external environment with receptors
• Integration: interpret sensory information (processing and higher order
functions)
• Motor: respond to information through stimulation of effectors
• Muscle contraction
• Glands secretion
DIVISIONS OF NERVOUS SYSTEM
• Central: brain and spinal cord
• Peripheral: all tissues outside of CNS (sensory input and motor output),
includes somatic and autonomic NS
TISSUE
Neurons: excitable cells, transmit electrical signals
• 30,000 neurons can fit on a pinhead
• Neurons do not touch→ gap is the synapse (messages sent across gap by
neurotransmitters)
• Can excite the next neuron or inhibit
• Can live for a lifetime and don’t divide
• High metabolic rate, constantly need oxygen and glucose, die within a few
minutes without oxygen
• 100 billion in brain and 1 billion in spinal cord
NEURONS
• Sensory (afferent) toward CNS (skin and muscles), unipolar and bipolar
• Motor (efferent) from CNS to muscles/gland, multipolar
Neuroglia
• AKA glial cells- supporting cells
• CNS: astrocytes (star, common, metabolism, create blood-brain barrier,
monitor interstitial fluid, secrete chemicals for embryological development,
stimulate formation of scar tissue), oligodendrocytes (produce myelin),
microglial (macrophages), ependymal (helps circulate cerebrospinal fluid, cilia,
lines CNS and spinal cord)
• PNS: Schwann, satellite
INTERNEURONS
• 99% of all neurons
• Grey matter: receive sensory information, direct information into a region of
CNS, initiate appropriate motor responses
• White matter: transmit information (sensory and motor) from 1 region of CNS
to another
SYNAPSE
• Electrical current travels down the axon: enough electrical current in brain to
power flashlight
• Vesicles with chemicals move toward membrane
• Chemical released and diffuse toward next cell
• Chemical opens up transport proteins and allow signal to go to next cell
FUN FACTS: BRAIN & CNS
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Brain
•
CNS
Mass of 100 billion neurons, learning occurs more and stronger as connections are
made with neurons
•
Cerebrum
• Largest part, responsible for thought/senses/language/memory (not a snapshot, must be put
together from information stored in other parts of the brain
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Cerebellum: muscle coordination/balance/posture
Brain stem: breathing/swallowing/heart/blood pressure
Spinal cord: column of nerves protected by vertebrae, conduct impulses between brain and
body, 268 mph
PNS
• Neurons that go from brain/spine to rest of body
• Sensory nerves: from body to brain (pain, temperature,
pressure)
• Motor nerves: from brain to body (response)
What Changes Neurons and Connections?
• Accidents- physical injury of neurons
• concussion - temporary disturbance of brain's ability to function to due to a hit in
the head
• Drugs/alcohol- bind to important receptors on neuron and repeated
•
binding can cause neuron death
Disease
• See disease chart