BY kate sierra Kathryn and Carson WHAT IS THE NERVOUS SYSTEM AND WHAT ARE ITS FUNCTIONS Complex series of nerves and specialized cells neurons or nerve cells that transmit electrical signals between parts of the body ID: 784547
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Slide1
Nervous System - Period 3
BY
kate
, sierra, Kathryn, and Carson
Slide2WHAT IS THE NERVOUS SYSTEM AND WHAT ARE ITS FUNCTIONS?
Complex series of nerves and specialized cells (neurons or nerve cells) that transmit electrical signals between parts of the body
Similar to electrical wiring
Takes
in and processes information through the senses and triggers
reactions
Coordinates
muscle activity, monitors organs, constructs and processes data received from senses and initiates
actions
Metabolic
processes also included
Slide3Slide4ORGANS AND THEIR FUNCTIONS
Brain and spinal chord – analyze and respond to information accordingly; sends signals to rest of the body; controls
simple musculoskeletal
reflexes
Eyes – send information to the brain and convert into vision
Ears – send information to brain and convert it into sounds
Sensory organs of
taste (taste buds, etc.) – send information to the brain and convert into taste
Sensory organs of
smell -
send information to the brain and convert into
smell
Sensory receptors located in the skin, joints, muscles, and other parts of the
body – send information to the brain and convert into feelings and response such as touch or heat
Slide5HOW DOES THE NERVOUS SYSTEM WORK?
Slide6THE NERVE AND ITS PARTS
A.
CELL BODY
-
contains
the nucleus and much of the
cytoplasm; most
of the metabolic activity of the cell, including the generation of ATP
and
synthesis of protein
.
B. DENDRITES - Short branch extensions spreading out from the cell body. Dendrites receive STIMULUS and carry IMPULSES from the environment or from other neurons towards the cell body C. AXON - Long fiber that carries impulses away from cell body. Each neuron has only ONE axon. The axon ends with AXON TERMINALS
Slide7TYPES OF NEURONS
Sensory neuron
Interneuron
Motor Neuron
Length of Fibers
Long dendrites and short axon
Short dendrites and short or long axons
Short dendrites and long axons
Location
Cell body and dendrite are outside of the spinal cord; the cell body is located in a dorsal root ganglion
Entirely within the spinal cord or CNS
Dendrites and the cell body are located in the spinal cord; the axon is outside of the spinal cord
Function
Conduct impulse to the spinal cord
Interconnect the sensory neuron with appropriate motor neuron
Conduct impulse to an effector (muscle or gland)
Slide8Axon is covered by lipid layer called
MYELIN SHEATH
that speeds up transmission of messages
Axon terminals may come into contact with dendrites, effectors, or receptors to pass on messages
Receptors are in sense organs; effectors are muscles or glands that coordinate a response
Impulses are passes from one cell to another through
SYNAPSES
(gap between axon of one neuron and dendrite or cell body of another neuron)
Chemicals, or neurotransmitters, bridge this gap to transfer information to each other through electrical signals received from receptors or effectors; neurotransmitters are released when an electrical impulse reaches the end of a neuron
Slide9QUICK SUMMARY
Nerve has a cell body with multiple extensions
The shorter extensions (
dentrites
) act like antennae and receive signals
The longer extension (axon) passes along signals to other cells which are relayed to the brain
Synapses and neurotransmitters bridge the gap between cells to relay messages to
the brain
Slide10TWO MAIN PARTS OF THE SYSTEM
central
Composed of the brain and spinal chord
Purpose: to
collect information and respond
accordingly
Living
nervous tissue has consistency of jelly and must have special protection from
damage
Interprets messages from the peripheral nervous system
PERIPHERAL
Composed of everything but the brain and spinal chordPurpose: to connect the limbs and organs to the central nervous systemConsists of 12 pairs cranial nerves and 31 pairs of spinal nerves, some are exclusively sensorySensory cells carry messages to the central nervous system and motor cells carry the signal from the CNS to the organs, muscles, etc.
Slide11THE NERVOUS SYSTEM AND OTHER SYSTEMS
BODY SYSTEM
Cardiovascular
Endocrine
Lymphatic
Respiratory
Digestive
INTERACTION
The brain receives information about blood pressure through baroreceptors; regulates heart rate and blood pressure
Hormones provide information to affect neural processing; controls pituitary gland and other glands
Brain stimulates defense mechanisms against infection
Brain monitors respiratory volume, blood-gas levels, and respiratory rateDigestive system provides building blocks for neurotransmitters; sends information relating to thirst or hunger; controls muscles for eating and waste removal
Slide12THE NERVOUS SYSTEM AND OTHER SYSTEMS
Slide13WHAT ARE RECEPTORS AND WHAT ARE THEIR FUNCTIONS?
Receptor:
an organ or cell
that responds to an external stimulus
and
transmits
a signal to a sensory nerve
Interoceptors
-transmits
pulses to detect stimuli inside of the body
Exteroceptors
- similar to interoceptors but detects stimuli outside of the bodyChemoreceptors-detects the concentration of oxygen in the blood streamPhotoreceptors-respond to the presence of lightMechanoreceptors-responds to mechanical pressure or distortion, touchThermoreceptors- responds to absolute and relative changes in temperature
Slide14DISEASES THAT AFFECT THE NERVOUS SYSTEM
Slide15MULTIPLE SCLEROSIS
Affects brain and spinal cord
Myelin sheath is damaged (material that surrounds and protects nerve cells)
Slows or blocks messages between brain and body
Symptoms include: weak muscles, difficulty with coordination or balance, difficulty thinking or remembering, feelings of numbness or prickling
Cause is unknown; disease can be mild to severe depending on the affected person
Currently no cure but medicine and physical therapy can manage and lessen
symptoms
Slide16PARKINSON’S DISEASE
Malfunction of vital nerve cells, mostly in the
substanita
nigra
portion of the brain
Malfunctioning neurons die and release dopamine (a chemical that messages the part of the brain that controls movement and coordination)
Progressive movement disorder, which means symptoms continue and worsen over time
As the disease worsens, dopamine levels decrease and the person loses control of their movements
Symptoms include: tremor, slowness of movement, rigidity, poor balance or posture
Cause is unknown; no cure currently but medication and surgery can manage
symptoms
Slide17HOW DOES THE NERVOUS SYSTEM HELP MAINTAIN HOMEOSTASIS?
The central nervous system is comprised of the brain and the spinal cord, whereas the peripheral nervous system is composed of the nerve extensions beyond those central pathways. Both, when combined, interconnect all of the parts of the body and allow for the processes creating homeostasis to occur. The autonomic nervous system regulates involuntary bodily
functions. Without interpretation and responses to sensations such as becoming too warm, the body would become imbalanced.
Slide18BIBLIOGRAPHY
http
://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0024762/?figure=1
https://faculty.washington.edu/chudler/nsdivide.html
http
://www.hopkinsmedicine.org/healthlibrary/conditions/nervous_system_disorders/overview_of_nervous_system_disorders_85,P00799/
http
://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0024762/
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0025454/ http://www.livescience.com/22665-nervous-system.html http://www.ninds.nih.gov/disorders/parkinsons_disease/parkinsons_disease.htmhttps://faculty.washington.edu/chudler/organ.html http://leavingbio.net/the%20nervous%20system_files/the%20nervous%20system.htm