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Nervous System of the Horse - Coggle Diagram
Nervous System of the Horse
Neurons
The equine nervous system controls body movement and functions of several body organs including sense organs.
central nervous system and peripheral nervous system contain billions of cells known as neurons
neurons connect with each other to form neurological circuits
information travels along circuits via electrical signals
Make up of Neurons
centre portion called a cell body
2 types of extensions called dendrites and axons
dendrites receive signals from other neurons and transmit electrical charges to the cell body
axons transmit the electrical charges away from the cell body
axon releases chemicals called neurotransmetters
neurotransmitters pass the signal to the dendrites of other neurons or to muscles or organs.
Pathway of Electrical Signal
dendrites receive a signal from neurotransmitters
cell body will undergo changes and process the info from dendrites
action potential is transmitted along the axon
myelin sheath insulates axon so the signal cant weaken
action potential reached axon terminal which causes neurotransmitter to be sent to the dendrites of another neuron
Action Potential
Depolarization
:
makes the cell less polar - membrane potential gets smaller)
voltage-gated sodium channels at the part of the axon closest to the cell body activate
lets positively charged sodium ions flow into the negatively charges axon and depolarize the surrounding axon.
once one channel opens and lets positive ions in, it sets the stage for the channels down the axon to do the same thing
through depolarization, the neuron actually swings past equilibrium and becomes positively charges as action potential passes through
Repolarization:
brings the cell back to resting potential
inactivation gates of sodium channels close, stopping inward rush of positive ions
at the same time, potassium channels open
more potassium inside the cell than out
cell loses positively charged ions and returns back towards its resting state.
a triggering event occurs that depolarizes the cell body
this signal comes from other cells connecting to the neuron
causes positively charged ions to flow into the cell body
positive ions flow into the cell to depolarize it but these ions pass through channels that open when a neurotransmitter binds to the denedrite
incoming ions bring the membrane potential closer to 0
if the cell body gets positive enough that it can trigger the voltage-gated sodium channels found in the axon, then the action potential will be sent
Hyperpolarization:
makes cells more negative than its typical resting membrane potential
as action potential passes through, potassium channels stay open a little bit longer and continue to let positive ions exit
the cell temporarily hyperpolarizes or gets even more negative than resting state
as potassium channels close, sodium-potassium pump re-estiblish the resting state
Types of Neurons
Peripheral Nervous System
Relay Neurons
transmits information between the sensory and motor neurons
able to bypass the brain in situations requiring a reflex response
Motor Neurons
carry responses to the sensory information from the spinal cord and brain to the rest of the body
causes movement, usually in the limbs
somatic nevous system
controls voluntary movements e.g. walking, concious thought
skeletal muscle tissue
automatic nervous system
controls involuntary responses e.g. breathing, reflex, digestion
smooth and cardiac muscle tissue
Sympathetic devision
(fight or flight)
movement
heart rate
respiratory system
e.g. running from predators, spooking, teritorial
Parasympathetic division
(rest or digest)
maintaining a relaxed condition and normal body function
e.g. stabled, grazing
Sensory Neurons
carry information from the body to the spinal cord or brain stem
information includes sensations of pain, position, touch, temperature, taste, hearing, balance, vision and smell
Central Nervous System
Spinal Cord:
conducts signals to and from the brain, controls reflex activities
Brain:
Receives and processes sensory information, initiates responses, stores, memories, generates thoughts and emotions