the nervous system Flashcards
How does the nervous system maintain homeostasis?
The nervous system regulates body structures and processes to maintain homeostasis despite fluctuations in the internal and external environment
Central Nervous system?
Network of nerves that includes the brain and spinal cord that integrates and processes information sent by nerves
Peripheral nervous system?
network of nerves that carry sensory messages to the central nervous system and send information from the central nervous system to the muscles and glands
Somatic nervous system?
Consists of sensory receptors in the head and extremities, responsible for conscious, voluntary reactions (punching something)
Autonomic nervous system
Responsible for involuntary, subconscious actions (heart beat)
The autonomic nervous system is split up into 2 parts:
Sympathetic: stress response, prepares body for an emergency
Parasympathetic: returns body to normal
What are neurons?
Basic structural and functional parts of the nervous system. Release chemicals that regulate various body processes
Dendrite? (Neuron structure)
receives signals from other neurons and relate the impulse to the cell body
Cell body? (Neuron structure)
The main part of a neuron, containing the nucleus and other organelles and processes input from the dendrites
Axon? (Neuron structure)
Long, cylindrical extension of a neurons cell body, transmits impulses away from the cell body along its length to the next neuron
White matter?
Nerves with a myelin sheath around it
Grey matter?
Nerves without a myelin sheath around it
Myelin sheath? (Neuron structure)
The fatty insulating layer around the axon of the nerve cell; speeds up the rate of nerve impulse transmission
Schwann cell?
Insulating cell that wraps around the axon of neuron, creating a myelin sheath
Node of ranvier?
Gaps, between Schwann cells where the membrane of the axon is exposed
Sensory neurons?
Gather information from sensory receptors and transmit these impulses to the central nervous system
Interneurons?
Found within the central nervous system, they act as a link between the sensory and motor neurons.
Motor Neurons?
Transmit information from the central nervous system to the effectors
Reflex arc?
Simple connection of neurons that results in a reflex action in response to a stimulus
Resting membrane potential?
The amount of force your nerves need to feel before your effectors feel physical pain
Synapse?
A small gap at the end of a neuron that allows a signal to pass from one neuron to the next
Neurotransmitter
Chemical secreted by neurons to carry a neural signal from one neuron to another, or from a neuron to an effector
acetylcholine?
An enzyme called cholinesterase is released into a synapse where it breaks down acetylcholine. Sarin destroyed this function by blocking the release of cholinesterase. With the buildup of acetylcholine, critical muscles enter a state of constant contraction of paralysis.
Dopamine?
Affects the brain synapses in control of body movements
