The human nervous system Flashcards
What is homeostasis?
When the body regulated its internal conditions as a reaction from external and internal changes to the environment.
What are some internal conditions homeostasis tries to regulate?
Body temperature
Water content
Glucose concentration.
What are receptors?
Cells that detect stimuli from the internal or external environment and send impulses.
What are coordination centres?
Areas which receive the information from the receptors and plan out the course of action to bring about balance again , they send signals and impulses to the effectors and usually involves the brain and spinal cord.
What are effectors?
Muscles or glands that receive impulses from the coordinators to carry out a response to create the optimum conditions for the cells by contracting or excreting.
What is the importance of the nervous system?
To find food, a mate and to survive.
What is the coordinator in the human body?
CNS (Central Nervous System)
What is the simplified nervous system? (in terms of using keywords)
- Stimuli
- Receptor
- Sensory neurone
- CNS
- Motor neurone
- Effector
- Response
What are the differences/similarities between sensory/relay and motor neurones?
Sensory neurones transmit impulses from the receptors to the CNS whereas motor neurones transmit impulses from the CNS to the effectors.
Both sensory and motor neurones have an axon which transmits electric impulses long distances in short times and a myeline sheath which insulates the axon to increase the rate of which they are transmitted. Whereas relay neurone only have a cell body with its nucleus and dendrites coming out of it.
Sensory neurones have a cell body containing the nucleus that is connected to the axon mid way, whereas motor neurones have their cell body and nucleus on one side of the neurone.
What are relay neurones and where are they found?
Neurones which transmit impulses from sensory neurones to motor neurones mostly in the spinal cord or brain.
What is the nervous system made of?
The central nervous system (the brain and spinal cord) and the Peripheral nervous system (nerves, receptors, effectors)
What Is a synapse?
A gap junction between neurones which allows electrical signals to be carried to other nerve/tissue cells.
What is a reflex?
An involuntary automatic rapid actions which intends to keep the body from harm to survive.
What is a reflex arc made of?
Sensory, relay and motor neurones.
How does an electric impulse get carried across a synapse between nerves?
Electric impulse reaches the axon terminal which there are synaptic vesicles containing neurotransmitters. The electric impulses stimulates the vesicles to release the neurotransmitters into the synapse where they diffuse across the gradient to the receiving receptor which triggers an impulse on the other neurone. Once the impulse is initiated the neurotransmitter gets absorbed again or reused.
