Nervous System Flashcards
What are the functions of the nervous system?
1, Maintaining homeostasis : regulates and coordinate physiology
- Receiving sensory input: Motor internal and external stimuli
- Integrating information. Brain and spinal cord process sensory input and initiate responses
- Controls muscles and glands
- Establishing and maintaining mental activity: Consciousness, thinking, memory, emotion.
What are the two divisions of the nervous system?
Central nervous system: Brain and spinal cord
Peripheral nervous system: All neurons and every other component outside of CNS
What are the two divisions of the PNS?
1) Sensory (afferent) division transmits sensory information to CNS
2) Motor (Efferent) divisions carry signals from CNS that allow the body to respond to changed conditions.
What are the two divisions of the Motor (efferent) division?
a) Somatic nervous system- Carries signals from CNS that allow the body to respond appropriately to changed conditions.
- Effectors: Skeletal muscles
- Single- neuron system
b) Autonomic nervous system- Carries out involuntary responses.
- Effectors: Smooth muscle, cardiac muscle, several glands
- Two neuron systems: (1) CNS to ganglion (2) ganglion to effector
What is a ganglion and where is it located?
a collection of neuronal bodies found in the voluntary and autonomic branches of the peripheral nervous system
What is the function of the sympathetic nervous system? What division of the nervous system is it a part of?
Apart of the peripheral nervous system and initiates the body fight or flight. Prepare s organs for stressful situations.
What is the function of the parasympathetic system? What division of the nervous system is it located in?
This is apart of the peripheral nervous system. “rest and digest” lets the body conserve and restore energy.
What are the two main cell types in nervous tissue?
Neurons- Electrically excitable cells of the nervous system
Glial cells- Supportive cells
*Non-neuronal cells of CNS and PNS
* Don’t produce electrical signals
What parts make up the structure of a Neron
- Dendrites: Cell extensions that receive information from the other neurons, often with extensions called dendritic spines.
- Cell body (Soma)- Typical cell functions such as protein synthesis and housekeeping; contains nissl bodies (Rough ER) which is the main site of protein synthesis
Structure of an Axon
- Axon: Conducts signal away from the cell body
- Axon hilock+ Initial segment= trigger zone, where electrical signals (AP) are generated,
Axolemma: axon plasma membrane
Axoplasm: axon cytoplasm
What neuron structure is the synapse part of? What is its function?
The axon
Synapse- Point of contact between axon ending and its effector?
Where do axons end? What do those endings contain?
Axons end at presynaptic terminals, which hold synaptic vesicles containing neurotransmitters.
Describe the axon transport mechanism
Axoplasm is moved from the cell body toward axon terminals.
-Can move cytoskeletal proteins and organelles.
The opposite is also true…
Damaged organelles, recycled plasma membranes, and substances taken in by endocytosis can be transported up the axon to the cell body.
Critical for the normal function of neurons.
Types of Neurons
Sensory- Carry signals from the environment to the CNS
Interneurons- Pass signals from one neuron to another within another CNS
Motor neurons- Sends signals to effector cells in muscles or glands
Nerves- are bundles of axons in the PNS
Glial cells of CNS: Astrocytes
Extensions form foot processes that cover surfaces of neurons, blood vessels, and pia mater.
Produce chemicals that promote tight junctions to form blood-brain barrier.
Regulate what substances can reach CNS from blood
