Week 8 - Nervous System Flashcards
What are the 3 basic functions of the nervous system?
three basic functions:
* sensory (input),
* integrative (process),
* and motor (output).
What are the two main subdivisions of the nervous system?
- CNS
Brain & Spinal Cord - PNS
All nervous tissue outside of the CNS
Nerves, ganglia, enteric plexuses & secretory receptors
What does the CNS do?
- Processes sensory information
- Source of thoughts emotions and memories
- Stimulate muscles to contract, glands to secrete
What is 3 systems make up the PNS? of?
Somatic Nervous System
Autonomic Nervous System
Enteric Nervous System
What does the Somatic Nervous System do?
- Sensory neurons that conveys info to the SNS from
somatic receptors in head body and limbs
receptors for vision, hearing, taste and smell - Motor neurons that conduct impulses from the CNS to the skeletal muscles only
What does the Autonomic Nervous System do?
Sensory neurons that convey information to the CNS from receptors in visceral organs eg stomach and lungs
motor neurons that conduct nerve impulses from CNS to smooth muscles, cardiac mucles and glands
Motor part of the ANS has two divisions - sympathetic and parasympathetic, what’s the difference?
Sympathetic - fight or flight
Parasympathetic - rest and digest
What is the Enteric Nervous System and what 2 things does it monitor and what 2/3 things does it control?
Brain of the gut
Sensory neurons monitor
chemical and functional changes wihtin GI eg stretching of walls)
Motor neurons control
secretion of GI tract organs (eg stomach acid) & activities of GI endocrine cells (secrete hormones)
contractions of GI tract smooth muscle,
What’s the difference between neurons and neuroglia?
Neurons form the complex processing networks within the brain and spinal cord, neurons also connect all regions of the body to the brain and spinal cord.
Neuroglia support, nourish, and protect neurons, and maintain the interstitial fluid that bathes them.
What are the three parts of a neuron?
- Cell body
- Dendrites
- Axon
What’s the difference between a dendrite and an axon?
Dendrites recive info
Axons send it
What is a synapse?
site of communication between two neurons or between a neuron and an effector cell
Where are synaptic vesicles that store a chemical called a neurotransmitter located?
tips of some axon terminals swell into synaptic end bulbs ; others exhibit a string of swollen bumps called varicosities
How are neurons classified, structurally?
- Multipolar neurons usually have several dendrites and one axon
- Bipolar neurons have one main dendrite and one axon
- Unipolar neurons have dendrites and one axon that are fused together to form a continuous process that emerges from the cell body
How are neurons classified, functionally?
- Sensory (or afferent ) neurons - most are unipolar
- Motor (or efferent ) neurons convey action potentials away from the CNS to effectors (muscles and glands) in the periphery (PNS) through cranial or spinal nerves - generally multipolar in structure.
- Interneurons are mainly located within the CNS between sensory and motor neurons (processing the information and then eliciting a response) mainly multipolar
What are the four types of CNS neuroglia?
astrocytes
oligodendrocytes
microglia
and ependymal cells
What are the two types of PNS neuroglia that surround axons and cell bodies?
Scwann cells
Satellite cells
What’s the difference between myelinated and unmyelinated?
- Axons that are myelinated are covered in a myelin sheath which electrically insulates the axon of a neuron and increases the speed of nerve impulse conduction.
- Axons without such a covering are said to be unmyelinated
What is the difference between a nerve and a tract?
A nerve is a bundle of axons in the PNS
A tract is a bundle of axons located in the CNS