Week 1 Neuro Flashcards
(57 cards)
What are the two main divisions of the nervous system
1) CNS: Brain and spinal cord
2) PNS: Peripheral nerves and ganglia
What two things do neurons do?
1) Conduct “electrical” signals (action potentials)
2) Release “chemical” signals (neurotransmitters)
What are the three functions of the nervous system?
1) Control of movement and some functions using motor nerves
2) Detection of external stimuli using sensory nerves
3) Association neurons in the CNS create connections like little highways, enabling behaviour, thoughts and emotions
What 3 components do neurons break down into?
Cell body, dendrites, axons
What are dendrites?
Recieves info from sensory receptors or other cells and sends it to the cell body
What are axons?
Delivers electrical signals from the cell body to another neuron or an effector group, which is a muscle or gland
How do neurons function?
Neurons move info quickly by sending electrical signals (action potential) from one location to another, and converting them to chemical signals at a synapse
What is the functional classification of neurons based on?
Based on the direction in which neurons conduct impulses
What do sensory or afferent neurons do?
Conduct impulses from sensory receptors (PNS) into the CNS
What do motor or efferent neurons do?
Conducts impulses from sensory receptors (PNS) out of the CNS, and to effector organs like muscles or glands
What do association or interneurons do?
Located in the CNS, they help integrate and coordinate CNS functions
What defines somatic motor neurons?
Reflex and voluntary control of skeletal muscles
What defines autonomic motor neurons?
Involuntary control of smooth muscle, cardiac muscle and glands
What can autonomic neurons be further subdivided as?
Can be further subdivided as sympathetic and parasympathetic
What are the 3 steps in a simple neural circuit?
1) Sensory, Afferent (carry signals to CNS).
2) Motor or Efferent (carry signals from CNS).
3) Interneurons - send signals from one neuron to another
What are the 4 types of neurons?
1) Pseudopolar (unipolar)
2) Bipolar
3) Multipolar
4) Anaxonic
What are pseudopolar (unipolar) neurons?
Sensory neurons with one process that splits into two ( meaning single extension divides into two branches, one branch acts like a dendrite to recieve signals and the other acts like an axon to send signals)
What are bipolar neurons?
Found in retina and cochlea, with two processes, meaning it has one dendrite and one axon to send signals, on opposite sides of the cell body.
What are multipolar neurons?
Most common type, used for motor and association functions, with many dendrites and one axon
What are anaxonic neurons?
Found in some CNS neurons, with no clear axon
What are the supporting cells in the PNS?
Schwann cells and satellite cells
What are schwann cells?
Supporting cells in the PNS, they form myelin sheaths around PNS neuron axons
What are satellite cells?
Supporting cells in the PNS, they support neuron cell bodies by wrapping around them, within ganglia of the PNS
What are the supporting cells of the CNS?
Oligodendrocytes, Microglia, Astrocytes, Ependymal cells