[EXAM 2] CNS Flashcards
What cells make up nervous tissue?
Neurons and Glia
What are neurons?
the functional unit of the nervous system
What are glia cells?
non-conducting support cells in contact with neurons
What systems make up the nervous system?
Central nervous system
Peripheral system
What is composed in the CNS?
Brain and spinal cord
What divisions make up the the peripheral nervous system?
Sensory Division–> Visceral Sensory Division/ Somatic sensory division
Motor Division–> Visceral Motor Division–> Sympathetic Division & Parasympathetic division & Enteric Division
–> Somatic Motor Division
What makes up a neuron?
Cell Body (soma, perikaryon) Nissl bodies Dendrites Axon Hillock Axon Myelin Sheath
What is a multipolar neuron?
many dendrites ,one axon
- from CNS to periphery (signal such as muscle to contract)
- integrative-neuron to neuron in CNS, ganglia, or special sense organs
What is a bipolar neuron?
one dendrite, one axon
-special sense organs- often the cells that translate something physical or mechanical into electrical impulse to be sent to the brain
What is a unipolar (pseudounipolar) neuron?
no dendrites, one axon
-Sensory- often found in ganglia ,carries signal from periphery to CNS
What is a anaxonic neuron?
many dendrites, no axon
What are motor neurons?
function: conduct impulses from CNS or ganglia to effector cells (muscles or glands)
Somatic efferent neurons: send voluntary impulses to skeletal muscle
Visceral efferent neurons- send involuntary impulses to smooth muscle Purkinje fibers and glands
What are interneurons?
form a network between sensory and motor neurons
What are sensory neurons?
Function: conduct impulses from the receptors or sense organs to the CNS
Somatic afferent fibers- convey sensations of pain, temperature, touch and pressure from the body surface, as well as pain and proprioception from organs within the body
Visceral afferent fibers- transmit pain impulses and other sensations from internal organs, mucous membranes, glands and blood vessels
What cells are myelinated?
Oligodendrocytes-CNS
Schwann Cell- PNS
What part of the nerve fiber do signals use to “skip” along the nerve fiber?
Node of Ranvier
Are Schwann cells myelinated?
Yes and they have extended cytoplasm
What are the two main demyelinated diseases talked about in lecture 1?
Multiple Sclerosis (Oligodendrocytes are having their myelin attacked by immune system) Guillain-Barre syndrome (Schwann cells are having their myelin attacked by immune system)
What is the order from smallest to largest of peripheral nervous tissue/connective tissue covering?
axon+myelin —> nerve fiber —> endonerium –> nerve fascicle –>perineurium–> epinerium –> nerve
Describe the difference between a chemical synapse and electrical synapse
differ morphologically and by mechanism
Chemical synapse
- Vesicles contain neurotransmitters stored in the axon terminal
- released when electrical impulse reaches the axon terminal
- bind to receptors on effector cell
- has a neural junction
Electrical synapse
-use gap junction channel and coupling potentials
What is a nucleus?
a group of neuron cell bodies in the CNS
What is a tract?
a group of nerve fibers traveling in parallel