Shared Flashcard Set

Details

Human Anatomy by Saladin 1stEd
Chapter 13: Nervous Tissue
44
Anatomy
Undergraduate 1
10/13/2006

Additional Anatomy Flashcards

 


 

Cards

Term
Central Nervous System (CNS)
Definition
Consists of the brain and spinal cord, which are enclosed and protected by the cranium and vertebral column
Term
Peripheral Nervous System (PNS)
Definition
comprises all the nervous system other than the brain and spinal column; composed of nerves and ganglia- divided into sensory and motor division
Term
nerve
Definition
a bundle of nerve fibers wrapped in fibrous connective tissue
Term
ganglion
Definition
a knotlike swelling in a nerve where the cell bodies of neurons are concentrated
Term
sensory (afferent) division
Definition
part of PNS; carries sensory signals by way of afferent nerve fibers from sensory receptors to the CNS
Term
visceral sensory division
Definition
carries signals mainly from the viscera of the thoracic and abdominal cavities such as the heart, lungs, stomach, and urinary bladder
Term
somatic sensory division
Definition
carries signals from receptors in the skin, muscles, bones, and joints
Term
motor (efferent) division
Definition
carries motor signals by way of efferent nerve fibers from the CNS to effectors (cells and organs that carry out the body's responses; mainly gland and muscle cells)
Term
visceral motor devision (autonomic nervous system)
Definition
carries signals to glands, cardiac muscle, and smooth muscle; usually involuntary and the system operates on an unconscious level; the responses of this system and its effectors are visceral relfexes
Term
sympathetic division
Definition
"fight or flight" accelerating the heartbeat and incresing respiratory airflow and inhibiting digestion
Term
parasympathetic
Definition
adapt the body to a state of rest, reducing the heart rate and respiratory airflow, but stimulating digestion
Term
somatic motor division
Definition
carries signals to the skeletal muscles; this output produces muscular contractions that are under voluntary control as well as involvuntary muscles contractions called somatic reflexes
Term
nerve cell or neuron
Definition
the functional unit of the nervous system; neurons carry out the system's communicative role
Term
3 physiological properties of neurons
Definition
excitability (irritability), conductivity, secretion
Term
sensory (afferent) neurons
Definition
specialized to detect stimuli such as light, heat, pressure, and chemicals, and to transmit information about them to the CNS; neurons can begin anywhere, but end in the brain or spinal cord
Term
interneurons (association neurons)
Definition
lie entirely within the CNS; they receive signals from many other neurons and carry out the integrative function of the nervous system; process store and retrieve information and "make decisions" about how the body responds to stimuli
Term
motor (efferent neurons)
Definition
send signals predominantly to muscle and gland cells, the effectors that carry otu the body's responses to stimuli; called motor because most of them lead to muscle cells
Term
soma or cell body
Definition
soma=body the control center of the neuron; has a single centrally located nucleus with a large nucleolus
Term
neurofibrils
Definition
the cytoskeleton of a neuron made of dense microtubules
Term
dendrites
Definition
thick processes that radiate from soma; primary site for receiving signals from other neurons
Term
axon hillock
Definition
part of the soma to which the axon attaches
Term
axon (nerve fiber)
Definition
specialized nerve fiber for rapid conduction of the nerve signals to points remote from the soma
Term
axoplasm
Definition
cytoplasm in the axon
Term
axolemma
Definition
membrane of the axon
Term
terminal arborization
Definition
an extensive network of fine braches at the distal end of the axon
Term
synaptic knob (terminal button)
Definition
a swelling that forms a junction (synapse) with a muscle cell, gland cell, or another neuron
Term
multipolar neuron
Definition
have one axon and tow or more usually many dendrites; most common type of neuron
Term
neuroglia or glial cells
Definition
protect the neurons and aid in their function; bind neurons together;
Term
oligodendrocytes
Definition
CNS resemble an octopus; form myelin in brain and spinal cord
Term
astrocytes
Definition
CNS cover brain surface and nonsynaptic regions of neurons; stimulate formation of blood-brain barrier; remove neurotransmitters and K+ from extracellular fluid (ECF) of brain and spinal cord; help to regulate composition of ECF; form supportive framework in CNS; form scar tissue to replace damaged nervous tissue
Term
ependymal cells
Definition
CNS line cavities of brain and spinal cord; secrete and circulate cerebrospinal fluid
Term
microglia
Definition
CNS phagocytize and destroy microorganisms, foreign matter, and dead nervous tissue
Term
schwann cells
Definition
PNS form neurilemma around all PNS nerve fibers and myelin around most of them; aid in regeneration of damaged never fibers
Term
satellite cells
Definition
PNS surround somas of neurons in the ganglia; function uncertain
Term
myelin sheath
Definition
an insulating layer around a nerve fiber, formed by oligodendrocytes in the CNS and Schwann cells in the PNS; consists of plasma membranes of glial cells
Term
myelination
Definition
the formation of myelin
Term
nodes of Ranvier
Definition
gaps btw the myelin sheath segments
Term
internodes
Definition
the myelin-covered segments of neurons
Term
action potential
Definition
a rapid voltage change in which a plasma membrane briefly reverses electrical polarity; has a self-propagating effect that produces a traveling wave of excitation in nerve and muscle cells
Term
nerve signal
Definition
a wave of action potentials traveling down the axon
Term
synapse
Definition
meeting btw a neuron and any other cell
Term
chemical synapse
Definition
a junction at which the presynaptic neuron releases a neurotransmitter to stimulate the postsynaptic cell
Term
parts at the synapse
Definition
synaptic knob ->synaptic cleft ->synaptic vesicles
Term
electrical synapse
Definition
adjacent cells are joined by gap junctions that allow ions to diffuse directly from one cell into the next ex: cardiac muscle cells
Supporting users have an ad free experience!