Exam 3 updated 2024 with correct
answers | 2025.
nervous system
detects changes, makes decisions, stimulates muscles and glands to respond, and maintains
homeostasis
neurons
-cell type of neural tissue
-react to changes
-send nerve impulses for communication
neuroglia
-cell type of neural tissue
-surround and support neurons
-nourish neurons
-send and receive messages
-help maintain blood-brain barrier
central nervous system (CNS)
-brain and spinal cord of dorsal body cavity
-integration and control center: interprets sensory input and dictates motor output
peripheral nervous system (PNS)
-connects CNS to other body parts
-cranial and spinal nerves: extend from brain and spinal cord
sensory (afferent) division
,-division of PNS
-somatic sensory fibers: convey impulses from skin, skeletal muscles, and joints to CNS
-visceral sensory fibers: convey impulses from visceral organs to CNS
motor (efferent) division
-division of PNS
-transmits impulses from CNS to effector organs: muscles and glands
-two divisions: somatic and autonomic nervous system
functions of nervous system: sensory input
-info gathered by sensory receptors about internal and external changes
-nervous system receives info
-sensory receptors gather info by detecting changes
-info is carried to CNS
functions of nervous system: integration
-processing and interpretation of sensory input (create sensations, add to memory, produce thoughts)
-coordinates sensory info
-makes decisions on body's response to sensory info
functions of nervous system: motor output
-activation of effector organs (muscles and glands) produces a response
-decisions are acted upon
-impulses are carried to effectors
-somatic nervous system: transmits voluntary instructions to skeletal muscles
-autonomic nervous system: transmits involuntary instructions from CNS to smooth muscles, cardiac
muscle and glands
histology of nervous tissue
-highly cellular, little extracellular space
-neuroglia and neurons
nervous system cells
-structural units
-large, highly specialized cells that conduct impulses
-extreme longevity
-amitotic
-high metabolic rate: requires continuous supply of oxygen and glucose
-all have cell body and one or more processes
-vary in size and shape
-differ in length and size of axons and dendrites
-axon: transmits impulse and releases neurotransmitters
cell body
,nucleus, cytoplasm, organelles, neurofilaments, chromatophilic substance
chromatophilic substance
cell body
dendrite
-branched receptive surfaces
-in motor neurons: 100s of short, tapering, diffusely branched processes
-receptive (input) region of neuron
-convey incoming messages toward cell body as graded potentials (short distance signals)
axon
transmits impulses and releases neurotransmitters
axon hillock
axon
, collaterals
axon
axon terminal
axon
synaptic knob
axon
schwann cells
myelin sheaths
melanin pigment
useful in identifying certain brain areas and diagnosing disease