1. Introduction Flashcards
what are the three main functions of the nervous system?
- controls and coordinates other organs and systems in the body
- allows us to sense our environment and make decisions based on what is tells us
- controls and coordinates our muscles and movements
what are the two main cell types found in the nervous system?
neurons and glial cells
throughout evolution there have been trends towards:
1) bilateral symmetry
2) specialized function of individual neurons
3) cephalization
what type of symmetry does the CNS have?
bilateral symmetry
in arthropods, each segment of the ventral nerve cord houses:
one ganglion
in the spinal cord, cell bodies are found in the in the _____, and they are not _____
gray matter, myelinated
what makes white matter white?
because of the myelinated axons
how many segments are in the cervical region of the spinal cord?
eight
how many segments are in the thoracic region of the spinal cord?
12
how many segments are in the lumbar region of the spinal cord?
5
how many segments are in the sacral region of the spinal cord?
5
how many segments are in the coccygeal region of the spinal cord?
1
which parts of the spinal cord receive sympathetic nerves?
the thoracic and lumbar (L1-L3) regions
what are the two main parts of the peripheral nervous system?
somatic and visceral/autonomic
- involves all spinal nerves that innervate the skin, joints and muscles
- under voluntary control
- motor neuron cell bodies (spinal cord)
- sensory neuron cell bodies (dorsal root ganglion)
these are all characteristics of the:
somatic nervous system
- neurons that innervate internal organs, blood vessels, glands
- control smooth muscle in blood vessels, intestines, cardiac muscle
these are all chracteristics of the:
visceral/autonomic nervous system
the _____ motor system controls skeletal muscle while the _____ motor system controls involuntary functions mediated by smooth muscle, cardiac fibers, and glands
somatic, visceral/autonomic
the major controlling centres of the visceral/autonomic motor system is the:
hypothalamus and brainstem tegmentum
located outside of the spinal cord and extend from the uppermost thoracic segments (T1) to the upper lumbar segments (L3)
sympathetic ganglia
sympathetic ganglia hose the cell bodies of sympathetic (postganglionic) motor neurons that:
innervate smooth muscle, cardiac, muscle, and glands
sympathetic ganglia are located close to the:
spinal cord
sympathetic preganglionic neurons use _____ as a neurotransmitter
acetylcholine
sympathetic postganglionic neurons use _____ as a neurotransmitter at their _____
norepinephrine, peripheral targets
activation of the sympathetic nervous system leads to:
- pupil dilation and eyelid retraction
- constriction of blood vessels in the skin and gut
- hair standing on end
- bronchi dilation
- heart rate acceleration
- stimulates adrenal medulla to release epinephrine and norepinephrine
parasympathetic ganglia are located close to the:
peripheral target tissue (further away from the spinal cord than sympathetic ganglia)
the parasympathetic ganglia receive information from the ____ and ____ parts of the spinal cord
brainstem (CN III, VII, I, and X), sacral (S2, 3, and 4)
parasympathetic ganglia house the cell bodies of motor neurons that innervate:
smooth muscle, cardiac muscles, and glands
parasympathetic preganglionic neurons use _____ as a transmitter
acetylcholine
parasympathetic postganglionic neurons use _____ as a transmitter at their peripheral target
acetylcholine
activation of the parasympathetic system leads to:
- pupil constriction
- dilation of blood vessels in the skin and gut
- bronchi constriction
- heart rate slowing
the brain has three major parts:
the borebrain, midbrain, and hindbrain
what are the five subdivisions of the brain?
- telencephalon
- diencephalon
- mesencephalon
- myelencephalon
both mammals and birds have large:
forebrains and cerebellums
the lobes of the brain are named after:
the bones they lie under
marks the posterior boundary of the frontal lobe
the central sulcus
what are the four main features of the cerebral cortex?
1) cell bodies of cortical neurons are arranged in layers or sheets
2) layer of neurons closest to the surface is separated from the pia mater by a zone that lacks neurons
3) at least one cell layer contains pyramidal cells that emit large dendrites that extend up to layer one
4) there are different types of cortex based on architecture
a cytoarchitectural map of the neocortex distinguishes many different:
zones or “areas” that serve different functions
produces the myelin sheath that surrounds axons in the peripheral nervous system (one cell furnishes one small axon segment)
Schwann cells
produces the myelin sheath that surrounds axons in the central nervous system (one cell furnishes the axons of many neurons)
oligodendrocytes
the most numerous of the glia with irregular star-shaped bodies with long processes called endfeet
astrocytes
these cells contact the surface of neurons, blood vessels, and endothelial cells in the blood-brain barrier
astrocytes
