Chapter 4 - Anatomy Flashcards
Nerve
bundle of axons in PNS
Tract
bundle of axons in CNS
Ganglion
collection of neuron cell bodies in PNS
Nucleus
collection of neuron cell bodies in CNS
White matter
brain region largely occupied by tracts, CNS, white because its myelinated
Grey matter
brain regions largely occupied by cell bodies, grayish color because aren’t myelinated
fiber
axon
spinal nerves
31 pairs in human
Types of spinal nerves:
cervical, thoratic, lumbar, sacral, coccygeal
Cervical
8 pairs, the most rostral, anterior, neck region
thoratic
12 pairs, chest cavity
lumbar
5 pairs, abdominal-like region
sacral
5 pairs, lower body
coccygeal
1 pairs, comes off tailbone
dermatome
region of skin area innervated by particular spinal nerve
dorsal roots
sensory portion of nerve that branches close to the cord and enters it dorsally (on backside)
dorsal root ganglia
in PNS, next to spinal cod, ganglia for each pair of nerves; swellings close to the dorsal cord that house the cell bodies of the axons in dorsal roots
dorsal horn
gray matter in dorsal core of spinal cord that contains the cell bodies on which collaterals or dorsal root axons synapse
ventral roots
gray matter in ventral core of spinal cord that contains cell bodies of motor neurons supplying axons in peripheral nerves
How many cranial nerves?
12
Cranial nerves
similar to spinal nerves except it connects head receptors and effectors directly to brain; each nerve numbered based on point of entry
How many nerves devoted to movement of eye muscles
3
How many nerves devoted to taste?
3
Some cranial nerves except which carry axons that are part of AutonomicNS
the vagus
sympathetic
contribute to physiologial response to emergency, potentially life-threatening situations; fight-or-flight
parasympathetic
helps to maintain relatively steady-state in basic bodily functions
sympathetic functions
increase heart rate, increases respiration, increases blood pressure, increases sweating, dilates pupils, takes energy away from digestion
parasympathetic functions
decreases everything, constricts pupils, promotes digestion
polygraph measures what?
respiration, heart rate, blood pressure, galvanic skin response (activation of sweating)
meninges
3-layer sac encasing brain and spinal chord
Dura mater
outer most layer
arachnoid
middle layer. cerebral spinal fluid fills space underneath
pia mater
inner most layer
Ventricles
cavity section
Lateral Ventricles
located in core of each cerebral hemisphere; filled with cerebral spinal fluid
3rd ventricle
receives fluid from lateral ventricles, located along midline separating large portion of diencephalon.
cerebral aqueduct
tube-like structure in midline of midbrain and hindbrain connecting 3rd and 4th ventricles
4th ventricle
located along midline of hindbrain. cerebral spinal fluid flows out of here by 2 routes: central canal of spinal cord, and subarachnoid space
Central canal
tube-like structure in core of spinal cord
Cerehrospinal fluid
filtrate of the blood made by cells lining ventricles
choroid plexus
cells lining the ventricle; mostly water and is isotonic with blood plasma
Hydrocephalus
condition in which CSF is obstructed at cerebral aqueduct during gestational development. Ventricles expand causing pressure on forebrain and results in mental retardation
medulla
critical; control respiration, heart rate, visceral reflexes (salivation, vomiting, coughing, gagging, swallowing, and chewing). receives sensory input from several cranial nerves
reticular formation
network of cells, important in general arousal and some brainstem reflexes. involved in control of movement
pons
area of fibers destined for cerebellum, crossing from one side of the brain to the other
cerebellum
involved in sensorimotor integration, motor timing, balance, learning
tectum
involved in auditory and visual procession. includes superior colliculus and inferior colliculus
substantia nigra
nucleus contains dopaminergic cells that project to the basal ganglia. cells degenerate in Parkinson’s disease
thalamus
sensory processing. all sensory systems, except olfactory, for synapse in thalamus before projecting to cortex
hypothalamus
performs homeostatic functions (feeing, drinking, etc)
olfactory bulbs
involved in smell. considered part of limbic system
limbic system
surrounds brainstem, includes hippocampus, amygdala, cingulate gyrus. olfactory bulb and hypothalamus, important in memory, emotional and motivated behaviors
basal ganglia
subcortical structures involved w/ motor planning. 3 major structures: caudate nucleus, putamen, globus pallidus
hippocampus
large structure between thalamus and neocortex, very important role in memory
neocortex
invaginated structure on surface of brain. higher order processing of sensory information, sensorimotor integration, language, and motor control. important in typically human behavior
corpus callosum
major fiber tract, axons cross from one cerebral hemisphere to the other,
anterior commisure
similar to corpus callosum but smaller
cerebral neocortex
ridges of neocortex are gyri and grooves are sulci
significance of invaginated structure
increased surface area
how many layers in neocortex composed of
6
4 lobes of the brain
frontal, parietal, temporal, occipital
Frontal
planning of movements, memory, emotions
parietal
body sensations
temporal
hearing advanced visual processing
occipital
vision
computerized axial tomography (CAT)
map brain areas, requires exposure to x-rays
magnetic resonance imaging (MRI)
map areas in detail, using magnetic fields
electroencephalograph (EEG)
records from scalp, measures by ms, low resolution on location of signal
evoked potentials
similar to EEG, in response to stimuli
Magnetoencephalograph (MEG)
similar to EEG, measures magnetic fields
Positron emission Tomograph (PET)
measures changes over time and location but requires exposing brain to radiation
Functional Magnetic Resonance Imaging (fMRI)
measures changes over about 1 second, identifies location within 1-2 mins, no use of radiation
lesion
controlled damage in lab animals
ablation
removal of brain area
gene-knockout
effects wherever that gene is active
transcranial magnetic stimulation
intense application temporarily inactivates a brain area
Stimulating electrodes
invasive, used with lab animals, seldom humans
Transcranial magnetic stimulation
brief, mild application activates underlying brain area