Chapter 4 Flashcards
Central Nervous System (CNS)
The brain and spinal cord
Peripheral Nervous System (PNS)
Connects the brain and spinal cord to the rest of the body - made up of somatic and autonomic nervous systems
Autonomic Nervous System
Part of the PNS, controls the heart, intestines, and other organs; some cell bodies are in brain/spinal cord and some in clusters along sides of spinal cord; has two parts: the sympathetic and parasympathetic nervous sytems
dorsal
toward the back
ventral
toward the stomach
planes of the head
horizontal, saggital and coronal
anterior
toward front end
posterior
toward back end
superior
above another part
inferior
below another part
lateral
away from midline
medial
toward midline
proximal
approximately close to point of origin/attachment
distal
more distant to point of origin/attachment
ipsilateral
on same side of body
contralateral
on opposite sides of body
Spinal cord
part of CNS within spinal column; communicates with all sense organs and muscles except those of the head
Bell-Magendie Law
entering dorsal roots (axon bundles) carry sensory information and exiting ventral roots carry motor information
dorsal root ganglia
Cell bodies of the sensory neurons in clusters of neurons outside the spinal cord
gray matter
densely packed material made up of cell bodies and dendrites (centre of spinal cord made up of this)
white matter
mostly made up of myelinated axons - messages sent from gray matter to brain /other parts of spinal cord through white matter
Sympathetic Nervous System
A network of nerves that prepare the organs for vigorous activity, consists of chains of ganglia just to the left and right of the spinal cord’s central regions (the thoracic and lumbar areas) - sympathetic axons prepare the organs for “fight or flight” by increasing breathing and heart rate and decreasing digestive activity
Parasympathetic Nervous System
Long pre-ganglionic axons extend from cord to parasympathetic ganglia near organs - shorter post-ganglionic fibres extend into organs; facilitates vegetative, nonemergency responses - decreases heart rate, increases digestive rate, and conserves energy
Laminae
rows/layers of cell bodies separated from others by a layer of dendrites/axons (molecular, external granular, pyramidal, internal granular, internal pyramidal, multiform layer)
tract
set of cells within CNS also known as a projection
nerve
set of axons in the periphery either from CNS to muscles or glands or from a sensory organ to CNS
nucleus
cluster of neurons inside CNS
ganglion
cluster of neurons outside CNS
Hindbrain
- medulla (vital reflexes)
- pons (axons from each half cross to opposite sides)
- cerebellum (motor control, balance, muscle tone)
cranial nerves
control sensations from the head, muscle mvt of head and parasympathetic output to organs (both sensory and motor neurons)
reticular formation
descending and ascending portions - descending helps control motor areas of cord, ascending sends output to cerebral cortex and selectively increases arousal/attention
brainstem
medulla, pons, midbrain, and certain structures of forebrain
raphe system
axons to much of forebrain that modify brain’s readiness to respond to stimuli
midbrain
dwarfed middle section of brain surrounded by forebrain
tectum
roof of midbrain
colliculi
superior and inferior - swellings on each side of the tectum
tegmentum
under tectum - includes nuclei for cranial nerves 3 & 4, parts of the reticular formation, and extension of pathways between forebrain and spinal cord/hindbrain
substantia nigra
midbrain structure that gives rise to a dopamine-containing pathway that facilitates readiness for movemen
forebrain
The most prominent part of the mammalian brain. Consists of two cerbral hemispheres, one left and right
cerebral cortex
outer covering of the brain (makes up 13%) - receives sensory information; neurons in each hemisphere communicate through 2 bundles of axons (corpus callosum and anterior commisure); 6 layers of laminae lie parallel to surface of cortex
basal ganglia
group of subcortical structures lateral to the thalamus, include three major structures: the caudate nucleus, the putamen, and the globus pallidus; critical for learning and remembering how to do something, important for attention, launguage, planning, and other cognitive functions
Limbic system
Interlinked structures that form a border around the brainstem. Includes the olfactory bulb, hypothalamus, hippocampus, amygdala, and cingulate gyrus of the cerebral cortex
Thalamus
control centre of brain - pair of structures (L and R) in centre of forebrain
hypothalamus
Small area near the base of the brain just ventral to the thalamus. Damage to any hypothalamic nucles leads to abnormalities in motivated behaviors, such as feeding, drinking, temperature regulation, sexual behavior, fighting, or activity level
pituitary gland
endocrine (hormone producing) gland attached to the base of the hypothalamus by a stalk that contains neurons, blood vessels, and connective tissue
hippocampus
Large structure between the thalamus and the cerebral cortex, mostly toward the posterior of the forebrain; critical for storing certain kinds of memories
nuculus basalis
lies on the ventral surface of the forebrain, receives input from the hypothalamus and basal ganglia and sends axons that release acetycholine to widespread areas in the cerebral cortex; key part of the brain’s system for arousal, wakefulness, and attention; patients with Parkinsons’ disease and Alzheimer’s disease have impairments of attention and intellect because of inactivity or deterioration of their nucleus basalis
ventricles
Four CSF-filled cavities within the brain - 1 large in each hemisphere that connect to a third at posterior end, fourth is in centre of medulla
CSF - Cerebral spinal fluid
Cells called the choroid plexus inside the four ventricles, a clear fluid similar to blood plasma
Meninges
Membranes that surround the brain and spinal cord
lobotomy
surgical disconnection of pre-frontal cortex from rest of brain
binding problem/large scale integration problem
question of how various brain areas combine to produce perception of a single object (damage to parietal cortex can result in binding problems)
broca’s area
part of left frontal cortex that, when damaged, affects ability to speak
ablation
removal of a brain area
lesion
damage to a brain area
gene knockout approach
biochemical method to direct a mutation to a particular gene
transcranial magnetic stimulation
magnets inactivate the neurone/brain area below (eg silencing the visual cortex will result in an inability to see but eyes will still respond to light)
optogenics
stimulation of neurons with laser light
Heschel’s gyrus
large in people good at identifying language sounds that are foreign
