Central Nervous System pt 1 Flashcards
what are the basic parts included in the CNS
brain and spinal cord b/c it is the central nervous system
describe the physical support of the CNS
extensive bone and connective tissue, CSF
describe the meninges
- type of membrane connective tissue continuous to spinal cord
- 2 names to distinguish regions (cranial [head] and spinal [spinal cord])
what are the layers of the meninges, and mention their location relative to another
- dura mater (outer)
- arachnoid mater (middle)
- pia mater (inner)
what is the purpose of arachnoid villi
they reabsorb cerebrospinal fluid
what is CSF
cerebrospinal fluid which cushions and circulates in and around CNS for a regulated extracellular environment for the neurons
compare plasma and CSF
extremely similar except CSF:
- lacks proteins
- high in Cl- ions
- low in Ca+2, K+ ions
where does the CSF circulate
through ventricles and in subarachnoid space (between pia mater and arachnoid membrane)
- in and around brain
what are the spaces called within the brain
- lateral ventricles
- third ventricle
- fourth ventricle
what produces CSF
choroid plexus
how is that our brains don’t ‘explode’ from too much CSF
rate of production by choroid plexus is same as rate of absorption by arachnoid villi into blood
what is a stroke
decreased blood supply to brain, leading to organ failure, paralyzation, and possible death
describe the types of strokes
- occlusion of cerebral blood vessel
- hemorrhage from cerebral blood vessel
why is blood crucial for the brain
dependent for its energy and nutrients which makes it sensitive to interruptions in blood flow
the brain has a _______ metabolic rate
high
what is the blood-brain barrier
physical barrier between blood and CSF b/c of tight junctions between the endothelial cells of capillaries
what is the purpose of the blood brain barrier
protect CNS from possible harmful substances in blood due to tight junctions
which molecules are able to diffuse through capillaries in brain, which aren’t?
hydrophobic molecules can diffuse, but hydrophillic molecules cannot due to blood brain barrier
describe the main difference(s) between a typical capillary and brain capillary
typical cap. has pores due to space between endothelial cells, whilst brain cap. has tight junctions
how can select hydrophillic solutes diffuse through the blood-brain barrier, include examples of solutes
carrier mediated transport; glucose, insulin, amino acids, choline
what are the types of communication fibres in the brain
association, commissural, projection
what is grey matter; what types of actions does it focus on
- butterfly shape in brain
- has axon terminals, neural cell bodies, dendrites, and nerve synapses
- focuses more on motor actions
what is white matter
- has bundled myelinated axons
- sensory actions
function of association fibres
connect one part to another in one half of the brain (either left or right hemisphere)
function of commissural fibres
connect one area of the brain to the same area across the hemisphere
function of projection fibres
connect one area of brain to a lower area OR to the spinal cord
- will often cross sides
- neurally connected
what is corpus collosum
connects right and left sides of brain (where you can find commissural fibres)
what are the functional halves of gray matter
dorsal (sensory) and ventral (motor)
what is one way to identify which side is the dorsal horn and which is the ventral horn on a diagram
dorsal side will have swelled cell body
what does the dorsal horn consist of
axon terminal, swelled cell body, dorsal root, dorsal root ganglion, afferent axons
what does the ventral horn consist of
cell body, efferent axon, ventral root
what axon(s) does a spinal nerve have
afferent and efferent (therefore called mixed nerves)
white matter is able to form communication between different levels of spinal cord and brain through__________. what are the types
tracts; ascending (spinal to brain) and descending (brain to spinal)
explain what the lateral spinothalamic tract may communicate
getting hurt and feeling pain
explain what the pyramidal tracts (later and anterior) may communicate
cramping of finger that needs to be stretched
describe the role of analgesic systems during stress
blocks synaptic transmission between pain-transmitting afferent neuron and interneurons in spinal cord
-blocking of pain signal to brain prevents perception of pain stimulus (survival mechanism)
what are the main parts of the brain structure
forebrain, cerebellum, brainstem
what are the subdivisions of the forebrain
cerebrum and diencephalon (which divides into thalamus and hypothalamus which has suprachiasmatic nucleus)
what are the subdivisions of the brainstem
midbrain, pons, medulla oblongata
describe the cerebellum and its functions
- bilaterally symmetrical, has cortex and nuclei
- motor coordination, balance, hand-eye coordination
what does the nuclei refer to in the context of neural biology and neuroscience
cluster of neurons in CNS
describe the brainstem; what type of a processing centre is it
- connector of forebrain and cerebellum to spinal cord
- processing center for most pairs of cranial nerves, reticular formation
what do the midbrain, pons, and medulla oblongata connect to
forebrain; cerebellum; spinal cord, respectively
what is reticular formation; what is it important for
diffusion network of nuclei which is important in sleep-wake cycles, arousal of cortex and consciousness
what does the ANS control
regulation of involuntary functions
what is the cerebral cortex
outermost portion of cerebrum with a thin, convulated layer of gray matter
describe gyri and sulci
gray matter for cerebral cortex; gyri = bumps, sulci = grooves
describe the neural processing in the cerebral cortex
highest level:
- perception of environment
- formulation of ideas
- recall of past events
- command of body movement
- complex integrating center
how can we divide the cerebral cortex and their relative locations
frontal lobe (front away from brainstem), parietal lobe (top of rounded part), occipital lobe (very back of brain), temporal lobe closest to brainstem and cerebellum
the cerebral cortex can be divided into functional areas that may cross lobes and cause it to have multiple functions. what are the main subdivisions we are to focus on?
broca’s area, primary motor cortex, primary somatosensory cortex, primary visual cortex, wernicke’s area
what is the function of the primary motor cortex
voluntary movement
what is the function of broca’s area
speech formation
what is the function of the primary somatosensory cortex
somesthetic sensations and proprioception
what is the function of the primary visual cortex
vision
what is the function of Wernicke’s area
language comprehension
what is the topographic organization of the cerebral cortex
based on mapping the brain by function; the brain is divided into the sensory cortex and the motor cortex and human body parts are aligned along the edge. their size describe how much of a focus it is for that area
what are cortical association areas, function
part of the brain that performs complex processing, requiring information from primary cortical areas for integration
- ex walking in the park and deciding whether to help someone based on how they call for help
what is brain lateralization, is it absolute
right and left brain have their ‘specializations’; not absolute b/c can be opposite for some people, sensory and motor pathways cross
what is generally said to be controlled by right side of brain, left side?
creativity, spatial perception
logic, analytical abilities, language
what are the important parts of the diencephalon
thalamus, hypothalamus, suprachiasmatic nucleus
what is the function of the thalamus
- integrates of sensory and motor info
- sensory relay to cortex
what is the function of the hypothalamus
integrating sensor for motor and sensory info
- communicates with ANS
- food intake
- thermoregulation
- neuroendocrine
what is the purpose of the suprachiasmatic nucleus
circadian rhythms, pineal gland
what are the structures of the limbic system
amygdala, hippocampus, fornix, cingulate gyrus, parts of the thalamus and hypothalamus
what are the functions of the limbic system
learning, emotions, behaviour
