Nervous System(Chapter 14) Flashcards
(53 cards)
1
Q
Brain
A
- major organizing and processing center of the NS
- site of consciousness, sensations,memory,intellect, coordination and control of complex muscle movements
- outer layer gray matter(cortex)=consist of nuclei of neurons,
- inner layer white matter (tracts)=consist of myelinated axons of neurons
2
Q
developmental patter of the brain
A
-brain and spinal cord arise from embryological tissue(ectoderm) beginning as a hollow, neural tube
3
Q
4 main parts of the brain
A
1) Cerebrum: largest anterior portion of brain, divided into R & L cerebral hemispheres
2) Diencephalon: (interbrain) consists of the hypothalamus, thalamus, epithalamus and the pineal gland.
3) Cerebellum: (little brain) 2nd largest part of the brain, also divided into R&L cerebellar hemispheres
4) Brainstem: (lower brain) consists of the midbrain, pons, and medulla oblongata
4
Q
Meninges(3 protective membranes that surround the brain)
-Dura Mater
A
- Dura Mater
- 2 fused layers:
- outer periosteal(endosteal) layer: adherent to cranial bone
- inner meningeal layer: 2 layers separated by space containing interstitial fluid and cerebral blood vessels, including a few large dural venous sinuses
5
Q
Dural sinuses
A
- venous channels found between layers of dura mater in the brain.
- they receive blood from the internal and external veins of the brain
- receive CSF from the subarachnoid space
- then empty into the internal jugular vein
- dural venous sinuses have no tunica media
- no valves
- csf found in subarachnoid space
6
Q
Dural folds
A
-inward extensions of dura mater that hold the brain in position and contain dural venous sinuses
7
Q
3 major dural folds
A
Falx cerebri: lies btw the 2 cerebral hemispheres(IN the longitudinal fissure)
Falx cerebelli: lies btw the 2 cerebellar hemispheres
Tentorium Cerebelli: located btw cerebrum and cerebellum(in the transverse fissure)
8
Q
Arachnoid mater
A
- Subarachnoid space- contains CSF around brain and spinal cord
- arachnoid granulations(villi)- knoblike projections of the arachnoid.
- Function: absorb CSF from subarachnoid space and empty it into sagittal sinus
9
Q
Pia mater
A
- a thin, vascular membrane that adheres to the convolutions of the brain via astrocyte processes
- supplies nutrients 02 to the surface of brain
10
Q
Cerebrum
A
-largest and most anterior portion of the brain
-consist of outer gray matter(cortex nuclei and inner white matter)
Function: site of conscious perception of somatic sensations, voluntary muscle movements, memory, intellect and personality
-somatic sensation: perssure, temp, pain, conscious memory
-R/L cerebral hemispheres
-olfactory bulbs- inferior aspect- contain sensory fibers from nose
-optic chiasma(anterior to pituitary)-optic nerves from retaina of eye cross over at optic chiasma
11
Q
gyri(gyrus)
A
- ridges or convolutions of gray matter(cortex)
- ex: precentral and post cendtral gyrus
12
Q
fissures/sulci
A
- deep/shallow grooves btw gyro of gray matter
- increase surface area of he cortex and separate each hemisphere into 4 lobes
13
Q
central sulcus
A
-btw frontal and parietal lobes
14
Q
precentral gyrus
A
- anterior to centeral sulcus
- CONTAINS PRIMARY MOTOR AREA of cerebral cortex
15
Q
lateral cerebral sulcus
A
- separates the frontal lobe from the temporal lobe
- 5th lobe lies within this sulcus
- insula-part of limbic system
16
Q
parietal-occipital sulcus
A
-separates parietal from the occipital lobe
17
Q
longitudinal fissure
A
-separates the cerebrum into r and left hemisphere, falx cerebri dura fold lies here
18
Q
postcentral gyrus
A
- posterior to the central sulcus
- contains primary somatosensory area of cerebral cortex
19
Q
transverse fissure
A
- along with tenorium cerebelli
- supports the posterior part of cerebrum
- separates the cerebellum from the cerebrum
20
Q
cerebrum(4 lobes)
A
- frontal lobe-btw central suclus and lateral cerebral fissure
- occipital lobe-posterior to parieto-occipital fissure
- partietal lobe-posterior to central sulcus(anterior to parieto-occipital lobe)
- temporal lobe- inferior to the lateral cerebral fissures
- insula-5th lobe of the brain and part of the limbic system, located beneath parts of the frontal, parietal, and temporal lobes
21
Q
Cerebral white matter tracts(3)
formed by myelinated axons
A
1) Association: transmit impulses btw gyri of same cerebral hemisphere
2) Commissural- horizontal tracts: transmit impulses btw gyri of right and left hemispheres
Ex: corpus callousum(largest), anterior and posterior commissures
3) Projection- transmit impulses from cerebrum to lower CNS(thalamus, brainstem, spinal cord)
ex: internal capsule: thick band that contains ascending and descending axons
22
Q
Function org of cerebral cortex
-sensory areas
A
-sensory areas involved in perception(conscious awareness of sensation)
23
Q
primary somatosensory area(post central gyrus, areas 1,2,3)
-sensory area
A
- receives sensory information from receptors in skin to localize points of body for light touch, pressure, pain or temp, and proprioception(join.muscle position).
- map of entire body is present here
- a larger regions of it receives impulses from lips.fingers than from the thorax or hip(sensory homunculus)
24
Q
Primary visual area( occiputal lobe, area 17)
-sensory area
A
- receieves impulses along fibers from retina via thalamus, perceives current visual image
- destruction of this area results in blindness
25
Primary Auditory area(superior temporal grus)
| -sensory area
- superior part of the temporal lobe
- receives impulses from cochlea(inner ear)
- via thalamus for hearing sounds(pitch and rhythm)
- association area recognizes sounds such as speech, music or noise
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Primary Olfactory Area(medial surface of temporal lobe)
| -sensory area
- receives impulses from olfactory receptors in nasal cavity for recognition of various odors
- tumors in the area causes client to experience pleasant or unpleasant ordors
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Primary gustatory area(postcentral gyrus in parital cortex)
| -sensory area
-receives impulses from taste buds and is involves in gustatory perception and taste discrimination
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Function org of cerebral cortex
| -motor area
-control execution of voluntary movements
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primary motor area(AREA 4- precentral gyrus of frontal lobe)
| -motor area
- has map of entire body
- controls voluntary movement of skeletal muscle groups
- more cortical area devoted to fingers than toes(motor homunculus)
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Motor (Brocas) speech area(AREA 44.45)
| -motor area
- plannining and production of speech
- control muscles of larynx,pharynx,mouth and breathing muscles
- CVA or damage in this area results in confluent aphasia or expressive aphasia(inability to tom or articulate words
- nonfluent aphasia
- expressive aphasia
- motor aphasia
- broca=brooken speech(way to remember)
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Function org of cerebral cortex
| -association area
- large areas pf all 4 lobes anterior to motor area
- connected with one another by association tracts.
- deal with integrative functions such as memory, emotions, reasoning, will, judgement, personality traits, and intelligence
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Somatosensory association area
| -association area
- posterior to the somatosensory area
- determine shape and texture of objects by feeling it
- determine orientation of one object to another
- relationship of one body part to another
- enables compare current sensation with past experiences
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Premotor area
| -association area
- association area anterior to primary motor area
- controls learned motor skills of complex and sequential nature and causes contraction of specific groups of muscles in a specific sequence
- typing, playing piano, writing or reading
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wernicke area(left temporal/parietal lobes)
-association area
```
- left temporal and parietal lobes
- interprets the meaning of speech
- understanding
- verbal communication by adding emotions, such as joy or anger, to spoken words
- CVA or damage in this area results in fluent aphasia or receptive aphasia, inability to understand spoken or written words
- word salad: string of words with no meaning
- person can speak but cannot arrange words in coherent fashion
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Prefrontal cortex(frontal association area)
- anterior to frontal lobe
- involve reasoning, intelligence, judgement, planning for the future
- conscience, recall of information
- complex learning, foresight, intuition, mood, development of abstract ideas and personality
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Common integrative area
-functions by integrating information to form thoughts and dictate an appropriate response
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Hemispheric lateralization(LEFT)
- receives somatic sensory signals from and controls muscles on right side of body
- controls muscles on right side of body
- reasoning
- numerical and scientific skills
- ability to use and understand sign language
- spoken and written language
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Hemispheric lateralization(RIGHT)
- Receives somatic sensory signals from and controls muscles on left side of body
- musical and artistic awareness
- space and pattern perception
- recognition of faces and emotional content of facial expressions
- generating emotional content of language
- generating mental images to compare spatial relationships
- identifying and discriminating among odors
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Basal Nuclei
- paired masses of gray matter in each cerebral hemisphere
- globus pallidus, putamen, caudate nucleus
- inititate and terminate movements, suppress unwanted movements and regulate muscle tone
- produce the inhibitory neurotransmitter dopamine
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Limbic system(emotional brain)
- ring of structures on the inner border of the cerebrum and floor of the diencephalon
- governs emotional aspect of the brain
- functions in emotional aspects of behavior and memory and is associate with pleasure and pain
- involved in olfaction
- includes:
- cingulate gyrus
- hippocampus
- dentate gryus
- amygdala
- mammillary bodies
- thalamus
- olfactory bulb
*(hippo mammal) has teeth(dent) w/friensds (amy, thala,olga) all are (cingul)
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Diencephalon
-it surrounds the 3rd ventricle and consist of thalamus, hypothalamus, circumventricular organs and epithalamus
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Diencephalon(thalamus/relay station)
- relay station for all sensory impulses
| - located superior to the midbrain and contains nuclei
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Diencephalon(hypothalamus)
- found inferior to the thalamus, had four major regions(mammillary, tuberal, supraoptic, and pre optic)
- major regulators of homeostasis
- regulation of emotional and behavioral patterns
- eating and drinking through the feeding center, satiety center, and thirst center
- thermostat of body- it aids in controlling body temp
- it controls ANS
- produces releasing and inhibiting hormones, oxytocin, and ADH
- regulates circadian rhythms and states of consciousness
44
Diencephalon(epithalamus)
- lies superior and posterior to the thalamus and contains the pineal gland and the habenular nuclei
- pineal gland secrets melatonin
- habenular nuclei are involved in olfaction, especially emotional responses to odors
45
Diencephalon(circumventricular organs)
- monitor chemical changes in the blood because they lack a blood-brain barrier
- cvo includes parts of the hypothalamus, the pineal gland, and pituitary gland
- function to coordinate homeostatic activities of the endocrine and nervous system
- site of entry into the brain of HIV
46
Cerebellum
- coordination of skeletal muscle contractions-
| - may have role in cognition and language processing
47
Brain stem and reticular formation
- parts btw spinal cord and diencephalon
- midbrain, pons, medulla oblongata
- extending throughout the brainstem is reticular formation; netlike region of gray and white matter
48
medulla oblongata
- continuous with upper portion of spinal cord
| - contain both sensory and motor tracts
49
structural region of medulla
- bulges of white matter called pyramids on the anterior aspect formed by corticospinal tracts
- decussation of pyramids results in neurons in the left cerebral cortex controlling skeletal muscles on the right side of the body and vice versa
- olive lateral to each pyramid containing inferior olivary nucleus
- nucleus provides instructions for cerebellum to make adjustments to muscle activity as you learn new motor skills
- right and left gracile nucleus and cuneate nucleus
- posterior column tracts form synapses in these nuclei
- postsynaptic neurons then relay sensory information to the thalamus on the opposite side of the brain
- axons ascent to the thalamus in white matter called medial lemniscus
- posterior column pathway end in nuclei medial lemniscus pathway
- nuclei are components of sensory pathways for gustation, hearing, equilibrium
- contains cranial nerves 8-12
50
medulla oblongata(function)
- cardiovascular center
- regulate rate and force of heartbeat
- diameter of BV
- medullary rhythmic area of resp center
- adjusts basic rhythm of breathing
- reflex center for swallowing coughing, sneezing, hiccuping
51
pons(bridge)
- located superior to the medulla
- provides connection btw cerebral cortex and opposite hemisphere of cerebellum
- tracts and cranial nerves nuclei
- contain pneumotaxic and apneustic resp center
- contains cranial nerves 5-7 and vestibular branch of cranial8
52
Midbrain
-extends from the pons to the diencephalon
-contains nuclei and tracts
-parts of the ventricle found here
-cerebral peduncles: consist of axons of the corticospinal, corticobulbar tracts(cortex to medulla)]
-tectum-situated posteriorly and contains four rounded elevations: 2superior ones called superior colliculli(coordinates head,eyes,and trunk movements in response to visual stimuli)
2 inferior colliculli(coordinate head eyes and trunk movements in response to auditory stimuli
-contains left and right sustantia nigra(produces dopamine, controls subconscious motor activities), the left and right red nucleus(controls muscle movements)
-contain origins for cranial nerves 3 and 4
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Reticular formation
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