Exam 5 Flashcards
What do nervous system functions include?
Sensory functions
Integrative
Motor planning
Which division of the nervous system is responsible for brain and spinal cord?
CNS
Which division is responsible for nerves and ganglia?
PNS
What are 3 physiolgical properties of a neuron?
Excitability, conductivity, secretion
Sensory Afferent neurons ..,,
Detect stimuli
Interneurons (association neurons) …
Receive signals from other neurons and make decisions about response
Motor (efferent) neurons…
Send signals to muscles to provide response
What is the control center of the neuron?
Neurosoma
What had compartmentalized ER?
Nissl bodies
What part if the neuron receives signals?
Dendrites
What part if the neuron sends action potentials?
Axons
What is the complex of branches at axons distal end?
Terminal arborization
What is the ending of an axon branch that communicates with another cell?
Synaptic knob
A neuron with many dendrites, one axon?
Multipolar
A neuron with one dendrite, one axon?
Bi polar
A neuron with no dendrites and has one axon?
Unipolar
A neuron with many dendrites and no axons?
Anaxonic
Of the CNS glia, Oligodendrocytes do what?
Myelinate to assist conductivity
What do the ependymal cells do?
Secrete and circulate cerebrospinal fluid
Why do microglia do?
Help in defense and disposal
What do astrocytes do?
Provide support and nourishment
Of the PNS glia, what does the Schwann cells do?
Myelinate to assist conduction
What do the satellite cells do?
Provide support and nourishment
What makes up the fatty white matter of CNS?
Oligodendrocytes
What are fiber segments covered by myelin?
Internodes
What are fiber segments with gaps in myelin?
Nodes of ranvier
What is the outermost layer of a Schwann cell?
Neuralemma
Signal conduction speed depends on two factors:
Diameter of fiber (larger = faster)
Presence it myelin (myelinated are fster)
Cut nerve fibers can regenerate if what?
Nerve cell bodies remain intact
Which cells secrete nerve growth factors?
Schwann cells
Can CNS neurons regenerate?
No
Meeting point of neuron and other cell?
Synapse
Adjacent cells joined by gap junctions
Ions diffuse from cell to cell
Quick transmission
No integration or decision-making
Electrical Synapse
What are the first embryonic traces of CNS?
Neural plate
Neural groove with neural folds
By 4 weeks, a hollow channel is created known as the what?
neural tube
The neural tube has three anterior bulges;?
Forebrain, midbrain and hindbrain
What happens in the 5th week of development?
Secondary vesicles
Which neural tube defects affects one to a few vertibrae and causes no functional problems?
Spina bifida occulta
Which neural tube defect is more severe and causes a sac to protrude from spice?
Spina bifida cystica
In what NTD causes a small brain?
microcephaly
In what NTD causes no brain
anecephaly
What bypathologist removed Albert Einsteins brain after 7 hours of deat?
Thomas Stoltz Harvey
What was found in Albert Einsteins brain that could have enabled his intelligence?
increased number of glial cells
What forms myelin in the spinal cord?
Oligodendrocytes
The automic nervous system is also called the?
visceral motor division
What divivsion tends to prepare the body for action?
symoathetic
Nerves are _____ of the organ system?
organs
What are examples of effectors of the nervous system?
Glands
What division carries signals to the smooth muscle in the large intestine?
visceral motor
About 90% of the neurons in the nervous system are what?
Association
WHat are the most common type of neurons?
Multipolar
The myelin sheath is formed by?
cells
The mechanism by which nervous system converts these action potentials into meaningful information is called neural _____?
coding
What are four functions of the spinal cord?
Conductivity
Neural integration
Locomotion
Reflexes
Sensory information _____ in the spinal cord.
Ascends
Motor function ________ in the spinal cord.
Descends
What is neural integration?
Processing of info from diverse sources
Why is locomotion?
Central patterns generators coordinate simple repetitive movements
What is an involuntary stereotyped response to stimuli?
Reflexes
What are the regions of the spinal cord?
Cervical
Thoracic
Lumbar
Sacral
Spinal enlargements are in which two regions?
Cervical and lumbar
Tough outer layer; epideral space
Dura mater= dura sheath
Middle layer; subarachnoid space with cerebral spinal fluid.
Arachnoid matter
Delicate inner layer; coccygeal and denticulate ligaments
Pia matter
-What contains little myelin –Two posterior (dorsal) horns –Two anterior (ventral) horns –Two lateral horns within thoracic and lumbar regions –Connected by a gray commisure
Gray matter
–Myelinated axons
–Three pairs of columns (funiculi). Each column is divided in tracts (fasciculi)
•Posterior (dorsal), lateral, and anterior (ventral) columns
White matter
What do ascending tracts do?
carry sensory info to brain, whereas descending tracts carry motor info from brain
Many tracts cross the midline at a what?
Decussation
If a tract crosses the midline then it’s origin is ____ to it’s destination.
Contralateral
If a tract does not cross midline then it’s origin is _______ to it’s destination?
Ipsilateral
What does the1st order neuron do?
conducts the stimulus to the spinal cord or brainstem.
What does the 2nd order neuron do?
conducts the stimulus to the thalamus (at the upper end of the brainstem)
What does the 3rd neuron do?
Conducts the stimulus to cerebral cortex
Which tract carries signal from the midthoracic and lower parts of the body?
gracile fasciculus
which tract joins the gracile tract at T6 and carries signals from the upper limbs and chest?
Cuneate fasciculus
Both ascending posterior column tracts contain what?
1st order neurons sensing body position, discrimitive touch, and pressure on the side of the body
What tract ascends in the anterior and lateral columns to end in the thalmus?
spinothalamic tract
What does the spinothalamix tract contain?
second order neurons sensing pain, temperature, tickle, itch, and light and crude touch from contralateral sensory neurons
What lacks the fine discrimination and doesnt generally give enough info to the brain to enable it ro recognise a familiar object by touch alone?
Crude (protopathic) touch
What does the spicoreticular tract do?
carries pain signals from tissue injure
Corticospinal tracts carry signals for precise limb movements from what?
motor cortex ( upper motoe neurons)
What do descending tracts do?
carry motor signals down the brainstem and spinal cord.
The upper neuron of the descending tract has what?
the soma in the cerebral cortex
The lower motor neuron contains what?
the axon in the brainsem or spinal cord
Where does the axon of the lower motor neuron end?
in the muscle or target organ
What is a nerve?
several axons wrapped by connective tissure
Endoneurium wraps what?
one axon
Perineurium wraps what?
a fascicle of axons
Epineurium wraps what?
entire nerve
Carry sensory signals from receptors to the CNS
Afferent fibers
Carry motor signals from the CNS to effectors
Efferent fibers
Innervate skin, skeletal muchles, bones, and joints?
Somatic fibers
Innervate blood vessels, glands, and viscera
Visceral fibers
Innervate widespread organs such as muscles skin, glands, viscera, and blood vessels
General fibers
Innervate more localized organs in the head, including the eyes, ears, olfactory and tase receptors, and muscles of chewing, swallowing, and facial expression
Special fibers
What is a ganglion?
a cluster of cell bodies outside the CNS
How many pairs of spinal nerves are there?
31
How many of each spinal nerves are in each region of Thoracis, lumber, sacral, coccygeal?
12,5,5,1 respectively
what do plexuses do?
receive fibers from anterior rami and give rise to peripheral nerves
The Cervical plexus is?
in neck
the brachial plexus is in?
shoulder
the lumbar plexus is in
lower back
the sacral plexus is
below lumbar
the coccygeal plexus is
lower sacrum and coccyx
What is a dermatome map?
diagram of the areas of skin innervated by each spinal nerve
Each spinal nerve except ______ receives a sensory input from a specific area of skin called dermatome?
C1
How is spinal nerve damaged assesd?
By testing the dermatomes, by pinpricks and noting the areas where the patient has no sensation
What are properties of a reflex?
requires stimulation
quick
involuntary
stereotyped
What is a visceral reflex?
Glans. cardiac muscle. and smooth muscle
controlled by autonomic nervous system
What is a somatic reflex?
Skeletal muscles
controlled by somatic nervous system
What is an ipsilateral reflex?
sensory input and motor output on same side
What is a contralateral reflex?
sensory imput from opposite side as motor output
What is intersegmental reflex?
sensory signal in one lever; motor output at a higher or lower level
syndrome of paralysis and absence of reflexes after transection of cord
Spinal shock
dangerous drop in blood pressure due to lack of sympathetic nervous system activity
Neurogenic shock
– paralysis of both lower limbs due to lesions from T1 to L1
Paraplegia
paralysis of all four limbs due to lesions above C5
quadriplegia
paralysis on one side of body usually due to stroke or brain lesions
Hemiplegia
The Brain si divided kinto 3 major regions: ?
Cerebrum, Cerebellum, and brainstem
Which region of the brain consists of two cerebral hemispheres, gyri (folds), and a longitudal fissure?
Cerebrum
Which region of the brain is marked by gyri, sulci, and fissures?
Cerebellum
Which region of the brain is the smallest of all and its major components are the diencephalon, midbrain, pons,and medulla oblongota. This part of the brain is crucial for survival
Brainstem
What is the outer part (cortex) of cerebrum and of cerebellum, as well as deep nuclei. It is the site of the neurosomas, dendrites, and synapses.
Gray matter
Deep in the brain and is composed of tracts or bundles of myelinated axons
White Matter
Within the cranium the dura mater has two layers: ?
Periosteal layer and meningeal layer
In some places, the layers separate to form dural sinuses. These sinuses are?
Superior sagittal sinus and Transverse sinus
In some places, dural sheets occupy spaces separating majr parts of the brain. What are these called and which parts do they separate?
Falx cerebri separate between hemispheres
Tentorium cerebelli separate between cerebrum and cerebellum
What are the three meninges?
Dura matter - yough, outer layer
Arachnoid mater - transparent, middle layer
Pia mater - delicate, inner layer
The brain has four interior chambers called what?
ventricles
The largest two ventricles are what and form what?
lateral ventricles which form an arc in each cerebral hemisphere
Each lateral ventricle is connected to what?
the third ventricle which contains the cerebral aqueduct
the cerebral aqueduct leads to what?
The fourth ventricle - whcih forms the central canal and contains the choroid plexus
What does the central canal located in the fourth ventricle of the brain extend through?
medulla oblongata into the spinal chord
What is covered by ependymal cells and produce cerebrospinal fluid?
Choroid plexus - similar to histollogicall to the fetus choroum
What is a clear, colorless liquid that fills the ventricles and calas of the CNS and bathes its external surface?
Cerebrospinal fluid (CSF)
What is the CSF produced by?
choroid plexus within ventricles
What does the CSF flow within?
ventricles, canals and in subarachnoid space around CNS
What is CSF absorbed by?
arachnoid granulations into blood of superior sagittal sinus
What does CSF provide?
buoyancy, protection, and chemical stability
The brain is how much of body weight?
2%
The brain receives ___% of blood and uses __% of oxygen?
15% blood; 20% oxygen
What is the blood-brain barrier (BBB)
seals capillaries in brain tissues and have tight junctions between endothelial cells
What is the blood- CSF barrier?
Seals chororod plexus within brain ventricles and has tight junctions between ependymal cells
Patches in regions of 3rd and 4th ventricles that lack BBB allow brain to monitor blood chemistry
Circumventricular organs (CVO)
What is developed from the myelencephalon?
Medulla Oblongata
The medulla oblongata begins where and extends to what?
Begins at the foramen magnum andextends to pons
The medulla contains several nuclei, three important ones are what?
Cardiac center, vasomotor center, and respiratory center
Anterior surface contains what physica traits?
Pyramaids (medial) and Olives (lateral)
The corticospinal tract of the interior structure does what?
controls muscles below the neck
The inferior olivary nucleus does what?
receives signals from many levels of the brain and relays them to the cerebellum
The reticular formation is involved in what?
many physiological functions of the body
The gracile and cuneate nuclei do what?
convey signals to the cerebrum and one’s conscious awareness
What does the tectospinal tract do?
mediated movements of neck and head
The posterior spinocerebellar tract is?
sensory info for the cerebellum
What developes from metencephalon?
Pons
Anterior surface contains what?
large bulge
Posterior aspect contains what?
peduncles that attach to cerebellum
Internally Pons contain parts of what?
several tracts and nerves
What develops from mesencephalon?
Midbrain
What is the tectum of the midbrain?
a rooflike region posterior to the aqueduct
The tectum exhibits what?
corpora quadrigemina - four bulges consisting of superior and inferior collicul
The superior colliculi contains what functions?
Vision attention tracking movements of objects and reflexively turning the head and eyes in response to stimuli
What does the inferior colliculi do?
receive and process auditory input from lower levels of the brainstem and relay it to toher parts of the brain.
What is the IC sensitive to?
time delays between sounds heard by the two ears, and aid locating the source of sound
The cerebral peducles contain what
Tegmentum with red nucleus
Substantia nigra
Cerebral crura anchor cerebrum to brainstem
Main function of tegmentum is what?
Fine motor control
The substantia nigra does what?
improves motor performance by supessing unwanted muscles contractions.
The cerebral crura do?
Anchor the cerebrum to the brainstem
What is a web of gray matter that runs through all levels of brainstem?
Reticular Formation
What are the functions of reticular formation?
somatic motor control, cardiovascular control, pain modulation, sleep and consciouslness and habituation
What is a narrow wormlike bridge that connects the cerebellar hemispheres?
Vermis
What is folia?
slender, parallel folds located in each hemispere.
The cerebellum has a surface cortex of what?
gray matter and a deeper layer of white matter.
What is arbor vitae?
a branching fern-like pattern in the white matter
In each hemisphere there are 4 masses of gray matter called what?
Deep nuclei
What kind of cells are contained in the gray matter of the cerebellum?
Numerous granule cells and large Purkinje cells
What are the functions of Medulla oblongata?
Centers for circulatory and respiratory control
sensory and motor functions for head and neck
What are functions for Pons
facial sensation and expression
control of chewing, respiration, and sleep
What are the functions for midbrain>
Red nucleus and substantia nigra for motor control
Central gray for pain awareness
superior coliculus for visual attention
inferior colliculus for auditory attention
Functions for reticular formation?
Sleep and consciousness
varied sensory, motor, and involuntary functions
Whaqt are functions for cerebellum?
Muscular coordination and fine motor control
varied cognitive functions
What is part of the forebrain and has three divisions that surround the third ventricle
Diencephalon
What are the three divisions of diencephalon?
Thalamus, hypothalamus, and Epithalamus
What is an ovoid mass that makes up 4/5ths of diencephalon?
Thalamus
In about 2/3 rds of people the two thalami are joined medially by a narrow?
intermediate amss
The thalamus is involved in what?
sensation, movement, memory, and emotion
The Thalamus is known as what?
“Gateway to the cerebral cortex”
What extends from optic chiasm to mammillary bodies?
hypothalamus
The hypothalamus is the major control center of what?
autonoic nervous system and endocrine system
What are the functions of the hypothalamus?
hormone secretion, autonomic effects, thermoregulation. food and water intake, sleep and cicradian rhythms, emotional responses, and memory
What consist mainly of kthe pineal gland, the habenula, and a think roof over the 3rd ventricle?
Epithalamus
What derives from embyonic telencephalon of forebrain?
Cerebrum
The cerebral hemispheres are separated by what?
a longitudinal fissure
The cerebral hemisphers are connected by what?
corpus callosum
What produces the large surface area?
Gyri and sulci
Which lobe extends from frontal bone to central sulcus?
Frontal Lobe
What is the frontal lobe concerned with?
cognition, speech, and motor control
Which lobe extends from central sulcus to parieto-occipital sulcus?
Parietal lobe
What is the importance of the parietal lobe?
interprets signals of general senses and taste
Which lobe extends from parieto-occipital sulcus to occipital bone
Occipital lobe
Function of the Occipital lobe?
principal visual center
Which lobe extends from temporal bone to lateral sulcus?
Temporal lobe
Main fuction on Temporal lobe?
Hearing, smell, learninbg, and memory
What is from deep to lateral sulcus?
Insula
What is function of insula?
Taste, visceral sensation, and language
What do the projection tracts of the cerebral white matter do?
travel vertically to carry info between cerebrum and rest of body
What are the commissural tracts of the cerebral white matter?
commissures cross between two hemispheres
What is the largest commissural tract?
corpus callosum
What are the Association tracts?
connect regions within same hemisphere
What is the surface of the hemisphers?
cerebral cortex
What percentage does the cerebral cortex make up of brain?
40%
What are cells with several short dendrites and no axon?
stellate cells
Stellate cells are the local processing of what?
sensory info
What are triangle shaped with apex pointing to brain surface anbd outputs neurons of cerebrum?
Pyramidal cells
What is “recently” evolved and contains six layers?
Neocortex
Prominent parts of this include: cingulate gyrus, hoppocampus, and amygdala
The limbic system
What are important functions of the limbic system?
emotion and learning
What are masses of cerebral gray matter buried deep in the whiter matter, lateral to the thalamus?
basal nuclei
The basal nuclei consist of at least three brain centers: ?
caudate nucleus, putamen, and globus pallidus
The basal nuclei is involved in what?
motor control
What is the first cortical region to receive input for that sense?
Primary sensory cortex
What isses projection fibers to distribute motor commands?
Primary motor cortex
Any cortical are that is not primary?
Association cortex
The association cortex is involved with integration functions such as what>
interpretation of sensations, though, memory, and motor planning.
The association area of the frontal lobe is a very important center of cognitive and emotional funtion, it is the ?
prefontal cortex
Vision deals with what?
Occipital lobe and primary visual cortex
Hearing deals with what/,.
Temporal lobe and insula and primary auditory cortex
Equlibrium deals with what?
cerebellum and several brainstem nuclei
Taset deals with what>
parietal lobe and primary gustatory cortex
Smell deals with what?
temporal and frontal lobes and orbitofrontal cortex
Postcentral gyrus is primary what?
somatosensory cortex
Precentral gyrys is primary what?
primary motor cortex
What is responsible for the recognition of spoken and written language, lying posterior to the lateral sulcus usually in the left hemisphere
The Wernicke area.
What area is responsible for the speech. It comes from the Wernicke area and is located inferior prefrontal cortex of the same hemi?
The Broca area
There are several areas involved with emotions, but the _____ is a moajor component.
Amygdala.
The amyghala outputs to what?
the hypothalamus and prefrontal cortex
What is the range of mental processes by which we acquire and use knowledge?
congnition
What are the two types of memory?
procedural and declarative
What is retention of motor skills such as tie shous, play violin, ride a bike?
Procedural
Retention of events and facts that one can put into words
declarative
What kind of memories does the amygdala create?
emotional memoires
The hippocampus consolidates what kind of memories?
declarative long-term memories
What is the difference in functions for each hemisphere?
cerebral lateralization
One hemisphere, usually the left is called the ?
categorical hemisphere
The categorical hemisphere is specialized for what?
spoken and written language
Uusally the right hemisphere is called ?
representational hemisphere
The representational hemisphere perceives info in a more hollstic way, allowing for what?
imagination and insight as well as musical and artistic skills
OLd OPie OCcassionally TRies TRIGonometry And Feels VEry GLOomy, VAGUe, And HYPOactive - (List of cranial nerves)
Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal
What is a sensory nerve for vision?
Optic nerve
What is a sensory nerve for smell?
olfactory nerve
A motor nerve for eye movement?
oculomotor nerve or trochlear nerve or abducens nerve
A mixed nerve for sensation of the face and control of chewing movements?
Trigeminal nerve
A mixed nerve for sensastion of taste and control of expreessions, and facial secretions
Facial nerve
A sensory nerve for hearing and equilibrium?
vestibulocochlear nerve
a mixed nerve with diverse sensory and motor function for head, neck, and thorax
glossopharyngeal nerve
a mixed nerve for taste and gastrointestinal sensation, and control of various organs
vagus nerve
a motor nerve for swallowing, head, neck and shoulder movements
accessory nerve
a motor nerve controlling movements of the tounge
hypoglossal nerve
Which disorder: Recent event of memory loss
reduced attention span, disorentation
atrophy of gyri of cerebral cortex and hippocampus
Alzheimer disease
Which disorder: AKA paralysis agitans
loss of motor function
degeneartaion of dopamine-releasing cells from substantia nigra
Parkinson disease
What are chemical messengers that are sevreted into the blood stream?
hormones
Hormones stimulate response in what?
distant targets
Compared to Exocrine glands, endocrine glands are?
ductless and secrete internally
Compared to the nervous system, endocrine effects tend to be _____?
slower and more sustained
Endocrine messengers can affect wider variety of what?
more distant targets
The two systems (Nervous & endocrine) coordinate responses, and some cells are called?
neuroendocrine cells
Major organs of the Endocrine System include:
Pineal, hypothalamus,pituitary, thyroid, thymus, adrenal gland, pancreas, parathyroid glands, and Gonads
What is flattened funnel shape and above and behind optic chiasm
Hypothalamus
What are the two parts of the pituitary gland?
Adenohypophysis and neurohypophysis
Which part of the piruitary gland is the interior three quaters.
Adenohypophysis
The adenohypophysis has 2 parts: ?
anterior lobe called pars distalis and the pars tuberalis
What are hormone secreting cells in the adenhypophysis?
acidophils and basophils
Which part of the pituitary is the posterior one-quater
neurohypophysis
What are the three parts of the neurohypophysis?
posterior lobe, stalk (infundibulum), and median eminence
The Adenohypophysis consists of a hypophyseal portal system, which is what?
a blood vessel connection to hypothalamus
Consists of nervous tissue that includes axons of hypothalamic neurons form hypothalamo-hypopseal tract
neurohypophysis
The pineal gland is at the roof of what ventricle?
Third
The pineal gland is at the posterior end of what>
corpus callosum
Secretion of the pineal gland peaks at what age range?
1-5 years
The pineal gland shrinks by __% at puberty?
75%
What does the pineal gland secrete?
Melatonin
What is a bilobed gland, in mediasinum, superior to heart?
Thymus
Maturation of what cells occur in the thymus?
white blood cells (T cells)
What stimulates the development of lymphatic organs and T cells?
Hormones
What is the largest endocrine gland in adults?
Thyroid
The thyroid consists of two lobes joined by what?
Isthmus
The thyroid is composed mostly of sacs called what?
thyroid follicles
Thyroid hormone (TH) is both thyroxine (T4) and triiodothyronine (T3), which all do what?
Raises metabolic rate
Which glands contain 4 small ovoid glands?
Parathyroid Glands
The parathyroid glands are in the neck, usually on the _______ side of thyroid.
posterior sided
Parathyroid hormone (PTH) is secreted by chief cells to raise what?
Calcium in blood
Which glands are superior to kidnets?
Adrenal glands
The adrenal medulla is how much of the gland?
10-20%
Chromaffin cells secrete epinephrine, norepinephrine, and ?
dopamine
The adrenal medualla raises what?
metabolic rate
What makes up 80-90% of the adrenal gland?
adrenal cortex
What is the most superficial layer of the adrenal cortex?
Zona glomerulosa
What is the intermediate, thisck layer of the adrenal cortex?
zona fasciculata
What is the deepest cortical layer of the zona reticularis?
deepest cortical layer
Epinephrine is a hormone and a neurotransmitter. It has many function in the body including: ?
regulating heart rate, blood vessel and air passage diameters, and metabolic shifts.
Epinephrine release is a crucial component of what?
fight or flight response of the sympathetic nervous system
What organ is below and behind the stomach?
The pancreas
What are dispersed clusters of cells with endocrine functions?
Pancreatis islets
Glucagon causes rise in blood sugar?
Alpha cells
Insulin causes absorption of blood sugar
Beta cells
Somatostatin regulates speed of digestion
Delta cells
pancreatic polypeptide inhibits digestive secretions of bile and pancreatic juice
PP cells
Gastrin stimulates stomach activities
G cells
In the Ovaries, inhibin inhibits what?
FSH secretion
In the Testes, in sustentacular cells inhibin inhibits what?
FSH secretion
Endocrine glands develop from what?
epithelia
In the pituitary, adenohypophysis develops from what?
ectoderm of pharynx
Neurohypophysis develops from what?
a bud off hypothalamus
The thryoid grows from what>
floor of pharynx, migrates posteriorly
which glands all shrink in size early in life?
adrenal, thymus, and pineal glands
Insulin secretion and effectiveness declines when?
in old age
Ovarian decline at menopause increase risk of what?
cardiovascular disease, osteoporosis, and dementa
Thyroid effectiveness declines in what?
elderly
What can endemic goiter result from?
hyposecretion of thyroid hormone.
Cortisol hypersecretion disrupts carb and protein metabolism causing what?
Cushing syndrome
Severe iodine deficiency can cause what?
hypothyroidism and even developmental brain disorders and sever goiter
