Lower brain Flashcards
What connects the pons to the diecephalon?
midbrain
One tract of the pair contains axons of motor neurons that conduct nerve impulses from the cerebral cortex to the spinal cord. What is this tract known as?
corticospinal
Where do the axons of the sensory neurons pass through?
From the medulla to the thalamus
The tectum contains 2 pairs of rounded elevations collectively known as?
Quadrigemina
What component of the posterior structures (passing through the mid brain) connects the 3rd ventricle to the 4th lower one?
cerebral aqueduct
What are the differences btw the superior and inferior colliculi?
superior are reflex centers for visual stimuli and inferior are parts of the auditory pathway
It coordinates pupillary reflexes and accomodation reflex. Also responsible for the involuntary turning of the eye. What is it?
superior colliculi
relays impulses from hearing receptors to the thalamus and responsible for the startle reflex. What is it?
Inferior colliculi
They are large darkly pigmented nuclei that release dopamine and their loss of neuron is associated with parkinson’s disease?
substantia nigra
The rubrospinal tract originates from here and it helps coordinate muscular movements?
Red nuclei
Which tract does the red nuclei work with to control large muscles of the shoulder and arm?
rubrospinal tract
Does the reticular formation of the brainstem contain any white matter?
yes
Does the reticular formation contain both the ascending sensory and ascending motor?
No, contains descending motor
What is the main function of neurons that descend from the reticular formation?
regulate muscle tone
What part of the reticular formation controls consciousness and participate in awakening from sleep using sensory axons?
Reticular activating system
The portion of the brain that possesses the most amount of neurons is known as?
cerebellum
The central of the cerebellum is known as vermis, the lateral lobes are the cerebellar hemispheres, what are surface ridges called?
folia (cerebellar cortex)
Also referred to as the tree of life, what is the white matter of the cerebellum called?
arbor vitea
What bundles of white matter conduct impulses btw the cerebellum and other parts of the brain?
cerebellar peduncles
What is the difference btw cerebral peduncles and cerebellar peduncles?
cerebral peduncles are anterior structures that conduct impulses from the cerebrum to the spinal cord, medulla, and pons, while cerebellar peduncles are posterior structures.
what are the functions of the cerebellum?
monitors motor movements (intention vs action), sends feedback to motor areas of the cerebral cortex, and regulates posture and balance
if the anterior and posterior lobes of the cerebellum initiate skeletal muscle movements, what does the flucolonodular do?
equilibrium and balance
What is ataxia?
inability to coordinate muscular movements due to cerebellar injuries or diseases
uncoordinated speech muscles is a symptom of what?
ataxia
What are the sub-components of the diencephalon?
Thalamus, hypothalamus, epithalamus, and subthalamus
The 2 halves of the thalamus are connected across the 3rd ventricle by a bridge of gray matter known as what?
intermediate mass?
It is the main relay station for most sensory impulses that reach primary sensory areas of the cerebral cortex, from the spinal cord, brain stem, or mid brain. What is it?
thalamus
without the thalamus, which function of the brain will be affected?
regulation of autonomic activities and consciousness
What is the thick band of white matter that separates thalamus and caudate nucleus from lentiform nucleus?
internal capsule
what is referred to as the major regulator of homeostasis?
hypothalamus
These serve as the relay stations for reflexes related to the sense of smell.
mammillary bodies
What is the stalk of tuberal region that connects the pituitary gland to the hypothalamus?
Infundibulum
It is also known as the bosses boss because it control the gland that controls the endocrine system
hypothalamus
what controls the autonomic nervous system, regulates eating, and controls body temperature?
hypothalamus
It is superior and posterior of the thalamus and comprises of the habenular nuclei and pineal gland. What is it?
eptithalamus
which portion of the epithalamus is involved with olfaction and which is involved with melatonin?
habenuclar nuclei and pineal gland respectively
what part of the brain is continuous with the spinal cord and are its sub-components?
brain stem; medulla oblongata, pons, and midbrain
which part of the brain is posterior of the brain stem?
cerebellum
The largest part of the brain is the?
cerebrum
what is the collective name for the 3 layers that line the brain?
cranial meninges
Starting with the innermost, what are the layers of the cranial meninges?
pia mater, arachnoid mater, and dura mater
What’s the difference between the cranial dura mater and spinal dura mater?
cranial has 2 layers while spinal has 1 layer
When is the external periosteal layer and internal meningeal layer not fused together?
when they seperate to enclose the dural venous sinuses that drain blood from the brain into the internal jugular vein
Which tissue separates the two hemispheres of the cerebrum?
falx celebri
Which tissue separates the two hemispheres of the cerebellum?
falx cerebelli
Which tissue separates the cerebellum from the cerebrum?
tentorium cerebelli
What is the source of the ATP synthesized by neurons in the brain?
glucose from blood circulation
what protects the brain cells form harmful substances and pathogens?
blood-brain barrier
what parts of the brain lack the blood-brain barrier?
pineal gland, pituitary gland, and hypothalamus
What part of the brain controls vomiting and senses toxins in the blood?
area postrema of the 4th ventricle
The BBB is made up of which components?
astrocyte foot processes and endothelial cells
How does water-soluble and lipid soluble substances cross the BBB?
water-soluble (glucose) cross by active transport and lipid-soluble (oxygen, CO2, alcohol, & anesthetics) cross easily
Substances like proteins can cross the BBB. T or F?
F
What are the functions of the cerebrospinal fluid (CSF)?
Protect the brain & spinal cord against chemical & spinal injuries; carries chemical nutrients to neurons and neuroglia
what membrane separates the first and second ventricles (lateral)
septum pellucidum
which ventricle is surrounded by halves of the thymus?
3rd ventricle
where is the 4th ventricle located?
Btw the brain stem and cerebellum
It buoys the brain and provides optimal ionic composition. What is it?
CSF
What has a network of capillaries covered by ependymal cells and produces CSF?
choroid plexuses
After formation in the choroid plexuses of each lateral ventricle, which opening does CSF flow through to get to the 3rd ventricle?
interventricular foramina
What part of the 3rd ventricle produces more CSF?
The roof
Through what openings does CSF enter the subarachnoid space from the 4th ventricle?
2 lateral apertures, and a median aperture
CSF is reabsorbed into the blood through?
arachnoid villi
Excess CSF accumulation in the ventricles of the brain leads to?
hydrocephalus
What happens to the head of a baby with hydrocephalus, whose fontanels has not yet closed?
It bulges
The brain stem comprises of a network of interspersed gray and white matter called?
reticular formation
Also known as the vital brain, this component regulates functions upon which life is most dependent on without voluntary action. What is it?
medulla
Where does the medulla begin?
foramen magnum
They are the bulges of white matter on the anterior where the largest motor tracts pass form the cerebrum to the spinal cord. What are they?
The pyramids
The corticospinal tracts are represented by?
The pyramids
What is the term used to describe the crossing of left pyramid to the right and vice versa?
decussation of pyramids
What are the masses of gray matter where neurons form synapses with one another in the medulla?
medullary nuclei
In addition to regulating rate and force of the heartbeat, what else does the medullary neclei do?
adjusts the basic rhythm of breathing and promotes swallowing of food (deglutination)
coughing, hiccupping, and sneezing are controlled by?
medullary nuclei
what other nuclei types are the in the medullar?
gustatory (input from taste buds), cochlear (input from cochlea of the ear), and vestibular (input from the inner ear)
Where does the inferior olivary nucleus relay to and from?
to the cerebellum from the cerebral cortex, red nucleus of the mid brain, and spinal cord propioceptors
what is the shape and location of the olives?
oval and lateral to the pyramids
Associated with touch conscious proprioception, ressure, and vibration, what are the posterior nucei?
Right and left gracile nucleus, and cuneate nucleus
How does the first order sensory neurons ascend?
from the posterior column of dorsal root to the posterior nuclei of medulla
How does the second-order neurons ascend?
from the posterior nuclei of the medulla to the thalamus through medial lemniscus
The tracts of the posterior columns and axons of the medial lemniscus are collectively known as?
column-medial lemniscus pathway
symptoms of injury to the medulla include?
paralysis, loss of sensation to the opposite side of the body, and irregular breathing or heart rate
What part of the brain is also known as a bridge that connects one part of the brain with another?
Pons
What is the function of pontine nucei?
They relay signals for voluntary movement form their origin in the cerebral cortex to the cerebellum
They are bilateral clusters of nuclei that helps to control respiration with the medullary rhythmicity area. What are they?
pneumotaxic and apneustic area
When the inspiratory center of the medullar is active, where does it generate impulses to?
external intercostal muscles
The elastic recoil of the lungs and thoracic wall is associated with?
exhalation; lack of inspiratory impulses
What coordinates the transition btw inhalation and exhalation?
Pneumotaxic ares turns off inspiratory area and apneustic area turns on inspiratory area
Where does the vestibular and cochlear branch of the vestibulocochlear nerve end?
Vestibular branch ends in the vestibular nuclei of pons and cochlear branch ends in nuclei in medulla oblangata
