The brain is covered by a three layered bag that spans from the skull to the surface of the brain. these layers are collectively called the _________.
meninges (singular meninx)
What are the three layers of the meninges?
Dura mater
Arachniod mater
Pia mater
Dura mater
Latin: "tough mother"
a leathery covering
Arachnoid mater
"spiderweb mother"
resembles a wet spiderweb
is normally filled with cerebrospinal fluid (CFS)
Pia mater
"delicate mother"
like a coating of paint on the surface of the brain, which cannot be sparated fron the substance (parenchyma) of the brain.
epidural space
space between the skull and the dura
subdural region
region between the dura and arachnoid
subarachnoid space
space between the arachnoid and the pial surface of the brain
Patients who suffer bleeding into the brain may have blood collecting in the ______ space; tearing apart the ______ region; or filing up the __________ space.
epidural, subdural, subarachnoid
Ventricles
Hollow spaces in the brain
Cerebrospinal fluid (CSF)
Located in the ventricles and subarachnoid space
A filtrate of blood plasma that cushions and supports the brain.
supply's a favorable environment for nearons
The ventricles include :
Lateral ventricles
third ventricle
fourth ventricle
Lateral ventricles
Shaped like the letter C with a tail.
are located beneath the white matter of the cerebral cortex.
there is no first and second ventricles but there should be.
The third ventricle
a slit-like space between the two eggs of the thalamus
The fourth ventricle
between the brainstem and he cerebellum
The ventricles are connected to each other by ________.
apertures
Interventricular foramina
connects the lateral ventricles and the third ventricle
The third and fourth ventricles are joined by the ______ _______.
cerebral aqueduct
The fourth ventricle communicates with the subarachnoid space surrounding the ____ and _____ _____ via three apertures: two lateral apertures and a single ______ aperture.
brain, spinal cord, median
Choroid plexus
where cerebrospinal fluid (CFS) is made
A special tissue tha is found mainly in the lateral ventricles and fourth ventricle
There the blood is filtered by ependymal cells, a type of glial cell.
CFS is almost identical to ______; it is slightly _____ in glucose and amino acids than plasma, and much lower in ______.
plasma, lower, protein
_______ circulates ans is turned over about four times a day. Because of this circulation, a _______ puncture may detect bleeding that originated (for example) in the subarachnoid _______ around the frontal cortex.
CSF, lumbar, space
Arachnoid villi
a collection of structures along the midline of the superior aspect of the skull.
The resorption of CSF is thought to occur here
Summary:
CSF Production, Circulation, and Resorption
Production: choroid plexus
Circulation:
-Lateral ventricles (cortex and basal nuclei)
-Third ventricle (thalamus)
-fourth ventricle (cerebellum and pons)
-subarachnoid space of spinal cord
-Subarachnoid space of brain
Resorption: arachnoid villi
-dumped back into venous circulation
True or false.
The skull of an adult is capable of expansion.
False.
The skull of an infant is capable of expansion an adults skull is bony and unyielding.
If the ventricles or apertures become occluded in an adult, a life-threatening condition known as __________ occurs.
hydrocephalus
Latin: "water-brain"
It can also result from overproduction of CFS, or from slow absorption of CFS
Blood Brain Barrier (BBB)
a collaboration between the lining of capillaries and the end-feet of astrocytes.
Keeps most substances in the bloodstream from entering the brain
Drugs must pass the BBB to affect the brain
If brain abscess developes, antibiotics have difficulty crossing the BBB
The area postrema
also called the "vomiting center"
small area of the medulla oblongata that has no BBB, which gives it access to any toxins or irritants which might be circulating in the blood.
if it detects them, then it triggers emesis (vomiting) through the nearby vagus nerve
True or False.
The Blood-Brain Barrier can keep out drugs (particularly antibiotics) that we might want to use to help patients.
True.
Hypothalamus
Located just underneath the thalamus
intimately associated with the pituitary gland
contains dozens of small nuclei, clusters of brain cells that are responsible for a particular function
The Main control center for body homeostasis
What are the homeostatic mechanisms for the body controlled by the hypothalamus?
