Cranium-Wilson Flashcards
The spinal cord is surrounded by what 3 sacs?
dura mater
arachnoid mater
pia (outer layer of cord)
The entire CNS, including the brain, is surrounded by?
dura mater
In the cranium, the dura mater is fused to? What are the two layers of the dura mater?
periosteum
two layers of the dura mater: pericranium/periosteum fused with dura mater proper
Reflecting the dura reveals which meninge that lies on and surrounds the surface of the brain?
arachnoid mater
What is the dural fold that separates the cerebral hemispheres?
falx cerebri
What is the function of the tentorium cerebeli dural fold?
- tentorium (tent) cerebelli covers the posterior cranial fossa.
- separates the cerebellum from the occipital lobe of the cerebral cortex
What is the diaphragm sellae?
a flat piece of dura mater with a circular hole allowing the vertical passage of the pituitary stalk of the pituitary gland
What is Rathke’s pouch?
In embryogenesis, Rathke’s pouch is an evagination at the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the anterior pituitary (adenohypophysis), a part of the endocrine system.
The pituitary gland has two parts. What types of tumors may each part form?
-ANTERIOR pituitary may form a craniopharyngioma
(from embryonic tissue) in CHILDREN
-POSTERIOR pituitary may form adenoma in ADULTS
Midline lesions at the chiasm cause what kind of deficits?
Deficits are binocular, bitemporal and heteronymous
Pituitary adenoma (enlargement of the posterior pituitary) begins as bitemporal ___________ quadrantanopsia.
Craniopharyngioma (enlargement of the anterior pituitary) begins as bitemporal ____________quadrantanopsia.
superior
inferior
All bones are surrounded by what?
periosteum
The two layers of the dura mater eventually become separated to form what?
venous sinuses: veins that drain blood away from cranium, the brain in particular
What is the falx cerebelli?
- not as prominent as the falx cerebri
- in the posterior cranial fossa the cerebellum
- a small sickle shaped fold of dura mater, projecting forwards into the posterior cerebellar notch as well as projecting into the vallecula of the cerebellum between the two cerebellar hemispheres.
T/F. Anterior pituitary is derived from the inside of the oral cavity embryologically.
True!
Some of the axons of the optic nerve coming from the right eye bulb will cross over and go to the left side of the brain. Vice versa.
optic chiasma is a place where retinal fibers/axons cross from one side of the brain to the other
-as the tumor enlarges, most of the direct pressure is on the optic chiasma causing a blockage of function of those axons producing partial blindness
The lateral quadrants of the visual field are?
temporal hemiretina
The medial quadrants of the visual field are?
nasal hemiretina
T/F. The brain does not have any pain fibers.
True!
The meninges covering the brain has pain fibers
What is the main nerve that supplies the meninges of the brain?
trigeminal nerve
Where does the meninges covering the anterior and middle cranial fossa get its innervation from?
V1 (anterior), V2, V3 (middle) of the trigeminal nerve
Where does the tentorium cerebelli get its innervation from?
V1 of the trigeminal nerve
Where does the meninges covering the POSTERIOR cranial fossa get its innervation from?
C2 and C3
If the dura mater is irritated or inflamed for any reason it was cause what?
headache
- pain from the dura mater is headache
- inflamed blood vessels stimulate pain fibers in the meninges
If the sensory nerves running with the blood vessels supplying the meninges get swollen or irritated, what will they cause?
headache
The brain is not innervated and can be damaged with no pain or sensation!!!!
FACTS!!!!!
However if blood comes into contact with the meninges, it is an irritant producing an extremely severe headache
Blood is a very caustic substance that will irritate the nerve endings and produce intense headaches when an individual has a hemorrhaging stroke. Explain.
- If the blood vessels that run with the dura mater become inflamed or swollen they can stimulate a pain stimulus
- Hemorrhage (release of blood into the cranium) can also
The middle meningeal artery is one of the branches of what artery? What does it supply?
maxillary artery in the infratemporal fossa
-supplies the dura
Middle meningeal artery runs where?
- runs between the skull and periosteum
- it produces a groove in the skull
What are the two terminal branches of the external carotid artery?
- superficial temporal artery
- maxillary artery
What are the 8 branches of the external carotid artery?
Some Anatomists Like Freaking Out Poor Medical Students
- Superior thyroid
- Ascending pharyngeal
- lingual
- facial
- occipital
- posterior auricular
- maxillary
- superficial temporal
The major branch of the maxillary artery gives access to the skull. Explain.
- middle meningeal artery gives access to the cranial vault by going through the foramen spinosum
- identify the groove by the middle meningeal artery depression which goes to the foramen spinosum
-the middle meningeal artery enters the skull through the foramen spinosum
Why is the relationship of the middle meningeal artery to skull important?
- the middle meningeal artery passes through the lateral part of skull which is very thin (pterion)
- skull fractures may tear the meningeal artery producing an epidural hematoma