L6,L7: The Brain Flashcards
In general terms, what is the telencephalon?
The brain
In general terms, what is the diencephalon?
The interbrain
What is the midline of the brain called that divides the two hemispheres?
The sagittal fissure
Explain the surface of the brain
- Covered by elevated ridges of cortex called giri
Giri are separated by grooves called sulci
What does the central sulcus separate?
The frontal lobe from the parietal lobe
What does the parietal occipital sulcus separate?
The parietal lobe from the occipital lobe
What does the deep lateral sulcus separate?
The temporal lobe from the frontal lobe and the parietal lobe above it
What is the hidden lobe and how can you find it?
- The insula
- Deep within the cerebral hemisphere
- Can only see it by separating the temporal lobe from the parietal and frontal lobe
What is the cebrebral cortex made out of
Grey matter
What are “tracks”?
White matter bunched together
What is the corpus callosum?
- A track
- Located deep within the cerebral fisser
- Extends from frontal lobe to occipital lobe
- COnnects the areas from teh two cerebral hemispheres
- Horizontally defined
What is the basal ganglia made of?
- Grey matter
- The caudate and lentiform nucleus
What is the internal capsule?
- A track
- Passes between two nuclei
- Moves info from the brain and spinal cord up
- Its axons connect cerebral cortex to the rest of our nervous system
- Vertically defined
Where is the diencephalon located?
The center of base of cerebrum
What structures make up the diencephalon?
The thalamus, hypothalamus and epithalamus
What does the thalamus do?
- First sensory integration spot for all senses except smell
- Redirects sensory information to correct higher-up structure
What does the hypothalamus do? Where is it located?
- Located under the thalamus
- Attached to pituitary gland
- Sends chemical factors that control the endocrine functions f the pituitary gland
What does the epithalamus do?
Produces melatonin (connected to pineal gland)
What are the three components that make up the brain stem?
1) The midbrain (mesencephalon)
2) The pons
3) The medulla oblongata
Where is the midbrain located?
Between the diancephalon and the pons
What are the cerebral penducles?
The anterior part of the midbrain that connects the brainstem to the thalamus
What is the superior colliculi?
A visual reflecx that coordinates head and eye movement
What is the inferior colliculi?
An auditory reflex, helps to process sound
Where is the pons located?
Between the medulla oblongata and the midbrain
- In front of the fourth ventricle and the cerebellum
- Connected to the cerebellum through horizontal fibers
What do the pyramids in the medulla do?
Axons within the pyramids control voluntary movement
Where is the medulla?
The bottom of the brainstrem
- Continuous with spinal cord
What does the medulla regulate?
- Rate and depth of breathing
- Blood pressure
- Vomitting, hiccupping, swallowing, coughing, sneezing
What is the cerebellum made up from?
- Two hemispheres
- A vermis that separates them
- The cerebellar peduncles
What is the function of the cerebellum
- Helps in coordinating physical movements
What makes up the meninges?
1) The dura mater
2) The arachoid mater
3) The pia mater
4) The dural sinuses (venous sinuses)
What is the role of the meninges?
To protect the brain and spinal cord
Describe the structure of the Dura mater
- Outermost layer of meninges
- Thickest and toughest layer within skull
- Consists of two sublayers glued together
What is the outermost (closest to skull) layer of the dura mater called?
The periosteal layer
What is the innermost (closest to brain) layer of the dura mater called?
The meningeal layer
What does the falx cerebri do?
Separates the two hemispheres of the cerebrum
What does the falx cerebelli do?
Separates the two hemispheres of the cerebellum
What does the tentorium cerebelli do?
Separates the cerebrum from the cerebellum
The falx cerebri, falx cerebelli, and tentorium cerebelli are all structures of what connective tissue membrane?
The dura mater
What are the dural sinuses?
Spaces formed by separation of the dural layers
- Some collect blood from brain
What is the arachnoid mater?
- Loose covering of the brain and spinal cord
What is the subarachnoid space?
A space filled with cerebral spinal fluid that contains blood vessels
- Space between brain and maters
- Collagen fibers connect brain to pia mater in this space in a meshwork-type structure
What is the pia mater?
Innermost layer of the meninges
- Clings tightly to brain
What is the ventricular system?
4 cavities (ventricles) and their connecting channels
All connected to each other through central canal
Describle the lateral ventricals
- Large, backwards c-shaped chambers
- Located deep within cerebral hemishphere
- Named components are related to where those components are found in the brain
- Each lateral ventricle opens up and drains into the third ventricle via two passageways called the interventricular foramen
The anterior horn of the lateral ventricle has parts in which lobe?
The frontal lobe
The posterior horn of the lateral ventricle has parts in which lobe?
The occipital lobe
The Interior horn of the lateral ventricle has components in which lobe?
The temporal lobe
The body of the lateral ventricle has components in which lobe(s)?
The frontal lobe and the parietal lobe
Describe the third ventricle
- Narrow slit-like cavity between the two halves of the thalamus
- Opens into and connects to the fourth ventricle by the cerebral aquiduct, which passes through the midbrain
Describe the fourth ventricle
- Located behind the pons, but in front of the cerebellum
- continous with central canal of spinal cord
- Opens up into subarachnoid space
What is the choroid plexus?
Found in 3rd and 4th ventricle and makes cerebral spinal fluid
The internal carotid arteries enter through….
the skull through the carotid canal
The vertebral arteries enter the skull through the…
froamen magnum
What is the basilar artery
The joining of the vertebral artieries
.- The basilar artery ends by dividing into the posterior cerebral arteries
How do the internal carotid artieres end?
They divide and give rise to the anterior and middle cerebral arteries
What is the circle of willis?
- A circle of blood vessels creates by the anterior cerebral arteries
- Involves the posterior cerebral arteries, the posterior communicating artery, the internal carotid arteries, the anterior cerebral arteries, and the anterior communicating artery
