Lab Brain Anatomy Flashcards
Meninges of the brain are:
Layers if tissue that cover and protect brain and spinal cord
Another name for tissue layers
Meninx
3 tissue layers of the brain:
- dura mater
- arachnoid mater
- pia mater
Dura mater
- outside layer of brain and spinal cord
- dense fibrous connective tissue
- protective covering
- anchors brain in skull
- forms dural sinus
- extends to separate major areas of the brain
Arachnoid mater
- middle layer
- fine spider web fibers
- spaces for blood vessels
Pia mater
- inner layer
- soft delicate tissue
- adheres to surface of the brain
Two tissue spaces of the brain:
- subdural space
* subarachnoid space
Subdural space:
•below dura mater
Subarachnoid space:
- under the arachnoid mater
* allows room for cerebrospinal fluid to circulate
What are the three meninges of the spinal cord?
- dura mater
- arachnoid mater
- pia mater
The 3 tissue spaces of the spinal cord:
- epidural space
- subdural space
- subarachnoid space
Epidural space of the spinal cord:
- between the spinal cord and bones of the vertebrae
* site of interjection of anesthesia
Subdural space of the spinal cord:
Beneath the dura mater
Subarachnoid space of the spinal cord:
•under arachnoid membrane
•cerebrospinal fluid circulates here
•site of lumbar or spinal tap
(Below L-1 level)- obtains CSF for analysis
6 areas of the brain
- medulla oblongata
- pons
- midbrain
- cerebellum
- diencephalon
- cerebrum
3 regions of the brain stem:
- medulla oblongata
- pons
- midbrain
The brainstem is the:
•lowest section of the brain
Medulla oblongata
- lowest section of brain
* attaches to the spinal cord
Pons
- above the medulla
* anterior to the cerebellum
Midbrain
- upper most section of the brain
- composed of 4 enlarged areas called corpora quadrigemina
- vermis divide into left and right hemisphere
Corpora Quadrigemina
- made of four sections
- 2 superior colliculi (lg)
- 2 inferior colliculi (smaller)
Cerebellum is located:
- posterior to the brainstem
* separated from the cerebrum by the transverse fissure
Sections of the cerebellum:
- 2 lateral sections called the right and left hemisphere
* separated by the vermis
Cerebellum surface structure:
- grooves on surface are called sulci
* raised areas referred to as convolutions
Diencephalon location
- can only be seen on the exterior of the brain from inferior surface
- only part visible, hypothalamus
- attachment of pituitary gland here
Cerebrum location:
Uppermost region of the brain
•largest section of the brain
Cerebrum lobes:
- divided into two hemispheres
* each hemisphere is subdivided into 5 lobes
5 lobe subdivisions:
- frontal lobe
- parietal love
- temporal lobe
- occipital lobe
- insula
Frontal lobe:
Anterior section
Parietal lobe:
Too middle surface
Temporal lobe
On lateral surface
•below parietal lobe
Occipital lobe
On posterior surface
3 surface markings
- longitudinal cerebral fissure
- central sulcus
- lateral cerebral fissure
Longitudinal cerebral fissure
•deep groove between the left and right hemispheres
Central sulcus
Shallower groove
•between parietal and frontal lobes
Lateral cerebral fissure
- deep groove
* between parietal and temporal lobes
Brainstem internal:
- Sagittarius sectional view
- medulla- attach to spinal cord
- pons- enlarged between medulla and midbrain
- midbrain- superior and inferior colliculi ( corpora quadraigemina)
Internal anatomy cerebellum:
- white matter does arbor vitae
* space between the cerebellum and the brainstem is the 4th ventricle
Internal anatomy of the diencephalon: 3 parts:
- thalamus
- hypothalamus
- pineal gland
Thalamus:
- largest part of the diencephalon
* contains intermediate mass in its center
Hypothalamus:
- below thalamus
- posterior to optic nerve
- pituitary gland attached here
Pineal gland:
- (body)
- posterior to the thalamus
- above colliculi of the midbrain
Cerebrum internal anatomy- sagittal sectional view: 3 components
- gray matter
- white matter
- corpus callosum
Cerebrum gray matter:
- outer layer
- called cortex
- thin
- contains cell nerve bodies
Cerebrum white matter:
- inside gray matter
- tracts and bundles of nerve cells
- with myelinated axons
Corpus callosum of cerebrum:
- large nerve tracts
* connecting the right and left hemisphere
Ventricles are:
- spaces within the brain
* where cerebral spinal fluid is made and circulates
4 ventricle structures of the brain:
- lateral ventricles 2
- 3rd ventricle
- 4th ventricle
Lateral ventricles of the brain:
- largest areas located below corpus callosum
* separated by a membrane called the septum pellucidum
Septum pellucidum:
- separates lateral ventricles
* a membrane
Third ventricle:
•located between the right and left sections of the thalamus and hypothalamus
Fourth ventricle
- space between the cerebrum and brainstem
- CSF flows here
- into subarachnoid spaces of the meninges
- or through the central canal of the spinal cord
3 connecting channels and openings are:
- interventricular foramen
- cerebral aqueduct
- choroid plexus
Interventricular foramen:
•between the lateral ventricles and the third ventricle
Cerebral aqueduct
Pathway for CSF flow from third to fourth ventricle
Choroid plexuses
- located in each of the ventricles
* where CSF is produced
2 blood circulation pathways in the brain:
- main arterial pathways
* circle of Willis
Main arterial pathways: 2
- internal carotid arteries
* vertebral arteries
Internal carotid arteries
•branch from the common carotid arteries in the neck
•carry blood to the anterior cerebrum and connect with the:
-anterior cerebral arteries
-middle cerebral arteries
-posterior communicating arteries
Vertebral arteries
•branch off subclavian arteries
•carry blood to:
-basilar artery
-posterior cerebral arteries (arteries to the cerebellum and pons)
Circle of Willis
- network of arteries
- form circular pathway around the base of the brain
- maintains constant blood flow into cerebrum
Blood vessels in the circle of Willis
- anterior cerebral arteries
- anterior communicating arteries
- posterior cerebral arteries
- posterior communicating arteries
