Brain and Cranial Nerves Flashcards
Name the parts of the brain:
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Cerebrum: split into right and left hemispheres
Cerebellum: small part at back/base of brain - fine motor control
Brainstem: midbrain, pons, medulla oblongata –> spinal cord
Label and describe the function of each:
What are meninges?
Name the three layers of membrane, superficial to deep:
Meninges are protective coverings for the brain and spinal cord.
- Dura mater
- Arachnoid mater
- Subarachnoid space
- Pia mater
Give some features of dura mater:
Give some features of arachnoid mater:
What does the subarachnoid space contain?
What is the pia mater?
Dura mater: very tough and fibrous, innervated and vascular, consists of 2 layers: periosteal (in contact with skull) and meningeal (in contact with meninges). These two layers may come apart to form dural venous sinuses
Arachnoid mater: spider web consistency, contain arachnoid granulations which reabsorb cerebral spinal fluid back into venous blood supply
Subarachnoid space contains cerebral spinal fluid (CSF)
Pia mater: follows contours of the brain exactly and coats the blood vessels/nerves entering/leaving the brain
Name the sheaths of dura mater which extend across different parts of the brain:
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- Falx cerebri: sits between left and right cerebral hemispheres
- Tentorium cerebelli: sits between cerebral hemispheres (above) and cerebellum (below)
- Diaphragm selli: sits over sella turcica
Name the two sources of blood supply to the brain and how they enter the brain:
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Vertebral artery: supply posterior part of brain - branch of subclavian artery, travles via transverse foramina of cervical vertebrae and enters cranial cavity via foramen magnum
Both vertebral arteries join together and become the basilar artery
Internal carotid artery: supplies anterior part of brain - branch of common carotid artery, travel within the neck and enter cranial cavity via carotid canal
What is the communication between vertebral and internal carotid arteries referred to as?
Name the arteries involved in this:
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The circle of Willis
- vertebral arteries
- basilar artery
- posterior cerebral artery
- posterior communicating artery
- internal carotid artery
- middle cerebral artery
- anterior communicating artery
- anterior cerebral artery
What do dural venous sinuses do?
Dural venous sinuses drain blood back towards jugular foramen and into internal jugular vein.
How is blood from the brain drained back towards the dural venous sinuses?
Cerebral veins extend directly from brain tissue back towards dural venous sinuses.
Name the system of spaces within the brain and what they are filled with:
What does the system consist of?
What does this fluid do and how is it recycled?
The ventricular system of the brain, filled with cerebro-spinal fluid.
Consists of 4 ventricles/spaces.
Cerebro-spinal fluid protects and nourishes the brain and is recycled via arachnoid granulations into dural venous sinuses, in order to be recycled into venous blood.