Brain and Cranial Nerves: anna made Flashcards
(77 cards)
Meninges
Three connective tissue layers protecting the brain
Pia mater
Adheres to brain surface
Areolar CT
Arachnoid mater
Lies external to pia mater
Arachnoid trabeculae extend to pia mater through subarachnoid space
Subarachnoid space contains cerebrospinal fluid (CSF)
Dura mater
Tough, outer membrane
Dense irregular connective tissue
Meningeal layer (deeper layer of dura)
Periosteal layer (more superficial layer of dura)
Epidural space
Between dura and skull; contains arteries and veins
Dural Extensions
Form partitions between brain areas; provide support
Falx cerebri
Located on midline; separates R & L cerebral hemispheres
Tentorium cerebelli
Separates occipital and temporal lobes from cerebellum
Falx cerebelli
Separates left and right cerebellar hemispheres
Diaphragma sellae
Forms “roof ” over sella turcica of sphenoid bone
Ventricular System and CSF: R&L Lateral ventricles
Through interventricular foramen
Ventricular System and CSF: Third ventricle
Through cerebral aqueduct
Ventricular System and CSF: Fourth ventricle
Through obex to central canal of spinal cord
Through lateral and medial apertures to subarachnoid space
Ventricular System and CSF: Subarachnoid space
Circulation of CSF
Choroid Plexus
- Specialized tissue in each ventricle
Dense capillary bed lined with ependymal cells - Production of CSF
Filtrate of blood
Circulates in ventricles and subarachnoid space
Clear liquid
No RBCs
Cushions brain
Transports nutrients and wastes
CSF
Filtrate of blood
Circulates in ventricles and subarachnoid space
Clear liquid
No RBCs
Cushions brain
Transports nutrients and wastes
Arachnoid villi
Projections of arachnoid mater into venous sinus
Dural venous sinuses
Drains blood from brain
Blood-Brain Barrier
- Regulates which substances enter the brain
- Composed of specialized capillaries
Wrapped by astrocytes
Tight junction connections
Four functional regions of the brain
Brainstem
Diencephalon
Cerebrum
Cerebellum
Gyri
Outward folds
Sulci
Inward folds
Fissures
Deep sulci
Medulla Oblongata
- Inferior region of brainstem
- Pyramids: Crossing of somatic motor axons
- Cardiac centers: Regulates heart rate and force
- Respiratory centers: Regulates respiratory rate
- Vasomotor centers: Regulates blood pressure