Structure of Nervous system (cranial nerves) Flashcards
What is the sulcus?
crevice/trench on brain surface
What is the gyrus?
ridge on the brain surface
What is the the foramina?
hole to allow structures to pass through
What is the choroid plexus?
lines ventricle system and produces CSF
What are Falx cerebri?
longitudinal crescent-shaped fold of dura between the cerebral hemispheres
What are tentorium cerebelli?
extension of the dura mater that seperates the cerebrum from cerebellum
-seperates cerebellum from inferior portion of occipital lobes
What is the ventricle?
system filled with CSF in the brain
What is a sinus?
sac/cavity in organ/tissue (e.g. frontal sinus, cavity containing air)
What is the sella turcica?
saddle shaped depression in sphenoid bone housing pituitary gland
What is the cerebrum?
“Brain”
-upper most region of nervous system, containing white and grey
What is the cerebellum?
the “little brain” in the back of the brain (hindbrain)
What are meninges?
3 membrane layers covering the brain consisting of:
- dura
- arachnoid
- pia mater
How many bones are in the skull?
22 bones (8 cranial, 14 facial)
How are bones of the skull joined?
by sutures
What kind of joint is a suture joint?
syndesmosis (fibrous) joint
What is the Cribriform plate?
The horizontal plate of the ethmoid bone separating the cranial cavity from the nasal cavity.
Describe the structure of the Meninges layers.
Outermost- dura mater
>very thick
Middle- arachnoid
>thin- difficult to see
>important because it is site of blood brain barrier and there is direct communication between CSF and blood
Innermost- pia mater
What is the Telencephalon?
cerebral hemispheres
-2 telencephalons
What are the Major Brain Lobes?
· Frontal lobe- mood and personality
· Temporal lobe- auditory information
· Parietal lobe- sensation, motor cortex
· Occipital lobe- vision
What is the Metencephalon?
Cerebellum
-balance, dexterity, coordination
Pons
-connection from spinal cord to the brain
What is the Mesencephalon?
Midbrain
-motor movements, visual and auditory processing
What is the Myelencephalon?
Medulla oblongata
-respiratory and cardiovascular control centres
What is the Diencephalon?
Thalamus + Hypothalamus
What is the Dural Venous Sinus?
Venous channels found between layers of dura mater in the brain which drain the cranium
*don’t mistake these sinuses for air filled spaces
What is the Superior/Inferior Sagittal Sinus?
dural venous sinuses which run along the superior and inferior border of the falx cerebri
-collect blood from the brain and direct it into internal jugular
What are arachnoid granulations?
projections of the arachnoid membrane into the dural sinuses that allow CSF entrance from the subarachnoid space into the venous system (communication between CSF and blood)
What is the blood brain barrier?
specialised interface between circulating blood and the CNS
protects the CNS by allowing certain types of molecules to pass
Why do veins in the brain not have valves?
to allow the free-flow of blood
What is the ventricular system?
four interconnected ventricles in the brain, each containing a region of choroid plexus involved in the production of CSF
this system is part of the blood brain barrier
Where is the 4th ventricle located?
between brain stem and cerebellum
Where is the 3rd ventricle located?
diencephalon
Where are the lateral ventricles located?
within cerebral hemispheres
What is the brain stem composed of?
Midbrain
Pons
Medulla Oblongata
How many pairs of cranial nerves are there?
12 pairs
What is the Olfactory Nerve (CN I)?
originates from olfactory bulb and enters skull through cribriform plate, innervating nasal cavity
What is the role of the Optic Nerve (CN II)?
transmits visual information from the retina to the brain
What is the role of the Vagus Nerve (CN X)?
originates from medulla and innervates many different tissues; important for sympathetic and parasympathetic innervation throughout the body
