Structure of the CNS Flashcards
What does dorsal refer to?
Dorsal refers to the top and outside part
What does ventral refer to?
Ventral refers to the lower and inside parts
What is anterior?
The front
What is posterior?
Behind
What is superior?
Above
What is inferior?
Below
What is the midline?
Midline is the line at which we’re symmetrical
What does medial mean?
Means closer to midline
What does lateral mean?
Means away from the midline
What does ipsilateral mean?
Its when two thing are located on the same side of the midline
What does contralateral mean?
Its when two things are located on either side of the midline
How is efferent and afferent defined?
E.G
A neuron projecting from the thalamus to the cortex is both a thalamic efferent and a cortical afferent
How many cranial nerves are there?
There are 12 bilateral cranial nerves
What are cranial nerves?
Are afferent sensory fibres and efferent motor fibres
How are cranial fibres numbered?
Numbered from anterior to posterior
Acronym for cranial fibres
O
What is cranial nerve I?
Is the olfactory I
What’s the function of cranial nerve I?
Purely sensory and involved in smell
How is information from the nose transmitted along cranial nerve I and to where?
Nose has olfactory epithelium which transmits information to the olfactory bulb and this transmits information to:
- Olfactory cortex(Conscious perception of smell)
- Hippocampus(Odor memory)
- Hypothalamus and amygdala(Motivational and emotional aspect of smell)
What is cranial nerve II?
Optic nerve
What is the function of cranial nerve II?
Purely sensory
Where does cranial nerve II take information from and to?
Takes information retinal ganglion cells to the lateral geniculate nucleus in the thalamus and to the visual cortex in the occipital lobe
What is cranial nerve III?
Oculomotor nerve
What is the function of cranial nerve III and what they involved in?
Motor
-Involved in eyeball and eyelid movement
Parasympathetic
-Concerned with pupillary constriction and accommodation
What nerve is cranial nerve IV?
Trochlear nerve
What is the function of cranial nerve IV and what is it involved in?
Motor
-Involved in eyeball movement
What is cranial nerve VI?
The abducens nerve
What is the function of cranial nerve VI and what’s it involved in?
Motor
-Involved in eyeball movement
What eyeball muscles are controlled by CN III?
- Superior rectus
- Inferior oblique
- Inferior rectus
- Medial rectus
What eyeball muscles are controlled by CN IV?
-Superior oblique
What eyeball muscles are controlled by CN VI?
-Lateral rectus
What eyeball muscles are controlled by CN II and for what?
Palpebrae muscles controlled by CNII for eyelid opening
What is cranial nerve V?
Trigeminal nerve
How many divisions does cranial nerve V have and to where and what is there function at those locations?
Ophthalmic -Sensory Mandibular -Sensory Maxillary -Sensory
What is cranial nerve VII?
Facial nerve
What functions does cranial nerve VII have and what are they involved in?
Sensory -Sensation of taste(Anterior 2/3 of tongue) Motor -Muscles of facial expression -Stapedius muscle Parasympathetic -Salivary glands -Lacrimal glands -Glands of the nose and palate
What is cranial nerve VIII?
-Vestibulocochlear nerve
What is the function of cranial nerve VIII and what is it involved in?
Sensory
-Mediates hearing and balance
What cells mediate hearing?
Cochlea cells
What cells mediate balance?
Vestibular hair cells
What are the pathway of information for hearing in cranial nerve VIII?
Cochlea cells–>Medial geniculate nucleus–>Auditory complex
What are the pathways of information for balance in cranial nerve VIII?
Vestibular cells–>Ventral posterolateral nucleus–>Vestibular cortex
What is cranial nerve IX?
Glossopharyngeal nerve
What are the functions of cranial nerve IX and what are they involved in?
Sensory -Pharynx -Auditory tube -Posterior 1/3 of tongue -Blood pressure changes in aorta Motor -Swallowing Parasympathetic -Salivary glands
What is cranial nerve X?
Vagus nerve
What are the functions of cranial nerve X and what are they involved in?
Sensory
-Sensation of pain associated with viscera
Motor
-Muscles for speech and swallowing
Parasympathetic
-Smooth muscle in heart, lung and abdominal organs
What is cranial nerve XI?
Accessory nerve
What is the function of cranial nerve XI and what is it involved in?
Motor
- In cranial
- Muscles of pharynx, larynx and soft palate
- In spinal
- Head and neck muscles
What is cranial nerve XII?
Hypoglossal nerve
What is the function of cranial nerve XII and what is it involved in?
Motor
-Involved in tongue movement for swallowing and speech
What is meninges?
It is what’s between our skull and brain
How many membranes does the meninges have?
3 layers:
- Dura mater
- Arachnoid membrane
- Pla matter
What are the qualities of the dura mater?
- Tough
- Inelastic
What does the arachnoid membrane adhere?
Adheres layers together
What is the pia mater and where does it adhere?
A thin membrane and adheres closely to the brain
What is the subarachnoid fluid filled with?
Filled with CSF
What is the ventricular system?
System by which body produces CSF in the choroid plexus
CSF pathway from cerebellum to blood vessels
- CSF flows from the cerebellum ventricles down to the brainstem and spinal spinal cord
- CSF enters subarachnoid space via apertures near the cerebellum
- CSF is absorbed by blood vessels in the subarachnoid space
What does the CSF protect?
CSF protects the brain from physical and chemical energy
What does the ventricular system regulate?
Regulates intracranial pressure
Why is the ventricular system essential?
Essential in exchanging nutrients and waste products between blood and CNS
What . supplied blood to the brain?
Two pairs of arteries supply blood to the brain
- The vertebral arteries
- The carotid arteries
What forms a structure called the circle of willis?
Branches of arteries form a structure called the circle of willis
What is the circle of willis prone to and due to what?
Prone to blood clot due to turbulence
What is most of the free lateral surface of the cerebellum supplied by?
Supplied by the middle cerebral artery
What is the most of the medial wall of the cerebral hemisphere supplied by?
Supplied by the anterior cerebral artery
What is the lymphatic system important in?
Important in delivering immune cells
Where is the lymphatic system located in the brain?
Sandwiched in the dura mater