Structure of the nervous system (cranial system) Flashcards
What does the CNS and PNS consist of?
1)CNS= brain and spinal cords
2)PNS= somatic and autonomic nervous system
what are the 3 major brain regions?
1)Forebrain
2)Brainstem
3)Cerebellum
what are the 4 axes of the brain? just give their names
1)Anterior-posterior
2)Rostral-Caudal
3)Dorsal- Ventral
4)Superior-Inferior
what is the anterior-posterior axes of the brain?
1)Anterior- front view of brain
Posterior-backside of the brain
what is the rostral-caudal axes of the brain?
Rostral- towards the front of the head/towards nose
Caudal-towards the4 back of the head/tail
what is the dorsal-ventral axes of the brain?
Dorsal-the top half of the brain
Ventral-bottom half of the brain
What is the superior-inferior axes of the brain?
superior- above head
inferior- below head
what are the 3 planes of the brain?
1)Coronal
2)Horizontal
3)Sagital
What is the coronal plane?
Divide the brain into a front (anterior) and a back (posterior) section
what is a horizontal plane?
Divide the brain into an upper (superior) and lower (inferior) section
what is a sagital plane?
Divides the. brain into 2 hemispheres
what is the sagital plane further characterised by?
1)Midsagittal (midline)
2)Parasagittal (more lateral)
in which lobe is the hippocampus located?
Temporal lobe
name 3 functions of the hippocampus
Learning
Memory
Regulation of hypothalamic-pituitary axis
why do we get amnesia?
due to hippocampus dysfunction
what are the 2 types of amnesia and what is their difference?
Anterograde amnesia= unable to create new memories
Retrograde amnesia= unable to recall past memories
What is the difference between afferent and efferent neurons?
Afferent neurons= carry info to the CNS
Efferent neurons= carry info away from the CNS
What are cranial nerves?
A set of 12 paired nerves in the back of your brain. They send electrical signals between your brain, face, neck and torso. They help you experience your senses
Name the 12 cranial nerves in order.
1)Olfactory
2)Optic
3)oculomotor
4)Trochlear
5)Trigerminal
6)Abducens
7)Facial
8)Vestibulocochlear
9)Glasopharyngeal
10)Vagus
11)Accessory
12)Hypoglossal
What is Cranial nerve 1? and what is its function?
1)Olfactory
2)Sensation of smell
What is Cranial nerve 2? and what is its function?
1)Optic
2)Sensation of vision
What is Cranial nerve 3? and what is its function?
1)Oculomotor
2)Somatic motor-eye and eyelid movement
2)Visceral (autonomic) motor-parasympathetic control of pupil size
What is Cranial nerve 4? and what is its function?
1)Trochlear
2)Somatic motor- eye movement
What is Cranial nerve 5? and what is its function?
1)Trigerminal
2) somatic sensory-sensation of touch on the face
2)somatic motor-movement of muscle for mastication (chewing)
What is Cranial nerve 6? and what is its function?
1)Abducens
2)Somatic motor- eye movement- controls lateral rectus
What is Cranial nerve 7? and what is its function?
1)Facial
2)somatic motor-movements of muscles of facial expressions
2)Special sensory-sensation of touch in the anterior tongue
What is Cranial nerve 8? and what is its function?
1)Vestibulocochlear
2)Auditory-vestibular (vestibulochoclear nerve)
2)Special sensory- Hearing and balance
What is Cranial nerve 9? and what is its function?
1)Glasopharyngeal
Special sensory-sensation of taste in the posterior tongue
Visceral sensory- detection of bp changes in the aorta
Somatic motor-movement of muscles in the throat
visceral motor-parasympathetic control of salivary glands
What is Cranial nerve 10? and what is its function?
1)Vagus/ CN X
Visceral sensory-sensation of pain associated with viscera (internal organs)
Somatic motor-movement of muscles in the throat
Visceral motor-Parasympathetic control of heart, lungs and abdominal organs
What is Cranial nerve 11? and what is its function?
1)Accessory/ CN XI
2)Somatic motor- movement of muscles in the throat and neck
What is Cranial nerve 12? and what is its function?
1)Hypoglossal / CN XII
2)Somatic motor-movement of the tongue (e.g swallowing or speech)
What 3 things provide support and protection to the brain?
1)Meninges
2)Ventricular system
3)Vasculature system
what are mininges? and what is their function?
3 membrane layers that cover the brain (and spinal cord)
They function to:
1)protect the brain and spinal cord
2)enable passage of css-ventricular system
3)support of cerebral and spinal blood vessels- Vasculature system
what are the 3 membranes that cover the brain/ Meninges?
1)Dura Mater= tough outer layer
2)Arachnoid= middle layer
3)Pia Mater= delicate inner layer
what is the function of the middle meninge (Arachnoid)?
Adheres the layer together
stops the brain from moving around
anchors the brain in the correct position in the skull so it doesn’t move
where is csf made and why is it important?
In the Arachnoid membrane layer of the subarachnoid space. It is important as It provides a chemical stability and nutrients.
What is the Ventricular system?
A series of interconnected CSF-filled spaces that lie at the core of the forebrain and brainstem
what are the 3 parts that the ventricular system comprises of?
1)Lateral ventricles
2)Third ventricle
3)Fourth Ventricle
what is responsible for producing csf that fills the 3 ventricles?
The Choroid plexus
what are the 3 functions of the ventricle system?
1)Protection of the brain
2)Transport e.g nutrients, waste products
3)other functions e.g regulation of buoyancy
what does the vasculature of the brain consist of?
Two pairs of arteries that supply blood to the brain: internal carotid arteries and vertebral arteries
Anterior circulation is supplied by what artery and where does it supply?
Anterior circulation is supplied by the internal carotid arteries and supplies the forebrain (cerebrum and diencephalon)
Posterior circulation is supplied by what artery and where does it supply?
Posterior circulation is derived from the vertebral arteries and supplies the brainstem, cerebellum and upper spinal cord
Describe the vertebral arteries location and what they split off into
Vertebral arteries converge near base
of pons to form the basilar artery
Basilar artery splits into the right and
left superior cerebellar arteries and
the posterior cerebral arteries at the
level of the midbrain
Posterior cerebral arteries send
branches – posterior communicating
arteries – that connect to the internal
carotid arteries
Describe the internal carotid arteries and where they split off into
Internal carotid arteries branch to
form middle cerebral arteries and the
anterior cerebral arteries
Anterior cerebral arteries are
connected by the anterior
communicating artery
Ring of connected arteries form the circle
of Willis at the base of the brain
