neuro: structure of the nervous system Flashcards
what is the human nervous system comprised of?
-central nervous system
-peripheral nervous system
what do the two categories of the nervous system consist of?
- cns - spinal cord and brain
-pns- somatic nervous system and autonomic nervous system (all parts of the nervous system except for the brain and spinal cord)
somatic nervous system: voluntary control of movement and locomotion
autonomic: innervation to the cardiovascular system and smooth muscle.
what is the autonomic nervous system divided into?
-sympathetic - fight flight - increased heart rate and blood pressure, depressed digestive functioning
-parasympathetic- rest and digest - decreased heart rate and blood pressure - increased digestive functioning
what are the major brain regions?
- forebrain
-brain stem - cerebellum
recap on some anatomical terms:
anterior posterior, rostral-caudal, dorsal-ventral, superior-inferior.
Anterior posterior : front, behind
rostral caudal: nose, tail
dorsal ventral: top, bottom
superior inferior: above, below
what sections do coronal, horizontal and Sagittal planes break the brain into?
- coronal (crown) - divide the brain into anterior (front) and posterior (back) sections
-horizontal- divide brain into superior (upper) and inferior ( lower) sections.
-sagittal: midsagittal (midline) or parasagittal (more lateral)
what is the function of the hippocampus?
-hippocampus is greek for “seahorse”
- learning
-memory
- regulation of hypothalamus-pituitary axis
what happens if you get a hippocampal dysfunction?
- anterograde amnesia (unable to create more memories)
- Retrograde amnesia (unable to recall past memories)
what do coronal sections of the brain show us?
coronal sections can reveal important regions within the forebrain, including the hippocampus (the hippocampus is a part of the temporal lobe) - look at ur notes for this lecture for the picture xox
what does the horizontal section show?
-the superior and inferior sections
can reveal imp regions within the forebrain including sub cortical structures such as the hippocampus - again for diagrams check your notes
what does the Sagittal section look like ?
- divide brain into left and right hemispheres and can be further categorised into mid sadittal and parasagittal.
- can reveal imp regions within the forebrain including various sub cortical structures such as THE HIPPOCAMPUS. For diagrams check notes
what are the cranial nerves?
-they are the twelve pairs of nerves that arise from the brain stem that perform a range of functions.
name all the cranial nerves
- first two nerves are CNS the rest are PNS.
I - olfactory (CNS)
II- optic (CNS)
III- oculomotor
IV- trochlear
V- trigeminal
VI- abducens
VII- facial
VIII- auditory-vestibular
IX- glossopharyngeal
X- vagus
XI- spinal accessory
XII- Hypoglossal
function of cranial nerve I?
-special sensory: sensation of smell
In our noses we have olfactory epithelium, which consist of olfactory receptor cells.
The function of olfactory nerve is to mediate thus information to the olfactory bulb, where it is then conveyed to other brain structures. These brain structures are the:
Frontal cortex (conscious perception of smell)
Hippocampus ( odour memory)
Hypothalamus amygdala (motivational and emotional aspects of smell)
function of cranial nerve II?
special sensory: sensation of vision
transmits information from rods and cones in the retina via the lateral geniculate nucleus to the visual cortex which is in the occipital lobe of the brain.
This is what allows us to interpret colours in our brain
Function of cranial nerve III?
-oculomotor
- somatic motor: it is involved in somatic motor function (controlling eye and eyelid movement)
- autonomic motor: involved in parasympathetic control of pupil size.
function of cranial nerve IV?
- trochlear
-somatic motor: eye movement
cranial nerve 3 is responsible for movement of the superior and inferior recuts muscle, moving the eye up and down. It is also responsible for the movement of the inferior oblique (which moves the eye outward) and the medial rectus (moving the eye inward)
Cranial nerve 4 is responsible for the movement of the superior oblique (moving the eye upwards)
function of cranial nerve V?
-trigeminal nerve
- somatic sensory: sensation of touch to the face
somatic motor: movement of muscles of mastication (chewing)
function of cranial nerve VI?
- abducens
-somatic motor: eye movement (like cranial nerve III and IIII) - cranial nerve VI is responsible for the movement of the lateral rectus muscle in the eye allowing for lateral movement of the eye.
function of cranial nerve VII?
- facial
-somatic motor: movement of muscles of facial expressions
special sensory: sensation of taste in the anterior tongue.
cranial nerve VIII?
- vestibulocochlear
-special sensory: hearing and balance
function of cranial nerve IX?
-glossopharyngeal
- involved in both sensory and motor functions
- special sensory: sensation of taste in posterior tongue
- autonomic sensory : detection of blood pressure changes in the aorta
-somatic motor: movement of muscles in the throat
-autonomic motor: parasympathetic control of salivary glands
function of cranial nerve X?
vagus nerve
Involved in both sensory and motor
- visceral (autonomic) sensory: sensation of pain associated with viscera (internal organs)
-somatic motor: movement of muscles in the throat
- visceral motor: parasympathetic control of the heart, lungs and abdominal organs
function of cranial nerve XI?
cranial nerve 10 and 11 are the most posterior nerves
- spinal accessory
- somatic motor: movement of muscles in the throat and neck
function of cranial nerve XII?
- hypoglossal
- somatic motor: movement of the tongue (eg swallowing and speech)
what are the three structures that protect and support the brain?
-meninges
- ventricular system
- vasculature system
describe the meninges?
- in Greek, meninges means ‘covering’
- it describes the three membranous layers that cover the brain and spinal cord.
which layers does the meninges comprise of (full detail) ?
- dura mater: outermost layer of the meninges. Tough inelastic layer that surrounds the brain and spinal cord and is adhered tightly to the brain.
-arachnoid mater: underneath the dura mater. Lies closely against the dura mater (is not attached to it)
-the dura mater and arachnoid mater are separated by the subdural space
- pia mater: deepest layer of the meninges, consist of a thin membrane that adheres closely to the surface of the brain.
-the pia mater is separated from the arachnoid mater by the subarachnoid space. It is a fluid filled space that consists of cerebral spinal fluid (CSF) - separates the two layers.
what is the function of the meninges?
-it’s main function is the support of the brain and the spinal cord.
- also has function in the passage of cerebrospinal fluid in relation to the ventricular system
- support of cerebral and spinal blood vessels (vasculature system)
what does the ventricular system comprise of?
- comprises of interconnected cerebrospinal fluid filled spaces that lie at the core of the forebrain and brain stem.
Comprises of:
- lateral ventricles
- third ventricle
- fourth ventricle
within each of these ventricles there is a special tissue called: choroid plexus. It is responsible for producing the cerebrospinal fluid that fills the ventricular spaces.
what is the function of the ventricular system?
- protection of the brain ( acts as a cushion for physical shock)
-transport (eg nutrients, waste products via the cerebrospinal fluid) - other functions include regulation of buoyancy.
which two arteries supply blood to the brain?
- internal carotid arteries
- vertebral arteries
which area specifically do the two arteries provide blood to the brain?
-internal carotid artery is a branch of the common carotid artery.
- vertebral arteries arise from the subclavian artery.
-These two arteries can be categorised into anterior and posterior blood supplies of the brain.
-Anterior circulation is provided from the internal carotid arteries- supplies the forebrain
-posterior circulation is derived from the vertebral artery which supplies the brain stem, cerebellum and upper spinal cord.
describe the vertebral arteries
- they converge near base of the brain of pons to form the basilar artery
- at the midbrain, the basilar artery splits into a right and left superior cerebellar artery and the posterior cerebral artery.
- posterior cerebral artery send branches , posterior communicating arteries that connect to the internal carotid arteries.
describe the internal carotid arteries
- they branch to form the middle cerebral arteries and the anterior cerebral arteries.
- anterior cerebral arteries are commented via the anterior communicating artery.
- a ring of connected arteries form the circle of Willis at the base of the brain.
Vasculature system function?
- delivery of oxygen
- removal of carbon dioxide
- transport (or nutrients, waste products etc.)
