neuro: structure of the nervous system

Question 1

what is the human nervous system comprised of?

Answer 1

-central nervous system
-peripheral nervous system

Question 2

what do the two categories of the nervous system consist of?

Answer 2

• 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.

Question 3

what is the autonomic nervous system divided into?

Answer 3

-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

Question 4

what are the major brain regions?

Answer 4

• forebrain
  -brain stem
• cerebellum

Question 5

recap on some anatomical terms:
anterior posterior, rostral-caudal, dorsal-ventral, superior-inferior.

Answer 5

Anterior posterior : front, behind

rostral caudal: nose, tail

dorsal ventral: top, bottom

superior inferior: above, below

Question 6

what sections do coronal, horizontal and Sagittal planes break the brain into?

Answer 6

• 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)

Question 7

what is the function of the hippocampus?

Answer 7

-hippocampus is greek for “seahorse”
- learning
-memory
- regulation of hypothalamus-pituitary axis

Question 8

what happens if you get a hippocampal dysfunction?

Answer 8

• anterograde amnesia (unable to create more memories)
• Retrograde amnesia (unable to recall past memories)

Question 9

what do coronal sections of the brain show us?

Answer 9

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

Question 10

what does the horizontal section show?

Answer 10

-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

Question 11

what does the Sagittal section look like ?

Answer 11

• 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

Question 12

what are the cranial nerves?

Answer 12

-they are the twelve pairs of nerves that arise from the brain stem that perform a range of functions.

Question 13

name all the cranial nerves

Answer 13

• 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

Question 14

function of cranial nerve I?

Answer 14

-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)

Question 15

function of cranial nerve II?

Answer 15

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

Question 16

Function of cranial nerve III?

Answer 16

-oculomotor
- somatic motor: it is involved in somatic motor function (controlling eye and eyelid movement)
- autonomic motor: involved in parasympathetic control of pupil size.

Question 17

function of cranial nerve IV?

Answer 17

• 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)

Question 18

function of cranial nerve V?

Answer 18

-trigeminal nerve
- somatic sensory: sensation of touch to the face

somatic motor: movement of muscles of mastication (chewing)

Question 19

function of cranial nerve VI?

Answer 19

• 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.

Question 20

function of cranial nerve VII?

Answer 20

• facial
  -somatic motor: movement of muscles of facial expressions
  special sensory: sensation of taste in the anterior tongue.

Question 21

cranial nerve VIII?

Answer 21

• vestibulocochlear
  -special sensory: hearing and balance

Question 22

function of cranial nerve IX?

Answer 22

-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

Question 23

function of cranial nerve X?

Answer 23

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

Question 24

function of cranial nerve XI?

Answer 24

cranial nerve 10 and 11 are the most posterior nerves

• spinal accessory
• somatic motor: movement of muscles in the throat and neck

Question 25

function of cranial nerve XII?

Answer 25

- hypoglossal - somatic motor: movement of the tongue (eg swallowing and speech)

Question 26

what are the three structures that protect and support the brain?

Answer 26

-meninges - ventricular system - vasculature system

Question 27

describe the meninges?

Answer 27

- in Greek, meninges means ‘covering’ - it describes the three membranous layers that cover the brain and spinal cord.

Question 28

which layers does the meninges comprise of (full detail) ?

Answer 28

- 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.

Question 29

what is the function of the meninges?

Answer 29

-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)

Question 30

what does the ventricular system comprise of?

Answer 30

- 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.

Question 31

what is the function of the ventricular system?

Answer 31

- 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.

Question 32

which two arteries supply blood to the brain?

Answer 32

- internal carotid arteries - vertebral arteries

Question 33

which area specifically do the two arteries provide blood to the brain?

Answer 33

-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.

Question 34

describe the vertebral arteries

Answer 34

- 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.

Question 35

describe the internal carotid arteries

Answer 35

- 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.

Question 36

Vasculature system function?

Answer 36

- delivery of oxygen - removal of carbon dioxide - transport (or nutrients, waste products etc.)