Structure of the Nervous system (neuro)

Question 1

Human nervous system

Answer 1

• the human nervous system is comprised of the central nervous system (CNS) and the peripheral nervous system (PNS)
• CNS is comprised of brain and spinal cord
• PNS is made up of the somatic nervous system and the autonomic nervous system

Question 2

Human brain

Answer 2

• the brain is the most complex organ in the human body
• controls basic fundamental life processes such as breathing, organ function and movement
• controls more complex processes such as thought, behaviour and emotion, and creating memories

Question 3

Major brain regions

Answer 3

1) Forebrain: telencephalon (or cerebrum) and diencephalon
2) Brainstem: midbrain, pons, medulla oblongata
3) Cerebellum

Question 4

Axes of the brain

Answer 4

• Anterior-posterior: anterior (front), posterior (behind)
• Rostral-caudal: rostral (nose), caudal (tail)
• Dorsal-ventral: dorsal (top), ventral (bottom)
• Superior-inferior|: superior (above), inferior (below)

Question 5

Planes of the brain

Answer 5

• Coronal: divide the brain into a front (anterior) and a back (posterior) section
• Horizontal: divide the brain into an upper (superior) and lower (inferior) section
• Sagittal: divide the brain into two hemispheres, further characterised as midsagittal (midline) or parasagittal (more lateral)

Question 6

Hippocampus

Answer 6

• the hippocampus is a region of the cerebral cortex embedded deep within the temporal lone
• function: learning, memory formation and retrieval, regulation of hypothalamus-pituitary-adrenal (HPA) axis
• dysfunction: virus can cause damage to hippocampus such as anterograde amnesia (unable to create new memories) and retrograde amnesia (generally unable to recall past memories)

Question 7

Coronal sections

Answer 7

• coronal sections can reveal important regions with the forebrain, including various sub-cortical structures (eg the hippocampus)

Question 8

Horizontal sections

Answer 8

• horizontal sections can reveal important regions with the forebrain, including various sub-cortical structures (eg the hippocampus)

Question 9

Sagittal sections

Answer 9

• sagittal sections can reveal important regions with the forebrain, including various sub-cortical structures (eg the hippocampus)

Question 10

Cranial nerves

Answer 10

• cranial nerves describe the twelve (l-Xll) pairs of nerves arising from the brainstem that perform a diverse range of functions:
  l. Olfactory
  ll. Opric
  lll. Oculomotor
  lV. Trochlear
  V. Trigeminal
  Vl. Abducens
  Vll. Facial
  Vlll. Auditory-vestibular (verstibulocochlear)
  IX. Glossopharyngeal
  X. Vagus
  Xl. Spinal accessory
  Xll. Hypoglossal

Question 11

Cranial nerves (l-ll)

Answer 11

Cranial nerve l (Olfactory):

• special sensory - sensation of smell
• olfactory receptor cells to olfactory bulb
• leads to frontal cortex (conscious perception of smell), hypothalamus amygdala (motivational and emotional aspects of smell) and hippocampus (odour memory)

Cranial nerve ll (Optic):

• special sensory - sensation of vision
• retinal ganglion cells to lateral geniculate nucleus (thalamus) to visual cortex (occipital lobe)

Question 12

Cranial nerves (lll- lV)

Answer 12

Cranial nerve lll (Oculomotor):

• somatic motor - eye and eyelid movement
• visceral (autonomic) motor - parasympathetic control of pupil size

Cranial nerve lV (Trochlear):
- somatic motor - eye movement

Question 13

Cranial nerves (V-Vl)

Answer 13

Cranial nerve V (Trigeminal):

• somatic sensory - sensation of touch to the face
• somatic motor - movement of muscles of mastication (chewing)

Cranial nerve Vl (Abducens):
- somatic motor - eye movement

Question 14

Cranial nerves (Vll-Vlll)

Answer 14

Cranial nerve Vll (facial):

• somatic sensory - movement of muscles of facial expressions
• special sensory - sensation of taste in anterior tongue

Cranial nerve Vlll (Vestibulocochlear):

• auditory-vestibular (vestibulocochlear) nerve
• special sensory - hearing and balance

Question 15

Cranial nerves (lX-X)

Answer 15

Cranial nerve lX (glossopharyngeal):

• special sensory - sensation of taste in posterior tongue
• visceral sensory - detection of blood pressure changes in aorta
• somatic motor - movement of muscles in throat
• visceral motor - parasympathetic control of salivary glands

Cranial nerve X (vagus):

• visceral sensory - sensation of pain associated with viscera (internal organs)
• somatic motor - movement of muscles in throat
• visceral motor - parasympathetic control of heart, lungs and abdominal organs

Question 16

Cranial nerves (Xl-Xll)

Answer 16

Cranial nerve Xl (spinal accessory):
- somatic motor - movement of muscles in throat and neck

Cranial nerve Xll (hypoglossal):
- somatic motor - movement of tongue (eg swallowing and speech)

Question 17

Protection and support of the brain

Answer 17

• meninges
• ventricular system
• vasculature sustem

Question 18

The Meninges

Answer 18

• the meninges describe the 3 membranous layers that cover the brain (and spinal cord)
• from superficial to deep, it comprises of: dura mater, arachnoid mater and Pia mater
• function: primary function is in protection of brain and spinal cord
• passage of cerebrospinal fluid (CSF) - ventricular system
• support of cerebral and spinal blood vessels - vasculature system

Question 19

Ventricular system of the brain

Answer 19

• ventricular system comprises of a series of interconnected, cerebrospinal fluid (CSF)-filled spaces that lie at the core of forebrain and brain stem
• comprises of lateral ventricles, third ventricle and fourth ventricle
• choroid plexus is responsible for producing the cerebrospinal fluid (CSF) that fills these ventricular spaces
• function: protection of brain (eg cushion of physical shocks)
• transport (eg nutrients, waste products)
• other functions include regulation of buoyancy

Question 20

Vasculature of the brain

Answer 20

• two pairs of arteries supply blood to the brain: the internal carotid arteries and the vertebral arteries
• anterior circulation is derived from the internal carotid arteries - supplies the forebrain (cerebrum and diencephalon)
• posterior circulation is derived from the vertebral arteries -supplies the brainstem, cerebellum and upper
  1) Verterbral arteries:
• converge near base of pons to form the basilar artery
• basilar artery splits into right and left superior cerebellar arteries and the posterior cerebral arteries at level of midbrain
• posterior cerebral arteries send branches - posterior communicating arteries - that connect to internal carotid arteries
  2) Internal carotid arteries:
• branch to form middle cerebral arteries and anterior cerebral arteries
• anterior cerebral arteries are connected by the anterior communicating artery
• ring of connected arteries from circle of Willis at base of brain
  functions:
• delivery of O2
• removal of CO2
• transport (eg nutrients, waste products)