ANHB2217

What comprises the central nervous system

Brain and the spinal cord

What comprises the peripheral nervous system

Spinal and cranial nerves

Function of nerve cells/neurons

Information-processing and signalling elements

Function of glial cells

Play supporting role

Multipolar neuron

Many dendrites

Bipolar/unipolar neurons

Two or one processes

Grey matter

Mainly cell bodies and dendrites

White matter

Mainly axons + myelin

Afferent

Towards

Efferent

Away

Motor fiber subdivision

Autonomic and somatic

Voluntary/somatic nervous system subdivisions

Somatic motor and special visceral motor

Involuntary/autonomic nervous system subdivisions

Autonomic and enteric nervous system

Primary brain vesicles

Prosencephalon, mesencephalon, rhombencephalon

Secondary brain vesicles

Telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon

Telencephalon

Cerebral hemispheres, commissures, central fissure

Diencephalon

Thalamus

Mesencephalon

Midbrain

Metencephalon

Pons + cerebellum

Myelencephalon

Medulla oblongata

Vermis

Connects two cerebellar hemispheres

Folia

Sulci and fissures of cerebellum

Spinal cord levels

Cervical (8), thoracic (12), lumbar (5), sacral (5), coccygeal (1)

Function of pia mater

Transmission of blood vessels to brain

Function of falx cerebri

Separates cerebral hemispheres

Function of falx cerebelli

Separates cerebellar hemisphers

Function of tentorium cerebelli

Separates cerebellum and occipital lobe

What is a cistern

Extended subarachnoid spaces

Function of arachnoid granulations

Absorb CSF from subarachnoid space back into venous blood

What would you look for when sampling CSF from cisterns?

Blood in CSF (CVA/stroke), leucocytes (signs of infection), bacteria (direct observation of pathogen)

Where is the cerebellomedullary cistern/cisterna magna?

Below cerebellum, just behind medulla of brainstem

Where is the interpeduncular cistern?

Near peduncles (which are above the pons) and below optic chiasm

Where does the spinal dura extend to?

To the level of S2

What does the epidural space, containing veins and fat, in the neural canal do?

Separates dura from periosteum of surrounding bone as spine has to move within vertebrae as you bend over

Where do the posterior and anterior nerve roots penetrate the dura?

Invertebral foramina.

What is the filum terminale?

Delicate strand of pia mater, extending from bottom of conus medullaris

What are denticulate ligaments?

Attach pia mater of spinal cord to arachnoid and dura

Location of anterior spinal artery

Ventral surface of spinal cord

Development of ventricular system

Neuroepithelium -> telencephalic vescicles (forming cerebral hemispheres) develop -> lateral ventricles from as cavity acquires extensions into each of the hemispheres

The cerebellum covers the dorsal aspect of_______

The 4th ventricle

All ventricular system cavities (ventricles, etc.) and passages (canals, foramina, cerebral aqueduct) contain ____ and are lined with ______

Cerebrospinal fluid, ependymal cells

What forms the roof of the 4th ventricle?

Thin membranes (superior and inferior vela) and cerebellum

Location of lamina terminalis

Between interventricular foramen and optic chiasm

CSF flow

Produced by choroid plexus -> lateral ventricles -> interventricular foramen (foramen of Monroe) -> 3rd ventricle -> cerebral aqueduct -> 4th ventricle -> foramina of Luschka and Magendie -> reabsorbed through arachnoid granulations/villi -> venous system

What can cause CSF blockages?

Tumour, aneurysm, bleed, congenital malformation

How to treat CSF blockage

Stent (tube) is run from expanded ventricle, under the skin, to peritoneal cavity where CSF is reabsorbed by peritoneum

What is hydrocephaly, what does it look like and how is it treated?

Build up of CSF in ventricles. Head enlarges if congenital and untreated. Treated by inserting shunt between ventricles and abdominal cavity to drain fluid.

Arnold Chiari malformation

Spinal cord attached to lower vertebrae, brainstem pulled down through foramen magnum. Can lead to blockage of cerebral aqueduct/hydrocephaly

Where does the brain receive its blood from?

Two carotid arteries and vertebral-basilar system

What is the Circle of Willis?

Anastomotic system on base of brain formed by vessels - supplies arterial blood to entire brain

What are the anterior cerebral arteries branches of, what do they supply, and how/where are they joined?

Branches of internal carotid; supply medial aspect of each cerebral hemisphere; joined anterior to optic chiasm by anterior communicating artery

Where can the middle cerebral arteries be seen?

In the lateral fissure

What are the posterior cerebral arteries terminal branches of and what do they supply?

Terminal branches of basilar arteries. Supply inferior surface of temporal and inferior and medial surface of occipital lobe

What does the anterior communicating artery join?

The left and right anterior cerebral arteries

What does the posterior communicating artery join?

The internal carotid with the posterior cerebral artery

The _____________ do not reach the cerebellum until after they have executed an S-shaped bend to supply the _________

Posterior inferior cerebellar arteries, lateral and dorsal medulla

What do the small penetrating vessels which arise from the middle, anterior and posterior cerebral arteries supply and what are they involved in?

Basal ganglia and diencephalon, stroke

Proper name for stroke

Cerebro-vascular accident (CVA)

Causes of stroke

Fatty embolisms, haemorrhages

What are the two prominent sulci on the lateral surface of the cerebral hemispheres?

Lateral (Sylvian) sulcus and central sulcus (of Rolando)

What are the motor and somesthetic receptive areas?

Precentral and postcentral gyrus

What is the prefrontal cortex functionally related to?

Motivation, attitude, personality characteristics and decision making

What is the inferior frontal gyrus divided into?

Opercular, triangular and orbital parts

What are the opercular and triangular parts centres for in the dominant hemisphere?

Motor control of speech (Broca's area)

Where does the primary sensory cortex receive input from?

Thalamus

What divides the parietal lobe into the inferior and superior parietal lobules?

Intraparietal sulcus

What are the transverse temporal gyri (Heschl's gyri) associated with?

Auditory processing

What is found in the posterior part of the superior temporal gyrus?

Wernicke's receptive speech area

What do the superior and inferior occipital gyri constitute?

Visual association cortex

What is the calcarine fissure the location for?

Primary visual cortex

Parts of corpus callosum

Genu, body, splenium

What is the hippocampus involved in?

Memory and emotion

What does the uncus overly?

The amygdala

What/where is the amygdala and what is it involved in?

A large nucleus at tip of temporal lobe; involved in emotion and memory but also has large olfactory input

What do the fibres of the pons continue to?

The cerebellum on either side as middle cerebellar peduncles

What needs to be done to see the insula?

Lateral fissure needs to be separated

What is the midline of the cerebellar hemispheres called?

Vermis

What does the inferior cerebellar peduncle attach the cerebellum to?

Dorsolateral aspect of the medulla

What gets stained blue on the slides?

Myelinated fibres

What are the cells in white matter, if any?

Glial cells

What are the fibres in grey matter, if any?

Axons and dendrites

What is the condenser of the microscope used for?

Can be raised or lowered to focus light on specimen

What does silver stain stain?

Fibres

What can Luxol blue stain?

Myelin

What can cresyl fast violet stain?

Cell bodies/contents of cell. Is good at showing mitochondria, nucleus and nucleolus

What does Van Giesens stain stain?

Collagen and other connective tissue

Why is the mammalian eye 'unintelligent'?

Optic nerve blocks portion of eye, nerve fibres on inside stop of light from reaching rods and cones

What is a tapetum?

Reflective layer of choroid in eyes of many animals, causing them to shine in the dark

What colour does haemotoxalin stain and what does it stain?

Deep blue-purple; stains nucleic acids/nuclei

What colour does eosin stain and what does it stain?

Pink; stains proteins, cytoplasm, extracellular matrix

Better methods of showing unstained tissue

Polarising microscopy, phase contrast, Nomarski

What does osmium stain?

Lipids

Where are the biggest 'Alpha' neurons found in the spinal cord?

Ventral horn of grey matter

What is polarising microscopy?

Uses polarising filters to make use of polarised light, configuring the movement of light waves and forcing their vibration in a single direction

What is phase contrast?

Converts phase changes in light passing through a transparent specimen to brightness changes in the image

What is Nomarski?

Differential Interference Contrast microscopy (DIC), enhances contrast in unstained, transparent samples

Which pathway carries information about course touch?

Anterior spinothalamic tract

Which pathway carries information about pain and temperature?

Lateral spinothalamic

Which pathway carries information about fine touch and proprioception?

Dorsal columns (fasciculus gracilis and fasciculus cuneatus)

Which tract carries information from muscle and joint receptors to cerebellum?

Spinocerebellar tract