Labs

Question 1

What is the Powerlab?

Answer 1

Recording hardware that measures electrical signals via different biological transducers.
Can measure finger pulse, blood pressure, respiration and electromyography.

Question 2

What is LabTutor and LabChart?

Answer 2

Computer software packages that control the Powerlab and display the measured electrical signals.

Question 3

How do you calculate BMI?

Answer 3

Weight divided by height (squared).

Question 4

What is the test used for measuring fat distribution?

Answer 4

Calculating the waist:hip ratio which is waist circumference divided by hip circumference.
Women: Below 0.8.
Men: Below 0.95.

Question 5

How can skeletal size be determined?

Answer 5

Measuring the circumference/diameter of a part of the body that is non-muscular and not a usual fat deposition site.
Elbow width is commonly used.

Question 6

What is the lean body mass?

Answer 6

The non-fat proportion of the body.

Question 7

How can lean body mass be estimated?

Answer 7

Measuring the body density using skinfold thickness measurements.
Calipers (exert a constant pressure at the jaws) measure the depth of dermal adipose tissue which whole body measurements can then be extrapolated from.

Question 8

What are the layers found in the cerebral cortex?

Answer 8

Layer I: Molecular layer.
Layer II: External granular layer.
Layer III: External pyramidal layer.
Layer IV: Internal granular layer.
Layer V: Internal pyramidal layer.
Layer VI: Fusiform layer.

Question 9

What is the difference between agranular and dysgranular?

Answer 9

Agranular describes cortical areas with no layer IV whereas dysgranular describes cortical areas with a rudimentary layer IV.

Question 10

What are the supporting cells to neurons?

Answer 10

Glia cells.

Question 11

Describe the cellular composition of a neuron.

Answer 11

Soma (cell body) with associated processes (dendrites and axons).
Dendrites radiate out for up to 1mm and are specialised for receiving nerve connections. Some have protuberances which are specialised for receiving connections from other neurons via synapses.
Axons conduct nerve impulses away from the soma for up to 1m. These generally do not taper like dendrites.

Question 12

Give 3 methods for staining neurons and their uses.

Answer 12

Nissl Stain: stains soma but not processes. Used to study distribution of somata in certain brain regions.
Fibre Stain: stains processes. Used to study complexity of neuropil.
Golgi Stain: randomly stains whole nerve cells for reasons unknown. Used to study and visualise whole individual nerve cells.

OTHER METHODS:
Electron Microscopy.
Histochemical/Immunohistochemical methods.
Receptor Autoradiography.
Neuroanatomical Tracing Methods.

Question 13

Define cytoarchitectonics.

Answer 13

The subdivision of CNS structures based on the organisation and distribution of neuronal somata within them.

Question 14

Define myeloarchitecture.

Answer 14

The distribution of fibre tracts in the brain.

Question 15

What makes up the white matter?

Answer 15

Myelinated axons.

Question 16

What makes up the grey matter?

Answer 16

Nerve cell bodies.

Question 17

What is the corpus callosum?

Answer 17

Thick region of white matter under the cortex that connects the left and right cerebral hemispheres.

Question 18

What separates the left and right cerebral hemispheres?

Answer 18

The longitudinal fissure.

Question 19

What is lateralisation of brain function?

Answer 19

The tendency for some neural functions or cognitive processes to be more dominant in one hemisphere than the other.

Question 20

What are gyrus and sulcus in neuroanatomy?

Answer 20

Gyrus is the ridge and sulcus are the depressions which increase the surface area of the cerebral cortex. Confined to skull limiting brain size.

Question 21

What is the approximate volume and weight of the human brain?

Answer 21

1-1.5l and 3 pounds.

Question 22

Why does a human brain in situ have a different volume to preserved brain?

Answer 22

Lost matter from Alzheimer’s/gained from a tumour.
Brain has lost it’s blood supply.
Preserved brain denser because lost CSF cushioning and shrinks with fixatives.

Question 23

What is the cerebellum?

Answer 23

Hindbrain structure which coordinates movement, balance and learning of complex motor skills.

Question 24

What is the Purkinje cell layer?

Answer 24

Layer of large neuron cell bodies located at the interface of molecular and granular layers.

Question 25

What is the shape of the Purkinje cell processes?

Answer 25

Spiky zig zag shaped like a spider’s web forming out like a tree into the molecular layer.

Question 26

What is stereology?

Answer 26

3D interpretation of 2D cross sections of materials or tissues.

Question 27

What conditions are associated with extensive damage to the hippocampus?

Answer 27

Amnesic states and dementia.

Question 28

What does Toluidine Blue stain?

Answer 28

Cell nuclei.

Question 29

What does the Weigert-Pal procedure stain?

Answer 29

Myelin.

Question 30

What is neuronal migration?

Answer 30

Brings cells into appropriate spatial relationships with each other. Final mitosis is in the ventricular zone; CNS neurons migrate within the neural tube but PNS migrate longer distances from the neural crest.
2 methods: (1) Guided by specialised adhesion molecules in extracellular matrix/cell surface. (2) Crawl along radial glia (cerebrum, hippocampus etc).

Question 31

What cells produce myelin in the CNS and PNS?

Answer 31

CNS: Oligodendrocytes.
PNS: Schwann Cells.

Question 32

What is the neocortex?

Answer 32

Most recently evolved area of the brain concerned with higher brain functions. Different to emotional centre in limbic brain and basic life functions in the dinosaur brain.

Question 33

What is the name of neurons which project axons over a long distance?

Answer 33

Golgi type 1. (Golgi type 2 are short/no axons).

Question 34

What are interneurons?

Answer 34

Involved in communication of sensory/motor neurons and CNS.

Question 35

What is the neurotransmitter used at a neuromuscular junction?

Answer 35

AcH broken down by acetylcholinesterase.

Question 36

What structures are found at the growing tip of neuronal processes?

Answer 36

Growth cone with filopodia and lamellipodium.

Question 37

What is the shape of an astrocyte? Give some possible functions.

Answer 37

Star shaped.

(1) Spatial buffering.
(2) Metabolic support.
(3) Guidance during migration.

Question 38

What is the function of glial cells and give some types.

Answer 38

Surround neurons providing support and insulation.
Oligodendrocytes and Schwann cells - insulate.
Astrocytes - BBB, provide nutrients, maintenance of ion concs and repair after trauma.
Ependymal cells - Line CSF filled ventricles and central canal of spinal cord.
Microglia - Macrophages of brain.
Satellite cells - Similar to astrocytes plus cushioning effect.

Question 39

What is a Langendorff preparation?

Answer 39

An isolated perfused mammalian heart useful for teaching physiology and pharmacology.

Question 40

What stimulates the contractions of the heart?

Answer 40

Action of the sinoatrial node (pacemaker)

Question 41

What are the affects of the sympathetic nervous system on the heart?

Answer 41

Noradrenaline/Norepinephrine at postsynaptic beta 1 adrenoreceptors increase the force and rate of the heart.

Question 42

What are the affects of the parasympathetic nervous system on the heart?

Answer 42

Acetylcholine at M2 muscarinic receptors decrease the force and rate of the heart.

Question 43

What drugs affect the neurotransmitters of the sympathetic and parasympathetic nervous systems in terms of heart control?

Answer 43

Propanolol blocks beta 1 adrenoreceptor.
Neostigmine inhibits cholinesterase.
Atropine blocks M2 receptor.