NEURO 1

Question 1

venous drainage of the brain

1. blood from the cerebral circulation drains into sinuses that are formed between the dura and arachnoid
2. the cavernous sinus does not receive blood from the orbit
3. cerebrospinal fluid is re-absorbed into the inferior sagittal sinus
4. the straight sinus receives venous blood from the inferior sagittal sinus and the great cerebral vein
5. venous blood from the cerebral circulation exits the cranium via the jugular foramina and is returned to the heart via the external jugular veins

Answer 1

4. the straight sinus receives venous blood from the inferior sagittal sinus and the great cerebral vein

Question 2

arterial supply of the brain

1. The majority of the blood supply comes from the two vertebral arteries
2. The left anterior cerebral artery carries blood to the motor cortex of the right leg
3. The basilar artery carries blood to the basal ganglia
4. An embolus of the internal carotid artery will infarct the cerebellum
5. The posterior cerebral arteries are direct branches from the internal carotid arteries

Answer 2

2. The left anterior cerebral artery carries blood to the motor cortex of the right leg

Question 3

Circle of Willis

1. Is formed by vessels of the anterior circulation of the brain only
2. The middle cerebral artery is a direct continuation of the internal carotid artery
3. Supplies blood to the cerebellum
4. Is an uncommon site for Berry aneurysms to occur
5. The communicating arteries act as a functional anastomoses between the left and right cerebral circulations

Answer 3

2. The middle cerebral artery is a direct continuation of the internal carotid artery

Question 4

stroke syndromes and the functional units of the brain

1. Wernicke’s area is located in the frontal lobe and Broca’s area is situated in the temporal lobe
2. A stroke affecting the circulation to the occipital lobe may result in memory problems
3. A stroke affecting the internal capsule is usually embolic
4. Strokes affecting one side of the motor or sensory cortex will result in a contra-lateral neurological deficit
5. A right hemisphere stroke is likely (i.e. > 50%) to cause dysphasia in a left handed individual

Answer 4

4. Strokes affecting one side of the motor or sensory cortex will result in a contra-lateral neurological deficit

Question 5

the primary motor cortex- 1

1. Occupies the post-central gyrus
2. Is supplied by the middle cerebral artery only
3. The largest muscles of the body are given the largest area of the motor cortex
4. Is also known as Brodmann’s Area 44
5. Muscles of the lower limbs are represented medially, whereas the muscles of the face are represented laterally

Answer 5

5. Muscles of the lower limbs are represented medially, whereas the muscles of the face are represented laterally

Question 6

the primary motor cortex- 2

1. The corticospinal tract originates from the ventrolateral (motor) thalamic nucleus
2. The corticospinal tracts pass between the basal ganglia and thalamus to enter the cerebral peduncle
3. The lateral corticospinal tract decussates at the level of the pons
4. A stroke affecting the motor cortex will result in a greater neurological deficit than the same sized stroke affecting the internal capsule
5. The motor cortex produces an abnormal rhythmical output in Parkinson’s disease

Answer 6

2. The corticospinal tracts pass between the basal ganglia and thalamus to enter the cerebral peduncle

Question 7

descending pathways

1. Upper motor neurons innervate muscles directly
2. Axons of the upper motor neurons are mainly located in the lateral white matter of the spinal cord
3. The cell bodies of lower motor neurones are located in the lateral horn of the spinal cord
4. A motor unit is defined as a particular muscle and all the motor neurons which are required to innervate it
5. Lower motor neurons leave the spinal cord posteriorly

Answer 7

2. Axons of the upper motor neurons are mainly located in the lateral white matter of the spinal cord

Question 8

the corticospinal tracts

1. The lateral corticospinal tract is entirely uncrossed
2. The lateral corticospinal tract carries fibres controlling muscles involved in balance and posture
3. The anterior corticospinal tract mainly supplies the contralateral side of the body
4. The anterior corticospinal tract is located antero-lateral to the anterior horn of grey matter
5. The lateral corticospinal tract contains fewer fibres than the anterior corticospinal tract

Answer 8

3. The anterior corticospinal tract mainly supplies the contralateral side of the body

Question 9

descending tracts

1. The tectospinal tract is involved in maintaining our upright posture by its effects on the muscles of the lower limb
2. The vestibulospinal tract consists of crossed fibres and controls head turning in response to visual stimuli.
3. The reticulospinal tract originates from cells found in the pons and the medulla and may act to facilitate or inhibit the activity of various ascending tracts
4. The rubrospinal tract is an uncrossed system which functions as a highly skilled version of the lateral corticospinal tract
5. The fibres of the corticospinal tract are somatotopically organised

Answer 9

5. The fibres of the corticospinal tract are somatotopically organised

Question 10

the muscle spindle-1

1. Muscle spindles are found in skeletal muscles. They are composed of intrafusal muscle fibres whereas skeletal muscle is composed of extrafusal muscle
2. The middle one-third of the spindle is associated with type 1a efferent sensory nerves
3. The two ends of the muscle spindle are non contractile while the central portion is contractile
4. Alpha motor neurons innervate the muscle fibres of the spindle
5. Gamma motor neurons innervate extrafusal muscle fibres

Answer 10

1. Muscle spindles are found in skeletal muscles. They are composed of intrafusal muscle fibres whereas skeletal muscle is composed of extrafusal muscle

Question 11

the muscle spindle- 2

1. Muscle spindles only detect muscle contraction
2. Muscle spindle activity contributes to the change in muscle resistance to stretch following a stroke
3. The startle reflex is an example of a stretch reflex
4. Muscle spindles detect changes in muscle tension
5. Muscle spindles are only involved in conscious aspects of proprioception

Answer 11

2. Muscle spindle activity contributes to the change in muscle resistance to stretch following a stroke

Question 12

the Golgi tendon organ- 1

1. Golgi tendon organs are situated within smooth and cardiac muscle
2. The sensory fibres leading from the Golgi tendon organ to the spinal cord are 1a afferent fibres
3. They measure the force developed by the muscle and any resultant change in length
4. Afferent impulses from the Golgi tendon organ result in the inhibition of alpha motor neurons of the muscle fibres associated with the activated Golgi tendon organ to regulate muscle tension at a normal range and also to protect the muscle from overload
5. They are only inhibitors of the skeletal alpha motor neurone

Answer 12

4. Afferent impulses from the Golgi tendon organ result in the inhibition of alpha motor neurons of the muscle fibres associated with the activated Golgi tendon organ to regulate muscle tension at a normal range and also to protect the muscle from overload

Question 13

the Golgi tendon organ-2

1. Golgi tendon organ produces a single output irrespective of the level of muscle tension
2. They are involved in the inverse myotatic reflex (clasp knife reflex)
3. They contain muscle fibres to alter tension
4. Golgi tendon organs possess faster afferent fibres than muscle spindles
5. Golgi tendon organ activity results in the inhibition of the antagonist muscles to the ones in which they are found

Answer 13

2. They are involved in the inverse myotatic reflex (clasp knife reflex)

Question 14

skin receptors

1. Large receptive fields are found in areas like the fingers where we have greatest tactile sensitivity
2. Some cutaneous receptors are phasic in response and others tonic
3. Tactile receptors act as transducers but do not show summation
4. Skin receptors are specialised neurone cell bodies
5. Receptive field sizes are not relevant to understanding the behavioural specialisations of humans

Answer 14

2. Some cutaneous receptors are phasic in response and others tonic

Question 15

The Dorsal Column-Medial Lemniscal System

1. Is a system characterised by slow conduction velocities
2. Is a tract which carries information regarding pain sensation from the skin to higher centres
3. Lies in the anterior white matter of the spinal cord
4. Fibres in the dorsal columns are arranged topographically
5. Decussation of the fibres of the DCML system occurs in the spinal cord as the tract ascends to the brain stem

Answer 15

4. Fibres in the dorsal columns are arranged topographically

Question 16

the plasma membranes of neurons

1. When in the resting state contains more open sodium (Na+) channels than open potassium (K+) channels
2. Is an excitable membrane
3. Is always associated with myelin sheaths
4. Contains very few active transport pumps
5. Has a positive resting potential inside with respect to the outside

Answer 16

2. Is an excitable membrane

Question 17

the resting membrane potential of neurons

1. Has a value which is positive inside with respect to the outside
2. Sodium/potassium pumps found in the membrane creates a concentration gradient of ions which is required to maintain the resting potential
3. Is mostly governed by the permeability of the membrane to sodium ions
4. Maintaining the concentration gradients requires transportation of potassium ions out of the cell and sodium ions into the cell
5. Is produced mostly as a result of sodium (Na+) diffusing out of the neuron

Answer 17

2. Sodium/potassium pumps found in the membrane creates a concentration gradient of ions which is required to maintain the resting potential

Question 18

an action potential

1. Occurs as sodium channels open in the membrane resulting in the membrane potential briefly becoming more positive on the inside with respect to the outside
2. The size of an action potential depends on the threshold level reached
3. During repolarisation (phase from peak back to resting potential) voltage gated sodium channels in the membrane open
4. Results in a change in the membrane potential from approx. -30mv to approx. +10mv
5. At +30mv the voltage gated Na+ channels close in response to the changed membrane potential

Answer 18

1. Occurs as sodium channels open in the membrane resulting in the membrane potential briefly becoming more positive on the inside with respect to the outside

Question 19

refractory periods

1. The relative refractory period is a time during which a second stimulus, needs to be stronger to produce a second action potential
2. Is a phenomenon which lasts between 50-100ms
3. The relative refractory period is followed by the absolute refractory period
4. Facilitates propagation of an action potential in either direction
5. Has no effect on the frequency of action potentials capable of being produced in a neuron

Answer 19

1. The relative refractory period is a time during which a second stimulus, needs to be stronger to produce a second action potential

Question 20

synapses

1. A synaptic cleft is a feature found in all types of synapses
2. The majority of synapses are electrical synapses
3. Chemical synapses are always inhibitory
4. Allows summation of input potentials to occur
5. Electrical synapses employ the use of neurotransmitters to evoke an action potential in the next neuron

Answer 20

4. Allows summation of input potentials to occur

Question 21

chemical synapses

1. Is the site where all neurotransmitters are synthesised
2. Each neuron forms only one synapse with any other neuron
3. Possess specific receptors on the post-synaptic membrane
4. The closure of calcium channels ultimately results in the release of neurotransmitters from the cell
5. Neurotransmitters travel from the post-synaptic membrane to the pre-synaptic cell via the process of diffusion

Answer 21

3. Possess specific receptors on the post-synaptic membrane