Question

21) Which of the following is not a biogenic amine? b. Epinephrine c. Serotonin d. Histamine e. Substance P 22) The output cells of the cerebellar cortex are which type of neuron? a. Golgi cells b. Purkinje cells c. Stellate cells d. Basket cells e. Pyramidal cells 23) Which of the following is nat a structural component of a myofibni? a. Sarcomere b. Actin c. Myosin d. Troponin e. Epimysium 24) Which of the following comparisons between Type I (slow-oxidative red) skeletal-muscle fibres and Type lb (fast-glycolytic white) skeletal-muscle fibres is correct? a. Type I fibres have fewer mitochondria b. Type I fibres are capable of generating more force C. Type l fibres fatigue more easily d. Type I fibres have a smaller diameter e. Type I fibres have a higher myosin-ATPase activity 25) Voluntary control of the distal musculature of the limbs is executed primarily via which descending tract? a. Reticulospinal b. Lateral corticospinal c. Anterior corticospinal d. Tectospinal 26) Parkinson's disease is caused primarily by the death of dopaminergic neurons in which CNS structure? a. Primary motor cortex b. Cerebellum c. Substantia nigra d. Dorsal striatum e. Red nucleus 27) Which cerebellar structure is primarily responsible for regulating muscle tone? a. Spinocerebellum b. Flocculonodular lobe с. vestibulocerebellum d. Caudal lobe e. Cerebrocerebellum

Answer 1

​​​​​​21. e. Substance-p is not a biogenic amine. The three catecholamines are dopamine, epinephrine and nor epinephrine. Seratonin or 5HT is an indolamine. Histamine is an imidazoleamine. But Substance-p is a neuropeptide .These are all neurotransmitters.

22. b. Purkinje cells are the output cells of the cerebellar cortex, where as cerebellar nuclei is forms the output of total cerebellum. Purkinje cells make the inhibitory connections onto the cerebellar nuclei.

23. e. Structural components of myofibril are thin actin and thick myosin filaments, proteins like troponin and tropomyosin, sarcomere between two z lines of myofibril. Endomysium is not a structural components of myofibril, it is the innermost connective tissue layer of skeletal muscle which connects muscle to bone.

24. e.

Type-I skeletal muscle fibres have higher myosin-ATPase activity. As they are slow they fatigue slowly. they have more mitochondria.

25. c.

Voluntary control of distal musculature of limbs executed primarily via Anterior corticospinal descending tract.

26. c.

Parkinson's disease is caused primarily by death of dopaminergic neurons in substantia nigra, a region of midbrain in  Cental Nervous System.

27. a.

Spinocerebellum is the Cerebellar structure responsible for regulating muscle tone and coordination of extremities.It includes vermal and paravermal zones of cerebellum.  Vermis the midline portion between two cerebellar hemispheres regulates muscle tone for posture and locomotion.