1. | the CNS to skeletal muscles |
2. | the CNS to the involuntary organs and smooth muscles of the body |
3. | the skeletal muscles of the CNS |
4. | the involuntary organs and smooth muscles of the body to the CNS |
Statement I: | The malleus is attached to the tympanic membrane and the stapes is attached to the oval window of the cochlea. |
Statement II: | At the base of the cochlea, the scala vestibuli ends at the round window, while the scala tympani terminates at the oval window which opens to the middle ear. |
1. | Statement I is incorrect; Statement II is correct |
2. | Statement I is correct; Statement II is correct |
3. | Statement I is correct; Statement II is incorrect |
4. | Statement I is incorrect; Statement II is incorrect |
A | B | C | |
1. | Reissener’s membrane | Tectorial membrane | Basilar membrane |
2. | Basilar membrane | Reissener’s membrane | Tectorial membrane |
3. | Tectorial membrane | Basilar membrane | Reissener’s membrane |
4. | Reissener’s membrane | Basilar membrane | Tectorial membrane |
I: | is enclosed by a Schwann cell that does not form a myelin sheath around the axon |
II: | is commonly found in autonomous and the somatic neural systems |
1. | iris anteriorly and choroid posteriorly |
2. | vitreous humor |
3. | sclera |
4. | ligaments attached to the ciliary body |
Myelin sheath around axons in peripheral nervous system and in central nervous system is produced respectively by:
1. Schwann cells; microglia
2. oligodendrocytes; Schwann cells
3. Schwann cells; oligodendrocytes
4. satellite cells; astrocytes
In the human eye:
I: The sclera regulates entrance of light into the eyeball.
II: The choroid makes colour vision possible.
III: The ciliary body controls the lens shape for near and far vision.
1. Only III is incorrect
2. Only I and II are incorrect
3. Only I and III are correct
4. I, II and III are correct
Identify the correctly matched pairs:
Part of human brain | Function | |
I | Corpus callosum | Tract of nerve fibres connecting two cerebellar hemispheres |
II | Thalamus | Major coordinating centre for sensory and motor signaling |
III | Hypothalamus | Control of body temperature, urge for eating and drinking |
IV | Limbic system | Equilibrium |
V | Medulla | Pneumotaxic centre for regulation of breathing |
A | Mechanism of vision | Light induces dissociation of the retinal from opsin → change in the structure of the opsin → membrane permeability changes → generation of action potentials in the ganglion cells through the bipolar cells → action potentials are transmitted by the optic nerves to the visual cortex. |
B | Mechanism of hearing | Vibrations are transmitted through the ear ossicles to the round window → vibrations generate waves in the lymphs → this induces a ripple in the Reissner’s membrane → the hair cells press them against the basilar membrane → nerve impulses generated are transmitted to the auditory cortex. |