Answer : (a)

Neurons produce an important brain chemical known as dopamine, but when the neurons die or become impaired, they produce less dopamine. This shortage of dopamine causes the movement problems of people with Parkinson's. Answer : (c)

Archnoid, Duramater, Piamater are layers of meninges While Choroid plexus is located in the ventricular system Answer : (d)

Pacinian corpuscles is Encapsulated pressure receptors, respond only to mechanical deformation. Answer : (d)

The presence of multiple types of cone visual pigments enables color vision Answer : (c)

The vestibulocochlear nerve (auditory vestibular nerve), known as the eighth cranial nerve, transmits sound and equilibrium (balance) information from the inner ear to the brain. Answer : (b)

Third , sixth and eleventh cranial nerves are Oculomotor, Abducens and Accessory Spinal Answer : (a)

Conditioned reflex - an acquired response that is under the control of (conditional on the occurrence of) a stimulusconditioned reflex or an acquired response that is under the control of (conditional on the occurrence of) a stimulus. A learned response performed by a trained animal to a signal that was previously associated with an event of consequence for that animal. Answer : (d)

380-760 nm is the wavelength range of visible spectrum. Human eyes are sensitive to this range. Answer : (c)

The hypothalamus is responsible for the regulation of certain metabolic processes and other activities of the autonomic nervous system Answer : (a)

Sympathetic nerves arise from near the middle of the spinal cord in the intermediolateral nucleus of the lateral grey column, beginning at the first thoracic vertebra of the vertebral column and are thought to extend to the second or third lumbar vertebra Answer : (b)

Eye is formed from: 1) Ectoderm a) Ectoderm of neural tube → retina, optic nerve fibers, iris. b) Surface ectoderm → corneal and conjunctival epithelium, lens, lacrimal and tarsal glands. 2) Mesenchyme → corneal stroma, sclera, choroid, iris, ciliary muscle, parts of vitreous, muscles lining anterior chamber. Answer : (b)

iodopsin a photosensitive violet pigment that occurs in the cones of the retina and is transformed by light into retinal and an opsin protein Answer : (c)

The medulla oblongata helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. This part of the brain is a center for respiration and circulation. Sensory and motor neurons (nerve cells) from the forebrain and midbrain travel through the medulla. The process of peristalsis is controlled by the medulla oblongata. Esophageal peristalsis is typically assessed by performing an esophageal motility study. Answer : (a)

General rules of spinal cord organization are (1) that neurons and axons that process and relay sensory information are found dorsally; (2) that preganglionic visceral motor neurons are found in an intermediate/lateral region; and (3) that somatic motor neurons and axons are found in the ventral portion of the cord. Answer : (c)

Stress is due to danger , body requires more energy to come out of danger or situation The sympathetic nervous system controls the body's automatic response to danger, increasing the heart rate, dilating the blood vessels, slowing digestion, and moving blood flow to the heart, muscles, and brain Answer : (c)

Membrane potential of resting neuron have 3 factors a) membrane proteins called sodium/potassium pumps activey pump 3 Na+ out and 2 K+ into cell b) large quantities of negatively charged protein molecules inside the cell cannot leak outside c) the membrane being permeable to K+ but impermeable to Na+. =Na+/K+ pump ensures that more potassium on inside than outside. simple diffusion K+ leaks out. Diffusion contributes to resting potential (b/c they are positive charged). Answer : (b)

acetylcholine, noradrenaline and serotonin are eurotransmitters Answer : (d)

They are found in the ampullae of each of the semicircular canals of the inner ear, The function of the crista ampullaris is to sense angular acceleration and deceleration. Answer : (c)

The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. The cornea, with the anterior chamber and lens, refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is approximately 43 dioptres. While the cornea contributes most of the eye's focusing power, its focus is fixed. Answer : (a)

The hypothalamus acts as the control center for hunger and satiety. Part of the hypothalamus, the arcuate nucleus (or, in humans, the infundibular nucleus), allows entry through the blood-brain barrier of peripheral peptides and proteins that directly interact with its neurons. Answer : (b)

The organ of Corti is the sensitive element in the inner ear and can be thought of as the body's microphone. Answer : (c)

Nerve impulses are mostly electrical signals along the dendrites to produce a nerve impulse or action potential. The action potential is the result of ions moving in and out of the cell A nerve impulse is an electrical signal that travels along an axon. The nature of nerve impulse is Electrochemical Answer : (c)

Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals, including humans, as a neurotransmitter Answer : (d)

The main purpose of a myelin layer is to increase the speed at which impulses propagate along the myelinated fiber. Answer : (d)

Subarachnoid space between the arachnoid membrane and pia mater that is filled with cerebrospinal fluid and contains the large blood vessels that supply the brain and spinal cord. Answer : (a)

Primary function of myelin sheath around vertebrate axon is toincrease in speed of conduction by preventing leakage of nerve impulse Answer : (c)

Autonomic centers for regulation of visceral function cardiovascular, respiratory, and digestive system activities. medulla oblongata controls the function of your autonomous nervous system, Answer : (d)

Outer most covering of brain is Duramater Answer : (b)

Reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the brain. Answer : (a)

Elevated body or environmental temperatures are the primary cause of increased sweating. Answer : (b)

All fibers cross left becomes right in the medulla. Thus Touch on the right side stimulate neurons on left somatic sensory area Answer : (c)

The organ of Corti is the sensitive element in the inner ear and can be thought of as the body's microphone. Vestibulocochlear nerve in the human ear, Eighth Cranial,Nerveserving the organs of hearing. Answer : (d)

Vagus nerve transmit impulses to muscles associated with speech, swallowing, the heart, smooth muscles of visceral organs in the thorax, and abdomen. Answer : (b)

Answer : (d)

Neuromotor transmitter between two nerves at synapse is Acetylcholine Answer : (a)

Cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity. Answer : (c)

The vagus nerve is the 10th cranial nerve Answer : (d)

b) large quantities of negatively charged protein molecules inside the cell cannot leak outside. c) the membrane being permeable to K+ but impermeable to Na+. =Na+/K+ pump ensures that more potassium on inside than outside. simple diffusion KA+ leaks out. Diffusion contributes to resting potential (b/c they are positive charged). Answer : (b)

Cornea and lens of eye are transparent and help in image formation on retina Answer : (a)

After a cell has been depolarized, it undergoes one final change in internal charge. Following depolarization, the voltage-gated sodium ion channels that had been open while the cell was undergoing depolarization close again. The increased positive charge within the cell now causes the potassium channels to open. Potassium ions (K+) begin to move down the electrochemical gradient (in favor of the concentration gradient and the newly established electrical gradient). As potassium moves out of the cell the potential within the cell decreases and approaches its resting potential once more. The sodium potassium pump works continuously throughout this proces Answer : (c)

A receptor is cholinergic if it uses acetylcholine as its neurotransmitter. All preganglionic fibers, whether they are in the sympathetic division or in the parasympathetic division, are cholinergic that is, these fibers use acetylcholine as their neurotransmitter Answer : (b)

The electrical potential difference across the resting plasma membrane is called a resting potential. Answer : (d)

Medulla oblongata have autonomic centers for regulation of visceral function cardiovascular, respiratory, and digestive system activities. Answer : (c)

Myelin sheath prevents leakage of nerve impulse Nodes of Ranvier: The action potential propagated by one node of Ranvier jumps to and is regenerated at the next node along the axon, thereby enabling the action potential to travel rapidly along the fibre. Answer : (c)

Shortsightedness is corrected using a concave (curved inwards) lens which is placed in front of amyopic eye Answer : (d)

Proprioceptors a sensory receptor which receives stimuli from within the body, especially one that responds to position and movement. The proprioceptors are sensors that provide information about joint angle, muscle length, and muscle tension, which is integrated to give information about the position of the limb in space. Answer : (a)

The Eustachian tube is a tube that links the nasopharynx to the middle ear. It functions are Mucus drainage and Pressure equalization Answer : (c)

cerebral cortex is essential for memory, attention, awareness, thought, language and consciousness Answer : (d)

The vestibular system includes the parts of the inner ear and brain that process the sensory information involved with controlling balance and eye movements. Answer : (b)