Unit 3 Control and Coordination 2023 with complete solution questions and answers

soma cell body of neuron dendrite Branchlike parts of a neuron that are specialized to receive information. axon the neuron extension that passes messages through its branches to other neurons or to muscles or glands ganglion collection of nerve cell bodies in the peripheral nervous system nerve A bundle of nerve fibers axon terminal end of axon myelin sheath A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses nodes of Ranvier gaps in myelin sheath along the axon sensory neurons neurons that carry incoming information from the sensory receptors to the brain and spinal cord motor neurons neurons that carry signals from the spinal cord to the muscles to produce movement interneurons neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs resting membrane potential -70mV graded potential a shift in the electrical charge in a tiny area of a neuron threshhold the level of stimulation required to trigger a neural impulse action potential a neural impulse; a brief electrical charge that travels down an axon nerve impulse the message carried by a neuron depolarization The process during the action potential when sodium is rushing into the cell causing the interior to become more positive. repolarization Return of the cell to resting state, caused by reentry of potassium into the cell while sodium exits the cell. Hyperpolarization The movement of the membrane potential of a cell away from rest potential in a more negative direction. synapse the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron meninges three protective membranes that surround the brain and spinal cord ventricle in brain a small cavity in the brain cerebrum Area of the brain responsible for all voluntary activities of the body cerebellum A large structure of the hindbrain that controls fine motor skills. brainstem The oldest part and central core of the brain, responsible for automatic survival functions. Neurotransmitters chemical messengers that cross the synaptic gaps between neurons hormone Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another mechanoreceptor a sensory receptor that responds to mechanical disturbances such as shape changes, being squashed... thermoreceptor A receptor that responds to changes in temperature. photoreceptor a receptor that responds to light chemoreceptor a sensory receptor that responds to specific chemicals. Some examples are taste. nocireceptor pain receptor reflex a simple, automatic response to a sensory stimulus, such as the knee-jerk response frontal lobe The lobe at the front of the brain associated with movement, speech, and impulsive behavior. parietal lobe A region of the cerebral cortex whose functions include processing information about touch, body position occipital lobe visual processing temporal lobe A region of the cerebral cortex responsible for hearing and language. autonomic nervous system the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). sympathetic nervous system the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations parasympathetic nervous system a set of nerves that helps the body return to a normal resting state voltage gated channels open or close in response to changes in membrane potential ligand gated channels channel that opens when a neurotransmitter attaches mechanically gated channels open in response to physical deformation of the receptor central nervous system brain and spinal cord periferal nervous system cranial and spinal nerves learned response a reaction that has been acquired by learning innate response rapid motor response to a stimulus sclera white of the eye cornea The clear tissue that covers the front of the eye choroid middle, vascular layer of the eye, between the retina and the sclera ciliary body ring of muscle tissue around the lens of the eye pupil opening in the center of the iris suspensory ligament attaches the lens to the ciliary body retina the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information fovea centralis tiny pit or depression in the retina that is the region of clearest vision optic disc blind spot rods retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond cones retinal receptors responsible for color vision lens the transparent structure behind the pupil that changes shape to help focus images on the retina vitreous humor the transparent jellylike tissue filling the eyeball behind the lens. aqueous humor fluid in the eye, found between the cornea and the lens odor gaseous molecules we smell olfactory epithelium contains the olfactory receptor neurons that respond to airborne molecules called odorants. taste buds the organ of taste transduction papillae rough, bumpy elevations on dorsal surface of tongue gustatory epithelial cells taste receptor cells basal epithelial cells stem cells that develop into support cells bony orbits of eye are protected by fat eyebrows protect eyes from sweat and sun lacrimal apparatus ... outer ear pinna and auditory canal middle ear hammer, anvil, stirrup inner ear contains cochlea, semicircular canals, and vestibular sacs energy conversion for touch mechanical to electrical vision energy conversion electromagnetic to electrical smell energy conversion chemical to electrical hearing energy conversion sound to mechanical to electrical hormone Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another exocrine gland that secretes its products through excretory ducts to the surface of an organ or tissue or into a vessel endocrine secreting internally humoral stimuli secretion of hormones in direct response to changing blood levels of ions and nutrients neural stimuli nerve fibers stimulate hormone release permissiveness Need second hormone to get full effect synergism when more than one hormone produces the same effects at the target cell, causing an amplified combined effect antagonism one hormone opposes the action of another steroid hormones hormones secreted by the adrenal cortex, derived from cholesterol, lipid soluble amino acid based hormone water soluble, short half life in blood anterior pituitary gland the anterior part of the pituitary gland; an endocrine gland whose secretions are controlled by the hypothalamic hormones posterior pituitary gland ADH and oxytocin hypothalamus a neural structure lying below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion thyroid regulates metabolism parathyroid in the neck; controls the calcium levels in your body, and normals the bone growth adrenal on top of the kidneys; prepares the body for action, controls the heart rate and breathing in times of emergency. pineal gland secretes melatonin pancreas Regulates the level of sugar in the blood testes testosterone ovaries estrogen and progesterone placenta A structure that allows an embryo to be nourished with the mother's blood supply