Lab 7 Quiz Sensory Physiology PDF

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anatomy physiology review for lab practical and quiz 7...

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Sensory Physiology https://quizlet.com/16320369/sensory-physiologylab-flash-cards/ Reflexes -

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Reflex action is initiated by an input stimulus and results in an output response Spinal reflexes require transmission from the periphery to the spinal cord and then back to the appropriate effector organ - ex) if one experiences a painful stimulus like burning a finger on a hot object, the spinal reflex immediately causes withdrawal of the finger; no action is required from the brain Eye reflexes and labyrinth reflexes involve centers of the brain - Integrative function of the central nervous system will be required

Eye Reflexes 1. Pupillary Reflex - dilation or constriction of the pupil -In a given intensity of light, the size of the pupil is normal. -When eye is in darkness, the pupil becomes larger -After flashing a light in one eye, the pupil constricts (becomes smaller), when removing the light, the light changes back to regular size -the pupillary reflex happens to protect the eye from bright light -Do both eyes change simultaneously? Both eyes do change simultaneously in response to light -What is the receptor in this reflex? The effector? The receptor is the retina in the eye and the effector are the smooth muscles in the iris. They both work together to constrict or dilate the pupil according to how bright the light is. -Place a hand over one eye. Observe the pupil of the uncovered eye. What happens to its diameter? This is called consensual reflex. Explain it. The diameter of the uncovered eye dilates and get bigger. Consensual reflex is the response of one side of the body when the other is stimulated (since the covered eye is exposed to darkness ie: pupil increases, the other pupil increased.) (increase or decrease of one pupil when the other pupil is exposed to a respective decrease or increase in light) 2. Accommodation reflex -when an object is distant, the pupils dilate -when an object is in near site, the pupil constricts (gets smaller) -what is the advantage of this? You can see objects from far away and the image focus on retina? -how does the eyeball shape or iris position change during accommodation for near vision? When the eye focuses on a near object the pupil constricts because of the ciliary muscles. They contract, allowing the sensory ligaments to relax which in turn allows the lens to relax so it becomes more curved. The lens becomes more bulged and curved -how sharp is the image of the far object when the near object is being viewed and how sharp is

the image of the near object when the far object is being viewed? When the near object is being viewed, the far image is not sharp. When the far object is being viewed, the near object is not sharp. -^describe the internal eye change which takes place when the eye focuses on near and far objects. NEAR: When the eye focuses on a near object the pupil constricts because of the ciliary muscles. The lens become bulged when they are looking at near objects which gives greater reflection and a sharper image. They contract, allowing the sensory ligaments to relax which in turn allows the lens to relax so it becomes more curved. FAR: For far away the cilliary muscles relax which cause the suspensory ligaments to be tight so the lens in flat and the radial muscles of the iris cause the pupil to dilate.

Tendon (Stretch) Reflexes 1. Patellar Reflex

-Gently tap the patellar tendon of the crossed leg with a reflex mallet and note the response When you hit the patella tendon, a response is sent to the thigh bone, sending your leg kicking out. This is the same for both left and right legs.

-Jendrassik’s Maneuver - subject clasps his/her hands and pulls vigorously at the same time that the tendon is tapped. How do you explain the responses obtained? Patellar reflex get enhanced during Jendrassik's Maneuver. 2. Achilles Reflex Student kneeling on a chair with foot bent downward to increase tension on the gastrocnemius muscle. Tests the reflex of the gastrocnemius muscle. Tap achilles and the foot flexes downwards in a plantar flexion of the foot. The response is greater when subject grasps the back of the chair. 3. Biceps and Triceps Reflex When the forearm is pushing down on table, the bicep muscle is squishy, and the tricep muscle is contracted. You have trouble contracting the bicep. When the forearm is attempting to lift the table, the tricep muscle is squishy, and the bicep muscle is contracted. You have trouble contracting the tricep. This happens because you cannot contract the bicep and tricep at the same time.

Ciliospinal Reflexes The ciliospinal reflex is the dilation of the eye on the same side (ipsilateral side) of a painful stimulus of the skin on the same side of the neck. This is a reflex response mediated over the sympathetic nervous system in response to a painful stimulus.

Plantar Reflex and Babinski Reflex In babies, the Babinski reflex is positive, upward flex of toes when being stroked on the sole of the foot which happens because babies are still going through myelination In adults, the normal response is for toes to curl downwards, if they curl upwards, that is a positive Babinski reflex which is often associated with damage to the pyramidal tract fibers.

Labyrinthine Reflexes Role of the labyrinthine system- to orient the body during movement and how this correlates to muscular movements and eye movements which reflexly maintain equilibrium. 1. Nystagmus- is a vision condition in which the eyes make repetitive, uncontrolled movements. These movements often result in reduced vision and depth perception and can affect balance and coordination. These involuntary eye movements can occur from side to side, up and down, or in a circular pattern - If a person is angulary accelerated in one direction, rotatory nystagmus- her/his eyes will move very slowly in one direction as though to maintain fixation on a moving target, then very rapidly swing back in the other direction. Rotatory nystagmus is caused by the acceleration of fluid in the semicircular canals which stimulates the cristae in the ampullae and produces the sensation of turning - Post-rotatory nystagmus- suddenly stopping the spinning person and observing them: however, all movements have been reversed and the direction of nystagmus will be reversed - When head is bent forward at an angle of 30 degrees and the subject is turning to the right, the movement of the eyes is side to side - When the head is bent to the right shoulder at an angle of 90 degrees, the eyes move up and down really fast because we are isolating the semicircular canal 2. Past pointing - The normal person is able to touch finger of operator with eyes open and closed - After rotating the subject to the right, stop them abruptly to touch operators finger. The subjects finger goes in the direction he was spinning. To the right of the finger 3. Equilibrium and the labyrinthine reflexes - With the head bent forward at 30 degrees and rotating to the right. Have the subject attempt to rise and walk. The subject appears to fall forward because his/her head was bent forward/down - repeat^ with head bent to the right shoulder at an angle of about 90 degrees The subject fell to the right where his head was tilted to

Proprioception and Spatial Orientation -

Subject hold his arms out. Try to bring fingertips together. Eyes open and closed With eyes open, fingertips connected. Eyes closed, fingertips were not connected. - To maintain balance, hands out, feet together. Eyes open and closed With eyes open, did not sway- maintained balance. Eyes closed sway more. - Subject stand first on one foot, then the other. Eyes open and closed Swayed when eyes were closed, not open - Subject look at ceiling and stand on one foot Swayed when eyes were closed *these tests evaluate and point out the contribution made by the eyes to static equilibrium

The five senses Touch 1. Tactile distribution- two point sensibility - Touch receptors vary in their density of distribution over various parts of the body. in areas like the back of neck it will take longer for your body to feel two distinct points because it is a larger portion of the body therefore there is not a lot of overlapping and a small portion of the brain is dedicated to it and it does not have as many nerves as small areas like the fingers and lips that have finer senses of “feel” or tactile discrimination 2. Tactile localization - the partner would put a pen mark and the subject to the best of their knowledge would need to point out the mark. in small areas like the fingertip, palm, and lips the distance was small. The forearm was the farthest distance Olfaction (smell) and gustation (taste): the chemical senses - Five qualities of taste: sour, sweet, salty, bitter, umami - The receptors respond to more than one taste quality, and most substances produce a mixture of the basic taste sensations 1. Taste discrimination - Can the subject accurately identify each taste? Yes, because there are different receptors for sweets, salts, bitterness, sours, and umami. Sweet- sugars, saccharin, alcohols Sour- hydrogen ions released by acids Salty- metal ions, and sodium chloride Bitter- alkaloids: quinine, caffeine, nicotine Umami- glutamate (amino acid) meats and cheeses - Can he/she taste the sugar immediately? Explain why this latent period occurs. Receptors respond to fluids better than solids; have to wait for it to dissolve in saliva 2. Threshold for taste reception

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The acuity of taste perception varies for different chemicals and between different individuals. Certain areas of tongue have strong receptors for a certain taste 3. Interaction of taste and smell - When you can smell a food, you can taste it better. When you can’t smell a food (when your nose is congested) you lose the taste of the food and only feel it as a solid in your mouth. 4. Heredity and taste perception - 70% of people can taste PTC (strong bitter taste) and 30% of people can’t. Some people have more receptors than others which helps them detect the bitter PTC taste Hearing - Weber test and rinne test are used to distinguish between conduction deafness and nerve deafness. - A 512 Hz tuning fork is used - strike on knee - Weber test: - In a loud room, hold the fork against the bridge of the nose. Normal hearing = the sound comes from midline position - What happens if one has defective middle ear function (conductive deafness), during the Weber test? - the sound will be heard better in the ear that is defective - What is the attenuation reflex? - tested for by the Weber test, an involuntary muscle contraction due to high sounds in order to protect the ear from being damaged - Rinne test - plug one ear, place the handle of the vibrating tuning for on the mastoid process. When the sound is no longer audible, place the tuning fork in front of the auditory canal. - How will a person with normal hearing react to the Rinne test as opposed to a person with conduction deafness? - they will hear the sound conducted through air a few seconds longer than the sound conducted through bone. The person with conduction deafness, however will hear as long or longer by bone conduction. The person with nerve conduction will hear longer by air conduction, but usually requires a louder sound to hear at all. condition

Weber test

Rinne test

No hearing loss

No lateralization

Sound perceived longer by air conduction

Conduction deafness (one ear has defective middle

Lateralization to the poorer ear

Sound perceived as long or longer by bone

ear function) Nerve deafness (defect in the auditory nerve or cochlear apparatus)

conduction Lateralization to the better ear

Sound perceived longer by air conduction

Vision 1. Near point - Near point for accomodation- determines the distance from the eye that the patient can hold the eyes together without double vision - What is meant by accommodation during the Near point test? - adjusting the refraction so that the image spot falls on the photoreceptors in the retina. achieved by altering the shape of the lens which alters the angle of incidence. - What muscles are involved in accommodation and how do they work? - ciliary muscles and suspensory ligaments are involved. At rest suspensory ligaments stretch its margins so the lens is flat (good for distant vision). By reducing the tension of the suspensory ligaments, the lens is allowed to rebound into its natural ovals shape (near vision). - what is presbyopia and what causes it? - Loss of the ability to see things nearby. You need to see objects at a distance. Ie-reading a book at a far distance. Presbyopia is caused by a hardening of the lens of your eye, which occurs with aging. As your lens becomes less flexible, it can no longer change shape to focus on close-up images. As a result, these images appear out of focus - What is myopia? - Nearsightedness, is the inability to see things clearly unless they're relatively close to your eyes. In people with myopia, the eyeball is too long or the cornea has too much curvature, so the light entering the eye is not focused correctly. Light rays of images focus in front of the retina, the light-sensitive part of the eye, rather than directly on the retina, causing blurred vision - You would use concave lenses to correct this condition 2. The blind spot - Is the area in the retina lacking photoreceptors where the optic nerve exits. It is located in the temporal side of the visual field in the back of the retina. 3. Visual activity

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The power to discriminate details A person’s visual acuity is stated as V=d/D - d= the distance at which the patient can read the letters - D = the distance at which a normal eye can read the letters - If you have 10/20 - it is subnormal vision because you need to be 10 feet closer to see the letter - If you have 30/20- it is above average 4. Test for color blindness - Color blindness is a genetic disorder where a particular gene is missing on the x chromosome. Most common are red and green mix ups which the person either lacks red or green cones in the retina - What wavelengths of light are responsible for stimulating blue, red and green cones? - (Red- 400->710 nm) - (blue-350->560nm) - (green-400->700 nm) - What is the young- helmholtz theory of color vision? - s a theory of trichromatic color vision – the manner in which the photoreceptor cells in the eyes of humans and other primates work to enable color vision (red, green, blue) - What is the ishihara test? - most common charts used for color blindness. Varied colored dots, arranged in each plate so a person with normal color vision can read one number and a person with color blindness perceives a different. - Why is color blindness more prevalent in males? - Men are much more likely to be colorblind than women because the genes responsible for the most common, inherited color blindness are on the X chromosome. Males only have one X chromosome, while females have two X chromosomes. ... This kind of inheritance pattern is called X-linked, and primarily affects males. 5. Visual fields of the eye: perimetry - The field of vision is the entire area seen by the eye when fixed in one position - Charting ones visual field is useful in localizing brain lesions or determining blindness in various retinal areas - Patient focuses on white dot - By repeating this in different planes and for different colors, one obtains a map of one’s visual fields for rod and cone vision - White disc around a perimeter, then change color of disc to red blue or green...