Chapter 14 - Senses Flashcards Preview

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Flashcards in Chapter 14 - Senses Deck (116):

What is Capsaicin

It is the chemical in peppers that makes them hot. Irritant to mammals causing a burning sensation.


Why is capsaicin illegal in equestrian sports

It can cause hypersensitivity and have an analgesic effect. It is a banned substance in competition


What is hypo-sensitivity

Sensitivity below normal limits usually due to a neurectomy or nerve block


What is hypersensitivity

Sensitivity above normal limits. Due to irritants put on skin


How does capsaicin cause a burning sensation

Capsaicin binds calcium channels on pain and heat sensing neurons causing premature depolarization. Does not actually cause tissue damage just perceived pain however it can trigger an inflammatory response which can cause tissue damage


What will prolonged exposure to capsaicin cause

Desensitization. Neurotransmitters become depleted and neuron's retreat back into dermis


What is a stimuli

Sensory receptors respond to environmental changes internally and externally


Identify what are the four types of stimuli and give an example for each

1. mechanical ex: touch hearing balance.
2. thermal ex: hot and cold.
3. electromagnetic ex: vision.
4. chemical ex:taste and smell.


What are sensory receptors

Modified afferent neuron endings a.k.a. dendrites


How are senses interpreted

Sensory receptors are depolarized by the stimuli and then sensory information is sent to specific region of the brain for interpretation


How are receptors classified by

Which stimulus is received, location(ex: proprioceptors), structure (encapsulated or nonencapsulated)


If there is a mechanical stimulus what receptor type will receive that information



If there is a thermal stimuli what receptor type will receive that information



If there is an electromagnetic stimulation what receptor type will get that information



If there is a chemical stimulation what type of receptor will receive that information



What stimulus type is associated with the following examples touch pressure vibration stretch

Mechanical stimulation


What stimulation type is associated with the following examples hot, cold, temperature changes

Thermal stimuli


What stimuli is associated with the following example light

Electromagnetic stimuli


Which stimuli is associated with the following example blood chemistry intestinal fluids and molecules smelled or tasted

Chemical stimuli


Which types of stimuli are associated with extreme stimulation

Mechanical, thermal, chemical


What receptor type is associated with extreme stimuli



What are some examples of non-encapsulated sensory receptors

Hair follicle receptors, Merkel disks, free nerve endings of sensory neurons


What is itchiness and what is it caused by

Pruritis and it is a sensation mediated by free nerve endings and dermis. Chemoreceptors find histamines released during inflammatory response impulses from the sensory receptors are perceived by the brain as itchiness


What is pain

Heat or cold outside the range of thermoreceptor's activate nociceptors and bring perceive signals from these receptors as pain. Extreme pressure and chemicals released from damage tissues stimulate the nociceptors


What are endorphins

Inhibitory neurotransmitters released by the central nervous system that block neurotransmitters released by nociceptors. Pain blocker. a natural opiate


What are opiates

Using pain management as analgesics. Mimic endorphins and block nociceptors. Can be used as sedative or general anesthetic. Opiate antagonist can we give into reverse action of opiates


What is anesthesia

Feet loss of sensation used to complete procedures that would be otherwise uncomfortable to the patient


What is general anesthesia

Complete loss of sensory perception consciousness. Patient is immobile in a controlled sleep does not feel pain inducer injection or inhalation


What is local anesthesia

Awesome sensation from a particular area. Sensory nerve fibers are blocked from depolarization and patient is conscious. Example lidocaine and Novacaine


What is analgesia

Perception of pain is lessened but not completely gone often used to reduce severe pain during traumatic injury and surgery


What are three examples of encapsulated sensory receptors

Meissners corpuscles, lamellar corpuscles, bulbous corpuscles


What are five special senses

Taste, smell, hearing, equilibrium, vision


What are five general senses

Visceral sensations, touch, temperature, pain (nociception), proprioception


What are three sensory neurons associated with touch and pressure

Messingers corpuscles, hair follicle receptors, Pacinian corpuscles


Where are Messner's corpuscles found

In papillary layer of dermis. Numerous in hairless sensitive regions


Where are hair follicle receptors found

Free nerve endings wrap around the base of hair follicle and it's found and hairy skin


Where are Pacinian corpuscles found

Located deep in dermis, perceived deep pressure


What are visceral sensations and give examples also what gland is responsible for its interpretation

Food and water deficiencies are detected by chemoreceptors and hypothalamus and interpreted as sensations of hunger and thirst


What detects changes in skin temperature.

Superficial thermal receptors detect changes in skin temperature.


Where are the free nerve endings for cold and heat located

Free nerve endings associated with cold I'm superficial dermis the papillary layer and those that are associated with heat and the deeper dermis the reticular layer


How is internal temperature monitored and regulated

Thermal receptors in hypothalamus monitor internal body temperature central nervous system sends motor responses for thermoregulation example shivering sweating panting to correct conditions of hypothermia or hyperthermia


Why is it important to keep an animal warm during anesthesia and recovery

General anesthetics block thermal receptors in hypothalamus patient unable to detect falling body temperature and thermoregulate. metabolism occurs much slower at lower temperatures


What is proprioception

Sense of body position and movement on a subconscious level


Where are proprioreceptors located and what are they

Proprioceptor's are stretch Mechanoreceptors located in synovial joint capsules tendons ligaments and muscles


Describe acute pain

Sharp, intense, short-term


Described chronic pain

Dull, aching, long term


Describes superficial pain

Skin, subcutaneous area


Describe deep pain

Muscles, joints, bones


Describe visceral pain

Internal organs


What is a pain threshold

Amount of stimuli that will trigger an action potential. All or none principal


What is pain tolerance

Function of the cerebral cortex is perception of pain some genetic component


What is referred pain

Visceral and superficial nociceptors sometimes travel along same sensory nerves sometimes pain from one area is perceived to be coming from another


Where are all sense organs located

In the head. Sense organs are extension of the central nervous system


What is taste called. Where are chemoreceptors located. Where are taste buds located.

Taste is called gustatory sense. Chemoreceptors are located in tastebuds of tongue, some in mucous membrane of mouth, pharynx epiglottis. Taste buds are found in the papillae the mounds of tissue on the tongue


How is taste interpreted

Chemicals dissolved in saliva bind to the microvilli of gustatory cells which are wrapped by a dendrite of the sensory neuron


What are the five different tastes human can perceive

Sweet-organic molecules , sour-acids, salty-metal ions, bitter-alkaloids, umami-amino acids


Describe the gustatory pathway

Nerves bring the sensation from taste buds to the medulla oblongata up into the thalamus and then to the gustatory cortex


What Are the autonomic reflexes in the medulla oblongata

Salivation, release of gastric acids and enzymes, gag reflex or vomit reflex


Why are cats tongues so rough

Due to papillae composed of keratin forming backwards facing barbs. Using grooming room cleaning of operative cooling and cleaning up after kill


What is smell? where are chemoreceptors located and how does how do smells get interpreted by the body

Smell is olfactory sense. Chemoreceptors are located in mucous membrane of nasal cavity use chemicals dissolve in mucous and bind to cilia. the neurons synapse with other sensory neurons in the olfactory bulb the form of factory nerves


What are pheromones

Species specific chemicals released to trigger a social response example aggression alarm trails territory sexual. There are chemoreceptors for various pheromones


What is lordosis behavior

When animals sticks it's butt up in the air and moves it's tail out-of-the-way. Sexually receptive behavior


What is the vomeronasal organ used for

It is an olfactory organ used mainly to detect pheromones. Involved in flehmen response of some animals


What is hearing. How do the stimuli of soundwaves get interpreted as noise

Hearing is the auditory sense. Mechanical stimuli of soundwaves vibrate air and molecules and auditory organs trigger impulses


What is the external ear and what is it do

The external air collects and funnels waves to the ear drum


What does the middle ear do

Amplifies and transmits vibrations to inner ear


What does the inner ear do

Sensory receptors convert vibrations into nerve impulses also has receptors for equilibrium


What is the pinnA

Composed of elastic cartilage and skin collects soundwaves and funnels them into the external auditory canal


What is the external auditory canal

L-shaped tube carrying soundwaves from pinna to tympanic membrane


What is the tympanic membrane

Connective tissue membrane separating external and middle ear vibrates at the same frequency as waves that strike it


What are ear hematomas and what are they caused by

Cannot are highly vascularized hematoma is caused by a rupture of blood vessels causing blood to accumulate between cartilage and skin. Generally caused by animal vigorously shaking head. Cauliflower ear


What is otitis externa

Inflammation of external auditory canal typically due to mites, bacterial or yeast infection causes redness pain and itching more common in floppy eared dogs due to reduced air circulation. Treatment ear cleaning and pathogen specific medication


What is the middle ear cavity

Mucous membrane line cavity within the Temporel bone filled with air and contains ossicles


What are ossicles

Three small bones that link the tympanic membrane to the cochlea of an ear amplify and transfer vibrations


What is the order that the ossicles go in

Malleus, incus, stapes


What is the Eustachian tube

Winning begins in middle ear leads to pharynx helps equalize pressure on both sides of the tympanic membrane


What is a cochlea and describe the pathway the vibrations take

Snail shaped organ containing three fluid filled canals within middle ear canal is organ of corti which contains Mechanoreceptors. vibrations of ossicles are transmitted to oval window which pass through fluid filled canals. canal membranes vibrate hair cells who's bending triggers an impulse to be sent down to the vestibulocochlear nerve


What is equilibrium

Mechanical sense that helps an animal maintain balance by keeping track of position of head. Maintaining balance is also assisted by visual and proprioceptive information


Where are the equilibrium Mechanoreceptors located

Vestibule and semicircular canals which are in the inner ear


What is the vestibule

Chamber located between between cochlea and semicircular canals of the inner ear. Composed of two spaces utricle and saccule continuous with the cochlear duct also filled with endolymph contains patches of sensory epithelial cells called macula covered by a gelatinous layer containing otoliths. When head moves, gelatinous layer + otoliths bend microvilli


What are the semicircular canals

Three fluid filled tubes position at right angles to each other. Sensory hair cells located in: ampulla at base of each semicircular Canal: cristae. gelatinous cup sits on top of the crista which is called: cupula


What is motion sickness

Disagreement between visually perceived motion and motion detected by vestibule. Motion is seen but not felt, motion is felt but non-seen. motion is felt and seen but disagrees


What is the main organ associated with vision. What are the accessory structures for the eyeball

The main organ for vision is the eyeball plus the optic nerve number two. The accessory structures for the eyeball are eyelids, nictitating membrane, eyelashes, Lacrimal apparatus and ocular muscles


What are the three layers that the eyes composed of and what makes up each layer

Fibrous: composed of sclera and cornea. Vascular: composed of choroid coat. Nervous: composed of retina


What two fluid filled regions does the lens separate the eye into

Aqueous compartment composed of aqueous humor. Vitreous compartment composed of the vitreous humor


Describe the Scalera and what is it composed of

The Scalera is a tough white layer composed of dense connective tissue and superficial blood vessels.


Describe the cornea and what is it composed of

Transparent window into eye. covers pupil and Iris composed of collagen and water


What is the ulcerative keratosis

Corneal ulcers. Damage to upper layers of cornea commonly due to trauma foreign bodies herpesvirus and chemicals. symptoms painful tearing squinting and rubbing eye. Diagnosed using fluorescent dye. Topical ointment is typical


What is the choroid layer of the eye

Is the vascular middle layer that is pigmented between Scalera and retina. supplies nutrients to retina above it and dark pigment absorbs excessive light rays


What is that tapetum lucidum

Reflective layer in cats that improves night vision


What is the iris

Vascular middle layer, colored part of eye. Composed of radial and circular muscles to alter size of pupil which is controlled by the autonomic nervous system


What is pupil

Hole in center of Iris


What is that Corpora nigra

Brown mass in horses and ruminants


What is the ciliary body

Extension of choroid layer produces aqueous humor. Ciliary muscles are connected to lens via suspensatory ligaments


What is accommodation

Where the shape of the lens changes to allow for near and far vision. If you're looking at a FarPoint your ciliary muscles are relaxed. If you're looking at a Nearpoint your ciliary muscles are contracted


What is the retina

Nervous layer of iron. Thin, delicate membrane lining the back of the eye. composed of several layers of cells. Light passes through many layers to stimulate photoreceptors


What layers are the retina composed of

Pigmented cells, photoreceptors a.k.a. rods and cones, bipolar cells, ganglion cells, nerve fibers


Where is the blind spot. And what is it mean

Blind spot is located right at the connection of the back of the Eye to the optic nerve. There are no photoreceptors there


What do rods do

Allow you to See light


What do cones do

Allow you to see color


What is the fovea centralis

Area of Hyclone density that allows for very sharp focus. Activated by squinting to have light focus on this region


Where is the aqueous compartment

anterior chamber, posterior chamber. Separated by lens


Where is the vitreous compartment located

After the lens and the part of the eye that touches the optic nerve


Where is aqueous humor made. How is it removed

It is made by ciliary body. It is removed by Canal of Schlemm


What is a glaucoma

Production of aqueous humor exceeds removal. Usually due to reduced drainage. Causes increased intraocular pressure. Which is measured by a tonal meter. Treatment surgery to unblock canal or partially destroy ciliary body


What is a cataract

Lens becomes cloudy causes reduction in vision. Can be a result of aging inherited diabetes, hypocalcemia etc


What are the eyelids

Palpebra. Superior and inferior folds of skin plus eyelashes lined by conjunctiva


What is the nictitating membrane

Third eyelid passive in domestic animals contains tear producing gland


What is a conjunctiva

Thin, transparent membrane lining eyelids and covering anterior of eyeball highly vascularized


What is conjunctivitis

Inflammation of conjunctiva can because by bacterial, viral infections, allergies, irritation due to dry eyes


How do they test for dry eyes

Schirmer test


What is that lacrimal apparatus

Tear producing and draining structures


What do the lacrimal glands do

Produce tears. Keeps conjunctiva moist, it reduces irritation and infection. Tears contain antimicrobial proteins


What is the lacrimal puncta

Drains tears into the nasolacrimal duct and into nasal cavity


What is epiphora

Overflow of tears due to overproduction or faulty drainage


What are the extraocular eye muscles

6-7 skeletal muscles attached to Scalera and back of orbit of the Eye. Hold Eye in-place and allow movement