Chapter 14 - Senses Flashcards
0
Q
Why is capsaicin illegal in equestrian sports
A
It can cause hypersensitivity and have an analgesic effect. It is a banned substance in competition
1
Q
What is Capsaicin
A
It is the chemical in peppers that makes them hot. Irritant to mammals causing a burning sensation.
2
Q
What is hypo-sensitivity
A
Sensitivity below normal limits usually due to a neurectomy or nerve block
3
Q
What is hypersensitivity
A
Sensitivity above normal limits. Due to irritants put on skin
4
Q
How does capsaicin cause a burning sensation
A
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
5
Q
What will prolonged exposure to capsaicin cause
A
Desensitization. Neurotransmitters become depleted and neuron’s retreat back into dermis
6
Q
What is a stimuli
A
Sensory receptors respond to environmental changes internally and externally
7
Q
Identify what are the four types of stimuli and give an example for each
A
- mechanical ex: touch hearing balance.
- thermal ex: hot and cold.
- electromagnetic ex: vision.
- chemical ex:taste and smell.
8
Q
What are sensory receptors
A
Modified afferent neuron endings a.k.a. dendrites
9
Q
How are senses interpreted
A
Sensory receptors are depolarized by the stimuli and then sensory information is sent to specific region of the brain for interpretation
10
Q
How are receptors classified by
A
Which stimulus is received, location(ex: proprioceptors), structure (encapsulated or nonencapsulated)
11
Q
If there is a mechanical stimulus what receptor type will receive that information
A
Mechanoreceptors
12
Q
If there is a thermal stimuli what receptor type will receive that information
A
Thermoreceptor
13
Q
If there is an electromagnetic stimulation what receptor type will get that information
A
Photoreceptor
14
Q
If there is a chemical stimulation what type of receptor will receive that information
A
Chemoreceptor
15
Q
What stimulus type is associated with the following examples touch pressure vibration stretch
A
Mechanical stimulation
16
Q
What stimulation type is associated with the following examples hot, cold, temperature changes
A
Thermal stimuli
17
Q
What stimuli is associated with the following example light
A
Electromagnetic stimuli
18
Q
Which stimuli is associated with the following example blood chemistry intestinal fluids and molecules smelled or tasted
A
Chemical stimuli
19
Q
Which types of stimuli are associated with extreme stimulation
A
Mechanical, thermal, chemical
20
Q
What receptor type is associated with extreme stimuli
A
Nociceptor
21
Q
What are some examples of non-encapsulated sensory receptors
A
Hair follicle receptors, Merkel disks, free nerve endings of sensory neurons
22
Q
What is itchiness and what is it caused by
A
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
23
Q
What is pain
A
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
24
What are endorphins
Inhibitory neurotransmitters released by the central nervous system that block neurotransmitters released by nociceptors. Pain blocker. a natural opiate
25
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
26
What is anesthesia
Feet loss of sensation used to complete procedures that would be otherwise uncomfortable to the patient
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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
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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
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What is analgesia
Perception of pain is lessened but not completely gone often used to reduce severe pain during traumatic injury and surgery
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What are three examples of encapsulated sensory receptors
Meissners corpuscles, lamellar corpuscles, bulbous corpuscles
31
What are five special senses
Taste, smell, hearing, equilibrium, vision
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What are five general senses
Visceral sensations, touch, temperature, pain (nociception), proprioception
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What are three sensory neurons associated with touch and pressure
Messingers corpuscles, hair follicle receptors, Pacinian corpuscles
34
Where are Messner's corpuscles found
In papillary layer of dermis. Numerous in hairless sensitive regions
35
Where are hair follicle receptors found
Free nerve endings wrap around the base of hair follicle and it's found and hairy skin
36
Where are Pacinian corpuscles found
Located deep in dermis, perceived deep pressure
37
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
38
What detects changes in skin temperature.
Superficial thermal receptors detect changes in skin temperature.
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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
40
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
41
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
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What is proprioception
Sense of body position and movement on a subconscious level
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Where are proprioreceptors located and what are they
Proprioceptor's are stretch Mechanoreceptors located in synovial joint capsules tendons ligaments and muscles
44
Describe acute pain
Sharp, intense, short-term
45
Described chronic pain
Dull, aching, long term
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Describes superficial pain
Skin, subcutaneous area
47
Describe deep pain
Muscles, joints, bones
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Describe visceral pain
Internal organs
49
What is a pain threshold
Amount of stimuli that will trigger an action potential. All or none principal
50
What is pain tolerance
Function of the cerebral cortex is perception of pain some genetic component
51
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
52
Where are all sense organs located
In the head. Sense organs are extension of the central nervous system
53
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
54
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
55
What are the five different tastes human can perceive
Sweet-organic molecules , sour-acids, salty-metal ions, bitter-alkaloids, umami-amino acids
56
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
57
What Are the autonomic reflexes in the medulla oblongata
Salivation, release of gastric acids and enzymes, gag reflex or vomit reflex
58
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
59
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
60
What are pheromones
Species specific chemicals released to trigger a social response example aggression alarm trails territory sexual. There are chemoreceptors for various pheromones
61
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
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What is the vomeronasal organ used for
It is an olfactory organ used mainly to detect pheromones. Involved in flehmen response of some animals
63
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
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What is the external ear and what is it do
The external air collects and funnels waves to the ear drum
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What does the middle ear do
Amplifies and transmits vibrations to inner ear
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What does the inner ear do
Sensory receptors convert vibrations into nerve impulses also has receptors for equilibrium
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What is the pinnA
Composed of elastic cartilage and skin collects soundwaves and funnels them into the external auditory canal
68
What is the external auditory canal
L-shaped tube carrying soundwaves from pinna to tympanic membrane
69
What is the tympanic membrane
Connective tissue membrane separating external and middle ear vibrates at the same frequency as waves that strike it
70
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
71
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
72
What is the middle ear cavity
Mucous membrane line cavity within the Temporel bone filled with air and contains ossicles
73
What are ossicles
Three small bones that link the tympanic membrane to the cochlea of an ear amplify and transfer vibrations
74
What is the order that the ossicles go in
Malleus, incus, stapes
75
What is the Eustachian tube
Winning begins in middle ear leads to pharynx helps equalize pressure on both sides of the tympanic membrane
76
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
77
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
78
Where are the equilibrium Mechanoreceptors located
Vestibule and semicircular canals which are in the inner ear
79
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
80
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
81
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
82
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
83
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
84
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
85
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.
86
Describe the cornea and what is it composed of
Transparent window into eye. covers pupil and Iris composed of collagen and water
87
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
88
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
89
What is that tapetum lucidum
Reflective layer in cats that improves night vision
90
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
91
What is pupil
Hole in center of Iris
92
What is that Corpora nigra
Brown mass in horses and ruminants
93
What is the ciliary body
Extension of choroid layer produces aqueous humor. Ciliary muscles are connected to lens via suspensatory ligaments
94
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
95
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
96
What layers are the retina composed of
Pigmented cells, photoreceptors a.k.a. rods and cones, bipolar cells, ganglion cells, nerve fibers
97
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
98
What do rods do
Allow you to See light
99
What do cones do
Allow you to see color
100
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
101
Where is the aqueous compartment
anterior chamber, posterior chamber. Separated by lens
102
Where is the vitreous compartment located
After the lens and the part of the eye that touches the optic nerve
103
Where is aqueous humor made. How is it removed
It is made by ciliary body. It is removed by Canal of Schlemm
104
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
105
What is a cataract
Lens becomes cloudy causes reduction in vision. Can be a result of aging inherited diabetes, hypocalcemia etc
106
What are the eyelids
Palpebra. Superior and inferior folds of skin plus eyelashes lined by conjunctiva
107
What is the nictitating membrane
Third eyelid passive in domestic animals contains tear producing gland
108
What is a conjunctiva
Thin, transparent membrane lining eyelids and covering anterior of eyeball highly vascularized
109
What is conjunctivitis
Inflammation of conjunctiva can because by bacterial, viral infections, allergies, irritation due to dry eyes
110
How do they test for dry eyes
Schirmer test
111
What is that lacrimal apparatus
Tear producing and draining structures
112
What do the lacrimal glands do
Produce tears. Keeps conjunctiva moist, it reduces irritation and infection. Tears contain antimicrobial proteins
113
What is the lacrimal puncta
Drains tears into the nasolacrimal duct and into nasal cavity
114
What is epiphora
Overflow of tears due to overproduction or faulty drainage
115
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
