Exam 5 Flashcards
What are sense receptors
Peripheral endings of sensory neurons that obtain information about the environment and are specific for the type of stimulus they detect
What are chemoreceptros
Receptors that detect ions or molecules the smell and taste senses rely on these
What are mechanoreceptors
They detect changes in pressure, position, or acceleration senses such as touch, stretch, hearing, and equilibrium
What are electromagnetic receptors
They detect infrared radiation, visible light, or magnetic fields
What are thermoreceptors
Detect hot or cold temperatures
What are pain receptors
Detect severe heat and pressure and chemicals released by inflamed tissue
What are the general senses
Visceral, touch, temperature, pain, and proprioception
What are special senses
Taste, smell, hearing, equilibrium, and vision
What are visceral sensations
Miscellaneous category of interior body sensations such as hunger, thirst, and hollow-organ fullness
What are the receptors used by visceral sensations
Chemical and mechanical
What are the receptors used by touch
Mechanical
What type of receptors are used for sensing temperature
Thermal
What type of receptors are used for sensing pain
Mechanical, chemical, or thermal
What type of receptors are used for sensing proprioception
Mechanical
What are the tactile senses
Touch which is the sensation of something in contact w/ the surface of the body and pressure which is the sensation of something pressing on the body surface
What are the 2 types of temperature senses
Superficial w/ receptors in the skin that detect changes in skin temperature and central w/ receptors in the hypothalamus that monitors the temperature of the blood
What are specific pain receptors
Nociceptors that are widely distributed inside and on the surface of the body that are simple nerve endings or more specialized structures to detect mechanical forces and temperature
What is the main purpose of nociceptors
To protect the body from damage
What are the parts of the pain process
Transduction, transmission, modulation, and perception
What is transduction
Takes 1 energy source and converts it into a different one by taking a pain stimulus and turns it into a nerve impulse
What is transmission
The nerve transmits the pain signal to the spinal cord
What is modulation
The spinal cord takes an impulse and determines the priority of the pain then sends it to the brain
What is perception
When an impulse has finally arrived to the brain and pain is perceived
How does pain blockers such as an epidural work to reduce pain
It stops modulation and interrupts the perception process decreasing the pain after and during a procedure
What are the 3 different pain locations
Superficial, deep, and visceral
What are the 2 types of pain duration
Acute or chronic
What is proprioception
Awareness of where the limb is in space that utilizes stretch receptors in the skeletal muscle, tendons, ligaments, and joint capsules to keep the CNS informed
What type of receptors stimulate taste
Chemical
What type of receptors stimulate smell
Chemical
What type of receptors stimulate hearing
Mechanical
What type of receptors stimulate equilibrium
Mechanical
What type of receptors stimulate vision
Electromagnetic
What is taste
Gustatory sensation is detected by 3 different types of papillae (receptors) sweet, salty, and bitter
What is smell
Olfactory cells in the epithelial patches in the nasal passages contains receptors and odor molecules dissolve in mucus
What path does olfactory information take making it more acute than taste
Passes directly to the cerebral cortex by the olfactory bulbs
What is hearing
The mechanical receptors take vibrations of air molecules and convert it into nerve impulses that are interpreted by the brain as sound
Where is the middle ear
In the tympanic bulla
Where is the inner ear
W/in the middle ear
What is the pinna’s role in hearing
It collects sound waves
What shape is the external auditory canal
L shaped
Where is the tympanic membrane
Separates the external ear from the middle ear
What is the tympanic membrane
The eardrum is a paper thin connective tissue membrane that stretches tightly across the opening btw the external auditory canal and the middle ear cavity
Can the tympanic membrane grow back if it ruptures
Yes
What is the middle ear
The eustachian tube that is filled w/ air that contains 3 ossicles that are caused to vibrate by the eardrum transmitting to the cochlea and 2 muscles
What are the 3 ossicles in the middle ear
Malleus (hammer), incus (anvil), and stapes (stirrup)
Where is the malleus
The outermost bone that is attached to tympanic membrane
Where is the incus
The middle bone in the middle ear
Where is the stapes
Attached to the membrane covering the oval window of cochlea
What are the muscles in the middle ear
The tensor tympani and stapedius
What are the functions of the muscles in the middle ear
They are involuntary muscles that aid in protecting the cochlea by tensing against the ear drum to reduce intensity of soundwaves to prevent hearing loss
What are the functions in the inner ear
Hearing and equilibrium
What is the cochlea
A snail shell shaped spiral cavity in the temporal bone
What is the Organ of Corti
A portion of a specific nerve ending that is filled w/ endolymph and contains hair cells that transduces sound to send to brain
What things are all found in the Organ of Corti
Endolymph, hair cells, supporting cells, and tectorial membrane
What are the steps of hearing
Sound wave vibrations cause the tympanic membrane and ossicles in the middle ear to vibrate, perilymph around the cochlear duct vibrates, cochlear duct moves, tectorial membrane and hair cells of the Organ of Corti rub against each other, nerve impulses are generated, and impulses travel to the brain and are interpreted as sound
What is equilibrium
Maintaining balance by keeping track of the head’s position and movements using the vestibule and semicircular canals
What is the vestibule
Located btw cochlea and semicircular canals that has 2 saclike spaces the utricle and saccule also has the macula
What is the macula
Sensory epithelium that lines the utricle and saccule and contains hair cells that are covered by gelatinous matrix and contains otoliths
What is the function of the macula
Gravity causes otoliths and gelatinous matrix to put constant pressure on the sensory hairs causing them to bend this generates a nerve impulse that gives the brain info about the position of the head
What are the semicircular canals
Located on the other side of the vestibule from the cochlea containing fluid filled membranous tubes that are arranged in 3 planes at right angles to each other giving 3D axis
What is the ampulla
The enlarged bulb area near the utricle end of each semicircular canal
What is the crista ampullaris
A receptor similar to macula that houses the cupula
What is the cupula
A cone shaped area of supporting cells and hair cells w/ their processes sticking up into gelatinous structure
What are the steps of sensing motion
The head moves, fluid movement lags in one plane of semicircular canals, fluid movement pulls on cupula, hairs are bent, nerve impulse is generated, and brain receives info about motion of the head
What are the three layers of the eyeball
Outer fibrous layer (cornea and sclera), middle vascular layer (choroid, iris, and ciliary body), and inner nervous layer (retina)
What is the cornea
It is transparent to admit light to the interior of the eye, has an orderly arrangement of collagen fibers, and only contains receptors
What is the sclera
The white of the eye
What is the limbus
The junction of the cornea and sclera
What is the choroid
Lies btw sclera and retina, consists mainly of pigment and blood vessels, and contains the tapetum lucidum a highly reflective area in the rear of the eye
What is the iris
The pigmented smooth muscular diaphragm that controls the amount of light that enters the posterior part of the eye and contains the pupil which is the opening in the center of iris
What is the ciliary body
A ring shaped structure behind the iris that contains tiny muscles that adjust the shape of the lens to allow near and far vision
What is the fundus
The caudal interior surface of the eye that contains the retina and ophthlamic disc
What is the retina
The neuro component of the fundus that contains rods and cones
What are the different layers of the retina
Pigment, photoreceptor, bipolar cell, ganglion cell, and nerve fibers
What is the optic disc
The blind spot of the eye where nerve fibers on inside of the retina converge and leave the eye to form the optic nerve
What are photoreceptor cells
Neurons w/ dendrites modified into sensory receptors for light broken up into rods and cones
What are rods
Photoreceptors that can’t distinguish colors and do not provide sharp vision, are sensitive to dim light, better at detecting motion than cones, most abundant in the periphery of the retina, and they have several hundred stacked membranous disks that contain the pigment rhodopsin
What are cones
Photoreceptors that see color, they produce sharp images but require bright light, cones are the most dense in an area in the back of the eye called the fovea, there are 3 types of cones red, green, or blue
What type of cones do dogs have
Blue and yellow
What is the lens
A soft translucent layers of fibers that are elastic and biconvex this helps focus a clear image on the retina through the accommodation process
What can change the shape of the lens
The ciliary muscles
What is lenticular sclerosis
A normal decrease in elasticity of the lens that occurs w/ age and causes hazy looks starting around 7-9 years old
What are cataracts
Eye disease that blocks light from the retina causing blindness, a glassy marble appearance, retina degeneration leading to leaking of the eye proteins, and glucoma
What are the 2 compartments of the eye
The aqueous chamber and the vitreous body
What is the aqueous chamber
Located in front of the lens, subdivided into the anterior and posterior chambers by the iris, and contains the clear water fluid that is the aqueous humor
What is the path of the aqueous humor
It is produced in the posterior chamber by the ciliary body and drained in the anterior chamber by the Canal of Schlemm
What is a glaucoma
Can present as acute which looks like a normal eye due to a rapid increase in pressure or chronic which is a gradual increase in pressure leading to a white swollen eye
What is the vitreous compartment
Contains clear gelatinous fluid called the vitreous humor filling the whole back of the eye behind the lens and ciliary body
What is the conjunctiva
The thin, moist, transparent membrane that covers the front portion of the eyeball (bulbar conjunctiva) and lines the interior surfaces of the eyelids (palpebral conjunctiva)
What is the conjunctival sac
Space btw bulbar and palpebral portions of the conjunctiva
What are eyelids
Upper and lower folds of skin lined by conjunctiva
What are the lateral and medial canthus
Corners where the eyelids come together and contains extra CT that makes the eyelid an almond shape
What are tarsal/meibomian glands
Their tiny openings that are found along the eyelid margin they produce a waxy substance to prevent tears from overflowing onto the face
What is the third eyelid
Nictitating membrane that is a T shaped plate of cartilage covered by conjunctiva located medially btw the eyelids and the eyeball and contains lymph nodules and accessory lacrimal gland on the ocular surface
What is horner’s syndrome
Globe of eye gets sunken back due to disfunction of the sympathetic nerves of the eye
What is the lacriminal apparatus
Structures that produce and secrete tears and train tears away from the surface of the eye
What is the tear drainage system
Lacrimal puncta, lacriminal sacs, and nasolacrimal duct
What are tears
Liquid film that moistens and protects the surface of the eye
What do tears from the inner mucous layer contain
Antibacterial substances
Where are tears produced in the middle tear layer
From the lacrimal glands and accessory lacrimal glands of the third eyelid to keep the cornea moist
What is the purpose of the outer oily layer
Produced from tarsal/meibomian glands to reduce evaporation of underlying tear layer preventing tears from flowing over the lid margin
What are the eye muscles
Small skeletal muscles that attach to the sclera capable of wide range of movements
What are the 3 different hormone groups
Peptide, steroid, and monoamine
What are peptide hormones
Hydrophilic chains of AA that have receptors located on cell membranes of target cells
What are steroid hormones
Synthesized from cholesterol they are hydrophobic so they attach to transport proteins and their receptors are located w/in the cell
What are monoamine hormones
Derived from AA and retain an amine group they have receptors for catecholamines located on cell membranes and receptors for thyroid hormones located in the nucleus
What is negative feedback
Activity decreased by rising levels of hormone
What is positive feedback
Activity increased by falling levels of hormone
What is the hypothalmus
Part of the diencephalon of the brain it controls activities of the pituitary gland and uses a portal system of blood vessels linking to the anterior portion of pituitary gland
How does the hypothalamus trigger the release of different hormones in the anterior pituitary hormone
Modified neurons secrete releasing and inhibiting factors into portal blood vessels each specific for a particular hormone
What hormones are produced in the hypothalamus and stored in the posterior pituitary
Antidiuretic hormone (ADH) and oxytocin
What is another word for the anterior pituitary
Adenohypophysis
What is another name for the posterior pituitary
Neurohypophysis
What are the hormones produced by the anterior pituitary
Growth hormone, prolactin, thyroid stimulating hormone, adrenocorticotropic hormone, FSH, LH, and melanocyte stimulating hormone
What is growth hormone
Somatotropin promotes body growth in young animals to regulate metabolism of proteins, lipids, and CHO in all body cells encouraging anabolism of proteins, causing release of lipids in storage and their catabolism, and discourages cells from using CHO
What is prolactin
Helps trigger/maintain lactation production and release continues as long as teat continues to be stimulated by nursing or milking
What occurs w/o stimulation from prolactin
Milk production stops and mammary gland shrinks back to a non lactating size
What is TSH
Thyrotropic hormone stimulates growth and development of thyroid gland causing it to produce its hormones its secretion is regulated by negative feedback from the thyroid by interacting among hypothalamus, anterior pituitary, and thyroid glands
What is ACTH
Stimulates growth and development of adrenal cortex and release of some of its hormones, production is regulated by negative feedback from hormones of the adrenal cortex, and can be released quickly as result of stress
What is melanocyte stimulating hormone
Associated w/ control of color changes in pigment cells of reptiles, fish, and amphibians
What is ADH
Vasopressin increases blood pressure by conserving blood volume is released when hypothalamus detects dehydration producing more concentrated urine
What does ADH deficiency cause
Diabetes insipidus leading to polyuria and polydipsia
What is the thyroid gland
Bilobed on either side of the larynx connected by the isthmus it produces thyroid hormone and calcitonin
What are the effects of thyroid hormone
Regulates metabolic rate of all body’s cells w/ a calorigenic effect increasing metabolism to generate body heat allowing animals to maintain constant internal body temp and affects metabolism of proteins, CHO, and lipids affecting anabolism of synthesis of proteins, maintaining homeostasis of blood glucose levels, and encourages catabolism of lipids
What is calcitonin
Produced by C cells located btw thyroid follicles lowering blood calcium levels resulting in excess calcium to be deposited in bones and exerts opposite effect of parathyroid hormone
What is the common reasoning for thyroid hormone deficiency
Iodine deficiency
What is the result of thyroid hormone deficiency
Even tho T3&T4 arent able to be produced TSH is still being released causing the thyroid gland enlarges causing a goiter this can also be caused by hyperthyroidism
What are common signs of hypothyroidism in dogs and cats
Lack of activity, hair loss, dry and dull hair, cold sensitivity, and anemia treated with levothyroxine
What are the common signs of hyperthyroidism in dogs and cats
Fatigue, weight loss, hunger, nervousness, and sensitivity to heat is treated w/ radiation (thiouracil, thiourea, sulfonamides, and chlorpromazine)
What is parathyroid hormone
Parathormone, produced by parathyroid glands, enhances cacium and phosphate absorption from the intestines by increasing active form of Vit D, and increases blood calcium causing kidneys to retain calcium, causes intestines to absorb calcium from food, and stimulates osteoclasts
What does primary hyperparathyroidism result in
Hypercalcemia
What are the produced in the adrenal cortex
Glucocorticoids (cause general hyperglycemic, help maintain BP, and help body resist effects of stress), mineralocorticoids (regulate levels of electrolytes), and sex hormones
What is adrenal disease
Hyperadrenocorticism (cushing’s syndrome) and hypoadrenocorticism (addison’s disease)
What is cushing’s syndrome
Excessive cortisol production it is pituitary dependent primarily occurs due to adrenocortical tumors symptoms consist of PU, PD, pot bellied appearance, think skin, alopecia, muscle wasting, and results in insulin resistance
What is addison’s disease
The result of atrophy or destruction of all of the layers of the adrenal cortex referred to as the great pretender because it mimics other disease symptoms include decreased cortisol +/- aldosterone production, hyponatremia, and hyperkalemia female standard poodles are the poster child after age 7
What is the adrenal medulla
The inner gland that resembles nervous tissue it produces 2 hormones epinephrine and norepinephrine that are controlled by the sympathetic portion of ANS
What are pancreatic islets
Islets of langerhans are alpha (glucagon), beta (insulin), delta (somatostatin)
What does insulin do
Lowers blood glucose levels causing glucose, AA, and FA in the blood to be absorbed into body cells
What does glucagon do
Raises blood glucose levels stimulating liver cells to convert glycogen to glucose and stimulating glycogenesis
What are the 2 types of diabetes mellitus
Type 1 insulin insufficiency at pancreas (dogs) and type 2insulin resistance at site of tissues (cat)
What are clinical signs of diabetes mellitus
Hyperglycemia, glucosuria, PU/PD, polyphagia, and weight loss
What are complications of pancreatic disease
Cataracts, retinopathy, neuropathy, EPI, hepatic lipidosis, glomerulonephropathy, and increased risk of bacterial infections
What is erythropoietin
Stimulated in the kidneys by hypoxia increasing production of RBCs resulting in increased blood oxygen level slows down secretion
What does erythropoietin deficiency result in
Nonregenerative anemia of chronic kidney disease
What is gastrin
Hormone produced by cells in stomach wall to act upon the stomach wall and secretion stimulated by presence of food results in secretion of hydrochloric acid and digestive enzymes increasing gastric motility
What triggers the SI to secrete secretin and CCK
The presence of chyme in duodenum
What is the function of secretin
Stimulates pancreas to secrete fluid to neutralize acidic chyme
What is the function of cholecystokinin
Stimulates pancreas to release digestive enzymes
What are the effects of both secretin and CCK
Slows movement of chyme and stimulates gallbladder to send bile to SI
What is the thymus
An important part of animal’s cell mediated immunity is a larger organ in young animals that atrophies later in life it produces thymosin and thymopoietin
What are the 3 functions of prostaglandins
Inflammation, pain/fever, and reproduction
Where are prostaglandins produced
Skin, intestine, brain, kidneys, lungs, repro organs, and eyes
What are prostaglandins
Tissue hormones that are derived from unsaturated FA
