A & P Exam 4 Flashcards
The endocrine system works with the ____ system to maintain homeostasis.
nervous
How does the endocrine system communicate with the rest of the body?
Hormones travel through bloodstream & act of specific target cells
Reaction to stimuli is ____ and duration of effects is ____ compared to the nervous system.
slow
long
Chemical messengers produced by endocrine glands and secreted directly into blood vessels.
hormones
A cell that has receptors for a particular hormone is referred to as the ___ of that hormone.
target
Hormone secretion is usually controlled by what?
negative feedback system
Some endocrine glands, such as ____ ____ and _____ ____ are under direct stimulation from the nervous system.
adrenal medulla
posterior pituitary
Secretion of ____ and _____ from the adrenal medulla is stimulated by sympathetic nervous system.
epinephrine & norepinephrine
Are these major or minor endocrine organs? Pituitary gland, thyroid, parathyroid, adrenal gland, pancreas (islets), gonads.
Major
Are these major or minor endocrine organs? Kidneys, stomach, small intestine, placenta, thymus, pineal body.
minor
This endocrine gland is part of the diencephalon section of the brain. Its functions include appetite control, body temp regulation, control of wake-sleep cycles, controls activities of pituitary gland. Portal system of blood vessel links this with the anterior pituitary gland.
Hypothalamus
What structure in the hypothalamus secrete releasing and inhibitory hormones into portal blood vessels?
Modified neurons
Including secreting releasing & inhibitory hormones, what else does the hypothalamus secrete? (2)
Antidiuretic hormone (ADH) Oxytocin
ADH & Oxytocin are transported to the ____ ____ for storage. They are released into the bloodstream by nerve impulses from the hypothalamus.
posterior pituitary
The pituitary gland is also known as the ____, which means to grow beneath.
hypophysis
This part of the pituitary gland is the most rostral portion. It is stimulated by hypothalamus and direct feedback from target organs and tissues to produce its hormones.
Anterior pituitary
The anterior pituitary is also known as the
adenohypophysis
This is the caudal portion of the pituitary gland. It does not produce any hormones; stores and releases hormones produced by the hypothalamus.
Posterior pituitary
The posterior pituitary is also known as the
neurohypophysis
Growth hormone is released from ____ gland. It is also known as somatotropin and somatotropic hormone.
anterior pituitary
Secretion of growth hormone by the pituitary is controlled by the ______ and ______ (somatostatin) from the hypothalamus.
growth hormone releasing hormone
growth hormone inhibitory hormone
____ is the only pituitary hormone that does not function through a target gland but instead exerts its effects on almost all tissues of the body.
GH (growth hormone)
This hormone: promotes growth in young animals, helps regulate metabolism of proteins, carbs, and lipids, increases protein synthesis in all cells of body, increases mobilization of lipids from storage in fat tissue and their breakdown for energy, decreases rate of glucose utilization.
GH
GH decreases rate of glucose utilization, also called
anti-insulin effects
In short, ___ enhances body protein, uses up fat stores, conserves carbs.
GH
Growth Hormone deficiency; congenital deficiency usually due to destruction of somatotrophs by a cyst; primarily seen in German Shepherds; lack of growth
Pituitary dwarfism
Excess secretion of GH prior to closure of physis
Pituitary Gigantism
Excessive secretion of GH after closure of physis; most commonly a fuctional adenoma of the somatotropic cells in the pituitary; older male cats; increase in body size, diabetes due to anti-insulin effects of GH.
Acromegaly
Secreted by AP, helps trigger and maintain lactation. Production & release continues as long as the teat or nipple continues to be stimulated by nursing or milking.
prolactin
Secretion of prolactin from the AP is normally inhibited by what hormone from the hypothalamus?
Prolactin inhibitory hormone
When the lactating teat is stimulated, the hypothalamus secretes what hormone which stimulates the AP to release prolactin?
Prolactin-releasing factor
Thyroid Stimulating Hormone (TSH) is also known as
thyrotropic hormone
This hormone secreted by the AP stimulates growth & development of thyroid gland & causes it to produce its hormones.
TSH
Secretion of TSH is regulated by feedback from the thyroid gland. It has direct effects on AP gland & through changes in _______ hormone produced by the hypothalamus.
thyrotropin-releasing hormone
This hormone secreted by the AP stimulates growth & development of the adrenal cortex & release of some of its hormones.
Adrenocorticotropic Hormone (ACTH)
ACTH is regulated by feedback from the hormones of the adrenal gland to the (2)
hypothalamus & AP
ACTH can also be released quickly as a result of stimulation of the hypothalamus by
stress
To override the inhibitory feedback system, the hypothalamus sends a burst of _____ hormone to the AP causing ACTH to be released quickly.
corticotropin-releasing hormone
This hormone is secreted by the AP. In females, it stimulates oogenesis and stimulates cells lining the follicles to produce and secrete estrogens. In males, it stimulates spermatogenesis.
Follicle-Stimulating Hormone (FSH)
This hormone secreted by the AP completes process of follicle development in ovary, increasing amounts of estrogens feedback to AP & cause reduced production of FSH and increased production of ___.
Luteinizing hormone (LH) LH
LH levels reach a peak when follicle is fully mature which usually causes
ovulation
After ovulation, LH stimulates cells in the empty follicle to multiply and develop into the
corpus luteum
The corpus luteum produces ___ hormones necessary for the maintenance of pregnancy.
progestin
In the male, LH stimulates ____ ___ within the testes to development and produce testosterone.
interstitial cells
This hormone secreted by the AP is associated with control of color changes in the pigment cells of reptiles, fish, and amphibians.
Melanocyte-Stimulating Hormone (MSH)
Administration of artificially large amounts of ___ to higher mammals can cause darkening of the skin from melanocyte stimulation.
MSH
The posterior pituitary gland, also known as ____, develops from the embryo’s nervous system & looks like nervous tissue under the microscope.
neurohypophysis
The PP stores what 2 hormones produced in the hypothalamus?
antidiuretic (ADH) and oxytocin
The PP periodically releases ADH & oxytocin into the bloodstream in response to ___ impulses from the hypothalamus.
nerve
This hormone secreted from the PP has it effects on the uterus, causing contraction of the myometrium at the time of breeding & at parturition; causes milk letdown.
Oxytocin
ADH helps prevent ____, loss of large quantities of water in the urine
diuresis
Receptors in the ____ detect changes in osmotic pressure of blood that result from dehydration/hemoconcentration.
Hypothalamus
ADH travels to the ____ and causes resorption of more water from urine and returns it to the bloodstream. It also causes vasoconstriction.
kidney
ADH deficiency; pituitary (lack of ADH) or nephrogenic (no response to ADH); PU/PD, inability to concentrate urine; modified water deprivation test; dDAVP (derivative of ADH), continuous access to water.
Diabetes insipidus
insipid means tasteless
What stimulates the thyroid gland to secrete thyroid hormone?
TSH
This gland consists of 2 lobes on either side of the larynx.
Thyroid gland
Thyroid hormone is produced in the ____ of the thyroid gland.
follicles
Each thyroid follicle consists of simple, cuboidal glandular cells surrounding a globule of thyroid hormone precursor called
colloid
What are the 2 thyroid hormones?
T3, triiodothyronine
T4, tetraiodothyronine
Thyroid hormones have negative feedback on what 2 endocrine glands?
hypothalamus and pituitary
Which thyroid hormone is produced in greater abundance but converts to the other before producing effects on target cells.
T4
These are effects of what hormones: influences development & maturation of CNS; growth & development of muscles and bones; calorigenic effect - regulates the metabolic rate of all body cells; allows animal to generate heat & maintain constant internal body temp.
Thyroid hormones
Production of thyroid hormones increase with exposure to ____ and then increases metabolic rate to generate more heat.
cold
TH affects metabolism of proteins, carbs, and lipids much like ___ does. Encourages synthesis of proteins if adequate energy sources, encourages breakdown of lipids for energy, discourages using carbs as energy source.
GH
Deficiency of thyroid hormone
Hypothyroidism
Hypothyroidism is most commonly what type? Lymphocytic thyroiditis and idiopathic atrophy of the thyroid gland.
primary hypothyroidism
CSX of what? Lethargy, weight gain, cold intolerance, alopecia.
Hypothyroidism
DX of what disease? Free T4 by ED, T4, TSH, Csx
Hypothyroidism
TX of hypothyroidism
thyroid hormone supplementation
Excessive thyroid hormone
Hyperthyroidism
Etiology of hyperthyroidism: ___ or ____ of thyroid gland typically in middle aged to older cats.
hyperplasia or neoplasia
CSX of what disease? PU/PD, polyphagia, weight loss, v/d, tachycardia, hyperactive
hyperthyroidism
DX of what disease: T4, free T4, Csx
hyperthyroidism
TX for hyperthyroidism
antithyroid drugs, sx, radioactive iodine
What disease? lack of iodine>decrease T4>increase TSH> hyperplasia of thyroid gland
goiter
Besides T3 & T4, the thyroid gland also secretes
calcitonin
Calcitonin is produced by ____ (____) cells located between thyroid follicles.
C cells (parafollicular cells)
This thyroid gland secretion helps maintain blood calcium levels, prevents hypercalcemia by encouraging excess calcium to be deposited in the bones.
calcitonin
___ is involved in muscle contraction, blood clotting, milk secretion, and formation & maintenance of the skeleton
calcium
Small, paled nodules in, on, or near the thyroid glands.
Parathyroid glands
What hormone do the parathyroid glands produce?
parathyroid hormone (PTH) or parathormone
This hormone helps maintain blood calcium levels and prevent hypocalcemia.
PTH
PTH prevents ___ by converting Vit D into its active form calcitriol, causes kidneys to reabsorb calcium, releases calcium from bones.
hypocalcemia
What is the active form of Vit D?
calcitriol
This causes intestines to absorb calcium from food and releases calcium from bones.
Calcitriol
____ __ is carried in the bloodstream to the liver, where it is converted into the prohormone calcidiol.
Vit D
Circulating calcidiol can be converted into ____, the biologically active form of vit D, either in the kidneys or by monocyte-macrophages in the immune system.
calcitriol
A decreased production of PTH by the parathyroid gland.
primary hypoparathyroidism
Primary hypoparathyroidism is ___ in dogs and cats.
rare
CSX of primary hypoparathyroidism are consistent with _____; weakness, seizures.
hypocalcemia
DX of primary hypoparathyroidism
measure serum PTH & ionized calcium
TX for primary hypoparathyroidism
calcitriol & calcium supplements
Neoplasia of the parathyroid gland; causes hypercalcemia.
Primary hyperparathyroidism
With progressive renal disease, renal synthesis of calcitriol is also reduced. This causes
renal secondary hyperparathyroidism
Commonly seen in reptile not getting enough calcium or Vit D>increases PTH> mobilized calcium from bones> rubber jaw
Nutritional secondary hyperparathyroidism (NSHP)
The adrenal glands consist of what 2 glands?
adrenal cortex
adrenal medulla
Which organ are the adrenal glands located near?
kidneys
What are the 3 layers of the adrenal cortex?
Zona glomerulosa
Zona fasiculata
Zona reticularis
The adrenal cortex is under direction of which AP hormone?
ACTH
What type of hormones are produced by the adrenal cortex?
steroid hormones
What are the 3 main groups of steroid hormones released from the adrenal cortex?
Glucocorticoids, Mineralocorticoids, Sex hormones
What are the different types of glucocorticoids? (3)
cortisone, cortisol, corticosterone
These hormones produced by the adrenal cortex are under the direction of ACTH; have a hyperglycemic effect; also help maintain blood pressure & help the body resist the effects of stress.
Glucocorticoids
Glucocorticoids are secreted by which 2 layers of the adrenal cortex?
zona fasiculata & zona reticularis
Sex hormones are secreted by which 2 layers of the adrenal cortex?
zona fasiculata & zona reticularis
The adrenal cortex produces androgens and estrogens, which are __ hormones, in small amounts.
sex
Mineralocorticoids (e.g., aldosterone) are secreted by which layer of the adrenal cortex?
zona glomerulosa
ACTH has only a mild impact on regulating secretion of this adrenal cortex hormone.
mineralocorticoids
This adrenal cortex hormone regulates levels of important electrolytes (NA & K) in the body by: telling the kidneys to reabsorb NA & H2O follows; telling the kidneys to eliminate K.
Mineralocorticoids
Secretions of this adrenal cortex hormone are regulated by electrolyte concentrations, blood volume, arterial pressure, renal function, etc.
mineralocorticoids
This part of the adrenal gland develops from nervous tissue & resembles nervous tissue microscopically. It produces epinephrine & norepinephrine.
Adrenal Medulla
What is the adrenal medulla controlled by?
sympathetic autonomic nervous system
Excessive production of cortisol
hyperadrenocorticism
Hyperadrenocorticism in dogs
Cushing’s
What disease: usually pituitary tumor, adrenal tumor, iatrogenic
CSX: PU/PD, polyphagia, panting, pot-belly, alopecia
DX: measure cortisol levels with ACTH stim test or low-dose dexamethasone suppression test
TX: trilostane - acts on adrenal cortex to block synthesis of steriods.
hyperadrenocorticism or Cushings
Hypoadrenocorticism is also called
Addison’s
What type of hypoadrenocorticism: idiopathic atrophy of all layers of adrenal cortex resulting in deficiency of both mineralocorticoids and gludocorticoids.
Primary adrenocortical insufficiency
What type of hypoadrenocorticism: reduced secretion of ACTH resulting in deficiency of glucocorticoids only
Secondary adrenocortical insufficiency
CSX: lethargy, anorexia, vomiting
DX: electrolytes, ACTH stim test
TX: mineralocorticoid supplement +/- glucoorticoid supplement
Hypoadrenocorticism/Addisons
Hyperadrenocorticism in ferrets is do to an
excessive production of sex hormones
What disease: hyperplasia or neoplasia of adrenal cortex linked to early spay/neuter
CSX: alopecia, swollen vulva in females, prostatic cysts in males
DX: adrenal panel to evaluate levels of sex hormones
TX: adrenalectomy, Lupron, melatonin, deslorelin
hyperadrenocorticism in ferrets
This organ is located near the duodenum and has both exocrine and endocrine functions.
Pancreas
Groups of cells scattered throughout the pancreas with endocrine functions.
Islets of Langerhans (Pancreatic Islets)
Alpha cells produce
glucagon
Beta cells produce
insulin
Delta cells produce
somatostatin
This hormone is regulated mainly by blood glucose concentration. It raises blood glucose levels by stimulating liver cells to convert glycogen to glucose and by stimulating gluconeogenesis.
Glucagon
This hormone is regulated by blood glucose concentration. It lowers blood glucose levels by causing glucose, amino acids, and fatty acids to be absorbed into the body cells.
Insulin
This hormone secreted by the pancreas is the same as growth hormone inhibitory hormone. It is secreted when food is ingested. It inhibits secretion of insulin, glucagon, & GH; diminishes activity of the GI tract.
Somatostatin
This pancreatic hormone prevents rapid exhaustion of food, making it available over a longer period of time.
Somatostatin
Loss of beta cell function resulting in hypoinsulinemia. CSX: PU/PD, polyphagia, wgt loss. DX: CSX along w/persistent, fasting hyperglycemia & glucosuria. TX: insulin injections
Diabetes mellitus
Neoplasia of beta cells that causes increased insulin production. CSX: weakness, seizures from hypoglycemia. DX: hypoglycemia, hyperinsulinemia. TX: SX, corticosteriods.
Insulinoma
What organ produces erythropoietin?
Kidneys
This hormone stimulates bone marrow to increase production of RBCs.
erythropoietin
Production of erythropoietin is stimulated by
hypoxia
As RBC production increases, more O2 feeds back to kidneys and slows production of
erythropoietin
Kidney failure results in ____ because of kidneys’ inability to produce erythropoietin.
anemia
The kidneys release ___ in response to decreased blood volume/blood pressure.
renin
Renin causes _____ to be converted to angiotensin I.
angiotensinogen
Angiotensinogen is produced by the
liver
Renin causes angiotensinogen to be converted to
angiotensin I
Angiotensin I is converted to angiotensin II by
angiotensin converting enzyme (ACE)
What causes the adrenal cortex to release aldosterone which causes the reabsorption of sodium from the kidneys.
Angiotensin II
Angiotensin II causes the adrenal cortex to release ___ which causes the reabsorption of sodium from the kidneys.
aldosterone
_____ causes the reabsorption of sodium from the kidneys, water follows sodium, therefore increasinng blood pressure.
Aldosterone
Angiotensin II also tells the posterior pituitary to release ___ thereby conserving water and increasing blood pressure.
ADH
____ is produced by G cells in the wall of the pyloric antrum.
Gastrin
Secretion of gastrin is stimulated by presence of ___ in the stomach.
food
Gastrin encourages muscular ___ of the stomach wall.
contractions
What 2 hormones are secreted by cells lining the small intestine?
Secretin and cholecystokinin
Secretion of ___ occurs in response to presence of acid in the duodenum.
secretin
Secretin stimulates the pancreas to secrete ___ to neutralize the acid. It also inhibits peristalsis of the stomach.
bicarbonate
______ stimulates the pancreas to release digestive enzymes into the duodenum in response to fats and proteins. It also inhibits peristalsis of the stomach.
Cholecystokinin
The placenta produces what 2 hormones to help support and maintain pregnancy?
estrogen & progesterone
The placentas of humans and horses release what hormone that makes fat stored in the mother’s body available for use.
Chorionic gonadotropin
_____ extends cranially from the level of the heart up into the neck region along both sides of the trachea. It is large in young animals & atrophies later in life.
Thymus
___ plays an important part in the animal’s developing immune system.
Thymus
The thymus secretes ____, a hormone that stimulates the development of T-lymphocytes.
thymosin
The pineal body secretes ___, a hormonlike substance that seems to affect moods and wake-sleep cycles. It may also play a role in the timing of seasonal estrous cycles in some species.
melatonin
These are hormonelike substances derived from unsaturated fatty acids and produced in a variety of body tissues (skin, intestine, brain, kidney, lungs, repro organs, eyes)
Prostaglandins
What prostaglandin causes rupture of the corpus luteum? Also called lutalyse.
PGF2alpha
_____ influence blood pressure, blood clotting, inflammation, GI, respiratory, reproductive & kidney function.
Prostaglandins
FSH>seminiferous tubules>
spermatogenesis
LH>interstitial cells>produce
androgens
The primary androgen is
testosterone
Testosterone has an overall ___ effect in that it stimulates buildup of proteins in muscle and bone.
anabolic
Ovaries are CONTROLLED by what 2 hormones?
FSH & LH
Ovaries PRODUCE what 2 hormones?
estrogens and progestins
Amount of estrogen produced by follicles ___ as follicles grow.
increases
Increasing estrogen levels cause the AP gland to ___ the production of FSH and ___ the production of LH.
reduce (FSH)
increase (LH)
_____ occurs when LH level peaks or LH surge.
Ovulation
In induced ovulators, ___ causes the release of LH from the AP.
breeding
Corpus luteum produces several hormones collectively called
progestins
What is the principle progestin that helps prepare the uterus to receive the fertilized ovum and is needed to maintain pregnancy.
Progesterone
The ___ system is the single most important route of waste-product removal in the body.
urinary
____ removes nearly all the soluble waste products from the blood and transports them out of the body. Urea, salts, & other products
Urinary system
The urinary system is also a major route of elimination for excess water in the body. Normally, urine is about ___% water.
95%
What other ways are waste products eliminated?
Resp. system: CO2
Sweat glands: water & salts
Digestive: bile
What is the study of the kidney?
Nephrology
The following are ways kidneys maintain ____:
removal of waste products; fluid balance regulation; acid-base balance regulation; production of hormones; influence release of ADH from PP; influence release of aldosterone from cortex of adrenal gland.
homeostasis
Where are the kidneys in relation to the abdominal cavity?
retroperitoneal
In most domestic animals (except pig) the right kidney is more ___ than the left.
cranial (righty tighty)
The kidneys are somehwat mobile and are pushed caudally as the diaphragm contracts. The left kidney is more ___ than the right.
mobile (lefty loosey)
The outer fibrous connective tissue layer of the kidney
capsule
The indented area on the medial side of the kidney. Ureter, nerves, blood & lymph vessel enter & leave kidney.
Hilus
What species has an outwardly lobulated kidney?
cattle
Most kidneys are bean shaped except the right kidney of the horse is ___ shaped
heart
Medulla of the kidney has numerous pyramid-shaped areas giving the medulla a scalloped appearance.
multipyramidal (multilobular) kidneys
___ is a cuplike extension of the renal pelvis into which the medullary pyramids fit. In cattle this empties directly into the ureter.
Calyx
Which species has a smooth outer kidney but is multipyramidal?
pigs
Medullary pyramids fuse to occupy the entire inner area of the kidneys. Ex: dogs, horses, cats, sheep.
Unipyramidal (unilobular) kidneys
The basic functional unit of the kidney
nephron
The ___ is composed of a glomerulus surrounded by Bowman’s capsule.
renal corpuscle
A “tuft” of capillaries within the renal corpuscle.
glomerulus
A double-walled capsule that surrounds in the glomerulus.
Bowman’s capsule
The space between the glomerulus and Bowman’s capsule is the
capsular space
The renal corpuscle filters ___ in the first stage of urine production.
blood
Fluid filtered out of blood in the renal corpuscle is called
glomerular filtrate
The renal corpuscle is located in the renal
cortex
What is the continuation of the capsular space of Bowman’s capsule called?
Proximal Convoluted Tubule (PCT)
This is the longest part of the tubular system of the nephron. It has a twisting path through the cortex.
PCT
Epithelial cells lining the PCT are ___ and have a brush border that increases surface area for reabsorption and secretion functions.
cuboidal
When glomerular filtrate enters the PCT, it is now called
tubular filtrate
The Loop of Henle continues from the PCT. The descending loop of henle descends into the ___ and makes a U-turn.
medulla
Epithelial cells in the descending Loop of Henle still have a
brush border.
Epithelial cells in the ascending Loop of Henle become ___ ____ and lose their ___ ____.
simple squamous
brush border
The distal convoluted tubule (DCT) is a continuation of the ascending
loop of Henle
DCT from all nephrons in the kidney empty into
collecting ducts
This structure in the kidneys: carries tubular filtrate through the medulla to the renal pelvis; primary site of action of ADH; regulation of potassium & acid-base balance.
Collecting ducts
Collecting ducts are the primary site of action of what hormone?
ADH - antidiuretic hormone
Up to __% of the blood pumped by the heart goes to the kidneys.
25%
Every __-__ min, all the circulating blood in the body passes through the kidneys.
4-5
Arterioles called ____ ___ ___ carry blood into the renal corpuscle and continue as glomerular capillaries.
afferent glomerular arterioles
Glomerular capillaries filter some of the ___ out of the blood and put it in the capsular space of Bowman’s capsule, now called glomerular filtrate.
plasma
Glomerular capillaries continue as ___ ____ ____ as they leave the renal corpuscle
efferent glomerular arterioles
The blood in the efferent glomerular arterioles is still arterial, ___ exchange hasn’t taken place yet. The only place in the body where blood entering and leaving capillaries is oxygenated blood.
oxygen
Efferent glomerular arterioles divide to form the
peritubular capillaries
Tubular reabsorption and secretion takes place here. Oxygen transfer to the cells of the nephron also takes place here.
peritubular capillaries
Nerve supply to the kidneys is primarily from the ___ portion of the autonomic nervous system.
sympathetic
The sympathetic nervous system ___ the diameter of blood vessels to kidneys.
decreases
Is nerve supply essential for the kidney to function?
no
Glomerular capillaries contain many large ___ in capillary endothelium.
fenestrations
What forces plasma from the glomerulus out into the capsular space?
high blood pressure
Are fenestrations large enough to allow blood cells or large proteins to pass through?
No
How fast plasma is filtered through glomerulus. Depends on the rate of blood flow.
Glomerular filtration rate (GFR)
Abnormal amounts of protein in the urine can be used as an indicator of
glomerular damage
Glomerular filtrate contains waste products that need to be cleared from the body. Glomerular filtrate is considered to be ___ the body.
outside
____ is the mechanism to get useful substances in glomerular filtrate back into the body by way of the blood.
Reabsorption
About 65% of all tubular reabsorption takes place in the
PCT.
Substances to be reabsorbed pass out of the tubular lumen through or between tubular epithelial cells, then enter interstitial fluid and pass through endothelium into
peritubular capillaries
Sodium has to be actively transported across cell membranes. Sodium attaches to a ___ protein.
carrier
Glucose and amino acids attach to the same carrier protein and follow sodium into the cell by passive transport. This is called
sodium cotransport
The amount of glucose that can be reabsorbed by the proximal convoluted tubules.
Renal threshold of glucose
If the blood glucose level gets too high, the amount of glucose filtered through the glomerulus exceeds the amount that can be reabsorbed, and the excess is lost in the
urine
The renal threshold of glucose for dogs is
180 mg/dL
The normal blood glucose for dogs is
62-108
The renal threshold of glucose for cats is
240 mg/dL
The normal blood glucose for cats is
60-124
Sodium ions are also reabsorbed in the (2)
ascending loop of Henle
DCT
Sodium ions are reabsorbed in exchange for hydrogen, ammonium, or potassium ions under influence of what hormone?
aldosterone
Magnesium is reabsorbed from the PCT, ascending loop of Henle, and the
collecting duct
Potassium and calcium reabsorption takes place in the PCT, ascending loop of Henle, and
DCT
Calcium moves through the epithelial cells under the influence of what hormone?
parathyroid hormone (PTH)
During reabsorption, water follows the sodium, glucose, amino acids, and chloride into the interstitial space and peritubular capillaries by
osmosis
Even though urea is a waste product, the body maintains a normal level of urea in blood, called
blood urea nitrogen (BUN)
Once water leaves the tubules during reabsorption, the concentration of other substances increases and they ____ diffuse out of the tubules.
passively
The excess of urea or other nitrogenous compounds in the blood. Elevated BUN/CREA
azotemia
Decreased blood flow to the kidneys due to dehydration, congestive heart failure and shock are causes of what type of azotemia?
prerenal azotemia
The inability of the kidney to adequately regulate urine production because of damage to the nephrons, i.e., toxins, inflammation, infections are causes of what type of azotemia?
renal azotemia
Obstruction that prevents urine from being expelled from the body (stones, blood clots, tumors) are causes of what type of azotemia?
postrenal azotemia
Waste products not filtered from the blood in the glomerular capillaries pass through the peritubular capillaries into the
tubules.
Secretion primarily occurs in the
DCT
Hydrogen, potassium, ammonium and urea are eliminated by
secretion
Some medications are eliminated from the body by secretion such as
penicillin and sulfonamides
When the tubular filtrate reaches the renal pelvis, it is considered
urine
Urine volume is determined by the amount of ___ contained in the tubular filtrate when it reaches the renal pelvis.
water
Urine volume is controlled by what 2 hormones?
ADH & aldosterone
____ (hormone) acts on the DCT and collecting ducts to promote water reabsorption.
ADH
____ increases reabsorption of sodium. (hormone)
aldosterone
ADH deficiency
Etiology: pituitary (Lack of ADH) or nephrogenic (no response to ADH)
CSX: PU/PD, inability to concentrate urine
DX: modified water deprivation test
TX: dDAVP, continuous access to water
diabetes insipidus
A continuation of the renal pelvis. Tube that exits the kidney at the hilus and connects to the urinary bladder.
Ureter
The ureters continually move urine from the kidneys to the urinary bladder by
peristaltsis
_____ epithelium allows ureters to stretch as urine passes through them on its way to the bladder.
transitional
Ureters enter the urinary bladder at an ____ angle.
oblique
This functions to collect, store, and release urine. It is composed of a muscular sac and neck.
Urinary bladder
The urinary bladder is lined with ___ epithelium that stretches as the bladder becomes filled with urine.
transitional
Wall of the urinary bladder contains ____ muscle bundles that run lenghtwise, obliquely, and in a circular direction
smooth
Neck of the bladder extends caudally from the sac into the __ canal and joins the urethra.
pelvic
When the trigger point is reached, a spinal reflex returns a motor impulse to bladder muscles causing them to contract. This contraction gives the sensation of
having to urinate
____ control of the muscular sphincter around the neck of the bladder results in temporary control of urination.
Voluntary
Expulsion of urine from the urinary bladder into the urethra is called (2)
Micturition or uresis
The urethra is lined with ___ epithelium which allows it to expand.
transitional
The _____ urethra is shorter and straighter than the long, curved ____ urethra.
female
male
The sphincter at the neck of the urinary bladder closes at the beginning of ____ to prevent semen from entering the bladder and mixing with urine.
ejaculation
What are the 4 orders in the Reptilia class?
Crocodylia, Squamata, Chelonia, Rhynocephalia
Alligators, caimans, and crocodiles are in which order?
Crocodylia
Snakes and lizards are in which order?
Squamata
Turtles, tortoises & terrapins are in which order?
Chelonia
These types of animals, including reptiles, are unable to generate body heat internally. Body temp depends on environmental temp. 2 exceptions: leatherback sea turtles & pythons
Ectotherms/Poikilotherms
Reptiles maintain body temps via _____ thermoregulation (basking, coiling).
behavioral
Reptiles’ ability to thermoregulate depends on access to temperatures within the
preferred optimal temperature zone (POTZ)
This is the range of temperatures in which the animal can perform all necessary metabolic functions
preferred optimal temperature zone (POTZ)
Ectotherms regulate temp depending on
metabolic needs
Ectothermy allows many reptiles to survive on ___ amounts of food.
small
If temperatures are too ____, reptiles can suffer from digestive problems, immunosuppression, and other disorders.
low
If temps are too ___, reptiles are forced to maintain a high metabolic rate and may suffer from energy deficits.
high
Reptiles will undergo ____ or brumation when temps drop below POTZ.
hibernation
The epidermis of reptiles is made of distinct scales formed by a ___ of the epidermis and is relatively impermeable.
folding
This type of keratin on reptiles is soft, flexible, and found in the interscalar skin.
alpha keratin
This type of keratin on reptiles in rigid and found in scales.
beta keratin
The dermis of reptiles is dense connective tissue that contains blood & lymph vessels, nerves and
chromatophores.
The subcutaneous space in reptiles is _____, making SQ injections inadvisable.
limited
The process of shedding the skin is controlled by the
thyroid gland
Shed skin of reptiles is called
exuvia
The process of shedding the skin is called
ecdysis
An enzyme-containing ___ is secreted between old and new epidermal layers during ecdysis.
lymph
During ecdysis, skin color ___ and spectale opacifies.
dulls
The term for abnormal shedding of the skin is
dysecdysis
Causes of dysecdysis include (4)
low humidity, dehydration, underlying illness, lack of cage furniture
Tx for dysecdysis
proper husbandry, soaking
The iris of reptiles is made of skeletal muscle and is under ___ control.
Voluntary
Since the iris of reptiles is under voluntary control, ___ are not predictable.
PLR’s
Snakes and some lizards have this clear, scale-like structure formed by the fusion of the upper and lower eyelids instead of eyelids.
Spectacle
The spectacle is ___ to topical medications
impermeable
Most reptiles have ____ developed extraocular muscles, with the exception of chameleons.
poorly
Chelonians have no ___ ___ so tears spill over the lid margin.
nasolacrimal duct
Most reptiles (exceptions: snakes & crocodilians) have ____ bones which help the eye maintain its shape.
scleral
Crocodilians are the only reptiles that have a ____ which help them see better in the dark.
tapetum
This structure is found in tuataras and some lizards. It is a rudimentary retina & cornea with no iris, lids, or musculature. It may play a role in hormone production & thermoregulatory behavior.
Parietal eye
The parietal eye is connected to the pineal body via the
parietal nerve
The location of the heart varies in reptiles. For ____, the heart is on midline just caudal to the thoracic girdle and ventral to the lungs.
chelonians
The location of the heart varies in reptiles. For most ____ the heart is within the thoracic girdle.
lizards
The location of the heart varies in reptiles. For ____ and some lizards, the heart is more caudal in the coelomic cavity.
Crocodilians
The location of the heart varies in reptiles. For ____, the heart is usually at junction of first & second third of the body length but is fairly mobile.
snakes
The heart of most reptiles has ___ atria and __ ventricle.
2 atria
1 ventrile
There are 3 regions within the ventricle that are functionally separate. What are they?
Cavum venosum
Cavum arteriosum
Cavum pulmonale
In times of ___ ____, reptiles can shunt blood away from the lungs.
oxygen deprivation
____ are the only reptiles that possess a four-chambered heart. It is very different from birds and mammals.
Crocodilians
When the vagus nerve of lizards is suddenly stimulated, it sets off a chain of events within the body, most notably a rapid reduction of BP and HR. This is called
vasovagal reflex
The vasovagal reflex is triggered by applying gentle pressure to both
eyeballs
Mature reptilian RBCs are different from mammalian in what 2 ways?
nucleated, oval
The WBC in reptiles that is analogous to neutrophils.
heterophils.
Because heterophils do not possess peroxidase & acid phosphatase which break down necrotic material, reptiles produce ___ pus instead of liquid material.
caseous
What are the different blood collection sites of reptiles? (5)
ventral coccygeal vein dorsal coccygeal vein jugular subcarapacial sinus cardiac puncture
Reptiles are capable of surviving long periods without breathing due to their large pulmonary volume, efficient ___ metabolism, and cardiac shunting capabilities.
anaerobic
Respiration in reptiles is driven by ___ levels in blood, as compared to CO2 levels in mammals.
O2
Reptiles do not have an epiglottis, only a ___ in the rostral portion of the oral cavity.
glottis
Paired ___ cartilages border the glottal opening and open during respiration
arytenoid
The only vocalizations of reptiles are hissing, grunting, and bellowing. This is because they do not have
vocal cords
A glottal keel is present in some species of snakes. This increases
volume of vocalizations
Tracheal rings are ___ in chelonians and _____ in lizards and snakes.
complete - chelonians
incomplete - snakes & lizards
The ___ are analogous to alveoli in mammals. They are fixed structures (do not expand or contract) surrounded by capillaries.
faveoli
This lung type is a simple, saclike structure. The cranial portion is the site of gas exchange. The caudal portion is avascular and comparable to avian air sac. Snakes and some lizards have this lung type.
Unicameral
This lung type is present is chelonians, some lizards, and crocodilians. It has many compartments and possesses intrapulmonary bronchi.
Multicameral
This lung type is present in iguanas and chameleons. It has characteristics of both unicameral & multicameral lungs.
Paucicameral
Most snakes only have a single ___ lung.
right
There is no true ___ in reptiles that would separate the thoracic & abdominal cavity in mammals.
diaphragm
Since reptiles do not possess a true diaphragm, they have one cavity called
coelomic cavity
The single bone in the middle ear of reptiles is called
columella
The columella connects to the tympanum and the ____ bone.
quadrate
Since the columella articulates with the quadrate bone, it allows snakes to be very sensitive to ground vibrations transmitted through the
mandibles
Concerning feeding, snakes & crocodilians are strict
carnivores
Snakes & lizards have deeply forked tongues which function as particle delivery system for vomeronasal organ or _____ organ, an accessory olfactory organ.
Jacobson’s
