The Endocrine System Flashcards
True or False: Endocrine glands have ducts
False
List the 3 chemical categories of animal hormones
- Peptide Hormones
- Steroid Hormones
- Monoamine Hormones
hydrophilic hormones made of amino acid chains, whose associated receptors are located on the cell membranes of their target cells
Peptide Hormones
hydrophobic hormones made of cholesterol-synthesized lipids, whose associated target cell receptors are intracellular
Steroid Hormones
hormones that can be either hydrophobic or hydrophilic and are derived from amino acids
Monoamine Hormones
the portion of steroid hormone molecules attached to transport protein molecules
Bound Hormone
the portion of steroid hormone molecules not attached to transport proteins and is the only form of the hormone that can leave the bloodstream to reach a target cell
Unbound (Free) Hormone
Give 3 examples of monoamine hormones
- Epinephrine - catecholamine
- Norepinephrine - catecholamine
- Thyroid hormones
Give 5 examples of steroid hormones
- Androgens
- Estrogens
- Glucocorticoid hormones
- Mineralocorticoid hormones
- Progestins
Give 5 examples of peptide hormones
- Antidiuretic hormone (ADH)
- Insulin
- Follicle-stimulating hormone (FSH)
- Prolactin
- Luteinizing hormone (LH)
a mechanism used to control and regulate processes by utilizing the consequences of the process to regulate the rate at which the process occurs
Feedback System
the type of hormone feedback when the activity is decreased by rising levels of the hormone
Negative Feedback
the type of hormone feedback when the activity is increased by falling levels of the hormone
Positive Feedback
What is the most common type of feedback system in the body?
Negative Feedback
Give an example of when positive hormonal feedback is used in the body
Female estrous cycle
What 2 ways are hormone secretion controlled?
- Feedback system
- Direct stimulation from the nervous system
Give an example of when hormone secretion is controlled by direct stimulation from the nervous system
Fight or Flight Response
List the 7 major endocrine glands
- Hypothalamus
- Pituitary Gland
- Thyroid Gland
- Parathyroid Gland
- Adrenal Glands
- Pancreas
- Gonads
What are the 4 functions of the hypothalamus?
- Appetite control
- Body temperature regulation
- Wake-sleep cycle controls
- Links the conscious mind with the rest of the body
a system of tiny blood vessels that links the hypothalamus with the anterior portion of the pituitary gland
Portal System
a hypothalamic hormone that causes the anterior pituitary to produce and release a particular hormone
Releasing Factors
a hypothalamic hormone that inhibits the anterior pituitary from producing and releasing a particular hormone
Inhibiting Factors
What is another name for the pituitary gland?
Hypophysis
the pocket in the sphenoid bone that houses the hypophysis
Pituitary Fossa
What is another name for the anterior pituitary gland?
Adenohypophysis
What is the function of the adenohypophysis?
To produce 7 different hormones when stimulated by the hypothalamus and direct feedback from target organs and tissues
List the 7 hormones produced by the adenohypophysis
- Growth hormone (GH)
- Prolactin
- Thyroid-stimulating hormone (TSH)
- Adrenocorticotropic hormone (ACTH)
- Follicle-stimulating hormone (FSH)
- Luteinizing hormone (LH)
- Melanocyte-stimulating hormone (MSH)
the hormone that promotes growth of bone and muscle, as well as regulates the metabolism of proteins, carbohydrates, and lipids in all of the body’s cells
Growth Hormone (GH)
too much glucose in the blood due to a lack of sufficient insulin
Hyperglycemia
the hormone that helps trigger and maintain lactation
Prolactin
the hormone that stimulates the growth and development of the thyroid gland as well as causes it to produce its hormones
Thyroid-Stimulating Hormone (TSH)
the hormone that stimulates the growth and development of the cortex of the adrenal gland and the release of some of its hormones
Adrenocorticotropic Hormone (ACTH)
the hormone that stimulates oogenesis and spermatogenesis
Follicle-Stimulating Hormone (FSH)
a hormone group, that includes LH and FSH, that stimulates the growth and development of the ovaries and testes
Gonadotropin
What effects does FSH have on females vs males?
Females:
1. Stimulates oogenesis
2. Stimulates the follicle lining cells to produce and secrete estrogens
Males:
1. Stimulates spermatogenesis
the process in which a single female reproductive cell develops and matures into an ovum in a follicle
Oogenesis
a female reproductive cell
Oocyte
female sex hormones
Estrogens
the development of male reproductive cells in the seminiferous tubules of the testes
Spermatogenesis
a male reproductive cell
Spermatozoa
male sex hormones
Androgens
the hormone that completes the follicle development process in females and stimulates the testes cells to develop and produce testosterone in males
Luteinizing Hormone
What is LH called in males?
Interstitial Cell-Stimulating Hormone (ICSH)
the rupture of a mature follicle and subsequent release of the reproductive cell in females
Ovulation
an endocrine structure developed from the remaining follicle cells after ovulation that produces progesterone
Corpus Luteum
a hormone produced by the corpus luteum that is necessary to maintain a pregnancy
Progesterone
cells in the testes that produce testosterone
Interstitial Cells
What is the primary androgen?
Testosterone
a hormone associated with the control of rapid color and pattern changes in pigment cells of reptiles, fish, and amphibians
Melanocyte-Stimulating Hormone (MSH)
What is another name for the posterior pituitary gland?
Neurohypophysis
What is the function of the neurohypophysis?
Its nerve endings store and release antidiuretic hormone and oxytocin produced in the hypothalamus
the hormone produced by the hypothalamus that prevents the loss of large quantities of water in the urine by causing the kidneys to reabsorb more water from the urine they are producing back into the bloodstream
Antidiuretic Hormone (ADH)
What is another name for ADH?
Vasopressin
the loss of large quantities of water in the urine
Diuresis
What triggers the release of ADH?
Increased osmotic pressure in the blood due to dehydration > hypothalamus detects the hemoconcentration
excessive production of very dilute urine
Polyuria
excessive thirst
Polydipsia
the hormone that targets the uterus during breeding and parturition, as well as the mammary glands postpartum
Oxytocin
How does oxytocin affect the uterus during breeding?
Causes contraction of the myometrium > aids the transport of spermatozoa to the oviducts
the uterine muscle
Myometrium
How does oxytocin affect the uterus during parturition?
Stimulates strong contractions of myometrium > aids the delivery of the fetus + placenta
How does oxytocin affect active mammary glands?
Stimulates myoepithelial cells around alveoli + small ducts to contract > milk squeezes down to lower part of the gland
the movement of milk down to the lower parts of the gland initiated by oxytocin
Milk Let-Down
the thyroid hormone precursor in the follicle globule
Colloid
What 2 hormones are produced by the thyroid gland?
- Thyroid Hormone
- Calcitonin
The thyroid hormone is actually how many hormones? What are they?
- T4 (thyroxine)
- T3 (triiodothyronine)
the hormone produced by the thyroid that helps regulate blood calcium levels by preventing hypercalcemia
Calcitonin
the hormone that helps maintain blood calcium homeostasis by preventing hypocalcemia
Parathyroid Hormone (PTH)
What 3 things does PTH do to prevent hypocalcemia?
- Causes kidneys to retain Ca+
- Causes the intestine to absorb Ca+ from food
- Withdrawal of Ca+ from bones
Where are the adrenal glands located?
Cranial end of the kidneys
How many adrenal glands are there?
2 - Left and Right (each with 2 glands within them)
List the 2 adrenal glands
- Adrenal Cortex
- Adrenal Medulla
the sub-gland of the adrenal glands that produces glucocorticoid hormones, mineralocorticoid hormones and sex hormones
Adrenal Cortex
List the 3 steroid hormone groups produced by the adrenal cortex
- Glucocorticoid hormones
- Mineralocorticoid hormones
- Sex hormones
the hormones produced by the adrenal cortex that have a hyperglycemic effect, help maintain blood pressure and help the body resist the effects of stress
Glucocorticoid Hormones
causing blood glucose levels to rise
Hyperglycemic Effect
the process of converting catabolized proteins and lipids into glucose in the liver
Gluconeogenesis
Give 3 examples of glucocorticoid hormones
- Cortisol
- Cortisone
- Corticosterone
the hormones produced by the adrenal cortex that regulate levels of electrolytes, such as sodium, potassium, and hydrogen ions, in the body
Mineralocorticoid hormones
the main mineralocorticoid hormone, whose target is the kidney, that affects levels of sodium, potassium, and hydrogen ions in the body
Aldosterone
How does aldosterone affect sodium, potassium, and hydrogen ion levels?
- Causes Na+ ions in water > reabsorbed from the urine back into the bloodstream
- K+ and H+ ions > pass out of the body in the urine
the sub-gland of the adrenal glands that produces epinephrine and norepinephrine
Adrenal Medulla
What is the function of the adrenal medulla?
Prepares the body for intense physical activity via stimulation from the sympathetic nervous system
the first portion of the small intestine
Duodenum
Which endocrine organ has both endocrine and exocrine functions?
Pancreas
clumps of cells scattered throughout the pancreas that produce glucagon, insulin and somatostatin
islets of Langerhans
What are the 3 main endocrine cells of pancreatic islets and what do they produce?
- Alpha Cells - produce glucagon
- Beta cells - produce insulin
- Delta cells - produce somatostatin
What are the 3 hormones secreted by the pancreas?
- Insulin
- Glucagon
- Somatostatin
the pancreatic hormone that lowers blood glucose levels
Insulin
the pancreatic hormone that raises blood glucose levels
Glucagon
the pancreatic hormone that inhibits the secretion of insulin, glucagon, and GH as well as diminishes the activity of the GI tract
Somatostatin
the main androgen produced by interstitial cells
Testosterone
Give the 3 main hormone groups produced in the ovaries
- Estrogens
- Progestins
- Relaxin
the female sex hormones responsible for the physical and behavioral changes that prepare the female for breeding and pregnancy and signal the male that the time for breeding is approaching
Estrogens
the female sex hormones produced by the corpus luteum that help prepare the uterus to receive the fertilized ovum and is necessary for pregnancy to be maintained once the fertilized ovum implants in the uterus
Progestins
the primary progestin hormone
Progesterone
the female sex hormone that causes the ligaments between the bones surrounding the birth canal to soften in preparation for parturition, as well as play a role in mammary development in some species
Relaxin
a condition in which a young animal does not grow normally due to a deficiency in GH
Dwarfism
a form of gigantism often caused by a pituitary gland tumor and excess GH
Acromegaly
a synthetic GH-like drug used to increase milk production in dairy cows
Bovine Somatotropin (BST)
a nonneoplastic noninflammatory enlargement of the thyroid gland caused by an iodine deficiency
Goiter
overdevelopment
Hyperplasia
a condition characterized by deficiency of thyroid hormone most commonly seen in dogs
Hypothyroidism
How do you treat hypothyroidism?
T4 (thyroxine) supplements forever
a condition characterized by excess thyroid hormone most commonly seen in cats
Hyperthyroidism
What is the treatment for hyperthyroidism?
Thyroidectomy or long-term thyroid-inhibiting drugs
a hypocalcemia condition in lactating cattle that causes disturbances in skeletal muscle function
Milk Fever
the term for a cattle that lies down and cannot get back up due to severe milk fever
Downer Cow
the condition caused by hypocalcemia that is categorized by muscle tremors and spasms that can progress to seizures if left untreated
Eclampsia
a condition that results from an overproduction of glucocorticoid hormones by the adrenal cortex
Hyperadrenocorticism (Cushing’s Disease)
a progressive condition that results from a deficiency of adrenocortical hormones and whose effects can be mimicked if long-term corticosteroids drugs are suddenly stopped
Hypoadrenocorticism (Addison’s Disease)
a class of drugs commonly used therapeutically in animals for their anti-inflammatory effect
Corticosteroids
List a few side effects of corticosteroids
- Suppression of the immune system
- WBC count alteration
- Slow wound healing
- Catabolic effect
- Premature parturition
- Hyperglycemia
- Suppression of adrenal cortex stimulation
- Iatrogenic hyperadrenocorticism
term meaning “caused by treatment”
Iatrogenic
a disease caused by a deficiency of insulin that results in hyperglycemia and glucosuria
Diabetes Mellitus
glucose in the urine
Glycosuria
the endocrine organ that produces the hormone erythropoietin
Kidneys
the hormone produced by the kidneys that stimulates red bone marrow to increase production of oxygen-carrying RBCs and help maintain blood oxygen homeostasis
Erythropoietin
a condition characterized by a decrease in blood oxygen
Hypoxia
the condition characterized by a red blood cell deficiency and typically accompanies serious kidney disease or kidney failure due to the damaged kidneys inability to produce enough erythropoietin
Anemia
What is the treatment for kidney failure?
Blood transfusion
the endocrine organ the produces the hormone gastrin via the cells in the organ wall
Stomach
the hormone produced in the stomach that stimulates gastric glands to secrete hydrochloric acid and digestive enzymes, as well as encourages muscular contractions of the stomach wall
Gastrin
the endocrine organ that produces secretin and cholecystokinin
Small Intestine
the hormone produced by the small intestine that stimulates the pancreas to secrete fluid rich in sodium bicarbonate into the duodenum to neutralize the acidic chyme from the stomach
Secretin
the hormone produced by the small intestine that stimulates the release of digestive enzymes from the pancreas into the duodenum
Cholecystokinin (CCK)
the endocrine organ that secretes hormones that help support and maintain pregnancy and vary based on species
Placenta
What endocrine organ secretes chorionic gonadotropin?
Placenta
the endocrine organ that plays an important role in the development of a young animal’s immune system, but atrophies and disappears after puberty
Thymus
How do thymosin and thymopoietin interact with the thymus?
Thymosin + thymopoietin cause primitive cells in the thymus to change into T lymphocytes (T cells)
the endocrine organ that produces melatonin and influences cyclic activities in the body
Pineal Body
a hormone produced by the pineal body that affects moods, wake-sleep cycles, and timing of seasonal estrous cycles of some species
Melatonin
hormonelike substances derived from unsaturated fatty acids that are produced and exert their effects within a variety of body tissues
Prostaglandins (Tissue Hormones)
How do prostaglandins differ from normal hormones?
They only regulate activities of neighboring cells
How many prostaglandins are there and how are they organized?
9 main groups
Group Names - Prostaglandins A through I
Subgroups - Subscript numbers and Greek Letters
