A & P 142 The Endocrine System Penrod - CVCC
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Lipid-Soluble - Steroid hormones HORMONES: Aldosterone, cortisol, androgens
Adrenal cortex
Hormones help establish these physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism's environment. Your biological clocks controls this, its study is called chronobiology.
Circadian rhythms
This peptide hormone stimulates synthesis of glycogen in liver cells and synthesis of triglycerides in adipose cells. The response to a hormone is not always the synthesis of new molecules, as is the case for this peptide hormone.
Insulin
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Insulin, glucagon, somatostatin, pancreatic polypeptide
Pancreas
Stimulates milk production. Target Area: Mammary glands
Prolactin (PRL)
Types of Anterior Pituitary Cells and Their Hormones: Secrete human growth hormone. Human growth hormone in turn stimulates several tissues to secrete insulin like growth factors (IGFs), hormones that stimulate general body growth and regulate aspects of metabolism.
Somatotrophs
A system of blood vessels in the brain that connects the hypothalamus with the anterior pituitary. Its main function is the transport and exchange of hormones to allow a fast communication between both glands.
The hypophyseal portal system
The water-soluble hormones include:
amine, peptide protein, and eicosanoid hormones
A semi-liquid gelatinous substance serving as the reservoir within each follicle cell space of the thyroid gland
colloid
In the cells and tissues of your body most T4 is ____________ to T3. T3 is the more _________ hormone; it influences the activity of all the cells and tissues of your body.
converted; active
Receptors, like other cellular proteins, are constantly being synthesized and broken down. Generally, a target cell has 2000 to 100,000 receptors for a particular hormone. If a hormone is present in excess, the number of target-cell receptors may decrease—an effect called _______-____________.
down-regulation
Circulating or local hormones of the endocrine system contribute to _______________ by regulating the activity and growth of target cells in your body. Hormones also regulate your ______________.
homeostasis; metabolism
thyroid gland produces a smaller than normal amount of thyroid hormone which lead to reduce metabolism (the person affected is usually overweight).
hypthyroidism
Antidiuretic hormone and oxytocin are examples of what hormones?
peptide hormones
Lipid-soluble hormones, including steroid hormones and thyroid hormones, bind to receptors within the
target cells
Hormone Transport in the Blood - The transport proteins, which are synthesized by cells in the liver, have three functions: 1. They make lipid-soluble hormones temporarily water-soluble, thus increasing their solubility in ___(1)___. 2. They ___(2)___ passage of small hormone molecules through the filtering mechanism in the ___(3) ____, thus slowing the rate of hormone loss in the urine. 3. They provide a ready reserve of hormone, already present in the bloodstream. In general, 0._(4)_-____% of the molecules of a lipid-soluble hormone are not bound to a transport protein. This free fraction _____(5)_____ out of capillaries, binds to receptors, and triggers responses. As free hormone molecules leave the blood and bind to their receptors, transport proteins release new ones to replenish the ______(6)______.
(1) blood (2) retard (3) kidneys (4) 0.1-10% (5) diffuses (6) replenish
Lipid-Soluble Hormones: 1. Steroid hormones are derived from ______(1)_____. Each steroid hormone is unique due to the presence of different chemical groups attached at various sites on the __(2)__ rings at the core of its structure. These small differences allow for a large diversity of functions. 2. Two thyroid hormones ( _(3)_ and _(3)_) are synthesized by attaching ___(4)____ to the amino acid tyrosine. The presence of two benzene rings within a T3 or T4 molecule makes these molecules very lipid-soluble. 3. The gas nitric oxide (NO) is both a ____(5)____ and a _______(5)______. Its synthesis is catalyzed by the enzyme ___(7)___ _________ ___________.
(1) cholesterol; (2) four; (3) T3 and T4; (4) iodine; (5) hormone and a neurotransmitter; and (6) nitric oxide synthase
Describe how both calcitonin and parathyroid hormone respond via negative feedback loops.
1. A higher-than-normal level of calcium ions (Ca2+) in the blood stimulates parafollicular cells of the thyroid gland to release more calcitonin. 2. Calcitonin inhibits the activity of osteoclasts, thereby decreasing the blood Ca2+ level. 3. A lower-than-normal level of Ca2+ in the blood stimulates chief cells of the parathyroid gland to release more PTH. 4. PTH promotes resorption of bone extracellular matrix, which releases Ca2+ into the blood and slows loss of Ca2+ in the urine, raising the blood level of Ca2+. 5. PTH also stimulates the kidneys to synthesize calcitriol, the active form of vitamin D. 6 Calcitriol stimulates increased absorption of Ca2+ from foods in the gastrointestinal tract, which helps increase the blood level of Ca2+.
Describe the steps for how cortisol is produced and how it can help an individual fight or flee a stressor?
1.) In response to psychological or physical stress of any kind or low blood levels of glucocorticoids, mainly cortisol, stimulate neurosecretory cells in the hypothalamus secretes corticotropin-releasing hormone (CRH) into the hypophyseal vein down to the anterior pituitary. 2.) In response to corticotropin-releasing hormone from the hypothalamus corticotrophs cells in the anterior pituitary are triggered to secrete adrenocorticotropic hormone (ACTH). ACTH flows in the blood to the adrenal cortex, where it will stimulate glucocorticoid secretion. 3.) Adrenocorticotropic hormone (ACTH), which, in turn, stimulates the zone fasciculata (the middle zone of the adrenal cortex) where it stimulates cortisol. Cortisol is scripted back into the blood cortisol provides the body with glucose by tapping into protein stores via gluconeogenesis in the liver. This energy can help an individual fight or flee a stressor.
Explain in detail from the begin how thyroxine (T4) and then triiodothyronine (T3) get released into the blood:
1.) When your hypothalamus senses levels of T3 and T4 are low, or that your body's metabolic rate is low, it secretes thyrotropin-releasing hormone (TRH). TRH travels down a hypophyseal portal blood vessel to the anterior pituitary where it diffuses. 2.) In response to the TRH, a glycoprotein hormone is synthesized and secreted by the thyrotrope cells (endocrine cells) in the anterior pituitary gland - the hormone that is synthesized and secreted by the thyrotrope cells hormone is the thyroid-stimulating hormone (TSH). 3.) TSH travels through the blood-stream to stimulate the thyroid gland to produce thyroxine (T4), and then triiodothyronine (T3). T3 and T4 are then released into your bloodstream where they stimulate the metabolism of almost every tissue in the body.
An enzyme that phosphorylates (adds a phosphate group to) other cellular proteins (such as enzymes). The donor of the phosphate group is ATP, which is converted to ADP.
A protein kinase
The hormone produced by the parafollicular cells of the thyroid gland it decrease the level of calcium in the blood by inhibiting the action of osteoclasts, the cells that break down bone extracellular matrix. It also opposes the effects of parathyroid hormone (PTH).
Calcitonin
The nervous system uses these ions as its electrically energy. These ions run the electrical system of the body, it is used to conduct electricity along nervous system, and it is used to make muscles contract. Adult normal levels in these ions should be in the 9's only not the 8's or the 10's.
Calcium
Stress hormones secreted at the adrenal gland acts on these receptors alpha1, beta 1, and beta 2. Produces epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine from the phenylalanine and tyrosine. Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response.
Catecholamines
Pituitary - Anterior Lobe (Adenohypophysis): Secrete adrenocorticotropic hormone (ACTH), which stimulates the adrenal cortex to secrete glucocorticoids (like cortisol). Also secretes melanocyte-stimulating hormone (MSH).
Corticotrophs
Types of Anterior Pituitary Cells and Their Hormones: Secrete adrenocorticotropic hormone (ACTH), which stimulates the adrenal cortex to secrete glucocorticoids such as cortisol. Some corticotrophs, remnants of the pars intermedia, also secrete melanocyte-stimulating hormone (MSH).
Corticotrophs
Secrete their products (hormones) into the interstitial fluid surrounding the secretory cells rather than into ducts. From the interstitial fluid, hormones diffuse into blood capillaries and blood carries them to target cells throughout the body. Because of their dependence on the cardiovascular system to distribute their products, these are some of the most vascular tissues of the body.
Endocrine glands
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Lipid-Soluble - Gas HORMONES: Nitric oxide (NO)
Endothelial cells lining blood vessels.
Secrete their products into ducts that carry the secretions into body cavities, into the lumen of an organ, or to the outer surface of the body.
Exocrine glands
True or false: Thyroxine (T4) is scarcer, but stronger; Triiodothyronine (T3) is more prevalent but weaker
False: Thyroxine (T4) is more prevalent but weaker; Triiodothyronine (T3) scarcer, but strong
Stimulates development of oocytes (immature egg cells) and secretion of estrogen in females; stimulates sperm production in the testes in males. Target Area: Ovaries and testes (gonads)
Follicle-stimulating hormone (FSH)
What functions are these describing? 1. Help regulate: • Chemical composition and volume of internal environment (interstitial fl uid). • Metabolism and energy balance. • Contraction of smooth and cardiac muscle fi bers. • Glandular secretions. • Some immune system activities. 2. Control growth and development. 3. Regulate operation of reproductive systems. 4. Help establish circadian rhythms.
Function of hormones
Action of Water-Soluble Hormones: A water-soluble hormone (the first messenger) diffuses from the blood through interstitial fluid and then binds to its receptor at the exterior surface of a target cell's plasma membrane. The hormone-receptor complex activates a membrane protein called a ___ __________. This activated in turn activates adenylate cyclase.
G protein
The creation of extra blood glucose from the breakdown of glycogen by the liver, in response to glucagon from the alpha cells of the pancreas.
Glycogenolysis
How are glycogenolysis and gluconeogenesis different?
Glycogenolysis and Gluconeogenesis differ in the way the glucose is produced: glycogenolysis does this with carbohydrate sources, while gluconeogenesis produces glucose from non-carbohydrate ones.
Pituitary - Anterior Lobe (Adenohypophysis): Secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which both act on the gonads. They stimulate the secretion of estrogen and progesterone, maturation of egg cells in the ovaries, and stimulate sperm production and secretion of testosterone in the testes.
Gonadotrophs
Types of Anterior Pituitary Cells and Their Hormones: Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) . FSH and LH both act on the gonads. They stimulate secretion of estrogens and progesterone and the maturation of oocytes in the ovaries, and they stimulate sperm production and secretion of testosterone in the testes.
Gonadotrophs
Auto immune disease where your body produces antibodies to stimulate the thyroid gland which in returns produces excessive thyroid hormone (hyperthyroidism).
Graves disease
A disease where there is an immune response of the body against the thyroid gland, which causes a decrease thyroid function.
Hashimoto Disease
These are chemicals which are released into your bloodstream. They act as messengers, affecting cells and tissues in distant parts of your body.
Hormones
Stimulates tissue growth in the liver, muscles, bones, as well as protein synthesis, tissue repair, and elevation of blood glucose levels. Target Area: tissue
Human-growth hormone (hGH)
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: All hypothalamic releasing and inhibiting hormones
Hypothalamus
This local hormone released by helper T cells (a type of white blood cell) during immune responses. This hormone helps activate other nearby immune cells, a paracrine effect. But it also acts as an autocrine by stimulating the same cell that released it to proliferate. This action generates more helper T cells that can secrete even more of these hormones and thus strengthen the immune response.
Interleukin 2 (IL-2)
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Lipid-Soluble - Steroid hormones HORMONES: Calcitriol
Kidneys
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Erythropoietin
Kidneys
Pituitary - Anterior Lobe (Adenohypophysis): Secrete prolactin (PRL), which initiates milk production in the mammary glands.
Lactotrophs
Types of Anterior Pituitary Cells and Their Hormones: Secrete prolactin (PRL), which initiates milk production in the mammary glands.
Lactotrophs
What are the target organs and principle actions of the hormone? Human growth hormone (hGH), also known as somatotropin
Liver; stimulates liver, muscle, cartilage, bone, and other tissues to synthesize and secrete insulin like growth factors (IGFs); IGFs promote growth of body cells, protein synthesis, tissue repair, lipolysis, and elevation of blood glucose concentration.
Stimulates secretion of estrogen and progesterone, including during ovulation, in females; stimulates testes to produce testosterone in males. Target Area: Ovaries and testes (gonads)
Luteinizing hormone (LH)
What are the target organs and principle actions of the hormone? Prolactin (PRL)
Mammary glands; Together with other hormones, promotes milk production by mammary glands.
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Amines HORMONES: Histamine
Mast cells in connective tissues
When in excess, can cause darkening of the skin; may influence brain activity (its exact role unknown—there is very little MSH in humans). Target Area: Brain
Melanocyte-stimulating hormone (MSH)
Osteoclast vs Osteoblast: Blood to bone; calcitonin (Hint: when thinking of calcitonin think of "TONe it down in the blood!")
Osteoblast
Osteoclast vs Osteoblast: Decreases calcium in the blood
Osteoblast
Osteoclast vs Osteoblast: Bone to blood; PTH; resorption
Osteoclast
Osteoclast vs Osteoblast: Increase calcium in the blood
Osteoclast
Osteoclast vs Osteoblast: a loss of calcium from blood, is due to reduced _______________ activity.
Osteoclast
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Lipid-Soluble - Steroid hormones HORMONES: Estrogens, progesterone
Ovaries
What are the target organs and principle actions of the hormone? Follicle-stimulating hormone (FSH)
Ovary & Testis; In females, initiates development of oocytes and induces ovarian secretion of estrogens. In males, stimulates testes to produce sperm.
What are the target organs and principle actions of the hormone? Luteinizing hormone (LH)
Ovary & Testis; In females, stimulates secretion of estrogens and progesterone, ovulation, and formation of corpus luteum. In males, stimulates testes to produce testosterone.
Pituitary: Posterior Lobe AKA the "Love Drug": Trigger - Secretes in response to uterine distention and stimulation of the nipples. Function - Stimulates smooth muscle contractions of the uterus during childbirth, as well as milk ejection in the mammary glands.
Oxytocin (OT)
____________ and _______________ hormone are synthesized in the hypothalamus and released into the capillary plexus of the infundibular process in the posterior pituitary.
Oxytocin and antidiuretic
While the anterior lobe shoulders most of the work in producing hormones, the posterior Lobe (Neurohypophysis) stores and releases only two:
Oxytocin and antidiuretic hormone (ADH), or vasopressin.
Paracrine signaling vs Endocrine signaling
Paracrine signaling is a form of cell-cell communication in which a cell produces a signal to induce changes in nearby cells, altering the behavior or differentiation of those cells. Signaling molecules known as paracrine factors diffuse over a relatively short distance (local action), as opposed to endocrine factors (hormones which travel considerably longer distances via the circulatory system)
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Parathyroid hormone
Parathyroid glands
Name the hormone: CONTROL OF SECRETION: Low blood Ca2 levels stimulate secretion; high blood Ca2 levels inhibit secretion. PRINCIPAL ACTIONS: Increases blood Ca2 and Mg2 levels and decreases blood hydrogen phosphate- level; increases bone resorption by osteoclasts; increases Ca2 reabsorption and hydrogen phosphate excretion by kidneys; promotes formation of calcitriol (active form of vitamin D), which increases rate of dietary Ca2 and Mg2 absorption.
Parathyroid hormone (PTH) from chief cells
Found at the apical (luminal) membrane of follicular cells in the thyroid gland it is also known as sodium-independent chloride/iodide transporter, it is an antiporter anion exchanger protein. It transports iodide from the cytoplasm to the follicle lumen. Its activity is necessary for production of thyroid hormone.
Pendrin
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Amines HORMONES: Melatonin
Pineal gland
Pituitary lobe that sexcretes hormones that regulate a wide variety of bodily functions. There are five anterior pituitary cells that secrete seven hormones: somatotrophs, gonadotrophs, lactotrophs, corticotrophs, thyrotrophs
Pituitary: Anterior Lobe (Adenohypophysis)
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Amines HORMONES: Serotonin
Platelets in blood
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Oxytocin, antidiuretic hormone
Posterior pituitary.
This transmembrane glycoprotein is known as (NIS), it is a molecular which transports two sodium cations (Na+) for each iodide anion (I−) into the cell. It mediates uptake of iodide into follicular cells of the thyroid gland it is the first step in the synthesis of thyroid hormone. Iodine uptake mediated by thyroid follicular cells from the blood plasma is the first step for the synthesis of thyroid hormones.
Sodium-iodide symporter
Pituitary - Anterior Lobe (Adenohypophysis): Secrete human growth hormone (hGH), aka somatotropin, which stimulates tissues to secrete hormones that stimulate body growth and regulate metabolism.
Somatotrophs
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Gastrin, secretin, cholecystokinin, GIP (glucose-dependent insulinotropic peptide)
Stomach and small intestine (enteroendocrine cells)
T4 is converted to the active ____ which is three to four times more potent than T4.
T3
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Lipid-Soluble - Steroid hormones HORMONES: Testosterone
Testes
This hormone regulates metabolism and resistance to stress, include cortisol, corticosterone, and cortisone. Of these three hormones secreted by the zone fasciculata, cortisol is the most abundant, accounting for about 95% of this hormones activity.
The glucocorticoids
Describe a general hypothalamic hormone production of hormones.
The hypothalamus senses low hormones, the hypothalamic hormones known as releasing hormones and inhibiting hormones are released into capillary networks in the median eminence. The bloodstream carries these hormones directly to the anterior lobe of the pituitary, where they stimulate or inhibit secretion of anterior pituitary hormones. The anterior pituitary makes a stimulating hormone and releases them into the blood.
Describe how the adrenal cortex is subdivided into three zones, and name the hormone each one secretes.
The outer zone, just deep to the connective tissue capsule, is the zone glomerulosa; secrete hormones called mineralocorticoids because they affect mineral homeostasis. The middle zone, or zone fasciculata; secrete mainly glucocorticoids , primarily cortisol The cells of the inner zone, the zona reticularis, they synthesize small amounts of weak androgens, steroid hormones that have masculinizing effects.
A neuronal nucleus in the hypothalamus. It contains groups of neurons that can be activated by stressful and/or physiological changes. These neurons project directly to the anterior or the posterior pituitary.
The paraventricular nucleus (PVN, PVA, or PVH)
A pea-shaped structure that measures 1-1.5 cm (0.5 in.) in diameter and lies in the hypophyseal fossa of the sella turcica of the sphenoid bone. It attaches to the hypothalamus by a stalk.
The pituitary gland
These specific hormones affect your body's metabolic rate and the levels of certain minerals in your blood.
Thyroid
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Lipid-Soluble - Thyroid hormones HORMONES: T3 (triiodothyronine), T4 (thyroxine)
Thyroid gland (follicular cells)
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Calcitonin
Thyroid gland (parafollicular cells)
What are the target organs and principle actions of the hormone? Thyroid-stimulating hormone (TSH), also known as thyrotropin
Thyroid gland; stimulates synthesis and secretion of thyroid hormones by thyroid gland.
A glycoprotein hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland, which regulates the endocrine function of the thyroid. This is pituitary hormone that travels through the blood-stream to stimulates the thyroid gland to produce thyroxine (T4), and then triiodothyronine (T3) which stimulates the metabolism of almost every tissue in the body.
Thyroid-stimulating hormone (TSH)
Stimulates thyroid gland to secrete thyroid hormones. Target Area: Thyroid gland
Thyroid-stimulating hormone (TSH)
Pituitary - Anterior Lobe (Adenohypophysis): Secrete thyroid-stimulating hormone (TSH), which controls secretions of the thyroid gland. This table represents the types of hormones secreted by the cells of the anterior pituitary.
Thyrotrophs
Types of Anterior Pituitary Cells and Their Hormones: Secrete thyroid-stimulating hormone. TSH controls the secretions and other activities of the thyroid gland.
Thyrotrophs
When the body needs to increase it's metabolic rate in can increase Thyroxine (T4) into this to have a larger effect
Triiodothyronine (T3)
True or False Considering that most hormones are required in very small amounts, circulating levels typically are low.
True
True or False Thyroid-stimulating hormone (TSH) binds to receptors on cells of the thyroid gland, but it does not bind to cells of the ovaries because ovarian cells do not have TSH receptors.
True
Roughly 99% of the exocrine cells of the pancreas are arranged in clusters called _______. The acini produce digestive enzymes, which flow into the gastrointestinal tract through a network of ducts. Scattered among the exocrine acini are 1-2 million tiny clusters of endocrine tissue called pancreatic _______.
acini; islets
During embryonic development, the adrenal glands differentiate into two structurally and functionally distinct regions: a large, peripherally located __________ __________, comprising 80-90% of the gland, and a small, centrally located __________ __________.
adrenal cortex; adrenal medulla
A hormone must first "_____________ ___ __________" to a target cell by binding to its receptors. The receptors for lipid soluble hormones are located inside target cells. The receptors for water-soluble hormones are part of the plasma membrane of target cells.
announce its arrival
With respect to regulation of blood Ca2 level, calcitonin and PTH are
antagonists
A hormone that decreases urine production. This hormone causes the kidneys to return more water to the blood, thus decreasing urine volume.
antidiuretic
This hormone's other name is, vasopressin, it reflects it's effect on blood pressure.
antidiuretic hormone (ADH)
Although a given hormone travels throughout the body in the _________, it affects only specific target cells.
blood
Endocrine glands secrete hormones, which circulating _________ delivers to target tissues.
blood
The main job of your thyroid gland is to produce hormones T4 and T3. To do this your thyroid gland has to take a form of iodine from your _______________ into the follicular cell and then into the ___________.
bloodstream; colloid
Both steroid hormones and thyroid hormones are effective when taken ____ _________. They are not split apart during _____________ and easily cross the intestinal lining because they are lipid-soluble.
by mouth; digestion
The thyroid makes three hormones which it releases (secretes) into the bloodstream. Two of these hormones, called thyroxine (T4) and triiodothyronine (T3), increase your body's metabolic rate. The other hormone _____________ helps to control the amount of calcium in the blood.
calcitonin
The adrenal medulla produces three
catecholamine hormones: norepinephrine, epinephrine, and a small amount of dopamine
Thyroid hormones affect every _____ and all the _________of the body. Too much thyroid hormone speeds things up and too little thyroid hormone slows things down.
cell; organs
Inside the follicles, in a region called the follicular lumen, this serves as a reservoir of materials for thyroid hormone production and, to a lesser extent, acts as a reservoir for the hormones themselves. This substance is rich in a protein called ________________.
colloid; thyroglobulin
When a water-soluble hormone binds to its receptor at the outer surface of the plasmamembrane, it acts as the first messenger. The first messenger (the hormone) then causes production of a second messenger inside the cell, where specific hormone-stimulated responses take place. One common second messenger is _______ ______. Neurotransmitters, neuropeptides, and several sensory transduction mechanisms also act via second-messenger systems.
cyclic AMP (cAMP)
The adrenal cortex produces steroid hormones that are essential for life. Complete loss of adrenocortical hormones leads to death due to _________________ and ______________ imbalances in a few days to a week, unless hormone replacement therapy begins promptly.
dehydration and electrolyte
If a hormone is present in excess, the number of target-cell receptors may decrease an effect called:
down-regulation
Synthetic hormones that block the receptors for some naturally occurring hormones are available as ________.
drugs
Taken together, all endocrine glands and hormone-secreting cells constitute the
endocrine system
The science of the structure and function of the endocrine glands and the diagnosis and treatment of disorders of the endocrine system is
endocrinology
In order to make T4 and T3, your thyroid gland needs iodine, a substance found in the food we eat. T4 is called this because it contains:
four atoms of iodine
Most water-soluble hormone molecules circulate in the watery blood plasma in a "______" form (not attached to other molecules), but most lipid-soluble hormone molecules are _________ to transport proteins.
free; bound
tissue or organ that makes a secretory products
gland
The principal action of ___________ is to increase blood glucose level when it falls below normal. Insulin, on the other hand, helps lower blood glucose level when it is too high.
glucagon
The synthesis of glucose from noncarbohydrate sources, such as amino acids and glycerol. It occurs primarily in the liver and kidneys whenever the supply of carbohydrates is insufficient to meet the body's energy needs.
gluconeogenesis
Several of the protein hormones, such as thyroid-stimulating hormone, have attached carbohydrate groups and thus makes them
glycoprotein hormones
Multiple nodule, generalized swelling, or enlarge of the thyroid glands can because by infection, iodine deficiency, malignant disease, and benign disease (may cause difficulty swallowing or breathing).
goiter
What do these represent changing the permeability of the plasma membrane, stimulating transport of a substance into or out of the target cells, altering the rate of specific metabolic reactions, or causing contraction of smooth muscle or cardiac muscle? These changes are possible because a single hormone can set in motion several different cellular responses.
hormonal effects
A mediator molecule that is released in one part of the body but regulates the activity of cells in other parts of the body.
hormone
To excite or get moving
hormone
Most of these enter interstitial fluid and then the bloodstream. The circulating blood delivers these to cells throughout the body.
hormones
The endocrine system also controls body activities by releasing mediators, called
hormones
Protein hormones include:
human growth hormone and insulin
excessive thyroid hormone that causes accelerated metabolism that consumes a lot of your energy (the person affected is usually thin).
hyperthyroidism
Think of the _________________ as the pituitary's older sibling—it not only controls the actions of the pituitary but it secretes at least nine hormones to the pituitary's seven.
hypothalamus
In addition, several organs and tissues are not exclusively classified as endocrine glands but contain cells that secrete hormones. These include the
hypothalamus, thymus, pancreas, ovaries, testes, kidneys, stomach, liver, small intestine, skin, heart, adipose tissue, and placenta.
The __________________ is part of the brain and produces TSH Releasing Hormone (TRH) which tells the ______________ ___________ to stimulate the thyroid gland (release TSH).
hypothalamus; pituitary gland
The almond-sized ________________ is located below the thalamus and sits just above the brainstem. All vertebrate brains have this. Its primary function is to maintain homeostasis in the body it links the nervous and endocrine systems by way of the ____________ ________. Its function is to secrete releasing hormones and inhibiting hormones that stimulate or inhibit (like their names imply) production of hormones in the anterior pituitary.
hypothalamus; pituitary gland
The pituitary gland is attaches to the hypothalamus by a stalk, the __________________, and has two anatomically and functionally separate portions: the anterior pituitary and the posterior pituitary.
infundibulum
T3 and T4 are partially composed of this element . A deficiency of this element leads to decreased production of T3 and T4, enlarges the thyroid tissue and will cause the disease known as simple goiter.
iodine
The function of the thyroid gland is to take _________, found in many foods, and convert it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3). Thyroid cells are the only cells in the body which can absorb this chemical element. From the follicular cells this chemical element through exocytosis goes into the colloid and combines with the amino acid ___________ to make T3 and T4. T3 and T4 are then released into the blood stream and are transported throughout the body where they control metabolism (conversion of oxygen and calories to energy).
iodine; tyrosine
The response to a hormone depends on both the hormone ______ and the __________ ______. Various target cells respond differently to the same hormone.
itself and the target cell
Chemically, hormones can be divided into two broad classes: those that are soluble in ________, and those that are soluble in _________. This chemical classification is also useful functionally because the two classes exert their effects differently.
lipids; water
The production of fat as either fatty degeneration or fatty infiltration; also applied to the normal deposition of fat or to the conversion of carbohydrate or protein to fat.
lipogenesis
Most endocrine hormones are circulating hormones—they pass from the secretory cells that make them into interstitial fluid and then into the blood. Other hormones, termed _______ hormones, act locally on neighboring cells or on the same cell that secreted them without first entering the bloodstream.
local
The major form of thyroid hormone in the blood is thyroxine (T4), which has a __________ half-life than T3. In humans, the ratio of T4 to T3 released into the blood is roughly ____ to 1.
longer; 20
The __________ and endocrine systems act together to coordinate functions of all body systems.
nervous
Specialized neuron clusters called _________________ _______ in the hypothalamus produce the hormones
neurosecretory cells
Both these and hormones exert their effects by binding to receptors on or in their "target" cells. Several mediators act as both these and hormones.
neurotransmitters
Hormones, like ________________________, influence their target cells by chemically binding to specific protein receptors.
neurotransmitters
This stress hormone is released as a neurotransmitter by sympathetic postganglionic neurons and as a hormone by chromatin cells of the adrenal medullae.
norepinephrine
Peptide and protein hormones, such as insulin, are not effective ______ medications because ___________ enzymes destroy them by breaking their peptide bonds. This is why people who need insulin must take it by injection.
oral; digestive
Osteoclast vs Osteoblast: a loss of calcium from bones, is due to reduced _______________ activity.
osteoblast
Osteoclast vs Osteoblast: Lay down bone
osteoblasts
Osteoclast vs Osteoblast: Bone remodeling is an ongoing process in which _____________ carve out small tunnels in old bone tissue and then ______________ rebuild it.
osteoclasts carve out small tunnels in old bone; osteoblasts rebuilds bone
This flattened organ located in the curve of the duodenum is both an endocrine gland and an exocrine gland.
pancreas
Attached to the hypothalamus, the ___________ _________ is a pea-sized, reddish-gray body that stores hormones from the hypothalamus and releases them into the bloodstream. This consists of an anterior lobe and a posterior lobe, each of which have distinct functions.
pituitary gland
The thyroid gland is under the control of the ____________ _________, a small gland the size of a peanut at the base of the brain. When the level of thyroid hormones (T3 & T4) drops too low, this produces Thyroid Stimulating Hormone (TSH) which stimulates the thyroid gland to produce more hormones. Under the influence of TSH, the thyroid will manufacture and secrete T3 and T4 thereby raising their blood levels.
pituitary gland
The endocrine glands include the:
pituitary, thyroid, parathyroid, adrenal, and pineal glands
What do lipid hormones bind to?
proteins
Three types of lipids:
steriles (signaling), fats (triglycerides), and phospholipids
The lipid-soluble hormones include:
steroid hormones, thyroid hormones, and nitric oxide.
Although a given hormone travels throughout the body in the blood, it affects only specific cells. Only these cells for a given hormone have receptors that bind and recognize that hormone.
target cells
In order to make T4 and T3, your thyroid gland needs iodine, a substance found in the food we eat. T3 is called this because it contains:
three atoms of iodine
Follicular cells of the thyroid produce this protein that is used entirely within the thyroid gland. This protein accounts for approximately half of the protein content of the thyroid gland. Each of this proteins molecules contains approximately 70-120 ___________ molecules. Once this protein is produced inside the follicular cells it is exocytosis out into the colloid.
thyroglobulin; tyrosine
The pituitary gland and the thyroid gland: A high TSH level means there isn't enough _________ _______________, and a low TSH level means there is too much.
thyroid hormone
The follicular space and the colloid that it contains serve as a reservoir for all the materials required for producing thyroid hormones. It is within each of these thyroid follicles that much of the activity leading to the production of __________ _____________ occurs.
thyroid hormones
These hormones are secreted at steady rates and maintain homeostasis. The hormone is formed in follicles lined by a single layer of follicular cells. These hormones are stored within the colloid contained within the follicles in the form of a protein called thyroglobulin. Also, contained within the colloid are enzymes needed for this hormone synthesis, and iodide (ionized form of iodine).
thyroid hormones
The pituitary gland and the thyroid gland work together. The pituitary gland makes, stores, and releases __________-____________ _____________ . When this hormone is secreted by the pituitary gland, it causes the thyroid gland to release more ____ and ____.
thyroid-stimulating hormone (TSH); T3 and T4
Thyroid hormones are made by the thyroid gland. The thyroid gland makes and releases two thyroid hormones:
thyroxine (T4) and triiodothyronine (T3)
Catecholamines are synthesized from this amino acid. T3 and T4 are synthesized by attaching iodine to this amino acid.
tyrosine
The thyroid hormones, triiodothyronine (T3) and its prohormone, thyroxine (T4), are ___________-based hormones produced by the thyroid gland that are primarily responsible for regulation of _________________.
tyrosine; metabolism
When a hormone is deficient, the number of receptors may increase. This phenomenon, known as: This makes a target cell more sensitive to a hormone
up-regulation
The connective tissue capsule that covers the adrenal gland just like the thyroid gland, is highly
vascularized.
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Leptin
Adipose tissue
What are the target organs and principle actions of the hormone? Adrenocorticotropic hormone (ACTH), also known as corticotropin
Adrenal cortex; Stimulates secretion of glucocorticoids (mainly cortisol) by adrenal cortex.
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Amines HORMONES: Epinephrine, norepinephrine (catecholamines)
Adrenal medulla
Stimulates secretion of glucocorticoids (cortisol) by the adrenal cortex during the body's response to stress. Target Area: Adrenal cortex
Adrenocorticotropic hormone (ACTH)
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Human growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, follicle stimulating hormone, luteinizing hormone, prolactin, melanocyte-stimulating hormone
Anterior pituitary
Pituitary: Posterior Lobe Also known as Vasopressin: Trigger - Secretes in response to dehydration, blood loss, pain, stress; inhibitors of ADH secretion include high blood volume and alcohol. Function - Decreases urine volume to conserve water, decreases water loss through sweating, raises blood pressure by constricting arterioles.
Antidiuretic hormone (ADH),
What are the target organs and principle actions of the hormone? Melanocyte-stimulating hormone (MSH)
Brain; Exact role in humans is unknown but may info hence brain activity; when present in excess, can cause darkening of skin.
Water-Soluble Hormones: 1. Amine hormones are synthesized by _________(1)__________ (removing a molecule of CO2) and otherwise modifying certain amino acids. They are called _____(2)____ because they retain an amino group (—NH3). The _______(3)_______—epinephrine, norepinephrine, and dopamine—are synthesized by modifying the ___(4)___ _______ ___________. ______(5)______ is synthesized from the amino acid histidine by mast cells and platelets. Serotonin and melatonin are derived from ________(6)_______. 2. Peptide hormones and protein hormones are ___(7)___ _______ _____________. The smaller peptide hormones consist of chains of _(8)_ to ____ amino acids; the larger protein hormones include _(9)_ to _______ amino acids. 3. The eicosanoid hormones (eicos- twenty forms; -oid resembling) are derived from ______(10)______ ______, a _(11)_-carbon fatty acid. The two major types of eicosanoids are _______(12)_______ and ________________. The eicosanoids are important local hormones, and they may act as circulating hormones as well.
(1) decarboxylating; (2) amines; (3) catecholamines; (4) amino acid tyrosine; (5) Histamine; (6) tryptophan; (7) amino acid polymers; (8) 3 to 49; (9) 50 to 200; (10) arachidonic acid; (11) 20 (12) prostaglandins (PGs) and leukotrienes (LTs)
T4 is converted to the active T3 within cells by ________(1)________. These are further processed by ________(2)________ and ________(3)________ to produce iodothyronamine (T1a) and thyronamine (T0a). All three isoforms of the deiodinases are selenium-containing enzymes, thus dietary selenium is essential for T3 production.
(1) deiodinases (5'-iodinase);(2) decarboxylation and (3) deiodination;
What is the action of the receptor-hormone complex? 1. A free lipid-soluble hormone molecule ___________ from the blood, through interstitial fluid, and through the lipid bilayer of the plasma membrane into a cell. 2. If the cell is a target cell, the hormone binds to and activates receptors located within the cytosol or nucleus. The activated receptor-hormone complex then alters gene expression: It turns specific genes of the nuclear DNA on or off. 3. As the DNA is transcribed, new messenger RNA (mRNA) forms, leaves the nucleus, and enters the cytosol. There, it directs synthesis of a new protein, often an enzyme, on the ribosomes. 4. The new proteins alter the cell's activity and cause the responses typical of that hormone.
(1) diffuses (2) retard (3) kidneys (4) 0.1-10% (5) diffuses (6) replenish
Local hormones usually are inactivated quickly; circulating hormones may linger in the blood and exert their effects for a few minutes or occasionally for a few hours. In time, circulating hormones are inactivated by the ___(1)___ and excreted by the ____(2)____. In cases of failure of these organs, excessive levels of hormones may build up in the blood.
(1) liver; (2) kidneys
Nervous system acts through ____(1)____ __________ (action potentials) conducted along __(2)___ of neurons. At ____(3)____, nerve impulses trigger the release of mediator (messenger) molecules called _________(4)_________.
(1) nerve impulses; (2) axons; (3) synapses; and (4) neurotransmitters
Local hormones that act on neighboring cells are called _____(1)______ , and those that act on the same cell that secreted them are called _____(2)______
(1) paracrines (beside or near);(2) autocrines (auto- self)
The anterior pituitary consists of two parts in an adult: The __(1)__ ________ is is the larger portion, and the __(2)__ ____________ forms a sheath around the infundibulum. It also consists of two parts: the __(3)__ ___________ , the larger bulbar portion, and the infundibulum. A third region of the pituitary gland called the __(4)___ _______________ atrophies during human fetal development and ceases to exist as a separate lobe in adults.
(1) pars distal; (2) pars tuberalis (3) pars nervosa (3) pars intermedia
In detail describe how thyroxine (T4) and triiodothyronine (T3) are created in a follicle cell:
1. Follicular cells of the thyroid produce thyroglobulin a protein this is used entirely within the thyroid gland. Thyroglobulin protein accounts for approximately half of the protein content of the thyroid gland. Each thyroglobulin molecule contains approximately 70-120 tyrosine molecules. Once thyroglobulin is produced inside the follicular cells via exocytosis it goes into the colloid. 2. Iodine is then transported from the follicular cells into the colloid. This is possible because there is a transmembrane glycoprotein called a Sodium-iodide symporter that transport iodine and sodium into the follicular cell. The sodium is pumped down concentrator gradient which transports two sodium cations (Na+) for each iodide anion (I−) into the cell. NIS mediated uptake of iodide into follicular cells of the throid gland. 3. At the luminal edge between the follicle cell and the colloid a sodium-independent chloride/iodide transporter known as "Pendrin" transports iodine into the colloid. Once the thyroglobulin and the iodine are in the colloid the iodine are added to the thyroglobulin gets iodized either one or two added to the thyroglobulin. When a 2 iodized thyroglobulin combines with a 1 iodized thyroglobulin you get T3 (triiodothyronine). When a 2 iodized thyroglobulin combines with a 2 iodized thyroglobulin you get T4 thyroxine.
Describe the regulation of secretion and actions of antidiuretic hormone (ADH).
1. High blood osmotic pressure stimulates hypothalamic osmoreceptors. 2. Osmoreceptors activate the neurosecretory cells that synthesize and release ADH 3. Nerve impulses liberate ADH from axon terminals in the posterior pituitary into the bloodstream 4. The blood carries ADH to three target tissues; Kidneys retain more water, which decreases urine output. Sudoriferous (sweat) glands decrease water loss by perspiration from the skin. Arterioles constrict, which increases blood pressure. 5. Low blood osmotic pressure inhibits hypothalamic osmoreceptors 6. Inhibition of osmoreceptors reduces or stops ADH secretion
Describe the regulation of secretion and actions of antidiuretic hormone (ADH).
1. High blood osmotic pressure — due to dehydration or a decline in blood volume because of hemorrhage, diarrhea, or excessive sweating—stimulates osmoreceptors, neurons in the hypothalamus that monitor blood osmotic pressure. Elevated blood osmotic pressure activates the osmoreceptors directly; they also receive excitatory input from other brain areas when blood volume decreases. 2. Osmoreceptors activate the hypothalamic neurosecretory cells that synthesize and release ADH. 3. When neurosecretory cells receive excitatory input from the osmoreceptors, they generate nerve impulses that cause exocytosis of ADH-containing vesicles from their axon terminals in the posterior pituitary. This liberates ADH, which diffuses into blood capillaries of the posterior pituitary. 4. The blood carries ADH to three target tissues: the kidneys, sudoriferous (sweat) glands, and smooth muscle in blood vessel walls. The kidneys respond by retaining more water, which decreases urine output. Secretory activity of sweat glands decreases, which lowers the rate of water loss by perspiration from the skin. Smooth muscle in the walls of arterioles (small arteries) contracts in response to high levels of ADH, which constricts (narrows) the lumen of these blood vessels and increases blood pressure. 5. Low osmotic pressure of blood (or increased blood volume) inhibits the osmoreceptors. 6. Inhibition of osmoreceptors reduces or stops ADH secretion. The kidneys then retain less water by forming a larger volume of urine, secretory activity of sweat glands increases, and arterioles dilate. The blood volume and osmotic pressure of body fluids return to normal.
Describe how the level of blood glucose controls secretion of glucagon and insulin via negative feedback
1. Low blood glucose (hypoglycemia) stimulates alpha cells to secrete 2. Glucagon acts on liver cells to: convert glycogen into glucose form glucose from lactic acid and certain amino acids 3. Glucose released by liver cells raises blood glucose level to normal 4. If blood glucose continues to rise, hyperglycemia inhibits release of glucagon 5. High blood glucose (hyperglycemia) stimulates beta cells to secrete 6. Insulin acts on various body cells to: accelerate facilitated diffusion of glucose into cells speed conversion of glucose into glycogen increase uptake of amino acids and increase protein synthesis speed synthesis of fatty acid 7. Blood glucose level falls 8. If blood glucose continues to fall, hypoglycemia inhibits release of insulin
Mechanism of action of the lipid-soluble steroid hormones and thyroid hormones. Lipid-soluble hormones bind to receptors inside target cells. Fill in the blanks: 1. LIPID-SOLUBLE HORMONE diffuses into ____ 2. Activated receptor-hormone complex alters _______ expression 3. Newly formed mRNA directs ____________ of specific proteins on ribosomes 4. New synthesis ______ cell's activity
1. cell 2. gene 3. synthesis 4.alter
oxytocin and antidiuretic hormones After their production in the cell bodies of neurosecretory cells, these hormone are packaged into secretory vesicles, which move by fast axonal transport to the axon terminals in the posterior pituitary, where they are stored until nerve impulses trigger exocytosis and release of the hormone. Blood is supplied to the posterior pituitary by the inferior hypophyseal arteries, which branch from the internal carotid arteries. In the posterior pituitary, the inferior hypophyseal arteries drain into the capillary plexus of the infundibular process, a capillary network that receives secreted these hormones. From this plexus, hormones pass intothe posterior hypophyseal veins for distribution to target cells in other tissues.
After their production in the cell bodies of neurosecretory cells, oxytocin and antidiuretic hormones are packaged into secretory vesicles, which move by fast axonal transport to the axon terminals in the posterior pituitary, where they are stored until nerve impulses trigger exocytosis and release of the hormone. Blood is supplied to the posterior pituitary by the inferior hypophyseal arteries, which branch from the internal carotid arteries. In the posterior pituitary, the inferior hypophyseal arteries drain into the capillary plexus of the infundibular process, a capillary network that receives secreted oxytocin and antidiuretic. From this plexus, hormones pass intothe posterior hypophyseal veins for distribution to target cells in other tissues.
This hormone helps regulate blood volume, blood pressure, and levels of Na, K, and H in the blood.
Aldosterone
WHAT IS THE SITE OF SECRETION? CHEMICAL CLASS: Water-Soluble - Peptides and proteins HORMONES: Prostaglandins, leukotrienes
All cells except red blood cells
Each pancreatic islet includes four types of hormone-secreting cells:
Alpha cells secrete glucagon; Beta cells secrete insulin; Delta cells secrete somatostatin; and F cells secrete
