Chapter 16: Endocrine
gonadocorticoids (sex hormones)
- Most *weak androgens* (male sex hormones) converted to testosterone in tissue cells, some to estrogens - May contribute to: - Onset of puberty - Appearance to secondary sex characteristics - Sex drive in women - Estrogens in postmenopausal women
High blood glucose
- pancreas releases insulin - body takes up more glucose - liver takes up glucose and stores it as glycogen - blood glucose decreases to normal
Glucagon
-A potent hyperglycemic agent -major target is the liver -promotes glycogenolysis, gluconeogenesis and release of glucose to the blood from liver cells
Actions of Thyroid Hormones
-Affects nearly every cells in the body -Increases the basal metabolic rate (BMR) - rate at which most metabolism occurs such as drugs, vitamins, nutrients, etc -Increases body heat (called the calorigenic effectbecause it burns calories). -Regulates growth and development, particularly in the skeletal and nervous systems of children -Regulates nervous system activity; general nervousness, hyperactivity, increased blood pressure, hypermotility of GI tract.
Hypothalamic hormones
-Corticotropin-releasing hormone (CRH) -Growth hormone-releasing hormone (GHRH) -Growth hormone-inhibiting hormone (GHIH) Also called somatostatin -Thyrotropin-releasing hormone (TRH) -Gonadotropin-releasing hormone (GnRH) will be covered in Chapter 27
actions of parathyroid hormone
-Net effect is to increase blood calcium and decrease phosphate levels -Rising calcium in the blood provides negative feedback to inhibit PTH release
Actions of glucocorticoids
-affect nearly every cell in the body -Proteins and lipids are converted to glucose - a process called gluconeogenesis (new glucose). In this way, theglucose eaten in the diet is "spared". -Keeps blood glucose levels constant -reduces inflammation but can dampen immune system -provides a natural resistance to stress
Pancreas
-exocrine: acinar cells produce enzyme-rich pancreatic juice used for digestion -endocrine: pancreatic islets produce hormones
Thyroid gland
-largest endocrine gland -located in the anterior neck -consists of two lateral lobes connected by a median tissue mass called the isthmus
Thymus
-lobulated gland located deep to the sternum -major hormonal products are thymopoietins and thymosins -these hormones are essential for the development of the T lymphocytes (t cells) of the immune system
Insulin
-moves glucose from the blood into body cells -lowers blood glucose levels -after glucose enters a cell, insulin binding triggers enzymatic activity -uses glucose to make ATO -stores glucose as glycogen -converts glucose to fat
Three key stages of DM
-polyuria - huge urine output -polydipsia - excessive thirst -polyphagia - excessive hunger and food consumption
Antiduretic hormone (ADH)
-prevents dehydration -released to enhance water retention -lowers urine output -alcohol inhibits ADH release and causes copious urine output
Actions of Mineralocorticoids
-regulate electrolytes in extreacellular fluids -Aldosteroe - most important - secreted when blood pressure falls -Causes body to retain sodium -Stimulates reabsorption of Na by the Kidneys -Water is retained along with the sodium, thus BP increases
Calcitonin
-secreted by the parafollicular cells of the thyroid gland -antagonist to parathyroid hormone (PTH): exact opposite actions
Adrenal Medulla
-secretes epinephrine (80%) and norepinephrine (20%) -Secretion of these hormones causes fight or flight response
Growth Hormone (GH)
-stimulated most cells, but target cells are bone and skeletal muscle -moves lipids from storage (fat depots) for use as fuel (lipolysis) -encourages breakdown of glycogen (stored glucose) in the liver. This raises blood glucose (called a hyperglycemic, or "anti-insulin" effect) -increases bone and cartilage growth -promotes protein synthesis (anabolic effect)
Parathyroid glands
-tiny glands embedded in the thyroid -PTH (parathormone) regulates calcium balance in the blood
LONG-TERM STRESS AND THE ADRENAL GLAND
A HORMONAL RESPONSE FROM CORTICOSTEROIDS
SHORT-TERM STRESS AND THE ADRENAL GLAND
A RESPONSE OF THE SYMPATHETIC NERVOUS SYSTEM
As a result of stress the anterior pituitary releases ________, which stimulates release of hormones from the adrenal cortex that retain sodium and water, increase blood sugar, and begin breaking down fats.
ACTH
Which hormone is released from the posterior pituitary when the solute concentration of the blood becomes concentrated?
ADH
What hormone also aids the stress response by promoting water retention and acting as a vasoconstrictor?
ADH (vasopressin)
Which of the following is NOT characterized by high levels of cortisol in the blood?
Addison's disease
Hyposecretion of mineralocorticoids
Addison's disease; almost always occurs as a whole gland
Anterior Pituitary Hormones
Adrenocorticotropic hormone (ACTH) Human growth hormone (hGH) Thyroid-stimulating hormone (TSH) Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) Prolactin (PRL)
The posterior pituitary
Antidiuretic hormone (ADH) and oxytocin are synthesized in the hypothalamus and stored in the posterior pituitary.
Which hormone aids in water resorption?
Antidiuretic hormone (ADH) stimulates the kidney tubules to reabsorb water.
Choose which condition has all of the following symptoms: hypertension, hyperglycemia, and a "moon face."
Cushing's disease
Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones?
GH (growth hormones)
Aldosterone production
Humoral and/or hormonal stimulus
Acromegaly
Hypersecretion of growth hormone
Cushing's disease
Hypersecretion of the adrenal cortex
Myxedema
Hyposecretion of the thyroid in adults
Cretinism
Hyposecretion of the thyroid in infants
Which of the following structures produces a hormone responsible for stimulating red blood cell production?
Kidney
Low blood glucose
Pancreas releases glucagon Liver breaks down glycogen and releases glucose into the blood Blood glucose rises to normal
Synergism
Synergism occurs when more than one hormone produces the same effects at the target cell and their combined effects are amplified. For example, let's say both hormone "A" and hormone "B" cause the liver to release glucose into the blood. When they act together, the amount of glucose released might be 150% of what is released if each hormone acts independently.
Which of the following is INCORRECTLY matched with its secreting organ?
TSH --> Posterior pituitary
What is directly required for the production of anterior pituitary gland hormones?
The anterior pituitary requires hormonal stimuli from the hypothalamus.
Which of the following pairs correctly matches the adrenal gland structure with the class of hormones it produces?
The zona glomerulosa produces mineralocorticoids
In order for a hormone to activate a target cell, the target cell must possess
a receptor
Hypersecretion (aldosteronism), is usually due to
a tumor
Hormones secreted into the hypophyseal portal system are detected by the
adenohypophysis
After Laia had a CT scan of her abdomen, they found a large mass in a gland sitting on top of the upper pole of her kidney. This gland is most likely the:
adrenal
Produce hormones involved in electrolyte balance and stress response
adrenal glands
What hormone, indicated by letter B, is released by the anterior pituitary to target the adrenal cortex when the body is under stress?
adrenocorticotropic hormone (ACTH)
What tropic hormone stimulates cortisol from the adrenal gland?
adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex to produce cortisol. Stress and ACTH are the main stimuli for cortisol.
Glucagon is secreted by ____ cells of the ______.
alpha cells; pancreas
Adenohypophysis
anterior lobe of the pituitary gland containing glandular tissue
Which of the following organs secretes thyroid releasing hormone?
anterior pituitary
Hypocalcemia could be caused by the ______.
apoptosis of parathyroid cells, failure of osteoclasts to respond to PTH (parathyroid hormone/parathormone), malfunction of the parathormone receptors in kidney tubule cells
Cushing's syndrome and aldosteronism have the same effects on ______.
blood pressure
What is the function of the ventral hypothalamic neurons?
control secretion of thyroid stimulating hormone (TSH)
In response to stress, which of the following changes would happen?
decreased insulin secretion
Which of the following is NOT a change that may be caused by hormonal stimulus?
direct control of the nervous system
Which of the following is NOT a category of endocrine gland stimulus?
enzymatic
Which of the following hormones is a part of the rapid response (rather than the prolonged response) to stress?
epinephrine
Which of the following is secreted through the activation of receptors in the adrenal medulla?
epinephrine and norepinephrine
Cushing's syndrome
excessive levels of glucocorticoids
The alpha cells in the pancreatic islets produce insulin.
false
Regulating hormones from the hypothalamus ________.
first enter into the hypophyseal portal system
Thyroid cells
follicular cells secrete thyroid hormone and parafollicular cells produce the hormone calcitonin
Adrenal cortex
glandular tissue
Alpha cells produce
glucagon
During an afternoon class, Raja starts to feel hungry and thinks his blood sugar level may be dropping. Which hormone is helping to PREVENT a drop in blood sugar level?
glucagon
Which hormone stimulates the breakdown of polymerized glucose?
glucagon
These hormones are produced in the zona fasciculata of the adrenal cortex. They help the body resist long-term stressors.
glucocorticoids
zona fasciculata
glucocorticoids (cortisol)
zona reticularis
gonadocorticoids (androgens)
Which of the following are symptom(s) of pheochromocytoma?
heart palpitations
Testosterone production
hormonal stimulus
When the pancreas releases insulin in direct response to blood glucose, this is an example of ________ stimulation.
humoral
Parathyroid hormone production
humoral stimulus
Several hormones are synthesized in the hypothalamus and transported to the anterior pituitary gland. The mechanism of transportation from hypothalamus to anterior pituitary gland is through the
hypophyseal portal system
A patient is displaying high volumes of urine output and severe dehydration. The most likely cause is
hyposecretion of ADH
Acromegaly may be caused by all EXCEPT which of the following?
hyposecretion of GH in adulthood
Damage of which of the following brain structures could cause central diabetes insipidus?
hypothalamas
Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized?
hypothalamas
produces hormones and is considered a neuroendocrine organ
hypothalamas
A nurse notices that her patient is taking daily doses of somatotropin. This drug is most likely being given to
increase growth rate in a child
Which of the following is an indirect effect of PTH?
increasing calcium absorption in the intestines
Which of the following is NOT a parathyroid gland mechanism to maintain adequate levels of blood calcium?
inhibition of calcitonin synthesis
After Bryan consumes 44 ounces of a sugary drink, his blood sugar will quickly increase. Assuming Bryan is a healthy person, which hormone would be secreted to bring his body back to homeostasis?
insulin
Betal cells produce
insulin
The long bone growth-promoting effects of growth hormones are mediated by
insulin-like growth factors
A major difference between neurotransmitters and hormones is that hormones are secreted
into the blood
The posterior lobe of the pituitary gland is NOT a true endocrine gland because ________.
it is only a hormone storage area that receives hormone from the hypothalamus for release
What is the target tissue for ADH?
kidney
Adipose tissue releases
leptin, which is involved in the sensation of satiety, and stimulates increased energy expenditure
The secretion of ________ helps regulate our circadian rhythms.
melatonin
Upon landing at the airport in Lagos, Nigeria, Eric feels wide awake even though the local time is 11pm. Which hormone supplement could he administer to help adjust to the new time zone?
melatonin
Zona glomerulosa
mineralocorticoids (aldosterone)
Blood levels of hormones are kept within very narrow ranges by _____ mechanisms
negative feedback
What is the most important regulatory factor controlling the circulating levels of thyroid hormone?
negative feedback
Neural Stimuli
nerve impulses stimulate hormone release
The posterior pituitary and hypothalamus have a ______ connection: the hypothalamic-hypophysealtract
neural
Epinephrine production
neural stimulus
Adrenal medulla
neural tissue
Type 2 Diabetes Mellitus (DM)
occurs later in life (although childhood obesity has been increasing) and characterized by normal insulin secretion but lack of sensitivity of insulin receptors in peripheral tissues (insulin resistance).
Hormonal stimuli
one hormone causes the release of another hormone
Produces the hormones that promote the development of the female secondary sexual characteristics at puberty
ovaries
Which of the following hormones is regulated by a neuroendocrine ("letdown") reflex?
oxytocin
adrenal (suprarenal) glands
paired, pyramid-shaped organs atop the kidneys
Martim is suffering from loss of calcium from his bones, which has caused several spontaneous fractures of the bones. This is MOST likely caused by hypersecretion from which gland?
parathyroid
Which gland secretes the most important hormone controlling calcium balance in the blood?
parathyroid
Alicja is experiencing an excessive rate of bone formation. Which of the following hormones would most likely be administered to solve this problem
parathyroid hormone
Miguel has been diagnosed with excessive levels of calcium in his blood. Which of the following hormones would most likely be responsible for this problem?
parathyroid hormone
In PEx-4, Activity 2, which of the patients tested was(were) in the borderline range for insulin-mediated glucose uptake?
patients 2 and 4
Which organ secretes growth hormone?
pituitary
A hypophysectomized rat is missing its _______.
pituitary gland
Storehouse for the hormones produced by the hypothalamus of the brain
pituitary gland
Eliska has gotten her lab results, which revealed below normal amounts of T3 and T4. This may indicate an abnormality in which gland?
pituitary, hypothalamus or thyroid
Neurohypophysis
posterior lobe of the pituitary gland containing neural tissue
Which hormone stimulates mammary glands to produce milk in nursing mothers?
prolactin
Oxytocin ________.
release is an example of a positive feedback control mechanism
The anterior pituitary hormones are released only when the hypothalamus sends a signal via
releasing (tropic) hormones
The hypothalamic-hypophyseal tract ________.
runs through the infundibulum
Endocrine glands
secrete their products (hormones), into the extracellular space rather than into ducts
Exocrine glands
secrete their products into ducts which carry the substance to a lumen or the body surface. Ex; sudoriferous glands, sebaceous glands, digestive glands
Humoral stimuli
secretion of hormones in direct response to changing blood levels of ions and nutrients (substances in the blood)
Kidneys secrete erythropoietin which
signals the production of red blood cells
Pineal Gland
small gland hanging from the roof of the third ventricle of the brain -secretory product is melatonin (day/night cycles)
Hypoparathyroidism
sometimes the result of thyroidectomy (the parathyroids are often removed along with the thyroid due to their close proximity) Hypocalcemia: weakness, muscle cramps or spasms
Gluconeogenesis
synthesis of glucose from lactic acid and non-carbohydrates
Up-regulation
target cells form more receptors in response to the hormone
Down-regulation
target cells lose receptors in response to the hormone
Produces the hormones that direst the production of the secondary male sex characteristics
testes
Glycogenolysis
the breakdown of glycogen to glucose
Which organ is responsible for synthesizing the hormone atrial natriuretic peptide (ANP)?
the heart
In PEx-4, Activity 1, propylthiouracil injections resulted in goiter formation in
the normal rat
hyperinsulinism
the opposite of DM - excessive insulin secretion (or overdosage), resulting in hypoglycemia
What determines whether a particular cell is able to respond to a hormone?
the presence of a specific hormone receptor
At age 85, Lyle's immune system does not respond to vaccines as well as it did when he was younger. The atrophy of which endocrine gland is likely responsible for this?
thymus
Hypersecretion of which gland would cause an excess of calcitonin in the blood?
thyroid
A person who just immigrated from Syria is experiencing a deficiency of iodine. Which organ would be most affected by this deficiency?
thyroid gland
The various hormones secreted by the anterior pituitary that regulate the secretion of hormones from other endocrine organs are called __________.
tropins
Antagonism
two hormones have opposite actions on a target cell
The Pituitary Gland (Hypophysis)
two-lobed organ that secretes nine major hormones
Hyperparathyroidism
usually caused by a parathyroid tumor
Type 1 Diabetes Mellitus (DM)
usually genetic, appears before age 15 and results in a total lack of insulin secretion
The anterior pituitary and hypothalamus have a ______ connection: the hypophyseal portal system.
vascular
Excess glucose can be found in the urine _______.
when the transport maximum for reabsorption in the kidney tubules is exceeded, as a result of type 1 diabetes or as a result of type 2 diabetes
