Chapter 18 Endocrine Test

hormones secreted by posterior pituitary

- antidiuretic hormone (ADH): targets circulatory system, kidneys, and sweat glands to stimulate water balance, raise blood pressure, and induce male aggression **also called vasopressin (VP or AVP)** - oxytocin (OT): targets uterus and mammary glands to stimulate uterine contractions and lactation

ovary hormones

- estrogen (estradiol & estrone): regulate menstrual cycle, maintain pregnancy, prepare mammary glands for lactation - progesterone: prepares uterus lining for implantation of a fertilized ovum -relaxin and inhibin **all help maintain female secondary sex characteristics**

pancreatic islet cell hormones

- glucagon: secreted by alpha cells, increase blood glucose level by converting glycogen to glucose - insulin: secreted by beta cells, decreases blood glucose levels by converting glucose to glycogen **insulin and glucagon are counter-regulatory hormones b/c their actions balance one another** - somatostatin: secreted by delta cells, inhibits insulin, glucagon, hGH (human growth hormone) - pancreatic polypeptide: secreted by F cells

hormones secreted by anterior pituitary

- human growth hormone (hGH): induces targets, liver, bones, muscles, to produce insulin growth factors (IGF) which stimulate body growth and higher metabolic rate - thyroid stimulating hormone (TSH): targets thyroid to release TH which regulates metabolism - follicle-stimulating hormone (FSH): targets reproductive system to stimulate production of eggs and sperm - luteinizing hormone (LH): targets reproductive system to stimulate production of sex hormones by gonads - prolactin (PRL): targets mammary gland to promote milk production and breast development - adrenocorticotropic hormone (ACTH): targets adrenal cortex to produce glucocorticoids, mineralocorticoids, and androgen hormones - melanocyte stimulating hormone (MSH): targets melanocytes to produce and release melanin, having effects on appetite and sexual arousal

pineal hormone

- melatonin: helps maintain the biological clock and secretes more in *darkness*, therefore it is very developed in nocturnal animals

glands of endocrine system

- pituitary - thyroid - parathyroid - adrenal - pineal - hypothalamus - thymus - pancreas - ovaries - testes - kidney - stomach - liver - small intestine - skin - heart - placenta

testes hormone

- testosterone is an androgen which is a male sex hormone that produces sperm and maintains male secondary sex characteristics

thymus gland

- thymosin: promotes proliferation and maturation of T cells, a type of lymphocyte (WBC), that destroys microorganisms and foreign substances

adrenal cortex hormones

- zona glomerulosa: synthesize mineralocorticoid hormones (ex: aldosterone)- regulate the concentration of Na+ and K+ in blood - zona fasciculata: secrete glucocorticoid hormones (ex: cortisol)- regulate metabolism and stress response - zona reticularis: synthesize weak androgens which are masculinizing hormones

types of hormones

1. autocrine 2. paracrine 3. endocrine

endocrine hormone functions

1. balance composition and volume of body receptors 2. regulate metabolism and energy production 3. direct the rate and timing of growth and development 4. exert emergency control during stress 5. oversee reproductive mechanisms

three types of water soluble hormones

1. peptide hormones: amino acid polymer 2. protein hormones: amino acid polymer 3. eicosanoids (prostaglandis & leukotrienes): synthesized from membrane lipids; mediate the inflammatory response

methods of hormone secretion

1. signals from nervous system 2. chemical changes in the blood 3. releasing hormones 4. mechanical stretching of endocrine cell *NOT COMMON*

three types of lipid soluble hormones

1. steroid hormones: derived from cholesterol 2. thyroid hormones (T3 & T4): synthesized by attaching iodine to tyrosine 3. gas nitric oxide: catalyzed by enzyme nitric oxide synthase **also a neurotransmitter**

*Which statement is true of hypothalamic releasing and inhibiting hormones?* A. Control the release and suppression of hormones from the anterior pituitary. B. Decrease growth of bones and soft tissues. C. Cause a decrease in blood osmolarity and an increase in blood volume. D. Control the rate and contraction strength of the heart.

A. Control the release and suppression of hormones from the anterior pituitary.

*Which of the following hormone interactions is mismatched?* A. Effects of epinephrine in stimulating lipolysis is increased when small amounts of thyroid hormones are present. - Antagonistic effect. B. Two hormones acting together exert a greater effect than either acting alone - Synergistic effect. C. Insulin promotes synthesis of glycogen by liver cells while glucagon stimulates glycogen break down in liver. - Antagonistic effect. D. Development of oocytes in ovaries requires both follicle stimulating hormone and estrogen - Permissive effect.

A. Effects of epinephrine in stimulating lipolysis is increased when small amounts of thyroid hormones are present. - Antagonistic effect.

*These are found in virtually all body cells except red blood cells, where they act as local hormones (paracrines or autocrines) in response to chemical or mechanical stimuli.* A. Prostaglandins and leukotrienes B. Growth factors C. Human chorionic gonadotropins D. Relaxin and inhibin

A. Prostaglandins and leukotrienes

*Which of the following statements is incorrect?* A. Thyroid hormones decrease metabolic rate. B. Thyroid hormones function in maintenance of normal body temperature. C. Thyroid glands help to regulate metabolism. D. Thyroid hormone up-regulate beta receptors. E. a and d are incorrect.

A. Thyroid hormones decrease metabolic rate.

*Most water soluble hormones circulate freely in blood plasma while most lipid soluble hormones are transported bound to transport* proteins. A. True B. False

A. True

*Ovaries are classified as endocrine glands as well as reproductive organs because they produce gametes as well as hormones.* A. True B. False

A. True

*The adrenal medulla is a modified sympathetic ganglion.* A. True B. False

A. True

*Three types of signals that control hormone secretion are nervous system signals, chemical changes in blood, and other hormones.* A. True B. False

A. True

*Local hormones that act on themselves are ________; local hormones that act on neighboring cells are _____.* A. autocrine; paracrine B. paracrine; autocrine C. circulating; traveling D. traveling; circulating

A. autocrine; paracrine

*In a thyroidectomized mouse, T3 and T4 levels would ________.* A. Increase B. Decrease C. Remain the same D. Initially rise then fall

B. Decrease

*Which of the following statements is incorrect?* A. Down-regulation may occur if a hormone is present in excess. B. Down-regulation results in an increase in the number of target-cell receptors. C. In up-regulation, a target cell becomes more sensitive to a hormone. D. If a hormone is present in excess, the number of target cell receptors decreases.

B. Down-regulation results in an increase in the number of target-cell receptors.

*Parathyroid hormone is regulated via negative feedback loops involving the pituitary gland.* A. True B. False

B. False

*The stress response is generally controlled by the limbic system which is stimulated by stressors.* A. True B. False

B. False

*Triiodothyronine and thyroxine levels are regulated by a negative feedback loop involving thyroid stimulating hormone and thyrotropin inhibiting hormone.* A. True B. False

B. False

*What two substances are necessary for the synthesis of thyroxine and triiodothyronine?* A. Iodine and taurine B. Iodine and tyrosine C. Calcium and taurine D. Calcium and aspartate E. Iodine and aspartate

B. Iodine and tyrosine

*The adrenal cortex is derived from ________ while the adrenal medulla is derived from _____________.* A. Ectoderm; mesoderm B. Mesoderm; ectoderm C. Endoderm; mesoderm D. Mesoderm; endoderm

B. Mesoderm; ectoderm

*The ________ pituitary contains hypothalamic neurosecretory cells and stores and releases hormones while the _____ pituitary produces and releases hormones.* A. anterior; posterior B. posterior; anterior C. pars tuberalis; pars distalis D. pars distalis; pars tuberalis

B. posterior; anterior

*Which of the following organs is/are incorrectly matched with the hormones they secrete?* 1. Kidneys - Renin 2. Placenta - Human chorionic somatotropic 3. Adipose tissue - Leptin 4. Heart - Atrial natriuretic peptide 5. Pancreas - Glucose-dependent insulin tropic peptide 6. Gastrointestinal tract - Cholecystokinin A. All of these are correctly matched. B. 1 and 2 are incorrectly matched. C. 5 is incorrectly matched. D. 5 and 6 are incorrectly matched. E. 3 and 5 are incorrectly matched

C. 5 is incorrectly matched

*Which of the following statements is incorrect?* A. The hypothalamo hypophyseal tract extends from the paraventricular and supraoptic nuclei to the posterior pituitary. B. The supraoptic nuclei of the hypothalamus secrete antidiuretic hormone. C. Oxytocin and antidiuretic hormones are released into the capillary plexus of the infundibular process of the anterior pituitary.

C. Oxytocin and antidiuretic hormones are released into the capillary plexus of the infundibular process of the anterior pituitary.

*Which of the following statements is/are incorrect?* A. The nervous and endocrine systems act together to help to maintain homeostasis. B. The nervous system acts through nerve impulses while the endocrine system uses hormones to control body activities. C. The endocrine uses neurotransmitters for communication while the nervous system communicates using hormones. D. Neurotransmitters and hormones may both exert effects by binding to target cell receptors. E. The endocrine system responds slowly while the nervous system responds quickly.

C. The endocrine uses neurotransmitters for communication while the nervous system communicates using hormones

*Which area of the adrenal gland is incorrectly matched with the product it synthesizes?* A. Zona glomerulosa - mineralcorticoids B. Zona fasciculata - glucocorticoids C. Zona reticularis - corticosteroids D. Adrenal medulla - epinephrine and norepinephrine

C. Zona reticularis - corticosteroids

*The level of blood glucose controls secretion of ________ by _____ feedback.* A. somatostatin and pancreatic polypeptide; negative B. somatostatin and pancreatic polypeptide; positive C. insulin and glucagon; negative D. insulin and glucagon; positive

C. insulin and glucagon; negative

Which of the following statements is/are correct? A. Control of glucocorticoid secretion occurs by negative feedback. B. The renin-angiotensin pathway controls secretion of aldosterone. C. Chromaffin cells are under autonomic control. D. All of these statements are correct.

D. All of these statements are correct.

*Which of the following statements is FALSE:* A. Eating a meal rich in carbohydrates would stimulate insulin release B. Decreased blood glucose level after exercise would stimulate glucagon secretion C. Protein-rich meals would stimulate glucagon secretion D. Eating a fatty meal would stimulate insulin release

D. Eating a fatty meal would stimulate insulin release

*Which hormone is related to the muscle atrophy that occurs with aging?* A. Calcitonin B. Insulin C. Follicle stimulating hormone D. Human growth hormone

D. Human growth hormone

*The responsiveness of a target cell to a hormone is determined by all of the following EXCEPT:* A. The concentration of the hormone in the blood B. The number of hormone receptors on the target cell C. Influences exerted by other hormones D. The amount of hormone that remains in the blood after all of the receptors are full

D. The amount of hormone that remains in the blood after all of the receptors are full

*Which of the following statements about melatonin is incorrect?* A. More melatonin is released during darkness than in light. B. Melatonin is thought to promote sleep. C. Melatonin is thought to contribute to the setting of the body's biological clock. D. The hypothalamus secretes melatonin. E. Melatonin is an amino acid hormone derived from serotonin.

D. The hypothalamus secretes melatonin.

*Stress can temporarily inhibit certain components of the immune system resulting in increased risk of disease.* A. a journal entry is posted twice. B. a wrong amount is used in journalizing. C. incorrect account titles are used in journalizing. D. a journal entry is only partially posted.

D. a journal entry is only partially posted.

*________ stimulates absorption of calcium from food in the gastrointestinal tract while _____ promotes release of calcium from bone.* A. thyroid hormone; calcitonin B. calcitonin; thyroid hormone C. parathyroid hormone; calcitriol D. calcitriol; parathyroid hormone

D. calcitriol; parathyroid hormone

*Which of the following glands are not exclusively classified as endocrine glands but contain hormone secreting cells?* A. Hypothalamus. B. Pancreas. C. Ovaries. D. Kidneys. E. All of these glands are correct.

E. All of these glands are correct.

*Which of the following statements regarding the stress response (GAS) is correct?* A. The fight-or-flight response begins with hypothalamic stimulation of the sympathetic nervous system and adrenal medulla. B. The fight-or-flight response rapidly increases circulation, promotes ATP production and decreases nonessential activities. C. The resistance reaction is initiated by releasing hormones of the hypothalamus and involves longer lasting reactions and acceleration of processes which produce ATP. D. Exhaustion results from depletion of body resources during the resistance stage. E. All of these statements are correct.

E. All of these statements are correct.

*Which thymic hormone plays a role in immunity?* A. thymosin B. thymic humoral factor C. thymopoietin D. a and b only E. all choices are correct

E. all choices are correct

parathyroid hormone (PTH)

PTH: raises calcium levels by releasing it from bone into the blood, *opposed by calcitonin*

RAAS (renin-angiotensin-aldosterone system)

Renin is released by kidneys in response to decreased blood volume/pressure; causes angiotensinogen to split & produce angiotensin I; lungs convert angiotensin I to angiotensin II; angiotensin II stimulates adrenal cortex to release aldosterone (indirectly increase BP) & causes an increase in potent vasoconstriction (directly increase BP)

thyroid hormones (T3 / T4 & Calcitonin)

T3 / T4: accelerate body growth, particularly of the nervous and skeletal systems most T4 released by the thyroid is converted by enzymes in the blood into T3, a more active hormone Calcitonin: decreases blood calcium levels and increase in blood phosphate levels

Addison's Disease (hyposecretion of aldosterone & glucocorticoids)

a condition that occurs when the adrenal glands do not produce enough cortisol or aldosterone; raise potassium and decrease sodium in blood, low bp, dehydration, and decreased cardiac output

hypophyseal portal system

a blood vessel system where blood flows from one capillary network into a portal vein and then into a second capillary network before returning to the heart

Seasonal Affective Disorder (SAD)

a depression caused by the body's reaction to low levels of sunlight in the winter months

adrenal glands

a pair of endocrine glands that sit just above the kidneys and contain two distinct regions, cortex and medulla

pineal gland

attached to the third ventricle and apart of the epithalamus

water soluble hormones

bind to receptors exposed to interstitial fluid on the surface of target cells as the first messenger, producing a second messenger, commonly cyclic AMP (cAMP), inside the cell where the response takes place

Diabetes Insipidus (DI)

caused by defects in ADH receptors or an inability to secrete ADH

thyroid gland

composed of follicular cells that store a 100-day supply of thyroxine (T4) and T3 in thyroglobulin (TGB), a glycoprotein made from oxidation and iodination of tyrosine molecules

Gynecomastia

condition of excessive mammary development in the male

neurohypophysis (posterior pituitary)

connected to hypothalamus; releases hormones synthesized by *neurosecretory cells* in hypothalamus

endocrine system

coordinates all of the body systems; consists of glands that control many of the body's activities by producing hormones

Hypoparathyroidism

deficiency of blood calcium which causes neurons and muscle fibers to depolarize and action potentials

pituitary gland

divided into the larger anterior, adenohypophysis, and smaller posterior, neurohypophysis

Hyperparathyroidism

elevated level of PTH causing excess resorption of bone matrix, raising Ca blood levels and phosphate ions

pancreas

endocrine and exocrine gland; pancreatic cell clusters, called acini, produce digestive enzymes that flow through GI tract and distribute endocrine tissue called pancreatic islets

Goiter

enlarged thyroid gland associated with hyperthyroidism, hypothyroidism, or euthyroidism *result of inadequate iodine causing low level of thyroid hormone to release TSH*

Hyperaldosteronism

excessive output of aldosterone from the adrenal gland leading to increased sodium, water retention and loss of potassium, causing weakness and muscle spasms

Cushing's Syndrome

hypersecretion of cortisol caused by a tumor

Acromegaly

hypersecretion of growth hormone during *adulthood* causing the bones of the hand, feet, cheek, and jaw thicken, while other tissues enlarge

Gigantism

hypersecretion of growth hormone during *childhood* leading to an abnormal increase in long bone length

Grave's Disease

hyperthyroidism where antibodies continually stimulate the thyroid gland to grow and release TSH which causes enlarged thyroid and protruding eyes

Dwarfism

hyposecretion of growth hormone during childhood- slows bone growth and closes epiphyseal plates before normal height is reached

Congenital Hypothyroidism (cretinism)

hyposecretion of thyroid hormone during youth causing slow growth and sexual development, and possible mental retardation

Myexedema

hypothyroidism in adults that causes facial tissue to swell, slow heart rate, low body temp, cold sensitivity, dry hair and skin, muscular weakness, and ability to easily gain weight

Diabetes Mellitus

insulin is not secreted adequately or body cells do not use insulin properly

hypothalamus

link b/w nervous & endocrine systems that controls the pituitary gland (hypophysis), which hangs from the hypothalamus on the infundibulum, and *its hormone secretion*

autocrine hormones

local hormones that are secreted and bind to the same cell

paracrine hormones

local hormones that are secreted into interstitial fluid and act on nearby cells

neurosecretory cells

located in hypothalamus and secrete releasing hormones into portal system that supply blood to the adenohypophysis

prostaglandis

mediate pain, platelet aggregation, fever, and inflammation; regulate smooth muscle contraction, gastric acid secretion, and airway size

hormones

mediator molecules that have effects on cells in local or distant parts of the body antagonism- when a hormone opposes another

Glucocorticoids

raises blood sugar levels to cope with stress, slow wound healing, and promote the breakdown of proteins and fats

lipid soluble hormones

require carrier protein for transport into blood and then freely pass through the plasma membrane to **bind to receptors in the cytoplasm or nucleus of the cell**

negative feedback system

the hormone output reverses a particular stimulus

adrenal medulla hormones

secrete the catecholamines, epinephrine (80%) and norepinephrine (20%), which prolong sympathetic response

exocrine glands

secrete their products into ducts

endocrine hormones

secreted into interstitial fluid and then absorbed into bloodstream to be systemically carried to any cell that displays the correct receptor

parathyroid glands

small masses of tissue on the posterior surface of the lateral lobes of the the thyroid, that regulate calcium and phosphate balance in blood, bones, and other tissues

endocrine glands

structures when stimulated, secrete endocrine hormones into the bloodstream in frequent bursts increasing the concentration of the hormone

Cogenital Adrenal Hyperplasia (CAH)

suprarenal glands are enlarged due to a low level of cortisol; causing an accumulation of weak androgens which in excess converts to testosterone *in women it can cause beard growth, deeper voice, clitoris that resembles a penis, increased muscularity, and decreased breast size*

adenohypophysis (anterior pituitary)

synthesizes and secretes hormones when signaled by the hypothalamus; connected to hypothalamus by blood vessels that form a portal system called hypophyseal portal system

General Adaptation Syndrome (GAS)

the body's adaptive response to a prolonged stress response occurs in three phases— alarm, resistance, exhaustion 1. alarm: fight or flight response 2. resistance: longer-lasting response that assures the tissues of the body can sustain metabolic needs 3. exhaustion: body's reserves become depleted to the point they cannot sustain the resistance stage **prolonged exposure causes wasting of muscle, suppression of immune system, ulceration of GI tract, and failure of pancreatic beta cells** OFTEN CAUSES DISEASE IF PROLONGED

positive feedback system

the hormone output reinforces and encourages stimulus