CHAPTER 11 OUTLINE & STUDY QUESTIONS: ENDOCRINE GLANDS

o Exocrine glands are ducted glands that are not included in the endocrine systemo Endocrine glands are ductless glands that secrete hormones (chemicals) into the

blood- Target cell- a cell that has specific receptors for a particular hormone- Endocrine glands are numerous and widespread in the body

o Diseases result from abnormal secretion of hormones- Hypersecretion – over secretion of a hormone- Hyposecretion- under secretion of a hormone

MECHANISMS OF HOROMONE ACTION o Hormones perform general functions of communication and control but a slower,

longer-lasting type of control than that provided by nerve impulses o Cells that respond to hormones are called target cells; organs containing target

cells are thus target organso Nonsteroid hormones (first messengers) bind to the receptors on the target cell

membrane, triggering intracellular second messengers such as cyclic AMP to affect the cell’s activities

o Steroids hormones1. Their primary effects are produced by binding to receptors within the target cell

nucleus; they influence cell activity by acting on DNA- a slower process than nonsteroid action

2. Secondary effects may occur when steroid hormones bind to membrane receptors to rapidly trigger functional changes in the target cell

REGULATIONN OF HORMONE SECRETION o Hormone secretion is controlled by homeostatic feedbacko Negative feedback- a mechanism that reverses that direction of change is a

physiologic system ** after eating a meal and absorbing sugars insulin lowers blood sugar level

o Positive feedback- (uncommon) a mechanism that amplifies a physiologic-change **contractions during labor

o Levels of regulation- endocrine regulation of body function usually operates at multiple levels of control at the same time for better efficiency and precision

PROSTAGLANDINS Prostaglandins (PGs) are powerful lipid substances found in a wide variety of body

tissues; PGs are modified fatty acids PGs are typically produced in a tissue and diffused only a short distance to act on

cells in that tissue; they are often called tissue hormones or paracrine agents Several classes of PGs include prostaglandin A (PGA), prostaglandin E (PGE) and

prostaglandin F (PGF) PGs influence many body functions, including respiration, blood pressure,

gastrointestinal secretions & reproductionPITUITARY GLAND

“MASTER GLAND” Structure of the pituitary gland

1. Anterior Pituitary (adenohypophysis)- made up of glandular epithelium2. Posterior Pituitary (neurohypophysis)- made up of nervous tissue3. Location- in a bony depression (Sella turcica) of sphenoid bone in the skull;

connected to the hypothalamus by a pituitary stalk ANTERIOR PITUITARY GLAND (adenohypophysis)

1. Names & functions of major hormonesa. Thyroid-stimulating hormone (TSH) – stimulates growth of the thyroid gland; also

stimulates it to secrete thyroid hormone

b. Adrenocorticotropic hormone (ACTH)—stimulates growth of the adrenal cortex and prompts it to secrete glucocorticoids (GCs) (mainly cortisol)

c. Follicle-stimulating hormone (FSH)—initiates growth of ovarian follicles each month in the ovary and stimulates one or more follicles to develop to the stage of maturity and ovulation; FSH also stimulates sperm production in the male

d. Luteinizing Hormone (LH)—acts with FSH to stimulate estrogen secretion and follicle growth to maturity; causes ovulation; causes luteinization of ruptured follicle and stimulates progesterone secretion by the corpus luteum; causes interstitial cells in the testes to secrete testosterone in the male

e. Growth Hormone (GH)—stimulates growth by accelerating protein anabolism; also accelerates fat catabolism and slows glucose catabolism; by slowing glucose catabolism, tends to increase blood glucose to higher than normal levels (hyperglycemia)

f. Prolactin (PRL) (lactogenic hormone)—stimulates breast development during pregnancy and secretion of milk after the delivery of the baby

POSTERIOR PITUITARY GLAND (neurohypophysis) 1. Names & functions of hormones

a. Antidiuretic Hormone (ADH)—accelerates water reabsorption from urine in the kidney tubules into the blood, thereby decreasing urine secretion

b. Oxytocin (OT)—stimulates the pregnant uterus to contract; may initiate labor; causes glandular cells of the breast to release milk into ducts; enhances social bonding

HYPOTHALAMUS A. Produces posterior pituitary hormones

1. Actual production of ADH and OT occurs in the hypothalamus2. After production in the hypothalamus, hormones pass along axons into the pituitary

gland3. The secretion and release of posterior pituitary hormones is controlled by nervous

stimulationB. Regulates anterior pituitary secretion

1. Releasing hormones (RHs) and inhibiting hormones (IHs) control secretion by anterior pituitary

2. RHs and IHs reach the anterior pituitary through a direct capillary connectionC. The hypothalamus controls many body functions related to homeostasis (temperature,

appetite, & thirst)

THYROID GLAND Located in the neck, just inferior to the larynx (see figure 11-6) Tissue made up of thyroid follicles filled with colloid

1. Names & functions of hormonesA. Thyroid Hormones- thyroxine (T 4) and triiodothyronine (T 3); produced by follicle cells and

stored in colloid of follicles- Accelerate catabolism and energy production (increasing the body’s metabolic

rate)B. Calcitonin (CT)—made by CT cells outside in the follicle walls

- Decreases the blood calcium concentration by inhibiting breakdown of bone, which would release calcium into the blood

PARATHYROID GLANDS: Small lumps of glandular tissue located on the posterior surface of the thyroid Name & Function of Hormone

a. Parathyroid Hormone (PTH)1. Increases blood calcium concentration by increasing the breakdown of bone with

the release of calcium into the blood; also promotes absorption of calcium from food and reduces loss of calcium in urine

2. PTH and CT have antagonistic effects that help maintain stable blood calcium concentrations needed for good health

ADRENAL GLANDS: Located on the superior

surface of each kidney; the outer region is glandular, and the inner region is secretory nervous tissue

1. Adrenal cortex a. Names of hormones

(corticoids)- Mineralocorticoids

(MCs)—chiefly aldosterone

- Glucocorticoids (GCs)—chiefly cortisol (cortisone)

- Sex hormones—small amounts of male hormones (androgens) secreted by adrenal cortex of both sexes

1. Three cell layers (zones)- Outer layer, secretes

mineralocorticoids- Middle layer, secretes

GCs- Inner layer, secretes

sex hormones

2. Mineralocorticoids—increase blood sodium and decrease body potassium concentrations by accelerating kidney tubule reabsorption of sodium and excretion of potassium

3. Functions of GCsa. Help maintain normal blood glucose concentration by increasing gluconeogenesis—

the formation of “new” glucose from amino acids produced by the breakdown of proteins, mainly those in muscle tissue cells; also aid the conversion to glucose of fatty acids produced by the breakdown of lipids stored in adipose tissue cells

b. Play an essential part in maintaining normal blood pressure—make it possible for epinephrine and norepinephrine to maintain a normal degree of vasoconstriction, a condition necessary for maintaining normal blood pressure

c. Act with epinephrine and norepinephrine to produce an anti-inflammatory effect, to bring about normal recovery from inflammations of various kinds

d. Produce anti-immunity and antiallergy effect; bring about a decrease in the number of lymphocytes and plasma cells and therefore a decrease in the number of antibodies

e. Secretion of glucocorticoid quickly increases when the body is the body is thrown into a condition of stress; high blood concentration of GCs, in turn, brings about many other stress responses (figure 11-10)

f. Chronic stress can disturb the body’s balance of metabolic and immune functions4. Adrenal sex hormones—male androgens similar to testosterone are produced in both

sexes; have a role in reproductive development Adrenal medulla

- Names & functions of hormones- Epinephrine (Epi) or adrenaline, and norepinephrine (NR)- Help the body resist stress by intensifying and prolonging the effects of

sympathetic stimulations; increased epinephrine secretion is the first endocrine response to stress

PANCREATIC ISLETSA. Islands of endocrine tissue scattered within the exocrine tissue of the pancreas, a

digestive gland near the junction of the stomach and small intestineB. Names & functions of hormones

- Glucagon – secreted by *alpha* cells// increases the blood glucose level by accelerating liver glycogenolysis (conversion of glycogen to glucose)

- Insulin – secreted by *beta* cells// decreases the blood glucose by accelerating the movement of glucose out of the blood into cells, which increases glucose metabolism by cells

SEX GLANDS

a. Female sex glands1. The ovaries contain two structures that secrete hormones- the ovarian follicles and

the corpus luteum 2. Effects of estrogen (feminizing hormone)

a. Development and maturation of breasts and external genitalsb. Development of adult female body contoursc. Initiation of the menstrual cycle

b. Male sex glands1. The interstitial cells of testes secrete the male hormone testosterone2. Effects of testosterone

a. Stimulates production of spermb. Maturation of external genitalsc. Beard growthd. Voice changes at pubertye. Development of musculature and body contours typical of the male

THYMUS1. Hormone: thymosin (group of related hormones)2. Function: plays an important role in the development and function of T cells (agents of the

body’s immune system)

PLACENTA

1. Hormone: chorionic gonadotropins, estrogens, & progesterone2. Function: maintain the corpus luteum during pregnancy

PINEAL GLANDa. A small gland near the roof of the third ventricle of the brain

1. Glandular tissue predominates in children and young adults2. Becomes fibrous and calcified with age

b. Called “the third eye” because its influence on secretory activity is related to the amount of light entering they eyes

c. Secretes melatonin, which:1. Inhibits ovarian activity2. Regulates the body’s internal clock

ENDOCRINE FUNCTIONS THROUGHOUT THE BODYA. Many organs (ex., stomach, intestines, & kidney) produce endocrine hormones

1. The stomach lining produces ghrelin, which affects appetite and metabolism2. The atrial wall of the heart secretes atrial natriuretic hormone (ANH), which stimulates

sodium loss from the kidneys3. Fat-storing cells secrete leptin, which controls how full or hungry we feel

B. Hormone actions occur in every organ of the body and are addressed throughout the rest of this book

CHAPTER 11 PRACTICE TEST: 1. _______________ glands secrete their products into ducts that empty onto a surface or into a

cavity2. ___________________ glands are ductless and secrete their products, called

_____________________, into intercellular spaces, where they diffuse into the blood3. The two major classes of hormones are ____________________ hormones, and

________________________ hormones4. A cell or body organ with receptors for a hormone that triggers a reaction is called a

________________________5. One example of a second messenger system involves the conversion of ATP into

___________________________6. The hormone receptors for nonsteriod hormones are located ______________________,

whereas the receptors for steroid hormones are located __________________________7. “Tissue hormones” is another name for ________________________________8. This part of the pituitary gland is made of nervous tissue: ___________________________9. This part of the pituitary gland is made of glandular tissue:_____________________________10.The hormone oxytocin is released by the ___________________ but is made in the

_______________________11.A tropic hormone secreted by the anterior pituitary gland is

a. Thyroid-stimulating hormoneb. Adrenocorticotropic hormonec. Luteinizing hormoned. All of the above

12.Antidiuretic hormone (ADH)a. Is made in the posterior pituitary glandb. Accelerates water reabsorption in the kidneyc. In high concentrations causes diabetes insipidusd. All of the above

13.This hormone is released by the anterior pituitary and stimulates breast development during pregnancy and is necessary for eventual milk production:a. Estrogenb. Oxytocinc. Prolactind. Progesterone

14.This hormone is released by the posterior pituitary and stimulates the contraction of the pregnant uterus:a. Estrogenb. Oxytocinc. Prolactind. Progesterone

15.Thyroxinea. Is symbolized by T3b. Is made in the thyroid glandc. Contains less iodine than triiodothyronined. All of the above

16.Calcitonina. Decreases the level of calcium in the bloodb. Increases the level of calcium in the bloodc. Stimulates the release of calcium from bone tissued. Both B and C

a. Released by the adrenal medulla; prolongs he effect of the sympathetic divisionb. Made in the heart; helps regulate blood sodiumc. Made in the pancreatic islets; decreases blood glucose levelsd. Has the opposite effect of calcitonine. Made by the alpha cells in the pancreatic islets

f. Made in the outermost layer of the adrenal cortexg. The most significant hormone released by the pineal glandh. The hormone made by the placenta and detected by home pregnancy testsi. Made by the middle layer of the adrenal cortex

___ parathyroid hormone___ mineralocorticoids___ glucocorticoids___ epinephrine___ glucagon___ insulin___ chorionic gonadotropins___ melatonin___ atrial natriuretic hormone

17.Match a. Pelvic cavityb. Mediastinumc. Neckd. Cranial cavitye. Abdominal cavity

___ pituitary___ parathyroids___ adrenals___ ovaries___ thymus

18.Matcha. Cyclic AMP is an example of oneb. Respond to a particular hormonec. Prostaglandinsd. Discharge secretions into ductse. Specialized homeostatic mechanism that regulates release of hormones

___ negative feedback___ tissue hormones___ second messenger___ exocrine glands___ target organ cells

19.Nonsteriod hormones serve as ________________________ ______________________ providing communication between ___________________________and ___________________________. Another molecule such as __________________ _________________ then acts as the ____________________ ____________________ providing _________________________ within a hormone’s ______________________ ______________________.

20.The pituitary gland lies in the ___________________ bone.a. Ethmoidb. Sphenoidc. Temporald. Frontale. Occipital

21.Which one of the following structures would NOT be stimulated by a tropic hormone from the anterior pituitary?a. Ovariesb. Testesc. Thyroidd. Adrenalse. Uterus

22.Which of the following is NOT a function of FSH?a. Stimulates the growth of ovarian folliclesb. Stimulates the secretion of estrogens

c. Stimulates the growth of seminiferous tubules d. Stimulates the interstitial cells of the testes

23.Which one of the following is NOT a function of LH?a. Stimulates maturation of a developing follicleb. Stimulates the secretion of estrogensc. Stimulates the formation of a corpus luteumd. Stimulates sperm cells to mature the malee. Causes ovulation

24.Which one of the following is NOT a function of GH?a. Increases glucose catabolismb. Increases fat catabolismc. Speeds up the movement of amino acids into cells from the bloodstreamd. All of the above are functions of GH

25.Which one of the following hormones is NOT released by the anterior pituitary gland?a. ACTHb. TSHc. ADHd. FSHe. LH

26.Which one of the following is NOT a function of prolactin?a. Stimulates breast development during pregnancyb. Stimulates milk secretion after delivery c. Causes the release of milk from glandular cells of the breastd. All of the above are functions of prolactin

27.The anterior pituitary gland secretes:a. Eight major hormonesb. Tropic hormones that stimulate other endocrine glands to grow and secrete c. ADHd. Oxytocin

28.TSH acts on the:a. Thyroidb. Thymusc. Pineald. Testes

29.ACTH stimulates the:a. Adrenal cortexb. Adrenal medullac. Hypothalamusd. Ovaries

30.Which hormone is secreted by the posterior pituitary gland?a. MSHb. LHc. GHd. ADH

31.ADH serves the body by:a. Initiating laborb. Accelerating water reabsorption from urine into the bloodc. Stimulating the pineal glandd. Regulating the calcium/phosphorus levels in the blood

32.Which disease is caused by hyposecretion of ADH?a. Diabetes insipidusb. Diabetes mellitusc. Acromegalyd. Myxedema

33.The actual production of ADH and oxytocin takes place in the:a. Anterior pituitary

b. Posterior pituitaryc. Hypothalamusd. Pineal

34.Inhibiting hormones are produced by the:a. Anterior pituitaryb. Posterior pituitaryc. Hypothalamusd. Pineal

35.Matcha. Anterior pituitaryb. Posterior pituitaryc. Hypothalamus

___ adenohypophysis___ neurohypophysis___ induced labor___ appetite___ acromegaly___ body temperature___ sex hormones___ tropic hormones___ gigantism___ releasing hormones

36.The thyroid gland lies (above, below) the larynx37.The thyroid gland secretes (calcitonin or glucagon)38.For thyroxine to be produced in adequate amounts, the diet must contain sufficient

(calcium or iodine)39.Most endocrine glands (do or do not) store their hormones40.Colloid is a storage medium for the (thyroid or parathyroid)41.Calcitonin (increases or decreases) the concentration of calcium in the blood42.Simple goiter results from (hyperthyroidism or hypothyroidism)43.Hyposecretion of thyroid hormones during the formative years leads to (cretinism or

myxedema)44.The parathyroid glands secrete the hormone (PTH or PTA)45.Parathyroid hormone tends to (increase or decrease) the concentration of calcium in the

blood 46.The adrenal gland is actually two separate endocrine glands: the ________________

______________ and the ___________________ ____________________47.Hormones secreted by the adrenal cortex are known as ___________________________48.The outer zone of the adrenal cortex secretes ____________________________________49.The middle zone secretes _________________________50.The innermost zone secretes _______________________________ _____________________51.Glucocorticoids act in several ways to increase _________________________52.Glucocorticoids also play an essential part in maintaining _____________________

____________________53.The adrenal medulla secretes the hormones _______________________ &__________________54.The adrenal medulla may help the body resist ______________________________55.Deficiency or hyposecretion of adrenal cortex hormones results in a condition called

___________________ __________________56.Match a. Adrenal cortexb. Adrenal medulla

___ mineralocorticoids___ anti-immunity___ adrenaline___ crushing syndrome___ “fight-or-flight” response

___ aldosterone___ androgens

57.Match a. Estrogenb. Progesteronec. Insulind. Testosteronee. Glucagon

___ alpha cells___ beta cells___ corpus luteum___ interstitial cells___ ovarian follicles

58.Match a. Melatoninb. ANHc. Testosteroned. Thymosine. Chorionic gonadotropins

___ placenta___ pineal___ heart atria___ testes___ thymus True or False

59.Almost every organ and system has an endocrine function. ____________60.ANH is an antagonist to aldosterone. __________61.Ghrelin regulates how hungry or full we feel and how the body metabolizes fat. __________62.Aldosterone stimulates the kidney to retain sodium ions and water, and ANH stimulates

loss of sodium ions and water. ____________63.Leptin is secreted by epithelial cells lining the stomach and boots appetite, slows

metabolism, and reduces fat burning. ______________64.All of the following are included in the endocrine system except:

a. Exocrine glandsb. Steroid hormonesc. Nonsteriod hormonesd. All of the above are included in the endocrine system

65.The luteinizing hormone (LH) stimulates:a. Breast development during pregnancy b. The development of ovarian folliclesc. Maturation of ovarian follicle and triggers ovulationd. Seminiferous tubules of testes to grow and produce sperm

66.Prostaglandins or tissue hormones influence:a. Respirationb. Gastrointestinal secretionsc. Blood pressured. All of the above

67.Which of the following is NOT stimulated by the anterior pituitary gland?a. TSHb. ACTHc. ADHd. FSH

68.Too much insulin in the blood:a. Has the same effect on blood glucose as the growth hormoneb. Increases blood glucose concentrationc. Stimulates retention of water by the kidneys

d. Decreases blood glucose concentration 69.The posterior pituitary gland and hypothalamus:

a. Release two hormonesb. Produce substances called releasing and inhibiting hormonesc. Cause the glandular cells of the breast to release milk into ducts for nursing a babyd. All of the body

70.In addition to producing thyroid hormones, the thyroid gland also secretes:a. Hydrocortisone b. Calcitoninc. Aldosteroned. Glucagon

71.The adrenal medulla produces that are:a. Not essential for lifeb. Helpful in responding to stress c. Responsible for “fight-or-flight” responsed. All of the above

72.The pineal gland produces several hormones in small quantities, with the most significant being:a. ANHb. Leptinc. Chorionic gonadotropinsd. Melatonin

73.What plays a critical role in the body’s defenses against infection?a. Pancreasb. Thymusc. Pineal bodyd. Thyroid

74.Match a. Pancreas b. Adrenal cortexc. Progesteroned. Diabetes mellituse. “third eye”f. Mineralocorticoidg. Occurs during laborh. Anterior pituitaryi. Thyroid glandj. Lipid soluble

___ steroid hormones___ positive feedback___ tropic hormones___ myxedema___ glucocorticoids___ aldosterone___ islets of Langerhans___ glycosuria___ pineal gland___ corpus luteum