Friday, March 21, 2014

KELENJAR ENDOKRIN - HORMON TUBUH



The Endocrine System

I.    An Overview of the Endocrine System

  1. A hormone is a chemical messenger secreted by one endocrine gland or cell into the bloodstream and targeted toward cells in another organ.  It’s another regulatory mechanism in addition to nervous system.
  2. A hormone binds to specific receptors on plasma membranes or cytoplasm of its target cells.  Only those cells bear the specific receptors are affected.   Receptors of some hormones are found only in a limited number of cells while receptors of other could be distributed more extensively. 
  3. The endocrine system is a collective term for all such hormone-secreting glands as well as the hormone-secreting cells located elsewhere.


II.  General Concepts about Hormones and Their Actions
      Hormones fall into three major chemical classes: steroids, biogenic amines, and peptide hormones.
Steroid hormones

  1. Include estrogens, progesterone, androgens, glucocorticoids, and aldosterone
  2. Derived from cholesterol
  3. Plasma membrane permeable
  4. Receptors located in the nucleus of their target cells
  5. Activate DNA transcription

Biogenic amines

  1. Include epinephrine, norepinephrine, dopamine, serotonin, melatonin, and thyroid hormones
  2. Synthesized from amino acids
  3. Plasma membrane impermeable (except thyroid hormones)
  4. Receptor located in plasma membrane (except thyroid hormones)
  5. Effects mediated through second-messenger systems

Peptide hormones

  1. Include all the hormones that are not listed above.
  2. Derived from proteins
  3. Plasma membrane impermeable
  4. Receptor located in plasma membrane

Hormone Receptors

  1. Hormones stimulate only those cells that have specific receptors for them.
  2. To each of many hormones, there can be several types and subtypes of receptors.
  3. Different subtypes of the receptors mediate different effects.
  4. The effects of each hormone on individual target cells are determined by the specific subtype of receptors that the cells carry.
  5. Hormones bind to their receptors located either in the plasma membrane or in the nucleus, and activate the receptors. The activated receptors then turn on or off certain metabolic pathways. The intermediate processes between receptor activation and the final biological effects of the hormone, are called signal transduction.

Up- and Down-Regulation of Receptors

Up-regulation: 

  • Long-term exposure to low levels of the hormone causes an increase in the number of receptors and sensitivity to the hormone.

Down-regulation (desensitization):

  • Long-term exposure to high levels of the hormone causes a decrease in the number of receptors and sensitivity to the hormone.

Hormone Deactivation

  • Hormones must be deactivated after carrying out their tasks. The liver performs this function in less than two minutes after they have gone into circulation in the bloodstream.


Individual Endocrine Glands

The Pituitary Gland /Hypofise

Anterior Lobe Hormones

The anterior pituitary synthesizes and secretes six hormones.

  1. Follicle-stimulating hormone (FSH) stimulates follicle and egg development in the ovaries, and sperm production in the testes.
  2. Luteinizing hormone (LH) stimulates female ovulation and growth of the corpus luteum. In males, LH stimulates the testes to secrete testosterone.
  3. Thyroid-stimulating hormone (TSH) or thyrotropin stimulates the thyroid to produce and secrete its hormones.
  4. Adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex to secrete its hormones, as well as fat catabolism in adipose tissue and insulin secretion by the pancreas.
  5. Prolactin (PRL) acts on the female mammary gland to promote milk synthesis. In males, it indirectly enhances the secretion of testosterone.
  6. Growth hormone (GH), or somatotropin, stimulates cellular growth, mitosis, and differentiation, promoting overall tissue and organ growth.

FSH, LH, TSH, and ACTH are called tropic hormones because their targets also are endocrine glands. Secretion of the tropic hormones are subject to the feedback control of their target hormones in the blood.

Posterior Lobe Hormones

The posterior lobe stores and secretes two hormones manufactured in the hypothalamus.


  1. Antidiuretic hormone (ADH) or vasopressin  : Two receptors, V1 and V2, mediates totally different effects. V1 receptors in vascular smooth muscles mediate vasoconstriction while V2 receptors in renal collecting ducts mediate an increase in water reabsorption.
  2. Oxytocin (OT) stimulates uterine labor contractions and milk release by mammary glands.

Hypothalamus

The hypothalamus secretes both releasing hormones and inhibiting hormones to regulate the release of anterior pituitary hormones.

  • They include thyrotropin-releasing hormone (TRH), corticotropin-releasing hormone (CRH), gonadotropin-releasing hormone (GnRH), prolactin-releasing factor (PRF), prolacting-inhibiting factor (PIF), growth hormone-releasing hormone (GHRH), and growth hormone-inhibiting hormone (GHIH).

Secretion of hypothalamic hormones is controlled normally via negative feedback inhibition by their target pituitary hormones.

The Pineal Gland

  1. The pineal gland (epiphysis cerebri) is attached to the roof of the third ventricle. Its size regresses with age.
  2. The pineal gland produces serotonin during the day, and melatonin at night. There may be a relationship between pineal gland and sexual maturation, mood, including depression and sleep disorders, and aging.


The Thymus
1.       The thymus, located in the mediastinum, undergoes involution after puberty.
2.       The thymus secretes thymopoietin and thymosins that regulate the development and activation of T-lymphocytes.

The Thyroid
1.       The thyroid, located below the larynx, is the largest endocrine gland, and receives the highest rate of blood flow per gram of tissue.
2.       Thyroid follicular cells secrete thryoxine (T4) and triiodothyronine (T3). Target cells convert T4 to T3. The effects of T3 on target cells increase the oxygen consumption and heat production in the cell, accounting for the calorigenic effect. This effect is stimulated by cold weather and pregnancy.
3.       C cells (parafollicular cells) secrete calcitonin, a hormone that lowers blood calcium levels by promoting calcium deposition in bone.

The Parathyroids
1.       The parathyroids (usually four) are located on the posterior of the thyroid.
2.       The parathyroids secrete parathyroid hormone (PTH) in response to hypocalcemia. PTH raises blood levels of calcium by promoting its absorption through the intestines, by inhibiting urinary excretion of calcium, and by increasing osteoclast activity. PTH reduces blood levels of phosphate.

The Adrenals

The Adrenal Medulla
·         The medulla secretes catecholamines (epinephrine and norepinephrine) in response to sympathetic stimulation. Their effects mimic those of the sympathetic nervous system but last longer because they are secreted into the bloodstream.

The Adrenal Cortex
1.         The adrenal cortex consists of three layers of modified epithelial cells: the outer zona glomerulosa, a middle zona fasciculata, and an inner zona reticularis.
2.         The cortex secretes more than 25 steroid hormones (corticosteroids) that fall into three categories: sex steroids (androgens, such as DHEA), mineralocorticoids (aldosterone), and glucocorticoids (cortisol).
3.         Glucocorticoid secretion, as stimulated by ACTH, stimulates fat and protein catabolism, and increases energy supplies in the bloodstream. These hormones are secreted in response to stress.

The Pancreas
1.         Insulin, from beta cells, is secreted in response to rising blood levels of glucose and other nutrients. Insulin promotes the synthesis of glycogen, fat, and protein, thus lowering blood glucose levels.
2.         Glucagon, from alpha cells, is secreted in response to low blood levels of glucose. It stimulates fat catabolism, glycogenolysis, and gluconeogenesis.
3.         Somatostatin (from delta cells) is chemically identical to GHIH, and is secreted by the pancreas as a paracrine secretion. It diffuses to alpha and beta cells and modulates their secretion of glucagon and insulin. 

The Gonads
1.       The gonads are both exocrine and endocrine.
2.       Ovarian follicles produce estradiol prior to menstruation, and progesterone afterward. The follicle secretes inhibin to prevent further release of FSH.
3.       Interstitial cells between seminiferous tubules secrete testosterone, which stimulates development of the male reproductive system and masculine physique. Sustentacular cells of the testes secrete inhibin, which also slows FSH release.

Endocrine Cells in Other Organs


  1. The heart secretes atrial natriuretic factor (ANF) when overstretched by high blood pressure. This increases urine output to help lower blood pressure.
  2. The kidneys produce calcitrol that affects the handling of calcium by the kidneys, small intestines, and bones, and erythropoietin that stimulates bone marrow to produce more red blood cells.
  3. The liver secretes somatomedians, some of the body's erythropoietin, and a prohormone, angiotensinogen.
  4. The stomach and small intestine produce enteric hormones that coordinate the activities of the digestive system.
  5. The placenta secretes hormones during pregnancy that regulate the pregnancy and prime the mammary glands.

Wednesday, March 19, 2014

LATIHAN SOAL EKSKRESI SEDERHANA

Kali ini postingan soal sebenarnya sederhana artinya soal tidak begitu sukar banget , namun saya translate menjadikan hal sederhana menjadi agak sulit nggak apa kita kan harus rasio studiorum yang berarti kita harus mendunia karena bukan sekolahmu saja belahar ekskresi namun yunani ,ausi,jerman dll juga mempelajarinya anak anaknya begitu ya semoga berguna OK



1. Osmolarity is a difference in _____ concentration, and water tends to move toward an
area of ______ solute concentration.
A. solute; lower
B. solute; higher
C. water; lower
D. water; higher

2. Which of the following excretory structures is used by birds?
A. urethra
B. cloaca
C. nephridia
D. flame cells

3. Which of the following nephron structures is mismatched with its function?
A. glomerulus – filtration
B. collecting duct – reabsorption
C. proximal convoluted tubule – secretion
D. distal convoluted tubule – secretion

4. The excretory system regulates body fluid concentrations by
A. forming or breaking water molecules from or to oxygen and hydrogen.
B. regulating excretion of ions.
C. controlling production of urine and feces.
D. Speeding up or slowing down production of metabolic wastes.
E. All of the choices are body fluid regulation mechanisms.

5. Excretion is a process in which ____ is (are) removed from the body.
A. water
B. salt
C. feces
D. metabolic wastes
E. hormones

6. Among aquatic animals, only ____ is (are) nearly isotonic to seawater.
A. humans
B. freshwater fish
C. planaria and hydra
D. marine invertebrates and cartilaginous fishes
E. salamanders

7. Since the body fluids of all bony fishes normally have a moderate amount of salt, this suggests that
A. their common ancestor evolved in salt water and only later did some groups invade fresh water.
B. their common ancestor evolved in fresh water and only later did some groups invade salt water.
C. they are poorly adapted to an aquatic life.
D. salt is not involved in body fluid regulation in aquatic animals.
E. they lack kidneys.

8. Which group has the highest concentration of urea in the body fluids?
A. marine bony fishes
B. freshwater bony fishes
C. cartilaginous fishes
D. reptiles
E. birds

9. Which type of animal is most likely to gain water by osmosis from its environment?
A. marine bony fishes
B. freshwater bony fishes
C. cartilaginous fishes
D. reptiles
E. birds

10. Nitrogenous wastes are produced by
A. production of nucleic acids.
B. breakdown of amino acids.
C. breakdown of fats.
D. breakdown of carbohydrates.
E. production of proteins.

11. Urea is a waste product in the metabolism of
A. fats.
B. glucose.
C. minerals.
D. proteins.
E. None of the choices are true.

12. The structure of ammonia is
A. -NH2.
B. -COOH.
C. NH3.
D. -NH3.
E. NH4.

13. A very highly soluble nitrogenous waste, excreted into water by bony fishes, aquatic invertebrates, and aquatic amphibians, is
A. urea.
B. uric acid.
C. amino acid.
D. ammonia.
E. uracil.

14. The main nitrogenous waste excreted by terrestrial amphibians and mammals is
A. urea.
B. uric acid.
C. amino acid.
D. ammonia.
E. uracil.

15. Deamination of amino acids will result initially in the formation of
A. ammonia.
B. urea.
C. glucose.
D. creatinine.
E. uric acid.

16. The main nitrogenous waste excreted by insect, reptiles, and birds is
A. urea.
B. uric acid.
C. amino acid.
D. ammonia.
E. uracil.

17. The nitrogenous waste that is produced with the least amount of energy in the process is
A. urea.
B. uric acid.
C. amino acid.
D. ammonia.
E. uracil.

18. The nitrogenous waste that is produced using the greatest amount of energy in the process is
A. urea.
B. uric acid.
C. amino acid.
D. ammonia.
E. uracil.

19. Nitrogenous waste material of an embryo that accumulates inside the eggshell of a bird or reptile is
A. urea.
B. uric acid.
C. amino acid.
D. ammonia.
E. uracil.

20. Which of the following is NOT a nitrogenous waste product?
A. ammonia
B. urea
C. uric acid
D. bile pigments

21. Malpighian tubules are the excretory system attached to the gut in
A. earthworms.
B. insects.
C. humans.
D. planarians.

22. Nephridia are the paired structures used in excretion in
A. earthworms.
B. insects.
C. humans.
D. planarians.

23. Urine is delivered to the body surface by way of a urethra in
A. earthworms.
B. insects.
C. humans.
D. planarians.

24. Ciliated flame cells propel fluids through the excretory system in
A. earthworms.
B. insects.
C. humans.
D. planarians.

25. The Greek root word meaning "kidney" is the basis for the term(s)
A. glomerulus.
B. diuresis.
C. dialysis.
D. nephron and nephridia.

26. The Latin root word meaning "ball" is the basis for the term
A. glomerulus.
B. diuresis.
C. dialysis.
D. nephron.

27. The kidney was one of the first organs to be successfully transplanted because it is so encapsulated and has limited vessels feeding into or out of it. How many major vessels must be cut in transplant surgery for one kidney?
A. two: the renal artery and vein
B. three: the renal artery and vein and the urethra
C. three: the renal artery and vein and the ureter
D. four: the renal artery and vein and the ureter and urethra
E. five: the renal artery and vein, two ureters and one urethra

28. The tube that transports urine from the kidney to the urinary bladder is the
A. urethra.
B. ureter.
C. collecting duct.
D. proximal convoluted tubule.
E. loop of the nephron (loop of Henle).

29. The urinary bladder is useful because it
A. helps with defecation.
B. is a place where white cells attack bacteria.
C. stores urine to prevent constant urination.
D. transports urine to the outside of the body.
E. filters wastes and recycles nutrients back into the bloodstream.

30. Which is NOT a function of the urinary system?
A. monitoring and maintaining blood pH at about 7.4
B. regulating blood pressure by regulating salt balance in the blood
C. elimination of nitrogenous wastes including urea, uric acid, and creatinine
D. hormone secretion to stimulate red blood cell production and regulate sodium ion levels
E. production of water from oxygen and bicarbonate ions (HCO3)

31. The microscopic anatomical unit of excretion found in the kidney is the

A. nephron.
B. glomerular (Bowman's) capsule.
C. glomerulus.
D. alveoli.
E. microvilli.

32. Which of these is the correct sequence of blood vessels about the nephron?
A. renal artery, capillary bed, afferent arteriole, efferent arteriole, renal vein
B. efferent arteriole, glomerulus, venule, afferent arteriole, collecting duct
C. afferent arteriole, glomerulus, efferent arteriole, capillary bed, venule, renal vein
D. afferent arteriole, glomerulus, capillary bed, efferent arteriole, venule, renal vein
E. renal vein, venule, efferent arteriole, capillary bed, glomerulus, afferent arteriole

33. What is the correct order an excreted water molecule moves from glomerulus to collecting duct?
A. loop of nephron–glomerular capsule–proximal convoluted tubule–distal convoluted tubule
B. glomerular capsule–proximal convoluted tubule–loop of nephron–distal convoluted tubule
C. glomerular capsule–proximal convoluted tubule–loop of nephron–distal convoluted tubule
D. proximal convoluted tubule–glomerular capsule–loop of nephron–distal convoluted tubule
E. glomerular capsule–proximal convoluted tubule–distal convoluted tubule–loop of nephron

34. The ____ capillaries are enclosed by the glomerular (Bowman's) capsule.
A. peritubular
B. glomerular
C. loop of nephron (Henle's loop)
D. collecting tubule
E. pulmonary

35. Which of the following statements about the glomerulus is INCORRECT?
A. Blood pressure primarily accounts for filtration.
B. Small molecules move from the glomerular (Bowman's) capsule into the glomerulus.
C. It is composed of capillaries.
D. It is connected to arterioles at both ends.
E. It is surrounded by the glomerular (Bowman's) capsule.

36. The concentration of protein in the blood is higher in post-glomerular blood as compared with that in arterial blood because
A. protein is digested in glomerular (Bowman's) capsule.
B. the kidney manufactures protein.
C. reabsorption of protein occurs.
D. as water passes into the capsule, the concentration of protein in the blood will increase.
E. water is a small molecule.

37. Which of the following is NOT one of the three steps (processes) involved in urine formation?
A. glomerular filtration
B. tubular reabsorption
C. countercurrent mechanism
D. tubular secretion

38. Where would the blood be most viscous (least fluid) as it passes through the kidney?
A. before the glomerulus
B. after passing through the glomerulus but before reaching the loop of the nephron
C. after the loop of the nephron
D. Blood remains equally viscous at all points in the human body including the kidney nephrons.

39. The correct sequence followed by a molecule from the blood to leaving the body in the urine, with some steps left out, is
A. ureter, glomerulus, proximal convoluted tubule, collecting tubule.
B. nephron, urethra, bladder, ureter
C. Bowman's capsule, loop of the nephron (Henle), distal convoluted tubule, renal pelvis.
D. distal convoluted tubule, glomerulus, renal pelvis, ureter.
E. loop of the nephron (Henle), renal pelvis, urethra, ureter.

40. The structure that surrounds the glomerulus and serves as the first part of the nephron to receive filtrate in the nephron is
A. distal convoluted tubule.
B. proximal convoluted tubule.
C. collecting tubule.
D. loop of the nephron (Henle).
E. glomerular (Bowman's) capsule.

41. Water, nutrients, and ions are moved from the glomerulus by means of
A. tubular reabsorption.
B. tubular secretion.
C. osmosis.
D. glomerular filtration.

42. Water follows sodium ions from renal filtrate into blood by means of
A. tubular reabsorption.
B. tubular secretion.
C. osmosis.
D. glomerular filtration.

43. Drugs such as penicillin are removed from the blood to the urinary filtrate by means of
A. tubular reabsorption.
B. tubular secretion.
C. osmosis.
D. glomerular filtration.

44. Nutrient molecules are taken back into the blood from the urinary filtrate by means of
A. tubular reabsorption.
B. tubular secretion.
C. osmosis.
D. glomerular filtration.

45. Selective reabsorption occurs in the ____ of the nephron.
A. glomerulus
B. distal convoluted tubule
C. proximal convoluted tubule
D. collecting duct
E. loop of the nephron (loop of Henle)

46. The liquid that collects in the cavity of the glomerular (Bowman's) capsule is
A. concentrated urine.
B. blood plasma minus blood proteins.
C. old bile ready for excretion.
D. glycogen and water.
E. albumin.

47. Tubular secretion allows hydrogen ions, creatinine, and penicillin to be excreted in the distal convoluted tubule. How are these molecules moved across?
A. fluid pressure similar to what happens in the glomerulus
B. passive diffusion
C. osmosis
D. active transport
E. reverse reabsorption

48. Glucose is found in glomerular filtrate but NOT in the urine because
A. the kidney stores glucose as glycogen.
B. kidney cells require glucose because energy is needed for active transport.
C. glucose is reabsorbed back into the bloodstream.
D. glucose is converted to amino acids in the kidney.
E. glucose molecules are too large to pass through the loop of the nephron (loop of Henle).

49. Normally, concentrations of wastes, such as urea, are
A. high in urine in comparison to plasma.
B. high in the filtrate but low in urine.
C. in trace amounts in urine but are high in blood.
D. not in the filtrate but are a little in the urine.
E. only found in the excretory organs where they originate from metabolism.

50. The glomerular (Bowman's) capsule and the glomerulus
A. return material to the blood.
B. filter material from the blood.
C. make urea.
D. contain urine in its final state.

51. Which mechanism used to form urine requires a high blood pressure?
A. glomerular filtration
B. tubular reabsorption
C. tubular secretion
D. phagocytosis
E. countercurrent mechanism

52. Which of the following is NOT true about the collecting ducts?
A. They are found within the medulla.
B. Fluid enters them from the distal convoluted tubule.
C. The fluid entering them is isotonic.
D. Water diffuses out of them into the medulla.
E. The urine within them becomes hypotonic to blood.

53. Penicillin leaves the blood plasma through tubular walls and not through the glomerulus. Therefore, penicillin is removed from the blood by the process of
A. osmosis.
B. glomerular filtration.
C. tubular secretion.
D. diffusion.
E. tubular reabsorption.

54. The loop of the nephron (loop of Henle)
A. is necessary for glucose reabsorption.
B. creates a low osmotic pressure in the medulla.
C. creates a high osmotic pressure in the medulla.
D. creates a low osmotic pressure in the cortex.
E. creates a high osmotic pressure in the cortex.

55. How can urine contain a higher concentration of wastes (be hypertonic) than the blood?
A. Urine cannot since the process is passive diffusion.
B. Reabsorption of water and salt in the loop of the nephron and collecting ducts leaves behind a more concentrated urine.
C. All stages in the kidney involve active transport.
D. Urine can be hypertonic for small molecules if it is hypotonic for an equal number of big molecules.
E. The whole nephron is impermeable to water.

56. Normally, concentrations of metabolically important substances, such as glucose, are
A. high in glomerular filtrate but only a trace in urine.
B. low in glomerular filtrate but high in urine.
C. high in glomerular filtrate and urine.
D. low in both glomerular filtrate and urine.
E. excluded from entering the excretory system altogether.

57. Patients with diabetes mellitus have frequent urination and increased thirst because
A. less water passes from the glomerulus to the glomerular capsule.
B. more water is driven from the glomerulus to the glomerular capsule than normal.
C. more salt is reabsorbed at the proximal convoluted tubule.
D. an increase in sodium ions causes more nerve stimulation and triggers urination.
E. increased glucose in the urine increases its osmolarity and less water is reabsorbed by blood.

58. The Latin root word meaning "urination" is the basis for the term
A. glomerulus.
B. diuretic.
C. dialysis.
D. nephron.

59. Which of the following would be an indication of kidney failure?
A. urea in the urine
B. salts in the urine
C. uric acid in the urine
D. large amount of protein in the urine
E. dilute urine

60. Albumin is the large protein molecule found in egg white and blood plasma. Table salt dissociates into sodium and chloride ions. Urea is assembled in the liver. In a healthy person, what is the fate of the majority of these molecules as they pass through a nephron?
A. All three remain in the bloodstream.
B. All three pass across to the glomerular capsule and are excreted in urine.
C. All three pass across to the glomerular capsule but the salt ions are mostly reabsorbed.
D. Albumin remains in the blood, salt ions and urea are passed across and excreted.
E. Albumin remains in the blood, salt ions pass across but are reabsorbed, and the urea is passed across and excreted.

61. All of the following statements are true about antidiuretic hormone (ADH) EXCEPT
A. It is released by the posterior lobe of the pituitary.
B. It increases the production of urine.
C. It causes reabsorption of water from the collecting duct.
D. It is released when the osmotic pressure of the blood increases.

62. Which statement is NOT true about ADH?
A. It increases the permeability of the collecting duct.
B. ADH increases water reabsorption.
C. ADH decreases urine volume.
D. It is secreted by the adrenal gland.
E. Hot sweaty days will cause more ADH release.

63. An increased amount of ADH leads to
A. an increased amount of urine.
B. a decreased amount of urine.
C. no change in the amount of urine.
D. kidney failure.

64. All of the following statements are true about renin EXCEPT
A. Renin is a hormone.
B. It is secreted in response to low blood pressure.
C. Its secretion may be inhibited when there is high Na+ concentration in the blood.
D. Renin converts a precursor protein into angiotensin.

65. The loop of the nephron (loop of Henle) will exhibit
A. active release of sodium from the descending limb.
B. active release of sodium from the ascending limb.
C. passive release of sodium from the ascending limb.
D. water release from the ascending limb.
E. active transport of water.

66. Why do physicians prescribe diuretic drugs to patients with high blood pressure?
A. Diuretic drugs decrease urine flow and the more fluid and watery blood is easier to pump.
B. Diuretic drugs increase urine flow and decrease the blood volume that must be pumped.
C. Diuretic drugs decrease urine flow and the kidney does not have to work as hard.
D. Diuretic drugs increase urine flow and the loss of nitrogenous wastes helps the heart.
E. Diuretic drugs increase urine flow and salt loss and salt was bad for the heart.

67. The overall effect of renin release will be to
A. lower blood pressure.
B. lower blood volume.
C. less hydrogen ions are excreted and less sodium and bicarbonate ions are absorbed.
D. inhibit aldosterone secretion.
E. increase blood pressure for homeostasis.

68. Which is NOT a correct step in the hormone regulation of blood pressure and reabsorption?
A. When blood volume and pressure are low, the kidney secretes renin.
B. When blood pressure is high, the heart atria secrete ANH.
C. High blood pressure causes the kidneys to secrete aldosterone.
D. Renin leads to production of angiotensin I and II and eventual reabsorption of sodium ions and water.
E. If you drink more water, the pituitary reduces ADH and more water and urine is excreted.

69. Which hormone from the adrenal cortex will cause the distal convoluted tubules to reabsorb more sodium ions?
A. renin
B. angiotensinogen
C. angiotensin II
D. ADH
E. aldosterone

70. If the blood is alkaline,
A. more hydrogen ions, sodium, and bicarbonate ions are excreted.
B. less hydrogen ions and more sodium and bicarbonate ions are reabsorbed.
C. less hydrogen ions are excreted and less sodium and bicarbonate ions are reasbsorbed
D. the kidneys reabsorb increased amounts of water.
E. the diet must be low in necessary acids.

71. In the kidney mechanism for buffering the acidity of the blood, when would hydrogen ions be excreted and bicarbonate ions be reabsorbed?
A. only when the lung system is not working
B. when the blood is acidic
C. when the blood is basic
D. when the blood is neutral pH, which is not normal
E. The kidney never excretes or reabsorbs hydrogen and bicarbonate ions.

72. Which of these characterizes the blood in the renal vein?
A. high in CO2 and high in urea
B. high in CO2 and low in urea
C. low in CO2 and low in urea
D. low in CO2 but high in urea

73. Terrestrial animals lose fluid by all of the following EXCEPT
A. excretion.
B. elimination.
C. sweat.
D. digestion.
E. respiration.

74. The source of the nitrogen in urea is the digestion of
A. proteins.
B. amino acids.
C. nucleic acids.
D. All of the choices are correct.

75. Body builders often ingest protein supplements. Which of the following could occur?
A. an increased urea production
B. an increased water demand
C. kidney and liver stress
D. All of the choices could occur.

76. Which of the following organisms are mis-matched with their organs of excretion?
A. Planarians–flame cells
B. Earthworms–nephridia
C. Malpighian tubules–reptiles
D. Kidneys–humans

77. Beyond maintaining water balance in the blood, the kidneys
A. maintain blood volume.
B. aid in regulation of blood pressure.
C. to some degree regulate ion balance in the blood.
D. All of the choices are kidney functions.

78. Some invertebrates have the ability to undergo anhydrobiosis, the ability to dry up
during dry conditions.
True False

79. The kidneys filter the total volume of blood about every hour.
True False

80. Marine bony fishes acquire large amounts of salt in the water they drink, so they must get rid of it through secretion at the gill surfaces.
True False

81. Some fishes pass from marine to freshwater environments during their life cycle but maintain the same kind of osmotic relationship with each environment.
True False

82. The most toxic form of nitrogenous waste excreted by animals is urea.
True False

83. Humans would get very sick or die if only seawater was available to drink.
True False

84. Insects living in a dry environment may excrete nitrogenous wastes as a dry pellet of uric acid.
True False

85. The human kidney has an outer cortex, an inner medulla, and a renal pelvis which collects and stores urine before it leaves the kidney.
True False

86. A single human kidney has about one thousand structural units called nephrons.
True False

87. The loop of nephron (Henle) is a site of counter-current exchange within the human kidney.
True False

88. Tubular secretion is the most important of the three distinct processes involved in urine formation in a human.
True False

89. The hormone aldosterone, produced in the adrenal cortex, is important in maintaining sodium and potassium balance in the blood by changing water reabsorption in the kidneys.
True False

90. The cells of the distal convoluted tubules have numerous mitochondria and microvilli to support active transport.
True False

91. Urine contains substances that underwent pressure filtration and substances that underwent tubular secretion.
True False

92. Blood pressure may be associated with filtration while osmotic pressure and active transport may be associated with reabsorption.
True False

93. Urine exits the human body via the ureter.
True False

94. An animal's excretory system functions in the regulation of body fluid concentrations.
True False

95. Explain why the excretory system is important in both waste removal and osmotic balance in humans.

96. Compare the uses of uric acid, urea, and ammonia as excretory products in animals, with emphasis on the toxicity levels and environments of the animals that use each form.

97. Describe the pathway that a molecule would follow from the time it leaves the bloodstream until it leaves the body in the urine in a human.

98. Compare the movement of water between the body and the environment in marine bony fishes, freshwater bony fishes, and cartilaginous fishes.

99. Compare the actions of the hormones aldosterone and antidiuretic hormone in regulation of sodium and water balance between urine and blood in humans.

JAWAB 

1. B
2. B
3. C
4. B
5. D
6. D
7. B
8. C
9. B
10. B
11. D
12. C
13. D
14. A
15. A
16. B
17. D
18. B
19. B
20. D
21. B
22. A
23. C
24. D
25. D
26. A
27. C
28. B
29. C
30. E
31. A
32. C
33. B
34. B
35. B
36. D
37. C
38. B
39. C
40. E
41. D
42. C
43. B
44. A
45. C
46. B
47. D
48. C
49. A
50. B
51. A
52. E
53. C
54. C
55. B
56. A
57. E
58. B
59. D
60. E
61. B
62. D
63. B
64. A
65. B
66. B
67. E
68. C
69. E
70. C
71. B
72. B
73. D
74. D
75. D
76. C
77. D
78. TRUE
79. FALSE
80. TRUE
81. FALSE
82. FALSE
83. TRUE
84. TRUE
85. TRUE
86. FALSE
87. TRUE
88. FALSE
89. TRUE
90. FALSE
91. TRUE
92. TRUE
93. FALSE
94. TRUE
95. Answers will vary.
96. Answers will vary.
97. Answers will vary.
98. Answers will vary.
99. Answers will vary.




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