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Osmoregulation and excretion are the mechanisms by which an organism regulates its internal fluid and electrolyte concentrations. In animals, these processes are carried out by the kidneys, liver, and other organs. Osmoregulation is the regulation of blood plasma osmoles and water concentrations in response to changes in osmotic pressure. In humans, osmoregulation maintains blood plasma osmolarity within a relatively narrow range. The cells of the body use a variety of osmotic and nonosmotic mechanisms to regulate fluid balance, including osmoreceptor reflexes, and by generating a variety of hormones and other signaling molecules that affect renal function. Excretion is the process of removing waste materials, or metabolic products, from the body, also called renal excretion. These are substances that are no longer useful to the body because they have been metabolized or otherwise used up. The kidneys are the primary organs involved in excretion. Other important organs involved include the skin, lungs, salivary glands, and the gastrointestinal tract.
Which of the following about bacterial cystitis is false?a) About one-third of all women will have it at some time during their life.b) Catheterization of the bladder markedly increases the risk of contracting the disease.c) Individuals who have a bladder catheter in place indefinitely risk bladder infections with multiple species of intestinal bacteria at the same time.d) Bladder infections occur as often in men as they do in women.e) Bladder infections can be asymptomatic.
The functional unit of a kidney is the _____________.a. pelvisb. nephronc. glomerulusd. renal pyramid
Review the action of steroid and peptide hormones in chapter 27 Which hormone should act faster, ADH or aldosterone? Why?
Which statement about nutrient absorption by the intestinal mucosal cells is true?$a .$ Carbohydrates are absorbed as disaccharides.$b$. Fats are absorbed as fatty acids and monoglycerides.c. Amino acids move across the plasma membrane only by diffusion.$d$. Bile transports fats across the plasma membrane.e. Most nutrients are absorbed in the duodenum.
Birds that feed on marine animals ingest a lot of salt, but they excrete most of it by means of $a .$ Malpighian tubules.$b$. rectal salt glands.$c .$ gill membranes.$d$. hypertonic urine.$e .$ nasal salt glands.
How are earthworm metanephridia like mammalian nephrons?$a .$ Both process coelomic fluid.$b .$ Both take in fluid through a ciliated opening.$c .$ Both produce hypertonic urine.d. Both employ tubular secretion and resorption to control urine composition.$e .$ Both deliver urine to a urinary bladder.
Which of the following substances has the lowest percent reabsorption by nephrons?a. glucoseb. waterc. bicarbonated. urea
What are the three types of nitrogenous wastes? Which animals are most likely to excrete each one, and why?
Draw a nephron and label the parts.
Diuretic drugs prevent ions from being reabsorbed from the nephron. Explain why a diuretic drug might lower blood pressure. Why do some patients have low levels of salts in their blood while taking a diuretic?
Nonshivering heat production involves the mitochondria of a. the extremitiesb. the kidneysc. brown adipose tissued. epithelial tissue
Match each structure with a function.a. start of nephronb. delivers urine to body surfacec. carries urine from kidney to bladderd. secretes ADHe. target of aldosteroneureterBowman's capsule urethra collecting tubule pituitary gland
Kidneys return most of the water and small solutes back to blood by way ofa. glomerular filtrationb. tubular reabsorptionc. tubular secretiond. both a and b
Bowman's capsule, the start of the tubular part of a nephron, is located in the _____________ .a. renal cortexb. renal medullac. renal pelvisd. renal artery
Malpighian tubules of _____________ eliminate uric acid.a. birdsb. marine fishes$c$ insectsd. earthworms
Kidneys send water and small solutes back to blood by way of _______.a. filtrationb. tubular reabsorptionc. tubular secretiond. both a and b
Match each structure with a function. ______ureter ______Bowman's capsule ______urethra ______collecting duct ______pituitary glanda. start of nephronb. delivers urine to body surfacec. carries urine from kidney to bladderd. secretes ADHe. target of aldosterone
Ammonia is converted to less toxic urea by the _________.a. liver b. stomachc. gallbladderd. rectum