BSC 2086 Human A&P 2 Lecture

Focus Figure 25.1: Medullary Osmotic Gradient Part A - Key Players in Medullary Osmotic Gradient

1. The long nephron loops of the juxtamedullary nephrons are located in the renal medulla. 2. The long nephron loops create the medullary osmotic gradient and act as countercurrent multipliers. 3. The vasa recta preserve the medullary osmotic gradient and act as countercurrent exchangers. 4. The collecting ducts use the medullary osmotic gradient to concentrate urine.

Chapter 25 Matching Questions 21-25

1. Vasa recta: Play a role in urine concentration. 2. Efferent arterioles: May lead into meandering vessels or bundles of long straight vessels. 3. Glomerular capillaries : Fenestrated vessels that allow passage of all plasma elements but not blood cells. 4. Peritubular capillaries : Low pressure, porous vessels that reabsorb solutes and water from the tubule cells. 5. Afferent arterioles: High pressure vessel that forces fluid and solutes into the glomerular capsule.

Part G Through the tubuloglomerular feedback mechanism, how would an increase in filtrate NaCl concentration affect afferent arteriole diameter? Afferent arteriole diameter would increase. Afferent arteriole diameter would stay about the same. Afferent arteriole diameter would decrease.

Afferent arteriole diameter would decrease.

Why do you have to carefully monitor certain patients who are on "loop diuretics" to lower their blood pressure? They may excrete too much protein instead. Certain diuretics are not specific and in addition to getting rid of excess water, additional ions like potassium will be secreted. You do not want them to build up too much water in the renal pyramid. They are at an increased risk for a urinary tract infection. Submit

Certain diuretics are not specific and in addition to getting rid of excess water, additional ions like potassium will be secreted.

Part D Identify the correct direction of urine flow from formation to exiting the kidney. Medulla, cortex, renal pelvis, ureter Cortex, medulla, ureter, renal pelvis Ureter, renal pelvis, medulla, cortex Cortex, medulla, renal pelvis, ureter

Cortex, medulla, renal pelvis, ureter

An efferent arteriole supplies blood to a glomerulus. True False

False

Part D The fibrous capsule is a layer of adipose tissue that surrounds the kidney. True False

False

The entire responsibility for urine formation lies with the nephron. True False

False

The proximal convoluted tubule is the portion of the nephron that attaches to the collecting duct. True False

False

Dissection Video Activity: Sheep Kidney (1 of 3) Part A Name the strong transparent covering that encases the kidney. Perirenal fat capsule Fibrous capsule Renal fascia Broad ligament

Fibrous capsule

Part B Where does the ureter penetrate the kidney? Hilum Carina Renal medullla Renal cortex

Hilum

Which of the following does NOT describe the juxtaglomerular complex? Its macula densa cells produce aldosterone. Its granular cells produce renin. It helps control systemic blood pressure. It regulates the rate of filtrate formation.

Its macula densa cells produce aldosterone.

Part E Which structure is found separating the renal pyramids? Renal pelvis Ureter Renal columns Renal papillae

Renal columns

Dissection Video Activity: Sheep Kidney (2 of 3) Part A Which region of the kidney is the most superficial? Renal cortex Renal column Renal medulla Renal pelvis

Renal cortex

Part B Where does filtration of the blood occur within the kidneys? Renal cortex Renal pelvis Renal pyramids Renal medulla

Renal cortex

Part C Where are the renal columns located? Renal pyramids Renal medulla Renal pelvis Renal cortex

Renal medulla

Part B - Vocabulary Terms

Renin is released by cells of the juxtaglomerular apparatus in response to afferent arteriole pressure and the degree of stretch of the arteriole wall. The specialized capillary bed responsible for the pressure that drives filtration is the glomerulus. An elevated level of urea in the blood is uremia. The structural and functional unit of the kidney is a nephron.

Which of the following processes would be considered as a secretory rather than an excretory activity? Feces elimination by the colon Carbon dioxide removal by the lungs Aldosterone release by the adrenal glands Sweat removal by the skin

Sweat removal by the skin

If the diameter of the efferent arterioles leading away from the glomerulus increases (vasodilation), which of the following is NOT likely to occur? Urine output will decrease. Glomerular filtration rate will decrease. Systemic blood pressure will decrease. Net filtration pressure will decrease

Systemic blood pressure will decrease.

The lab results of a newly admitted patient indicate renal impairment. How might this affect the dosing regimen of drugs that are excreted by the kidney? The drug should not be given. The dosage should be increased. The dosage or the dosage interval may need to be reduced. The dosage interval should be shortened.

The dosage or the dosage interval may need to be reduced.

Which statement does NOT accurately describe the gross anatomy of the kidneys? The recess where blood vessels and nerves enter the kidney is called the hilum. The left kidney is lower in position because of crowding by the liver. The kidneys have partial protection from the rib cage. The fibrous capsule prevents infections from spreading to the kidney.

The left kidney is lower in position because of crowding by the liver.

Building Vocabulary Activity: The Urinary System Part A - Prefixes, Roots, and Suffixes

The prefix juxta- means situated near. The prefix nephr- means kidney. The prefix glomerul(o)- means glomerulus of the kidney. The prefix ur- means urine, urinary tract, or urea.

Which of the following is NOT a characteristic of the cortical nephrons? Cortical nephrons form the majority of nephrons in the kidney. The efferent arteriole of the cortical nephrons supplies the peritubular capillaries. Cortical nephrons have a short nephron loop. Their nephron loop is closely wrapped with vasa recta.

Their nephron loop is closely wrapped with vasa recta.

Part C The ureter, blood vessels, and nerves penetrate the kidney on its medial surface. True False

True

The position of the kidneys behind the peritoneal lining of the abdominal cavity is described by the term retroperitoneal. True False

True

Which of the following is NOT associated with the renal corpuscle? a vasa recta a fenestrated capillary an efferent arteriole a podocyte

a vasa recta

Part E The myogenic mechanism of renal autoregulation primarily involves smooth muscle in which blood vessels? efferent arterioles glomeruli afferent arterioles systemic arterioles

afferent arterioles

The thin segment of the nephron loop's descending limb ________. aids in the passive movement of water out of the tubule aids in the passive excretion of nitrogenous waste helps to pack a greater number of nephron loops into a smaller space is easily broken and replaced often

aids in the passive movement of water out of the tubule

Part C The reabsorption of sodium in the DCT is regulated primarily by __________. renin and angiotensin parathyroid hormone aldosterone aldosterone and ANP

aldosterone and ANP

Part E Filtrate in a typical healthy nephron will NEVER include __________. glucose amino acids and fatty acids blood cells and proteins K+ and Na+ ions

blood cells and proteins

Part D How are nutrient molecules such as glucose and amino acids reabsorbed through the apical surfaces of the tubule epithelia? by simple diffusion by primary active transport by osmosis by secondary active transport

by secondary active transport

Which arteries branch off the arcuate arteries? interlobar arteries segmental arteries renal arteries cortical radiate arteries

cortical radiate arteries

Upon reaching what point in the nephron is reabsorption (1) dependent upon the body's needs at the time and (2) regulated by hormones? ascending limb of the loop of Henle proximal convoluted tubule descending limb of the loop of Henle distal convoluted tubule

distal convoluted tubule

In what part of the renal tubule does parathyroid hormone (PTH) promote the reabsorption of calcium ions? proximal convoluted tubule (PCT) descending limb of the nephron loop collecting duct distal convoluted tubule (DCT)

distal convoluted tubule (DCT)

Part B GFR regulation mechanisms primarily affect which of the following? glomerular hydrostatic pressure (HPg) blood osmotic pressure (OPg) capsular osmotic pressure (OPc) capsular hydrostatic pressure (HPc)

glomerular hydrostatic pressure (HPg)

Your patient's urinalysis shows a large amount of protein in the urine. This suggests a problem in the ____________ glomerulus peritubular capillaries proximal convoluted tubule collecting duct

glomerulus

What two structures constitute the renal corpuscle? glomerulus and glomerular (Bowman's) capsule renal tubule and collecting duct glomerulus and renal tubule proximal convoluted tubule and nephron loop

glomerulus and glomerular (Bowman's) capsule

Part B Which of the following materials is NOT reabsorbed in the nephron loop? glucose water sodium ions chloride ions

glucose

Which of the following is the most likely to cause pyelonephritis? increased blood flow to the kidneys decreased blood flow to the kidneys renal failure infection of the urinary bladder

infection of the urinary bladder

Part F What does a high concentration of NaCl in the renal tubule at the juxtaglomerular apparatus (JGA) most likely indicate? insufficient NaCl reabsorption due to low GFR excessive NaCl reabsorption due to low GFR excessive NaCl reabsorption due to high GFR insufficient NaCl reabsorption due to high GFR

insufficient NaCl reabsorption due to high GFR

Which of the following is NOT a major urine formation process? tubular reabsorption micturition glomerular filtration tubular secretion

micturition

What is the function of the macula densa cells of the juxtaglomerular complex (JGC)? monitor the NaCl content of the filtrate pass regulatory signals between other cells of the juxtaglomerular complex sense blood pressure in the afferent arteriole produce filtrate

monitor the NaCl content of the filtrate

Part C Which of the following are mechanisms of intrinsic control of glomerular filtration (renal autoregulation)? myogenic mechanism and tubuloglomerular feedback tubuloglomerular feedback and the renin-angiotensin mechanism myogenic mechanism and sympathetic nervous system control sympathetic nervous system control and the renin-angiotensin mechanism

myogenic mechanism and tubuloglomerular feedback

Which of the following is NOT a part of the juxtaglomerular complex? granular cells mesangial cells macula densa podocyte cells

podocyte cells

What area of the nephron is responsible for the reabsorption of most of the water from the filtrate as well as most nutrients? collecting duct descending nephron loop distal convoluted tubule proximal convoluted tubule

proximal convoluted tubule

Where in the nephron does most solute reabsorption occur? glomerulus distal convoluted tubule proximal convoluted tubule collecting duct

proximal convoluted tubule

Art-based Question: Urinary System, Question 1 Identify the functional area of the kidney at letter B. renal column renal cortex renal pelvis renal pyramid

renal pyramid

Part H Granular cells of the juxtaglomerular apparatus (JGA) regulate GFR indirectly through which mechanism? sympathetic nervous system controls renin-angiotensin mechanism tubuloglomerular feedback mechanism myogenic mechanism

renin-angiotensin mechanism

Approximately 80% of the energy used for active transport is devoted to the reabsorption of __________. sodium potassium glucose water

sodium

Part B - Properties of the Countercurrent Multiplier Which of the following is NOT a property used to establish the medullary osmotic gradient? the descending limb's permeability to water and impermeability to salt the ascending limb's impermeability to water and permeability to salt the filtrate flow through the ascending and descending limbs of the long nephron loops of juxtamedullary nephrons the blood flow through the ascending and descending portions of the vasa recta

the blood flow through the ascending and descending portions of the vasa recta

Video Tutor: Regulation of Glomerular Filtration Rate Part A Which of the following best describes glomerular filtration rate (GFR)? the volume of urine leaving the kidneys per minute the volume of blood flowing through the glomerular capillaries per minute the volume of filtrate created at the glomerulus per liter of blood flowing through the glomerular capillaries the volume of filtrate created by the kidneys per minute

the volume of filtrate created by the kidneys per minute

Part D Macula densa cells of the juxtaglomerular apparatus (JGA) regulate GFR through which intrinsic mechanism? myogenic mechanism sympathetic nervous system control renin-angiotensin mechanism tubuloglomerular feedback

tubuloglomerular feedback