BIO 139          URINARY OBJECTIVE ASSIGNMENT                         

 

NAME : KEY

 

1.         Name the organs and functions of the urinary system and locate the organs in the diagram below.

 

ORGANS

FUNCTIONS

KIDNEYS

 

FILTER METABOLIC WASTES FROM BLOOD

URETERS

 

MAINTAIN BLOOD HOMEOSTASIS

URINARY BLADDED

 

 

URETHRA

 

 

2.         Explain what the term renal refers to.  The term renal means KIDNEY.

 

3.         Define the term retroperitoneal.  THE KIDNEYS AND URETERS ARE LOCATED BEHIND THE PARIETAL PERITONEUM.

 

4.         Using the cross-section diagram of a kidney below, locate the renal capsule, renal cortex, renal medulla, renal pyramids, minor calyces, major calyces, renal sinus, renal pelvis, and ureter.

5.         Discuss the many ways in which the kidney maintains the blood.

The kidney maintains blood pressure, blood pH, blood volume, blood composition, and red blood cell concentration.

 

6.         Name the functional unit of the kidney.  THE NEPHRON

 

7.         Distinguish between a renal corpuscle and renal tubule, and identify each component on a microscopic section of the kidney in the diagram below.

THE RENAL CORPUSCLE IS COMPOSED OF A GLOMERULUS SURROUNDED BY BOWMAN’S CAPSULE.  THE RENAL TUBULE IS COMPOSED OF A PROXIMAL CONVOLUTED TUBULE, DESCENDING LOOP OF HENLE, ASCENDING LOOP OF HENLE, DISTAL CONVOLUTED TUBULE (AND COLLECTING DUCT).

8.      Trace a drop of blood from the heart through a nephron and back to the heart.  A.  Fill in the flowchart below.  B.  Label the vessels in the diagrams below.

 

AORTA

RENAL ARTERY

INTERLOBAR ARTERY

ARCUATE ARTERY

INTERLOBULAR ARTERY

AFFERENT ARTERIOLE

GLOMERULAR CAPILLARIES

EFFERENT ARTERIOLE

PERITUBULAR CAPILLARIES

INTERLOBULAR VEIN

ARCUATE VEIN

INTERLOBAR VEIN

RENAL VEIN

INFERIOR VENA CAVA

 

9.         Explain what is meant by, the components of, and the significance of the juxtaglomerular apparatus (JGA).  The JGA is composed of the

 

            JUXTAGLOMERULAR  cells of the AFFERENT ARTERIOLE and the MACULA DENSA cells of the DISTAL CONVOLUTED TUBULE.

 

             Label these components below.

 

10.       Fully discuss urine formation.  First name the three major processes involved in urine formation, and then explain each in detail (i.e. definition, location, forces involved, and what’s going where).  Finally name the normal constituents of urine and track the urine out of the body (What is the scientific name for this?).

 

            The three steps of urine formation are

  1. GLOMERULAR FILTRATION,

 

  1. TUBULAR REABSORPTION, and

 

  1. TUBULAR SECRETION.

 

10A occurs in the GLOMERULUS, 10B occurs through the

 

PROXIMAL CONVOLUTED TUBULE,

 

and 10C occurs through the DISTAL CONVOLUTED  tubule.

 

10A is defined as substances being filtered from blood in the GLOMERULUS into filtrate in BOWMAN’S CAPSULE.

10B is defined as substances being transported from the filtrate in the

PROXIMAL CONVOLUTED TUBULE, into the blood in the PERITUBULAR CAPILLARIES.

10C is defined as “wastes and excesses” being transported from the blood in the

PERITUBULAR CAPILLARIES to the “urine” in the DISTAL CONVOLUTED  TUBULE.

11.       Explain why proteins are not filtered out of the blood in the glomerulus.

 

            THEY ARE TOO LARGE TO FIT THROUGH THE FENESTRATIONS IN THE GLOMERULAR CAPILLARIES.

 

12.       Name the force responsible for glomerular filtration and place the appropriate numerical values in the glomerulus and Bowman’s Capsule below.

 

            GLOMERULAR HYDROSTATIC PRESSURE  (60mmHg vs. 18mmHg)

13.       Discuss the negative feedback mechanisms involved in regulation of glomerular filtration rate (GFR).   First, write an introductory sentence, and provide a flow-chart summarizing the process. 

 

           


 

14.       Explain the process by which most reabsorption occurs in the PCT, and list the substances that are reabsorbed here.   

Most substances are reabsorbed by active transport.  Glucose is transported by facilitated diffusion, water by osmosis, and all others including urea, uric acid, amino acids, electrolytes, drugs, etc. are transported by AT.

 

 

15.       Explain the significance of anti-diuretic hormone (ADH) and which portion of the nephron it targets.

Anti-diuretic hormone secreted by the posterior pituitary gland (in response to Angiotensin II), targets the DCT to reabsorb water back into the blood.  It helps regulate blood volume and blood pressure.

 

 

16.       List the wastes excreted in urine, and explain what metabolic processes these by-products result from.

Urea is a by-product of amino acid metabolism and uris acid is a by-product of nucleotide metabolism.

 

 

17.       Explain the structure and function of the ureters, urinary bladder, and urethra.

 

STRUCTURE

FUNCTION

 

URETER

 

Long, thin, smooth muscle tubes extending from kidneys to bladder; lined by transitional ET; retroperitoneal

Peristalsis

 

URINARY BLADDER

 

Smooth muscle organ, lined by transitional ET, lies in pelvic cavity behind the symphysis pubis

Stores urine

 

URETHRA

 

Passageway from bladder to outside

 

Micturation

 

18.       Define the term micturition.  Elimination of urine; urination

 

19.       Discuss the differences between male and female urethras.  Female urethras are only a few cm in length, while male urethras are much longer as they are held within the penis.

 

20.       Trace a drop of urine from its initial collection point as the "glomerular filtrate".

Glomerular Filtrate in Bowman’s Capsule

Proximal convoluted tubule

Descending Loop of Henle

Ascending Loop of Henle

Distal convoluted tubule

Collecting Duct

Minor calyx

Major calyx

Renal Pelvis

Ureter

Urinary Bladder

Urethra