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PRE-LAB EXERCISES
Open Atlas. From the Views menu, go to System Views and scroll down to Urinary System Views.
You are responsible for the identification of all bold terms.
A. Urinary System Overview
In the Urinary System Views section, select View 1. Urinary System (M). Locate the paired, bean-
shaped kidneys near the top of the view, select one of them to open the content box, and use the
up-arrow to find and choose Urinary System from the list. Then, select the book icon, read the
description of the urinary system, and use this information to answer the following questions.
Bladder
Kidneys
Ureters
Penis
Urethra
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1. List the organs of the urinary system and locate them in the view. You may want to use the Fade
Others tool to get a clearer view of the highlighted structures.
2. Describe the main function of the urinary system.
3. What is the excretory product of the urinary system?
4. In men, the urethra passes through which two organs of the reproductive system?
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Go back to the Urinary System Views and open View 2. Urinary System (F) to locate all the
organs of the female urinary system. Complete the following statement so it accurately
compares the male and female urinary systems.
5. In the __________________________________ urinary system, the __________________________________ is much
longer.
Bladder
Kidneys
Ureters
Urethra
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B. Urinary System Overview
In the Urinary System Views section, select View 3. Pelvic Region (M). Use this view to answer the
following questions.
1. Adjust the view so you can see the paired kidneys near the top and rotate the view to see the dorsal
portion of the kidneys. How would you describe their relationship to the intestines and the spine?
Ureter
Urethra
Pelvic floor
Intestines
Bladder
Prostate
Glans penis
Penis
Kidneys
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2. Locate the bladder. Note that it rests on the pelvic floor. Select the bladder and use the up-arrow
in the content box to find and choose Urinary System from the list. Use the Fade Others tool to get
a clearer view of the highlighted structures. Locate the urethra as it leaves the bladder and follow its
path. The first section of the male urethra passes through the __________________________________.
3. The last section of the male urethra travels through the __________________________________ portion of
the penis and the __________________________________ (the tip of the penis).
Go back to the Urinary System Views and open View 4. Pelvic Region (F). Use this view to
answer the following questions.
Peritoneum
Vertebral column
Kidneys
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1. Adjust the view so you can see the anterior peritoneum covering the abdominal organs. Select the
peritoneum and use the book icon to read the definition. The peritoneum is a
__________________________________ membrane. The inner layer forms the lining that covers the
__________________________________.
Rectum
Pelvic floor
Kidney
Ureter
Uterus
Bladder
Urethra
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2. Rotate the view, select one of the kidneys, and use the book icon to read the definition. The kidneys
are defined as retroperitoneal organs. What do you think “retroperitoneal” means?
3. Hide the peritoneum and rotate the view to see the bladder from the side. The female bladder lies on
the pelvic floor underneath the __________________________________.
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IN-LAB EXERCISES
Open Atlas. From the Views menu, go to System Views and scroll down to Urinary System Views.
A. The Kidneys: Vasculature
In the Urinary System Views section, select View 9. Renal Vasculature (M). Use this view to answer
the following questions.
1. In this view, you can see a cone-shaped endocrine gland on top of each kidney. These are the
__________________________________, which release hormones affecting the function of the kidneys.
Inferior vena cava
Right renal artery
Right renal vein
Descending aorta
Left renal artery
Left renal vein
Adrenal glands
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2. Select either of the large arteries entering the kidneys to view the renal blood supply and use the
book icon to read the definition.
a. These large arteries are branches of the __________________________________.
b. The large arteries entering the kidneys are called the __________________________________.
c. Which of these arteries is higher?
d. Which is longer?
3. Select either of the large veins leaving the kidneys to view the venous drainage of the kidneys and
use the book icon to read the definition.
a. These large vessels drain into the __________________________________.
b. Which of these veins is higher?
c. Which is longer?
Note that as blood enters the kidneys, it brings oxygen to renal tissues and is filtered by the kidneys.
Blood leaving the kidneys is depleted of oxygen and has been filtered.
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B. The Kidneys: Internal Anatomy
In the Urinary System Views section, open View 8. Kidney Section (F). Use this view to answer the
following questions.
1. Select the outer part of the cross section of the right kidney and use the book icon to read the
definition (Kidney back, R). Define the following terms:
a. Adipose capsule
b. Cortex
c. Medulla
2. Select one of the several pyramid-shaped structures on the inside of the kidney. Which structures
make up the bulk of the renal pyramids?
Cortex
Renal pyramids
(medulla)
Renal pelvis
Renal columns
Ureters
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3. Where are the renal columns found?
4. Urine from the pyramids is channeled into the __________________________________.
5. Locate the large renal pelvis in the center of the kidney. Urine from the renal pelvis is channeled
into the __________________________________.
6. Nephrons are the functional units of the kidneys that make up most of the cortex and the medulla.
a. Nephrons are composed of a series of __________________________________ and
___________________________________.
b. The primary site of filtration is in a spherical capillary network called the
__________________________________.
c. Inside the corpuscle, blood passes through a spherical capillary network called the
__________________________________.
d. Filtrate from the blood enters a cavity called the __________________________________. From there,
the filtrate is passed through the tubules until it enters the renal pelvis as urine.
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C. The Ureters and the Bladder
In the Urinary System Views section, select View 11. Ureters (M). Use this view to answer the
following questions.
1. Select either of the ureters and use the book icon to read the definition.
a. What is the function of the ureters?
Kidneys
Entrance of left ureter
Trigone
Ureters
Bladder
Entrance of right ureter
Prostate
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b. How is urine propelled through the ureters?
c. How long is each ureter?
2. In the system tray on the left side of the screen, deselect the skeleton system icon to hide the
skeletal structures from the view. Rotate the view and observe where the ureters enter the bladder.
The ureters enter the bladder through openings in the __________________________________ bladder floor.
3. In the system tray on the left side of the screen, deselect the muscular system icon to hide the
muscles from the view. Rotate the bladder for a posterior view, showing both ureters. The triangular
region of the bladder, marked by the entrance of the two ureters and the external urethral orifice, is
the __________________________________ of the bladder.
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Go back to the Urinary System Views and open View 14. Bladder (F). Note that the bladder
is located entirely inside the pelvis, protected by the pelvic bones. Select any part of the
bladder, use the book icon to read the definition, and answer the following questions.
1. The bladder mucosa is covered by a __________________________________ epithelium and is arranged
in folds called __________________________________.
2. A layer of smooth muscle, called the __________________________________, gives the bladder wall its
elasticity.
3. Approximately how much urine can the bladder hold before the urge to micturate is triggered?
Detrusor muscle
of bladder
Urethra
Ureter
Rugae
Bladder
Entrance of
left ureter
Bladder neck
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Go back to the Urinary System Views and open View 17. Bladder Section (M). Locate the
following structures in the cross-section view.
1. Bladder inner surface
2. Detrusor muscle layer
3. Neck of the bladder (the region joining the urethra)
Prostate
Bladder neck
Detrusor muscle
Bladder inner surface
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D. The Male Urethra
In the Urinary System Views, select View 21. Urethral Orifice (M). Use this view to answer the
following questions.
1. Select any part of the urethra and use the book icon to read the definition. Locate and name the
three portions of the male urethra.
2. The prostatic urethra is completely within the __________________________________.
3. In the prostate, the urethra is joined by paired __________________________________ ducts.
4. The membranous urethra passes through the __________________________________ and receives ducts
from the paired __________________________________ glands.
Ureters
Prostatic urethra
Ejaculatory duct
Membranous urethra
Bladder
Glans penis
Spongy urethra
Corpus spongiosum
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5. Select the corpus spongiosum and use the Hide tool in the content box to hide it. Select the
spongy urethra and rotate the view to observe where it exits the penis. Note that only half of the
urethra will be highlighted. Next, select the glans penis and use the Hide tool in the content box to
hide it, so you can view the end of the spongy urethra. Note how it expands slightly in the tip of the
penis. The spongy portion of the urethra is divided into two sections: the
__________________________________ section and the __________________________________ section.
6. The male urethra carries two products: __________________________________ and
__________________________________.
Go back to the Urinary System Views and open View 23. Urethral Sphincter (M). Use this view
to answer the following questions.
Bladder
Internal
urethral sphincter
Prostatic urethra
Membranous urethra
Prostate
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1. Locate and highlight the internal urethral sphincter. It controls the passage of urine from the
bladder into the urethra. Control of this sphincter is involuntary, and it opens when the volume of urine
in the bladder triggers the __________________________________ reflex.
2. A second, voluntary external urethral sphincter encircles the __________________________________
urethra. This muscle allows for voluntary control over micturition.
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E. The Female Urethra
In the Urinary System Views, select View 20. Bladder and Uterus (F). Note that the bladder is
located entirely within the pelvis under the uterus. Use this view to answer the following questions.
Urethra
Vestibule
Uterus
Bladder
Perineal membrane
Urethral orifice
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1. Locate and select the urethra. It passes through the __________________________________ and exits
through the __________________________________. With the urethra highlighted, rotate the view to observe
where it exits the vulva. It is very small, so you may need to zoom in.
2. Locate the urethral orifice, which surrounds the end of the urethra. Select it and use the book
icon to read the definition. The urethral orifice is contained inside the __________________________________,
directly in front of the opening of the __________________________________.
Urethral orifice
Vestibule
Bladder
Perineal membrane
Vagina
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Go back to the Urinary System Views and open View 24. Urethral Sphincters (F). Use this
view to answer the following questions.
1. Select the neck of the bladder, where it joins the urethra. Now, hide the neck and locate the internal
urethral sphincter. This involuntary sphincter opens during the _________________________________ reflex.
2. Locate the external urethral sphincter. This muscle allows for __________________________________
control over micturition.
Internal
urethral sphincter
Vagina
Uterus
Bladder
Bladder neck
Urethra
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G. Microanatomy: Nephrons
From the Views menu, select Microanatomy, scroll down, and open View 19. Nephrons.
Cortex
Renal column
Renal pyramids
Interlobular arteries
Arcuate arteries
Nephrons
Interlobar artery
Segmental anteries
Cortex
Proximal convoluted tubule
Interlobar
veins
Descending
limb of loop
of Henle
Interlobar vein
Arcuate veins
Nephrons
Afferent
arteriole
Peritubular capillaries
Glomerular capsule
Efferent arteriole
Vasa recta
Collecting duct
Ascending
limb of loop
of Henle
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1. Locate the cortex, the renal pyramids, and the renal columns of the medulla.
2. Locate the renal artery as it enters the kidney (it does not enter the renal pelvis as the diagram
suggests). The first branches of this artery that are located inside the kidney are the ________________
__________________ and these extend into the renal columns as __________________________________. The
branches that arc over each pyramid are called __________________________________, and smaller branches
called __________________________________ extend further into the cortex. These arteries supply the
nephrons.
3. Locate and select the large, light-colored tubule passing through the renal pyramid. In the content
box, select the arrow and choose Nephrons at the top. This will highlight all nephron structures.
There are three nephrons in this view, but there are approximately one million of them in each kidney.
Nephrons are complex structures that include a capsule, tubules, and associated blood vessels.
4. Locate the small, spherical glomerular capsule in the center nephron, at the top of the image.
Select this capsule and use the book icon to read the definition. Inside the capsule, you’ll see a
spherical capillary network called a __________________________________. High blood pressure in these
specialized capillaries forces fluid out of the blood vessels and into the capsular space. This fluid,
called filtrate because it has been filtered by the glomerulus, leaves the capsule and enters the
__________________________________. As the tubule travels down into the medullary pyramid, it is called the
__________________________________ and as it travels back up into the cortex, it is called the
__________________________________. As the filtrate passes through the loop of Henle (also called a
nephron loop), it is modified by the loop’s epithelium. These epithelial cells are
__________________________________ in shape and have a “brush border,” meaning they are covered with
__________________________________. As the tubule exits the medulla, it is called the
__________________________________. As the tubule straightens out again and exits via the renal pyramid, it
is called a __________________________________.
5. As filtrate travels through the nephron loop, the tubule cells secrete
___________________________________ and excess ions into the filtrate. As the loop travels down into the
medulla and back, it passes through salt gradients that facilitate the reabsorption of
__________________________________ and other necessary molecules as required.
6. When these processes are complete, the filtrate is called __________________________________. Fluid
from the collecting duct flows into the __________________________________.
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7. Locate the arteriole entering the capsule to form the glomerulus. It is called the
__________________________________. The arteriole exiting the capsule, coming from the glomerulus, is the
__________________________________. This arteriole branches into a network of
__________________________________ that surround the proximal and distal convoluted tubules.
These capillaries interact with the convoluted tubules to reabsorb water and adjust the
concentrations of solutes in the filtrate. Blood leaving the peritubular capillaries enters the
______________________________ veins, which join the __________________________________ veins that arc over
the pyramids. The arcuate veins join to become the __________________________________ veins in the renal
columns. These join the _______________________________ veins, which take blood out of the kidneys to
drain into the __________________________________.
8. Look at the nephron on the right side of the view. It has a much longer loop of Henle, extending
much further into the medulla, than the one in the center. The center nephron is called a cortical
nephron. The one on the right is a juxtamedullary nephron, as its capsule is adjacent to the
medulla. Approximately 20—30% of nephrons are juxtamedullary nephrons, which are responsible for
creating most of the physiological gradients in the kidney. To help create these gradients, there are a
series of capillaries, branching from the peritubular capillaries and associated with the loop of Henle,
collectively called the __________________________________. This network returns blood to the efferent end
of the peritubular capillaries and to the interlobular veins.
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PUTTING IT ALL TOGETHER
A. Draw an outline of the urinary system. Label each organ and use arrows to indicate the flow of urine.
B. Answer the following questions:
1. Look at Views 21. Urethra and Orifice (M) and 22. Urethra and Orifice (F). What are the main
differences between the male and female urinary systems?
2. Look at Views 23. Urethral Sphincter (M) and 24. Urethral Sphincters (F). Which structure gives us
voluntary control over micturition?
3. In View 1. Urinary System (M), select one of the kidneys, use the up-arrow in the content box
to choose Urinary System from the list, and use the book icon to read the definition. Which of the
following do you think is not a function of the kidney?
a. Removal of waste product from the body
b. Control of micturition
c. Regulation of electrolyte balance (e.g. sodium, potassium, and calcium)
d. Regulation of acid-base homeostasis
e. Controlling blood volume and maintaining blood pressure
TIME TO PRACTICE!
GO TO THE URINARY SYSTEM QUIZZES AND TAKE QUIZ 1 OVERVIEW, URINARY (M),
QUIZ 2 OVERVIEW, URINARY (F), QUIZ 3 KIDNEYS, QUIZ 4 URINARY & REPRO (M), AND
QUIZ 5 URINARY & REPRO (F).
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Source: Urinary System Views: View 1. Urinary System (M)
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Source: Urinary System Views: View 2. Urinary System (F)
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Source: Urinary System Views: View 3. Pelvic Region (M)
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Source: Urinary System Views: View 4. Pelvic Region (F) (Part 1)
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Source: Urinary System Views: View 4. Pelvic Region (F) (Part 2)
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Source: Urinary System Views: View 9. Renal Vasculature (M)
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Source: Urinary System Views: View 8. Kidney Section (F)
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Source: Urinary System Views: View 11. Ureters (M)
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Source: Urinary System Views: View 14. Bladder Section (F)
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Source: Urinary System Views: View 17. Bladder Section (M)
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Source: Urinary System Views: View 21. Urethral Orifice (M)
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Source: Urinary System Views: View 23. Urethral Sphincter (M)
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Source: Urinary System Views: View 20. Bladder and Uterus (F) (Part 1)
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Source: Urinary System Views: View 20. Bladder and Uterus (F) (Part 2)
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Source: Urinary System Views: View 24. Urethral Sphincters (F)
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Source: Microanatomy Views: View 19. Nephrons (Part 1)
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Source: Microanatomy Views: View 19. Nephrons (Part 2)