BIOS 256 Week 4 Lab Instructions Urinary System

Student Name

Chamberlain University

BIOS-256: Anatomy & Physiology IV with Lab

Prof. Name

Date

Kidney Week 4 Lab Instructions: Urinary System Activity

Lab Deliverables and Materials

For Week 4, all students must complete Part A of the urinary system lab. This section is a critical component of the overall course and carries a weightage of 30 points in the lab grade. The activity involves hands-on exploration of the kidney’s anatomy through dissection and analysis.

Materials Required

To complete this lab, students should have access to the following:

• A kidney specimen (preferably preserved mammalian kidney)

• Dissection tools (scalpel, scissors, and forceps)

• A dissecting tray

Students must refer to the course syllabus under “Due Dates for Assignments & Exams” to verify the exact submission deadline for this lab activity.

Activity: Kidney Dissection

The kidney dissection activity is adapted from McGraw-Hill laboratory resources. It provides an opportunity for students to visually identify and analyze the kidney’s internal and external structures, reinforcing lecture concepts through practical application.

Dissection Instructions

1. Carefully remove the superficial adipose tissue surrounding the kidney with fingers or a blunt tool.

2. Locate the ureter, which emerges from the renal hilum—the medial concavity of the kidney.

3. Position the kidney on the dissection tray and make a coronal incision starting at the hilum, extending across the kidney’s full length, and returning to the starting point.

4. Gently divide the kidney into two symmetrical halves.

5. Place the dissected halves with the inner surfaces facing upward for proper examination.

6. Compare the dissected specimen with the reference diagram in the lab manual.

7. Match and identify the internal structures using the descriptions provided in Table 1.

8. After structure identification, proceed to answer the critical thinking questions.

Table 1: Identification of Kidney Structures (10 points)

Critical Thinking Questions

1. Trace the path of urine from the renal papilla to the ureter. (5 points)

Urine is first released from the nephron at the renal papilla. From there, it flows into the minor calyx, which channels it toward the major calyx. The urine then collects in the renal pelvis before entering the ureter, which delivers it to the urinary bladder for temporary storage until excretion.

2. Trace the flow of blood throughout the kidney, starting with the renal artery and ending with the renal vein. (5 points)

Blood enters the kidney via the renal artery, which branches into segmental arteries. These arteries divide further into interlobar arteries, then progress into arcuate arteries, and finally into cortical radiate (interlobular) arteries. From there, blood flows into afferent arterioles, enters the glomerulus for filtration, and leaves via efferent arterioles. Depending on nephron type, it moves into either the peritubular capillaries or vasa recta. The venous return pathway follows the interlobular veins, then arcuate veins, interlobar veins, and eventually drains into the renal vein, which empties into the inferior vena cava.

3. Trace the path of filtrate, starting with the glomerulus and ending at the collecting duct. (5 points)

Filtration begins in the glomerulus, where plasma is filtered into Bowman’s capsule. The filtrate then flows through the proximal convoluted tubule, which is primarily responsible for nutrient and water reabsorption. From there, it travels through the nephron loop (loop of Henle), followed by the distal convoluted tubule for further regulation of electrolytes and water. Finally, the filtrate passes into the collecting duct, which channels it toward the renal papilla for eventual passage into the calyces and renal pelvis.

4. List and describe at least five functions of the urinary system/kidneys. (5 points)

References

Hall, J. E., & Guyton, A. C. (2021). Guyton and Hall Textbook of Medical Physiology (14th ed.). Elsevier.

BIOS 256 Week 4 Lab Instructions Urinary System

Marieb, E. N., & Hoehn, K. (2019). Human Anatomy & Physiology (11th ed.). Pearson Education.