Skip to main content
Human A&P BIO 304 · American River College ← Course home (Week 6)

BIO 304 . WEEK 6 . FRIDAY . LAB WORKBOOK

Blood Vessels and Hemodynamics

Arteries, veins, capillaries, and the physics of blood pressure and flow.

Print this page. You will draw your own diagrams from the directions below, then hand-label the structures listed. Drawing by hand is the integrity mechanism for this course.

← Back to syllabus hub

Part 1 of 2

Anatomy Lab

1A. What you will draw

Blood vessels are not just pipes. Each type has structural features tuned to a specific job. Today you'll draw the three vessel types in cross-section, then a capillary bed in action.

Box A. Artery, vein, and capillary in cross-section

Directions

  1. Draw three round vessels side by side: an artery (left), a vein (middle), and a capillary (right). Make them the right relative sizes (capillary is much smaller).
  2. Artery: thick wall with three layers. Innermost: tunica intima (endothelium). Middle: tunica media (thick smooth muscle and elastic fibers, this is what makes arteries elastic). Outermost: tunica externa (connective tissue). Lumen is small relative to wall thickness.
  3. Vein: thinner wall, also with three layers but tunica media is much thinner. Larger lumen relative to wall. Show one-way valves inside the vein (small flaps).
  4. Capillary: very thin wall, just a single layer of endothelium plus a basement membrane. Lumen barely bigger than a single red blood cell.
  5. Label all three tunica layers in the artery and vein; label endothelium and basement membrane in the capillary.

Box B. Capillary bed

Directions

  1. Draw an arteriole entering from the left and branching into a meshwork of capillaries. The capillaries reunite into a venule that exits to the right.
  2. Label arteriole, capillaries, venule.
  3. At the arteriole-capillary junction, draw small smooth muscle rings: precapillary sphincters. Label.
  4. Note: precapillary sphincters open or close to direct blood flow into or away from this capillary bed depending on tissue need.
  5. In the surrounding tissue, draw 4 to 6 cells. Show arrows of oxygen and nutrients leaving the capillaries to enter the cells, and arrows of carbon dioxide and waste leaving the cells to enter the capillaries.

1C. Structures to label (12)

After you finish each drawing, label every structure below directly on your sketch.

  1. Tunica intima
  2. Tunica media
  3. Tunica externa
  4. Endothelium
  5. Basement membrane
  6. Smooth muscle
  7. Elastic fibers
  8. Vein valves
  9. Arteriole
  10. Capillary
  11. Venule
  12. Precapillary sphincter

Part 2 of 2

Physiology Lab

2A. Blood pressure relationships

Use the relationship BP equals cardiac output (CO) times total peripheral resistance (TPR). Answer each question. Show short work where math or reasoning is helpful.

1. If cardiac output increases by 20 percent and peripheral resistance stays the same, what happens to blood pressure?
2. If a patient's peripheral resistance drops by half (e.g., during septic shock vasodilation) and cardiac output stays constant, what happens to blood pressure?
3. Cardiac output equals heart rate times stroke volume. If heart rate is 70 bpm and stroke volume is 70 mL, what is the cardiac output in liters per minute?
4. Predict what happens to mean arterial pressure when a person stands up quickly from lying down (consider gravity and venous return).
5. Explain mechanistically why having one-way valves in veins matters for venous return, especially in the lower limbs.
6. Capillaries are the site of all exchange between blood and tissues. Explain why capillary walls are so thin and why blood flow through capillaries is slow.

2B. Synthesis questions

Answer each in 2 to 4 sentences. Use the language from this week's lecture and your drawings as evidence.

1. A patient has chronic hypertension (sustained high blood pressure). Predict the long-term changes in the arterial wall structure, and explain why hypertension increases the risk of stroke, heart attack, and kidney damage.
2. Varicose veins are dilated, twisted veins, typically in the legs. Explain mechanistically what fails (which structural feature), and why varicose veins are more common in people who stand for long periods.
3. A patient goes into septic shock: massive systemic vasodilation drops their blood pressure dangerously low. Use the BP equation to explain what is changing and why, then predict the body's compensatory responses (heart rate, sympathetic activity, ADH release).

3. What to submit

Complete both the Anatomy Lab (your own drawings, hand-labeled, plus the structures list) and the Physiology Lab (activity and synthesis questions). Photograph or scan every page and upload to Canvas before the deadline listed on the schedule. Hand-drawn, hand-labeled work is the integrity mechanism for this course. Typed or AI-generated diagrams are not accepted.