6 Oct 2026
Blood Vessels, Blood Pressure, Capillary Exchange, and Edema
CHAPTERS
0:00 Blood Vessel Structure
12:24 Practice — Blood Vessel Types
21:58 Practice — Blood Pressure Drops Across Systemic Vessels
22:52 Blood Pressure: Vessel Resistance + Cardiac Output
29:18 Practice — What Determines Blood Pressure?
30:29 How the Brainstem Regulates Blood Pressure
38:04 How a Beta Blocker Works
39:29 Practice — Brain Regulation of Blood Pressure
39:56 Reflexes That Help Regulate Blood Pressure
45:42 Practice — Reflex Regulation of Blood Pressure
45:55 How the Kidneys Help Regulate Blood Pressure
48:53 Practice — Kidney Regulation of Blood Pressure
48:57 Venous Return, Immobility, and Clot Risk
52:50 Practice — Venous Return and Clot Risk
54:41 Types of Capillaries
59:16 Practice — Types of Capillaries
59:54 Tissue Perfusion
1:04:13 Practice — Tissue Perfusion
1:05:02 Circulatory Shock
1:16:21 Practice — Circulatory Shock
1:16:53 Capillary Exchange
1:19:49 Practice — Capillary Exchange
1:20:33 Edema: Too Much Fluid in the Interstitial Space
1:25:28 Practice — Edema
EPISODE DESCRIPTION
Why does blood pressure fall as blood moves through the systemic circulation? How can your brainstem and kidneys change blood pressure? Why does immobility increase the risk of a blood clot? And what actually makes fluid accumulate in the tissues during edema?
In this Science with Susanna episode, we build the physiology of blood vessels and circulation from the ground up — with a special focus on the concepts future healthcare professionals need to understand before they encounter them in pathophysiology, pharmacology, and patient care.
Rather than memorizing isolated facts, you’ll repeatedly connect structure → function → regulation → clinical consequences. We work through vessel structure, vascular resistance, cardiac output and blood pressure, nervous-system and kidney regulation, beta blockers, venous return, capillary types, tissue perfusion, circulatory shock, capillary exchange, and the major physiological mechanisms that produce edema.
Along the way, short practice questions and application checkpoints give you a chance to stop, think, and use the physiology before moving on.
Science with Susanna is designed for students building their healthcare foundation. The goal isn’t to turn an introductory A&P course into medical school. It’s to identify the high-yield physiology that explains why things happen — so concepts like hypertension, shock, thrombosis, poor perfusion, and edema make sense when you encounter them again in nursing, allied health, and other clinical courses.
Learn the mechanism. Connect it to the patient. Build a foundation you can actually use.
