How does the heart adjust its output to meet the changing needs of the body—and what happens when the pump, the electrical system, or both begin to fail?

In this Anatomy & Physiology lecture, we build cardiac output from the ground up and connect it to the clinical concepts future healthcare professionals will encounter again and again.

We’ll explore cardiac output, stroke volume, ejection fraction, contractility, preload and afterload, and then use those concepts to understand heart failure. From there, we move into the heart’s electrical conduction system, ECG basics, common arrhythmias, premature ventricular contractions, and the important role of electrolytes in cardiac function.

The goal isn’t simply to memorize cardiovascular terminology. It’s to understand the physiology well enough that the clinical picture begins to make sense.

Science with Susanna is designed to help students build strong, understandable science foundations for their future careers in healthcare. Whether you’re headed into nursing, respiratory therapy, imaging, physical or occupational therapy, dental hygiene, or another healthcare profession, my goal is to help you understand the why behind what you’ll eventually see in your patients.

Chapters

(00:00) Cardiac Output
(09:01) Practice - Cardiac Output
(09:33) Changing Cardiac Output
(14:21) Practice - Changing Cardiac Output
(15:32) Preload and Afterload
(18:38) Afterload
(22:02) Practice - Preload and Afterload
(22:33) Heart Failure
(26:40) Compensations for Failing Hearts - Weak Ventricle and Stiff Ventricle
(33:17) Practice - Congestive Heart Failure
(34:34) Cardiac Conduction System
(39:35) Practice - Conduction System of the Heart
(41:09) ECG - Electrocardiogram
(45:16) Practice - ECG
(45:48) Arrhythmias - An Introduction
(51:34) Practice - Arrhythmias - An Introduction
(51:52) Premature Ventricular Contraction
(54:25) Electrolytes and the Heart
(57:00) Practice - Electrolytes and the Heart

How does the body move from a temporary platelet plug to a strong fibrin clot—and how is that clot eventually removed?

In this Science with Susanna live lecture, we break down blood clotting and blood types in a clear, step-by-step way for pre-health students preparing for nursing, physical therapy, occupational therapy, dental hygiene, diagnostic imaging, and other healthcare programs.

You’ll follow the sequence from platelet activation through the coagulation cascade, thrombin formation, fibrin clot formation, and thrombolysis. The lecture also reviews ABO blood types, transfusion mismatches, the Rh factor, and Rh incompatibility during pregnancy. Practice sections are included throughout so you can pause and test your understanding.

This episode is especially helpful for students studying Anatomy and Physiology, reviewing for an exam, or building the physiology foundation needed for future healthcare courses.

Chapters

00:00 Platelets
04:52 Practice - Platelets
06:55 Clotting Factors and the Coagulation Cascade
27:59 Thrombolysis
31:45 Practice - Thrombolysis
35:15 Blood Types
36:55 Practice - Blood Types
38:57 Blood Type Mismatch and Rh Factor in Pregnancy
43:59 Practice - Blood Type Mismatch and Rh Factor in Pregnancy

Science with Susanna makes challenging anatomy and physiology concepts easier to understand—without losing the science.

How do bones grow, remodel, maintain blood calcium, and repair themselves after a fracture?

In this Science with Susanna live lecture, bone tissue and physiology are broken into clear, manageable concepts designed especially for pre-health students preparing for nursing, physical therapy, occupational therapy, dental hygiene, diagnostic imaging, and other healthcare programs.

Topics include skeletal development, endochondral ossification, growth plates, long-bone anatomy, microscopic bone structure, bone disorders, bone remodeling, calcium regulation, fracture healing, and common fracture types.

This episode is ideal for students taking Anatomy and Physiology, reviewing before an exam, or building a strong science foundation for future healthcare courses.

Chapters

00:00 Placenta transfers calcium from mother to baby
02:08 Endochondral Ossification
05:29 Practice – Endochondral Ossification
07:42 Long Bone Anatomy
12:34 Practice – Long Bone Anatomy
13:18 Epiphyseal Plates
15:26 Microscopic Anatomy of Bone
21:56 Rickets, Brittle Bone Disease, and Osteoporosis
23:56 Bone Cell Types
27:26 Practice – Bone Cell Types
28:01 Factors That Affect Bone Deposition and Breakdown
32:44 PTH and Calcitonin Regulate Blood Calcium
35:56 Practice – PTH and Calcitonin Regulate Blood Calcium
37:00 Four Steps of Bone Repair
39:19 Practice – Four Steps of Bone Repair
40:47 Fracture Types

Science with Susanna makes challenging anatomy and physiology concepts easier to understand—without losing the science.

Welcome to Science with Susanna, where anatomy and physiology are explained clearly for beginning healthcare students.

What exactly is blood—and how does the body continuously replace and recycle its blood cells?

In this live lecture, we explore the major components of blood, the specialized structure of erythrocytes, and the process of hematopoiesis. We follow red blood cells from their formation in the bone marrow through their eventual breakdown and recycling.

We also examine blood types, practice interpreting blood-type information, and discuss examples of abnormal red blood cells and leukemia. Practice questions are included throughout the lecture to help you check your understanding and apply the material.

This episode is designed for beginning healthcare students studying anatomy, physiology, or foundational health sciences.

Chapters

00:00 Components of Blood
02:53 Practice: Components of Blood
05:03 Erythrocyte Structure
11:03 Practice: Erythrocyte Structure
11:45 Hematopoiesis
24:50 Practice: Hematopoiesis
32:31 Blood Types
41:55 Practice: Blood Types
46:26 Abnormal Red Blood Cell Examples
48:45 Leukemia
50:55 Practice: Components of Blood Revisited
52:02 Practice: Erythrocyte Structure Revisited
59:21 Practice: Erythropoiesis
1:00:52 Red Blood Cell Breakdown
1:04:41 Practice: Red Blood Cell Breakdown

Explore the foundations of cell biology and human tissues in this live classroom lecture from Science with Susanna.

We begin with the major structures inside a cell and examine how organelles—including the nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and mitochondria—work together. We then follow genetic information from DNA to protein, review the cell cycle and mitosis, and introduce the major tissue categories of the human body.

The episode concludes with a closer look at epithelial and connective tissues, including simple squamous, simple columnar, stratified squamous, simple cuboidal, and pseudostratified ciliated columnar epithelium, as well as adipose tissue, blood, cartilage, bone, tendons, ligaments, and the dermis.

Practice sections are included throughout so you can pause, retrieve the information from memory, and check your understanding.

(00:00) Cell Structure
(12:21) Practice: Cell Structure
(16:57) Cell Structures Up Close
(20:01) Why DNA Stays in the Nucleus
(24:58) Practice: DNA
(25:58) Protein Synthesis
(30:22) Cell Cycle and Mitosis
(38:31) Practice: Cell Cycle
(41:53) Epithelial Tissues
(49:34) Practice: Epithelial Tissues
(52:45) Connective Tissues
(58:10) Practice: Connective Tissues

How does the liver keep your blood glucose stable, create alternative fuels, transport cholesterol, process bilirubin, and detoxify ammonia?

In this Science with Susanna live lecture, we explore the liver’s central role in metabolism and connect these processes to conditions healthcare students will encounter—including diabetes mellitus, insulin resistance, diabetic ketoacidosis, jaundice, liver failure, anemia, and vitamin deficiencies.

You’ll learn how insulin and glucagon direct the liver’s handling of glucose, why the liver produces ketones during fasting, how LDL and HDL transport lipids, what happens to bilirubin after red blood cells are broken down, and how toxic ammonia is converted into urea. The lecture concludes with a practical overview of vitamins D, B12, folate, K, and other clinically important nutrients.

Chapters

00:00 Glucagon and Insulin Tell the Liver What to Do With Sugar
11:29 Practice: Glucagon and Insulin Effects on the Liver
12:10 Ketogenesis
21:15 Practice: Ketogenesis
23:50 Cholesterol Synthesis and Lipoproteins
27:27 Bilirubin Processing
34:29 Protein Breakdown: Ammonia to Urea
35:34 Summary of the Liver’s Metabolic Roles
38:53 Story Time: Oh No! He’s in Liver Failure!
40:59 Vitamins for Healthcare Foundations

This episode is designed for beginning healthcare students studying anatomy and physiology, metabolism, nutrition, and foundational pathophysiology.

How Food Becomes Fuel: Liver Function, Digestion, ATP, and Free Radicals | Live Lecture Series

In this episode of Science with Susanna, we follow nutrients from digestion and absorption all the way to cellular energy production.

We begin with the liver’s major functions, including bile production, blood-glucose regulation, glycogen storage, ketone production, plasma-protein synthesis, cholesterol production, and the modification of medications. We also connect liver dysfunction with jaundice, fatty liver disease, cirrhosis, gallstones, and impaired blood clotting.

Next, we examine how the nervous system controls digestion, including the cranial nerves involved in chewing and swallowing, parasympathetic stimulation through the vagus nerve, and the independent activity of the enteric nervous system. We then trace the complete digestion and absorption of a hamburger, following carbohydrates, proteins, and fats from the mouth through the stomach, small intestine, portal circulation, lymphatic system, and liver.

Finally, we explore how cells turn nutrients into ATP. We compare aerobic and anaerobic respiration, explain hypoxia and ischemia, and connect limited oxygen delivery with lactate production and acidosis. The lecture concludes with free radicals, antioxidants, oxidative stress, and ischemia-reperfusion injury.

Practice questions are included throughout to help you apply the physiology and prepare for critical-thinking exam questions.

00:00 — Bile Production and Major Liver Functions
12:57 — Practice: Liver Functions
13:46 — Neural Control of Digestion
17:38 — Practice: Neural Control of Digestion
23:11 — Summary of Digestion
27:44 — Absorption of Nutrients
29:54 — Practice: Absorption of Nutrients
31:22 — Digestion of a Hamburger: Putting It All Together
43:21 — Aerobic Respiration: Making ATP Using Oxygen
53:28 — Anaerobic Respiration: Making ATP When Oxygen Is Limited
59:47 — Practice: Anaerobic Respiration
1:03:09 — Free Radicals, Antioxidants, and Oxidative Stress
1:07:03 — Practice: Free Radicals

Science with Susanna

Build the chemistry foundation you need for anatomy, physiology, and other healthcare courses. In this episode, Susanna explains atoms, ions, electrolytes, pH, enzymes, and the four major biological macromolecules using clear examples connected to the human body and patient care.

You’ll learn how protons, neutrons, and electrons affect atomic behavior; why sodium, potassium, calcium, and magnesium carry electrical charges; how the body regulates blood pH; and how enzymes support anabolic and catabolic reactions. The episode also explores carbohydrates, proteins, lipids, and nucleic acids—including their building blocks and major functions in the body.

Knowledge checks are included throughout so you can pause, retrieve the information from memory, and strengthen your understanding.

Science with Susanna makes foundational science approachable for students preparing for nursing and allied health programs.

CHAPTERS

0:00 Atomic Structure
9:10 Practice: Atomic Structure
11:25 The pH Scale
14:55 Practice: The pH Scale
16:51 The Four Macromolecules
25:50 Practice: Macromolecules
27:28 Enzymes and Chemical Reactions
34:29 Practice: Enzymes
37:12 Understanding the Periodic Table
41:53 Practice: The Periodic Table
44:03 Hydrogen Ions, Blood pH, and Buffers
45:18 Carbohydrates
49:19 Practice: Carbohydrates
51:57 Proteins
56:31 Practice: Proteins
58:45 Lipids
1:01:34 Practice: Lipids
1:04:09 Nucleic Acids
1:05:53 Anabolic and Catabolic Reactions

In Part 2 of the BIO 202 Digestive System lecture, we continue through the gastrointestinal tract and examine how the digestive organs coordinate digestion, absorption, motility, and hormonal regulation.

Topics include the anatomy of the small and large intestines; the liver, gallbladder, and pancreas; major digestive hormones; stomach motility and acid production; GERD, peptic ulcers, and gastroparesis; and the functions of the gastric glands. We also connect intrinsic factor and vitamin B12 absorption to pernicious anemia and neurological symptoms.

Practice questions throughout the lecture demonstrate how these concepts may appear on a multiple-choice lecture exam.

Chapters

00:00 — Small Intestine
09:57 — Practice: Small Intestine
11:05 — Large Intestine Anatomy
18:44 — Liver and Pancreas Anatomy
25:32 — Practice: Liver and Pancreas Anatomy
29:39 — Selected Hormones of Digestion
42:02 — Practice: Digestive Hormones
42:05 — Stomach Physiology
51:00 — Practice: Stomach Physiology
56:28 — Gastric Glands and Their Products
1:01:27 — Practice: Gastric Glands and Their Products

This lecture is designed for students in Anatomy and Physiology II and other beginning healthcare courses.

Science with Susanna | BIO 202 Live Lecture Series

In this introductory Anatomy & Physiology lecture, we build the foundational terminology needed to understand the human body. We begin with the levels of organization—from molecules and cells to tissues, organs, organ systems, and the complete organism—and review the major structures and functions of the body systems.

We also introduce abdominal quadrants and regions used in patient charting, with clinical connections to appendicitis, diverticulitis, gallstones, pancreatitis, hernias, bladder infections, and referred cardiac pain. The lecture then explores the serous membranes surrounding the heart, lungs, and abdominal organs before introducing homeostasis and the negative and positive feedback mechanisms that help regulate the body.

Retrieval-practice activities are included throughout to help students actively test what they know.

Chapters

00:00 Organization of the Human Body
05:29 Practice: Levels of Organization
10:01 The Body Systems
26:46 Practice: Body Systems
28:37 Abdominal Quadrants and Regions
32:30 Abdominal Practice & Clinical Connections
35:35 The Pericardium
38:45 Peritoneum and Pleura
42:46 Homeostasis
47:56 Negative Feedback
49:18 Positive Feedback

Science with Susanna
Anatomy • Physiology • Microbiology
Clear, clinically relevant science for future healthcare professionals.

Follow Science with Susanna for more Anatomy & Physiology and Microbiology lectures, study support, and review.

Topics: Anatomy and Physiology, A&P, levels of organization, organ systems, abdominal quadrants, abdominal regions, pericardium, peritoneum, pleura, serous membranes, homeostasis, negative feedback, positive feedback, healthcare students

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