Anatomy and physiology is a college-level science course that teaches you the structure of the human body (anatomy) and how each part works (physiology). Most schools offer it as a two-semester sequence, often labeled Anatomy & Physiology I and II, and it serves as a gateway requirement for nursing programs, pre-med tracks, and dozens of other health-related careers. If you’re seeing it on a degree plan or prerequisite list, here’s what the class actually involves and what to expect.
What the Course Covers
The central theme is the connection between structure and function. You learn what a body part looks like, where it sits in the body, and then why that design matters for what it does. A kidney, for example, isn’t just a bean-shaped organ near your lower back. You’ll study the tiny filtering units inside it (called nephrons) and trace exactly how they filter blood, reabsorb water, and produce urine.
The course walks through virtually every system in the human body:
- Cells, tissues, and glands: the building blocks everything else is made from
- Integumentary system: skin, hair, and nails, plus how skin regulates temperature and provides protection
- Musculoskeletal system: bones, joints, and muscles, including how muscles contract and produce movement
- Nervous system: the brain, spinal cord, and nerves that relay signals throughout the body
- Cardiovascular system: the heart, blood vessels, and the mechanics of blood pressure and circulation
- Respiratory system: lungs and airways, and the gas exchange that keeps cells oxygenated
- Endocrine system: hormone-producing glands and how hormones regulate everything from growth to metabolism
- Lymphatic and immune systems: how your body defends against infection, including the difference between innate immunity (what you’re born with) and adaptive immunity (what you develop after exposure)
- Gastrointestinal system: the digestive tract from mouth to intestines
- Urinary system: kidneys and bladder, and how waste gets filtered and excreted
- Reproductive system: male and female anatomy and the physiology of reproduction
- Special senses: vision, hearing, taste, smell, and touch
Genetics also gets a section, typically early in the course, since understanding DNA and gene expression helps explain how cells differentiate into all those different tissue types.
Homeostasis: The Concept That Ties It Together
If there’s one idea you’ll encounter in every single unit, it’s homeostasis. This is the body’s ability to maintain a stable internal environment even when external conditions change. Think of it as your body’s thermostat: when you exercise and your temperature rises, your cardiovascular, integumentary, and muscular systems work together to cool you down through sweating and increased blood flow to the skin.
You’ll study both negative feedback loops (which counteract a change to restore balance, like cooling down after overheating) and positive feedback loops (which amplify a process until it’s complete, like blood clotting at a wound site). Nearly every system gets examined through the lens of what happens when homeostasis fails. Disorders of the urinary system, for instance, are taught not as a memorization exercise but as a way to understand what goes wrong when the kidneys can’t properly filter blood or regulate fluid balance.
What Happens in the Lab
Most anatomy and physiology courses include a lab component that meets separately from the lecture, typically once a week for two to three hours. Labs are where abstract concepts become tangible, and they make up a significant portion of your grade.
A large part of lab time involves anatomical model identification. You’ll stand in front of plastic models of the skeleton, brain, heart, muscles, and spinal cord and be expected to label structures by name. Practical exams (sometimes called “lab practicals”) test this skill directly: you move from station to station, identify a pinned or tagged structure on a model, and write down its name and often its function.
Physiological testing labs have you run simple experiments on yourself or classmates. Common ones include measuring muscle fatigue by timing how long you can sustain repeated contractions, testing reflexes with a reflex hammer as part of a simulated neurological exam, and mapping tactile sensation to see how nerve density varies across different parts of the skin.
Dissection varies by school. Some programs include cat or pig dissections to give you hands-on experience with real tissue. Others rely entirely on models and digital tools. Brain dissection, for example, is sometimes replaced with model-only study. If dissection is a concern for you, check the specific course syllabus before enrolling.
Prerequisites and Course Structure
Anatomy and physiology isn’t usually a course you walk into on day one of college. Most schools require at least one introductory biology course with a lab, completed with a C or better. Some also require introductory chemistry, since understanding chemical bonds and pH levels helps when you get to topics like enzyme function and blood chemistry. At Dallas College, for instance, the prerequisite is a four-credit biology course completed within the last three years, or a passing score on a biology placement exam. Students also need to be college-level ready in reading and writing, since the course involves dense textbook material and written lab reports.
The two-semester split typically divides the body systems roughly in half. A&P I often covers cells and tissues, the integumentary system, the skeletal and muscular systems, and the nervous system. A&P II picks up with the endocrine, cardiovascular, respiratory, digestive, urinary, and reproductive systems. Homeostasis and feedback mechanisms thread through both semesters.
Expect a heavy memorization load. You’ll learn hundreds of anatomical terms, bone markings, muscle names and their attachment points, nerve pathways, and hormone functions. The physiology side adds conceptual depth on top of that, asking you not just to name a structure but to explain the process it carries out. Successful students typically spend 10 to 15 hours per week studying outside of class, using a mix of flashcards, model review sessions, and practice diagrams.
Who Takes This Course
The most common students in an anatomy and physiology class are those headed into healthcare. Nursing programs almost universally require both semesters, and many set a minimum grade of B or higher for admission. Beyond nursing, the course is a prerequisite or foundational requirement for programs in physician assistant studies, physical therapy, occupational therapy, dental hygiene, respiratory therapy, athletic training, and dietetics.
Pre-med and pre-dental students take it as well, though their medical school applications typically require additional upper-level biology courses. The class also feeds into less obvious career paths: health education, medical writing, clinical research coordination, pharmaceutical sales, public health policy, and recreational therapy all build on a working knowledge of how the human body functions.
Some students take it purely out of interest, particularly fitness professionals, massage therapists, or personal trainers looking to deepen their understanding of the body. Community colleges often see a mix of career-changers, recent high school graduates, and working adults in the same section.
How to Prepare
If you haven’t taken a biology course recently, brush up on cell structure, basic chemistry (atoms, molecules, pH), and the scientific method before the semester starts. Familiarity with medical terminology prefixes and suffixes gives you a real advantage. Knowing that “osteo” means bone, “cardi” means heart, and “itis” means inflammation lets you decode unfamiliar terms on the fly instead of memorizing each one from scratch.
During the course, consistency matters more than cramming. The material builds on itself, so falling behind on the skeletal system makes the muscular system harder, which makes the nervous system harder after that. Many schools offer open lab hours where you can practice on models outside of scheduled lab time. Using those sessions regularly is one of the strongest predictors of doing well on practicals.