--- title: "Tricuspid Valve | Anatomy and Physiology II" description: "Tricuspid valve is the right atrioventricular valve between the right atrium and right ventricle, controlling one-way blood flow in Anatomy and Physiology II." canonical: "https://fiveable.me/anatomy-physiology-ii/key-terms/tricuspid-valve" type: "key-term" subject: "Anatomy and Physiology II" unit: "Unit 1" --- # Tricuspid Valve | Anatomy and Physiology II ## Definition The tricuspid valve is the right atrioventricular valve between the right atrium and right ventricle. It opens to let blood move forward during diastole and closes during systole to stop backflow. ## What It Is The tricuspid valve is the right atrioventricular valve in Anatomy and Physiology II, located between the right atrium and the right ventricle. It is called the tricuspid valve because it has three cusps, or flaps, that open and close with each heartbeat. Its job is simple but strict: let blood move from the right atrium into the right ventricle, then seal shut when the ventricle contracts. That one-way movement keeps blood moving through the heart in the right order before it is sent to the lungs through the pulmonary valve. The timing matters. During diastole, when the ventricles are relaxed, pressure in the right atrium is higher than pressure in the right ventricle, so the valve opens and blood flows in. During systole, ventricular pressure rises fast, which pushes the cusps together so blood does not leak backward into the atrium. The valve is not just hanging there like a door on a hinge. Its cusps are supported by chordae tendineae, which are tough cords attached to papillary muscles in the ventricle wall. When the ventricle contracts, those structures keep the cusps from flipping backward into the atrium. That support system is often grouped as the valvular apparatus. In a lab diagram, you may see the tricuspid valve labeled along with the chordae tendineae and papillary muscles because they work as a unit. If one part is damaged, the valve may not close tightly. A common example is tricuspid regurgitation, where blood leaks backward into the right atrium when the ventricle contracts. In a heart diagram or case study, that usually points to a valve that is not sealing properly, which can reduce the efficiency of right-sided blood flow. ## Why It Matters The tricuspid valve matters because it is one of the main checkpoints in the heart’s right-side circulation. In Anatomy and Physiology II, you are not just memorizing a name, you are tracing how blood moves chamber to chamber and why pressure differences make valves open or close. This term also connects structure to function, which is a huge theme in the cardiovascular unit. When you know that the right atrium empties into the right ventricle through the tricuspid valve, you can make sense of flow patterns on heart diagrams, in dissection images, and in questions about what happens during systole versus diastole. It also helps explain what goes wrong in valve disease. If the tricuspid valve does not close completely, blood can move backward into the right atrium instead of forward toward the lungs. That backflow changes efficiency and can show up in clinical scenarios, lab labeling, or textbook case questions. This is one of those terms that makes later topics easier too, because once you understand one atrioventricular valve, the rest of the heart’s valve system starts to look more logical instead of random. ## Connections ### right atrium The right atrium is the chamber that receives deoxygenated blood returning from the body. The tricuspid valve sits at its outlet, so blood must pass through the valve before entering the right ventricle. If you are tracing blood flow, the right atrium is the chamber just before the tricuspid valve opens. ### right ventricle The right ventricle is the chamber that receives blood through the tricuspid valve and then pumps it toward the lungs. The valve closes when this ventricle contracts, so blood moves forward instead of slipping back. That makes the right ventricle the pressure side of the valve cycle. ### [valvular apparatus](/anatomy-physiology-ii/key-terms/valvular-apparatus) The valvular apparatus includes the tricuspid valve cusps, chordae tendineae, and papillary muscles working together. This connection matters because the valve does not function alone. If you are labeling a heart model or dissected specimen, these parts often appear together and explain why the valve stays stable during contraction. ### [pulmonary valve](/anatomy-physiology-ii/key-terms/pulmonary-valve) The pulmonary valve comes after the right ventricle, not after the right atrium. Students sometimes mix the two up because both are right-sided valves, but they do different jobs. The tricuspid valve controls atrium to ventricle flow, while the pulmonary valve controls ventricle to pulmonary trunk flow. ## On the AP Exam A quiz item on the tricuspid valve usually asks you to identify it on a heart diagram, match it with the right atrium and right ventricle, or predict what happens when the ventricle contracts. You may also get a flow-order question, where you trace blood from the body through the right side of the heart and name the valve it passes through. In lab, you might label the cusps, chordae tendineae, and papillary muscles on a model or specimen. In a case-style question, tricuspid regurgitation would point you to backward flow into the right atrium. The main move is to connect the valve’s position with its direction of blood flow and the phase of the heartbeat. ## tricuspid valve vs pulmonary valve These are often mixed up because both are on the right side of the heart, but they are in different places and open at different points in the blood pathway. The tricuspid valve is between the right atrium and right ventricle. The pulmonary valve is between the right ventricle and the pulmonary trunk. ## Key Takeaways - The tricuspid valve is the right atrioventricular valve, located between the right atrium and right ventricle. - It opens during diastole and closes during systole, keeping blood moving in one direction. - Its three cusps are supported by chordae tendineae and papillary muscles, which help prevent the valve from flipping backward. - If the tricuspid valve does not close properly, blood can leak back into the right atrium in tricuspid regurgitation. - In heart diagrams, this valve is one step in the right-side pathway before blood reaches the pulmonary valve. ## FAQs ### What is the tricuspid valve in Anatomy and Physiology II? The tricuspid valve is the right atrioventricular valve between the right atrium and right ventricle. It opens to let blood move forward into the ventricle and closes when the ventricle contracts so blood cannot flow backward. ### Why is it called the tricuspid valve? It is called tricuspid because it has three cusps, or flaps. Those cusps work together as one valve structure, with support from the chordae tendineae and papillary muscles. ### What happens if the tricuspid valve fails to close? If it does not close fully, blood can leak backward into the right atrium instead of moving forward. That is called tricuspid regurgitation, and it reduces the efficiency of right-side heart pumping. ### How is the tricuspid valve different from the pulmonary valve? The tricuspid valve is between the right atrium and right ventricle, while the pulmonary valve is between the right ventricle and the pulmonary trunk. They work in sequence, but they control different steps in blood flow. ## Related Study Guides - [1.2 Cardiac Chambers and Valves](/anatomy-physiology-ii/unit-1/cardiac-chambers-valves/study-guide/t0uLiedG3N8ipQ8R) ## About This Document Canonical Fiveable pages are available as Markdown at the same path plus `.md`. - [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns - [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing - [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`) - [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`) ## Structured Data ```json {"@context":"https://schema.org","@graph":[{"@type":"LearningResource","@id":"https://fiveable.me/anatomy-physiology-ii/key-terms/tricuspid-valve#resource","name":"Tricuspid Valve | Anatomy and Physiology II","url":"https://fiveable.me/anatomy-physiology-ii/key-terms/tricuspid-valve","learningResourceType":"Concept explainer","educationalLevel":"AP® / High School","about":{"@id":"https://fiveable.me/anatomy-physiology-ii/key-terms/tricuspid-valve#term"},"audience":{"@type":"EducationalAudience","educationalRole":"student"},"dateModified":"2026-07-03T02:21:03.693Z","isPartOf":{"@type":"Collection","name":"Anatomy and Physiology II Key Terms","url":"https://fiveable.me/anatomy-physiology-ii/key-terms"},"publisher":{"@type":"Organization","name":"Fiveable","url":"https://fiveable.me"}},{"@type":"DefinedTerm","@id":"https://fiveable.me/anatomy-physiology-ii/key-terms/tricuspid-valve#term","name":"tricuspid valve","description":"The tricuspid valve is the right atrioventricular valve between the right atrium and right ventricle. 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