Structure of the Mammalian Heart | A-level Biology | OCR, AQA, Edexcel скачать в хорошем качестве

Structure of the Mammalian Heart | A-level Biology | OCR, AQA, Edexcel

Structure of the Mammalian Heart in a Snap! Unlock the full A-level Biology course at http://bit.ly/2Z5pqjH created by Adam Tildesley, Biology expert at SnapRevise and graduate of Cambridge University. SnapRevise is the UK’s leading A-level and GCSE revision & exam preparation resource offering comprehensive video courses created by A* Oxbridge tutors. Our courses are designed around the OCR, AQA, SNAB, Edexcel B, WJEC, CIE and IAL exam boards, concisely covering all the important concepts required by each specification. In addition to all the content videos, our courses include hundreds of exam question videos, where we show you how to tackle questions and walk you through step by step how to score full marks. Sign up today and together, let’s make A-level Biology a walk in the park! The key points covered of this video include: 1. External Structure of the Heart 2. Internal Structure of the Heart 3. Cardiac Muscle External Structure of the Human Heart The human heart consists of two closely associated pumps that force blood around the circulatory system. The right side of the heart pumps blood around the pulmonary circuit to re-oxygenate after returning from body tissues. The left side of the heart pumps blood round the systemic circuit to deliver oxygen to respiring tissues of the body. The coronary arteries deliver oxygen and nutrients to the heart tissue and cardiac veins remove the cellular wastes. Internal Structure of the Human Heart The atria are thin-walled elastic chambers that receive blood from the veins. The ventricles are thick-walled chambers that pump blood out of through the arteries. The atria and ventricles are separated by atrio-ventricular valves that prevent flowing in the wrong direction. The arteries leading from the ventricles by semilunar valves. Cardiac Muscle The muscle in the heart is special because it can contract automatically without a signal from the brain - it is called cardiac muscle. Cardiac muscle is a specialised type of muscle found in the walls of the heart. Cardiac muscle consists of branched myofibrils separated by intercalated discs. The structure of cardiac muscle ensures that contraction of the heart has a pumping effect. Summary The heart consists of two pumps left and right that force blood around the systemic and pulmonary loops of the circulatory system The heart consists of chambers called atria and ventricles that are separated by atrio-ventricular valves Cardiac muscle is a specialised form of muscle tissue that makes up the walls of the heart chambers