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CIRCULATORY SYSTEM - Coggle Diagram

- - - - The heart pumps oxygenated blood to the body and deoxygenated blood to the lungs
        
        heart is a double pump. The right side of the heart sends deoxygenated blood to the
        lungs, while the left side sends oxygenated blood to the rest of the body.
    - - left atrium
        left ventricle
        right atrium
        right ventricle
    - - Myocardium
        
        made up of cardiac muscle - middel layer
      - Endocardium
        
        intermost layer
        
        smooth and single layer
        
        does not have blood vessels
        
        the part that contacts with blood.
      - Pericardium
        
        outermost tough connective tissue
        
        made up of two layer innermost membrane is called epicardium.
        
        pericardium is attached to the
        diaphragm
    - - In the right side of the heart, the AV valve is called the tricuspid valve, because it has 3-
        flaps.
      - In the left side, it is called the bicuspid, or mitral valve.
    - - diastole (relaxation phase),
        
        from veins, into heart chambers.
        
        Both atria contract and pump blood into the ventricles
        
        • Both ventricles contract and pump blood into the arteries that exit the heart
        
        • All chambers relax briefly before the cycle repeats
      - systole (contraction phase),
        
        from atria into ventricles
    - - Nervous Control of Heart Rate
        
        Parasympathetic nerves (Vagus nerves)
        
        release acetylcholine, which slows the heart and
        decreases the force of contraction.
        
        Sympathetic nerves (accelerator nerve
        
        release adrenaline which speeds the
        heart rate and increases the strength of contraction.
      - Non-nervous Control of Heart Beating Rate
        
        High pH (Decreases)
        
        Low pH (Increases)
        
        Low temperature (Decreases)
        
        High temperature (Increases)
        
        Stimulants like caffeine or nicotine (Increases)
        
        Mineral ions The rate is influenced directly
        
        Endocrine factors (e.g. insulin)
    - - Pulmonary Circulation
        
        Blood returning to the heart from the body tissues is low in oxygen and high in carbon dioxide.
        
        This blood enters the right atrium and
        flow into the right ventricle.
        
        The right ventricle
        pumps it through the pulmonary arteries to
        the lungs.
        
        The pulmonary arteries are the only arteries that carry deoxygenated blood.
        
        As the blood travels through the capillaries in the lungs, it gains oxygen and gets rid of carbon
        dioxide.
      - Systemic Circulation
        
        From the left atrium,the blood enters the
        left ventricle.
        
        The systemic circulation begins in the left
        ventricle of the heart.
        
        From the left ventricle,the blood is pumped
        out into the aorta.
        
        The aorta branches and
        forms the arteries that serve all parts of the body
        
        The arteries divide and subdivide,forming arterioles and finally forming the capillaries
        
        The superior vena cava returns blood from the head, arms, and chest; the inferior vena cava returns blood from the lower body regions.
  - - - a middle layer of smooth
        muscle and elastic fibers
      - outer layer of fibrous
        connective tissue
      - an innermost layer of
        squamous endothelium
    - - Arteries and arterioles carry blood away from the heart . Arteries branch into smaller diameter vessels called arterioles
    - - The wall of the capillaries consists of a single layer of endothelium.
        
        Arterioles conduct blood into elaborate networks of tiny capillaries, microscopically thin
        vessels
        
        Capillaries are so narrow that red blood cells pass through them single file
        
        They are so numerous that increase surface area for gas and fluid exchange with the
        interstitial fluid.
      - Velocity of blood flow is slowest in the capillary beds, as a result of the high resistance and large total cross-sectional area .Blood flow in capillaries is necessarily slow for exchange of materials.
    - - Veins and venules carry blood towards the heart.
        
        After picking up carbon dioxide and other wastes from cells, capillary blood drains into larger
        vessels, called venules, which empty into still larger veins.
        
        The walls of the veins have fewer elastic and muscular fibers than those of the arteries, buttheir thickness increases as they approach the heart.
        
        Blood is under low pressure in the veins, and backflow of the blood is prevented by the
        semi-lunar valves.
  - - - is the force blood exerts on vessel walls,
      - • depends on cardiac output and resistance of vessels to expansion
      - • decreases as blood moves away from the heart
    - - measured as
      - • systolic pressure—caused by ventricular contraction, and
      - • diastolic pressure—low pressure between contractions.
  - - - Defence
      - Regulation
      - Protection
      - Transport
    - - plasma(55%)
      - cell-based portion(40–45%)
        
        Red blood cells
        
        Platelets
        
        White blood cells
  - - - can occur when the blood supply is cut off from the heart, often by a blood clot
    - - is a hardening of the arteries
    - - mitral valve bulges out or prolapses because it does not close evenly
    - - occurs if the heart is not receiving enough blood
    - - general, arrhythmia means “no rhythm”
    - - heart muscle is not getting enough oxygen to
    - - usually caused by a sedentary lifestyle and an unhealthful diet
- - - - human body involves several kinds of physical and chemical barriers. This includes skin, sweat, tears, saliva, mucus, stomach acid and urine.
    - - If a pathogen is able to pass the first-line defense and starts an infection, second-line defense become activated.
      - Phagocytes
        
        are white blood cells, which ingest foreign invaders and cellular debris by
        
        phagocytosis. Three important types of phagocytes are: macrophages, neutrophils, dendritic cells.
      - Natural killer cells
        
        They attack body’s own cells that have become cancerous or have been invaded by viruses.
      - Interferons
        
        When the pathogen is a virus, the infected cells produce a protein, called interferon, which causes nearby uninfected cells to produce enzymes that block the reproduction of viruses and activate macrophages. In this way, healthy cells are protected from viral attacks.
      - Inflammatory response
        
        A reaction of the body that causes swelling, redness, warmth, and pain in the area of an infection.
  - - - any substance that can cause an immune response by lymphocytes.
    - - Humoral immunity is provided by B cells and the antibodies that they secrete into the blood that attack pathogens outside the body’s cells. B cells produce specific antibodies to destroy pathogens.
    - - Cell-mediated immunity is produced by a type of T cell called the cytotoxic T cell that attacks infected body cells, killing both the cell and any pathogens inside it.
- - - - Its composition similar to blood but lymph lacks RBC and has
        less blood proteins.
    - - occur in the tissues of almost all organs, (except the brain, spinal cord and
        eyes).
      - dead-end in the extracellular fluid surrounding body cells.
      - lymph vessels have smooth muscle in
        their walls and one-way valves that prevent backflow.
    - - A lymph node is a bean-shaped organ of the lymphatic system, distributed widely throughout the body including the armpit and stomach and linked by lymphatic vessels.
      - Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles andcancer cells.
      - Include the lymph nodes, spleen, thymus, tonsils, adenoids and patches of tissue in the small intestine
        and appendix.
  - - - Hemoglobin in the blood of the protein of the red blood cell count falling below the normal level or decreased availability
    - - It is a disease caused by plaques formed on the walls of the coronary arteries.
    - - It is a malignant disease that manifests as a result of the bone marrow filling with abnormal cells and the spread of these cells to the blood and all tissues.