biology

Subdecks (6)

Cards (216)

  • The Heart
    A hollow, muscular organ that pumps blood throughout the body.
  • septum
    Separates Oxygenated/ Deoxygenated blood
  • atria
    top chambers of the heart
  • ventricles
    bottom chambers of the heart
  • wall of left ventricle
    -thicker than right ventricle
    -pumps blood to all parts of body
  • tricuspid and bicuspid valves (3/2 flaps)
    -located between atria and ventricles
    -prevent backflow of blood
  • chordae tendineae
    tendons that hold valves in place (heart strings)
  • papillary muscle
    where tendons are attached to heart
  • pacemaker
    A device that delivers electrical impulses to the heart to regulate the heartbeat
  • vena cava
    Brings deoxygenated blood from the body to the heart
  • pulmonary vein
    brings oxygenated blood to heart from lungs
  • pulmonary artery

    brings deoxygenated blood from heart to the lungs
  • aorta
    large artery brings oxygenated blood from heart to all around the body
  • control of heartbeat
    -controlled by pacemaker (SA node), located in wall of right atrium
    -SA node sends out electrical signals that cause the atria to contract
    - signal is pivked up by AV node
    -AV node sends signals causing ventricles to contract
  • systole
    Contraction of the heart muscle
  • diastole
    relaxation of heart muscle
  • effect of smoking on heart
    -nicotine increases heart rate and blood pressure
    -carbon monoxide reduces the amount of O2 carried by blood
    -other chemicals increase risk of clots
  • effect of diet on heart
    -saturated fat is linked with high cholestrol
    -high sodium intake raises blood pressure
  • effect of exercise on heart
    -exercise strengthens cardiac muscle
    -improves circulation and reduces cholestrol
  • coronary artery (branched off the aorta)

    The artery that supplies heart tissue with oxygenated blood
  • coronary vein
    Drains the heart muscle tissue of deoxygenated blood and returns it back into the right atrium.
  • heart muscle
    -composed if cardiac muscle
    -contractile tissue
    -does not fatigue
  • heart layers (3)
    Pericardium - outside, protection
    Myocardium - Cardiac muscle
    Endocardium - Endothelial cells
  • Why do we need a circulatory system?
    - Removes waste products of metabolism to excretory organs
    - circulates 02 + Co2
    - Delivers nutrients to the body's cells
  • closed system
    The blood always remains in the vessels
    - blood flow can be controlled
    - blood flows at high pressure, nutrients reach the cells quickly
  • Capillaries
    The vessels in which material enters and exits
  • pulmonary circuit

    carries blood to the lungs for gas exchange and returns it to the heart
  • systemic circuit

    Circuit of blood that carries blood between the heart and the rest of the body.
  • Arteries
    Blood vessels that carries blood away from the heart
  • Veins
    Blood vessels that carry blood back to the heart
  • What are veins and arteries composed of?
    Connective tissue - collagen + elastic fibres
    Muscle and elastic fibre
    Endothelium - endothelial cells
  • skeletal muscle
    The blood flow in veins is helped along by the squeezing of the skeletal muscles
  • Differences between arteries and veins
    Arteries have narrower lumen.
    Veins have larger lumen, valves to prevent backflow due to low pressure of blood.
  • portal system
    A blood pathway that begins and ends in capillaries. E.g. Hepatic portal vein - intestines- liver
  • Plasma
    yellow liquid -90% water
    -plasma proteins, clotting proteins (fibrogen), antibodies, salts
    - 55% of the blood volume
    - Most Co2 transported as hydrogencarbonate ions
  • Function of blood plasma
    Transport nutrients, waste, Co2
  • white blood cells (leukocytes)
    Contain:
    2 types:
    Made in:
    Function:
    Large nucleus
    - Monocytes
    - Lymphocytes
    Made in: Red bone marrow
    Function: fight infection
  • red blood cells (erythrocytes)
    Consist of:
    Shape:
    Adaptions:
    Made in:
    Function:
    No nucleus/mitochondria
    Haemoglobin (4+ iron)
    Shape: Biconcave
    Large surface area for more rapid diffusion of gases
    Flexible - fit into narrow vessels
    Made in: Red bone marrow, sternum, ribs, breast bone
    Function: Transport O2
  • Platelets (thrombocytes)
    Function:
    Fragments of cells
    Function: clotting
  • Monocytes
    Phagocytes - cells that move to surround and engulf bacteria or pathogens
    Monocytes -> Macrophages