Circulatory

• Blood

  Connective tissue because it has a matrix
• Components of blood

  • Plasma
  • erythrocytes (red blood cells)
  • leucocytes (white blood cells)
  • thrombocytes (platelets)
• Plasma


  The liquid part of blood, a mixture of water with dissolved substances such as sugar and salts. Transports cells, nutrients, wastes, hormones and proteins
• Erythrocytes

  • Red blood cells
  • Biconcave in shape
  • No nucleus -> increase flexibility -> ability to move through blood vessels
  • Short life span because of no nucleus
  • Transports oxygen from the lungs to the cells
• Types of leucocytes

  • Neutrophils
  • Monocytes
  • Lymphocytes
  • Basophils
  • Eosinophils
• Leucocytes


  White blood cells, protects the body from infection
• Thrombocytes


  • Platelets
  • Small fragments of cells
  • When blood vessel is injured platelets adhere to the lining and form a scaffold for blood clotting
• Transport of oxygen


  • 97% is carried in combination with haemoglobin molecules in red blood cells, when combined it creates oxyhemoglobin
  • 3% in carried in plasma
• Transport of carbon dioxide

  • 7-8% Dissolved in plasma
  • 22% carbaminohaemoglobin
  • 70% bicarbonate ions in plasma
• Transport of nutrients and waste

  • Nutrients + wastes dissolved in blood plasma
  • Nutrients obtained from food we eat
  • Inorganic nutrients transported as ions (sodium ions)
  • Organic nutrients (glucose, vitamins, amino acids, fatty acids, glycerol)
  • Metabolic wastes are substances produced by cells that cannot be used and would be harmful if accumulated (urea, creatine)
• Blood clotting


  • Minimises blood loss and prevents infections. There are 3 steps:

  1. Vasoconstriction

  2. Platelet plug

  3. Coagulation
• Heart


  The pump that pushes blood around the body, it is located between the two lungs in the mediastinum. It is completely enclosed in the membrane pericardium which holds the heart it place but also allows it to move when it beats. The heart is made of cardiac muscle and the left and right sides are separated by the septum.
• Heart chambers


  • Right atrium= receives blood from the body and passes it to right ventricle
  • Right ventricle= pumps blood to lungs
  • Left atrium= receives blood from lungs and passes it to left ventricle
  • Left ventricle= pumps blood to body
• Heart valves


  • Stops blood from flowing backwards
  • Atrioventricular valves between atria and ventricles
  • Semilunar valves at the exit of the ventricles
• Types of blood vessels

  • Arteries
  • Capillaries
  • Veins
• Arteries


  Carry blood away from the heart, have smooth muscle in their walls and divide into smaller arterioles which will connect to capillaries. Muscles in the artery walls can contract which reduces the diameter of the artery this reduces blood flow to an organ, this is called vasoconstriction. The opposite is vasodilation when muscles relax and increase blood flow. The two main arteries are the aorta and pulmonary
• Capillaries


  Microscopic blood vessels that link arteries and veins together, they have no valves. They carry blood to almost every cell in the body this enables them to get their requirements from the blood and to pass their wastes into the blood. Capillary walls are only 1 cell thick, this allows substances to pass easily.
• Veins


  Carry blood towards the heart and do not have muscular walls but do have valves to prevent backflow. They divide into smaller venules which connect to capillaries and blood pressure in veins is low. Main veins are:

  • superior vena cava (brings blood from above heart to right atrium)
  • inferior vena cava (brings blood from below heart to right atrium)
  • pulmonary vein (brings blood from lungs to left atrium)
• Blood flow regulation

  • By changing output of blood from heart
  • By changing blood vessel diameter
• Cardiac cycle


  1. Systole (pumping phase, heart muscles contract)

  2. Diastole (filling phase, heart muslces relax)

  3. Atrial systole (contraction of atria, forces remaining blood into ventricles. Atria then relax and refill)

  4. Ventricular systole (contraction of ventricles, forces blood into arteries. Left and right side of heart operate together)
• Cardiac output


  • Heart rate = beats per minute
  • Stroke volume = volume of blood forced from a ventricle of the heart with each contraction
  • Cardiac output = stroke volume X heart rate
• ABO blood groups


  • Group A (antigen A + antibody B = donate A +AB, receive A+O)
  • Group B (antigen B + antibody A = donate B + AB, receive B+O)
  • Group AB (antigen A+B, no antibody = donate A+B, receive A+B+AB+O)
  • Group O (no antigen + antibody A+B = donate A+B+AB+O, receive O)
• Rh blood groups


  Based on Rh antigens, Rh positive or Rh negative
• Blood transfusionsreasons


  Given to a person suffering excessive blood loss, anaemia, and leukaemia.
• Types of blood transfusions

  • Whole blood
  • Erythrocytes concentrates
  • Platelets concentrates
  • Plasma
• Lymphatic system


  Collects fluid (lymph) that escapes from blood capillaries and returns it to the circulatory system, also part of the body's defence against disease
• Components of the lymphatic system

  • Lymph capillaries
  • Lymph vessels
  • Lymph nodes
• Lymph vessels


  One-way system carrying fluid (lymph) away from the tissues to large veins, movement aided by smooth muscle, skeletal muscle, and valves.
• Lymph nodes


  Occur at intervals along lymph vessels, most numerous in neck, armpits and groin. Each node is surrounded by a capsule of connective tissue and inside the node is lymphoid tissue. This tissue contains lymphocytes, macrophages and plasma cells that help protect the body against disease. Lymph filters through the lymph tissue in the lymph node and passes out into a vessel on the other side
• RBC's suited to transport oxygen

  • Contains haemoglobin, combines with oxygen
  • No nucleus, more room for haemoglobin
  • Biconcave disc shape, increases surface area for oxygen exchange
• Lymph


  Escaped fluid from the blood capillaries
• Antigen


  Sit on surface of red blood cells
• Antibody


  Float around in plasma
• Antigen-antibody complex


  Antibodies attach onto antigens, if the antibody is foreign the complex will not be made and the blood coagulate.
• Heart

  label:

  A) Aorta

  B) Superior vena cava

  C) Right atrium

  D) Pulmonary valve

  E) Tricuspid valve

  F) Inferior vena cava

  G) Right ventricle

  H) Pericardium

  I) Left Ventricle

  J) Aortic valve

  K) Mitral valve

  L) Left atrium

  M) Pulmonary vein

  N) Pulmonary artery