Transport in blood - CS Biology

• What does blood contain?

  • Blood is a fluid tissue.
  • It is made up of plasma, red blood cells, white blood

  cells and platelets.
• Plasma has about 90% water in which the following are dissolved and transported:

  • proteins such as fibrinogen, prothrombin and antibodies
  • mineral salts such as chlorides and sulfates of calcium and sodium
  • food substances such as glucose, amino acids and fats
  • waste products such as urea, uric acid and creatinine
  • hormones
• Red blood cells or erythrocytes

  • Constitute 99% cells in the blood
  • Produced in the bone marrow
  • Destroyed at the spleen
  • Limited lifespan of 120 days
• Function of red blood cells:

  • transport Oxygen gas and taken the Carbon dioxide gas.
  • Biconcave shape (increases surface area to volume ratio for efficient uptake of oxygen)
  • Elastic (enables cells to squeeze through tiny blood capillaries)
  • Filled with red pigment haemoglobin (essential for binding oxygen)
  • Absence of nucleus (allows more haemoglobin to be packed into the cell)
• White blood cells or leucocytes

  • Larger than red blood cells
  • Fewer in number compared to red blood cells
  • Produced in the bone marrow
  • Destroyed at the spleen
  • Limited lifespan of a few days although they have a nucleus
  • Colourless as they do not contain haemoglobin
  • Irregular in shape and contain a nucleus each
  • Mobile – they are able to move, change their shape and squeeze through walls of thinnest blood capillaries.
• Types of white blood cells:

  1. Lymphocytes

  • Large rounded nucleus
  • Small amount of non-granular cytoplasm
  • Produce antibodies against microorganisms

  2. Phagocytes

  • Lobed nucleus
  • Granular cytoplasm
  • Able to ingest foreign particles
• Blood platelets or thrombocytes

  • Not true cells
  • Fragments of cytoplasm which are membrane

  bound

  • Important for the clotting of blood
• Transport system in humans

  • Also known as the cardiovascular system as it is made up of heart and blood vessels.
  • Also known as the circulatory system as blood circulates around the body.
• • Heart

  A muscular pump which pumps blood out of the heart and around the body.

  • Arteries

  Blood vessels that carry blood away from the heart.

  Aorta to arteries to arterioles.

  • Capillaries

  Microscopic blood vessels that arise from branches of the arterioles.

  • Veins

  Many venules unite to form bigger veins which carry blood towards the

  heart.

  • Venules

  Capillaries are linked to small veins called venules.
• At the capillary bed

  arterial blood contains:

  • oxygen
  • glucose

  venous blood contains:

  • CO2
  • metabolic waste products
• Types of blood vessels

  1. artery

  • Carries blood away from the heart

  2. Capillary

  • Allows exchange of materials between blood and tissue

  3. Vein

  • Carries blood towards the heart
• Double circulation is when blood passes through the heart twice as it moves from the pulmonary circulation and into the systemic circulation.
• Structure of the heart

  • Roughly conical shape
  • Lies between lungs and behind chest-bone
  • Surrounded by pericardium (two membranes with fluid to

  reduce friction when the heart is beating).

  • Consists of four chambers: two atria and two ventricles
• • Atria

  have relatively thinner walls to force blood into the ventricles.

  • Left ventricle

  has thicker muscular walls than the right ventricle as it has to pump blood into the systemic circulation.

  • Right ventricle

  has relatively thick muscular walls to move blood into the pulmonary circulation.
• Blood vessels associated

  with the heart

  -aortic arch

  (carries blood from heart to upper body)

  -pulmonary artery

  (blood coming out from heart to lungs)

  -pulmonary veins

  (blood coming out lungs to heart)

  -superior vena cava

  (carries blood from upper body to heart)

  -inferior vena cava

  (carries blood from lower body to heart)

  A) aortic arch

  B) pulmanory artery

  C) pulmanory veins

  D) pulmanory artery

  E) inferior

  F) superior

  
• Pathway of blood through the heart

  1. Deoxygenated blood from all area of the body via capillaries, veins then vena cava to atria to right atria.
  2. Right atrium contracts and blood flows into right ventricle

  3. Right ventricle contracts and blood leaves through pulmonary arch and artery

  4. The lungs take the CO2 and release O2 to be absorbed by blood(cleaning process)

  5. Oxygenated blood from the lungs flows to left atrium via pulmonary veins

  6. Left ventricle contracts and blood flows towards aortic arch

  7. Blood leaves the heart via the aortic arch and is pumped to rest of body