B3 Transport - The Full Topic

Blood

• Blood is the "fluid of life". It is essential for transportation of essential minerals, as well as oxygen around the body. Blood also gets rid of waste gases and products, such as CO2 and urea.
• Blood is transported in three vessels;
• Arteries- carry oxygenated blood from the heart around the body. They have three layers, and are rough on the outside, and smooth on the inside. [They carry blood at a high pressure, so the walls are fairly thick. A pulse can be felt in arteries, due to the high pressure.] < Not necessary, but interesting :)
• Veins- carry de-oxygenated blood back to the heart. They have the same three layers as arteries, but they are much thinner, as the blood pressure is lower. No pulse can be felt. The blood in veins is much darker due to the lack of oxygen.
• Capillaries- are the smallest blood vessel in the body. They act as a link between arteries and veins. They are one epithelial cell thick. Water and other molecules can diffuse through this wall.

Plasma

Plasma is the straw-coloured fluid in which the blood cells are suspended. It carries the blood cells to wherever they are destined in the body. It is made up of about 90% water, and the other 10% is dissolved mineral ions and salts etc. It is highly important because it also gets rid of waste materials such as C02, urea and other products of digestion.

Haemoglobin

Haemoglobin is a protein within red blood cells. It is responsible for the red colour of the cells. As blood passes through the lungs, the red blood cells pick up oxygen atoms, which combine with the haemoglobin to form oxyhaemoglobin. This is how the blood cells transport oxygen round the body. Clever, huh? ;)

• Humans have a double circulatory system, made up of the pulmonary system  and the systemic system.
• The circulatory system consists of the blood vessels, heart and blood.
• The circulatory system is very important in warm-blooded animals.It means more oxygenated blood can reach different parts of your body quickly.
• All cells need oxygen for respiration, the more active the cell - the more it respires ... - the more oxygen needed!

Pulmonary System...

Transports deoxygenated blood from the heart to the lungs, where they pick up  oxygen and back.

Systemic System...

Transports oxygenated blood from the heart around the body and back.

Muscle Contraction

 There are three kinds of muscle,

•  cardiac (the heart),
• skeletal (biceps, triceps, etc) and s
• smooth (oesophagus, oviducts, [uncontrollable muscle])

Muscle contractions require ATP.

We get that ATP from aerobic respiration in the mitochondria:

 Glucose + oxygen --> carbon dioxide, water and ATP

 Glycogen = lots of glucose molecules in an insoluble storage form found the liver and muscles

Increased Breathing Rate

-          More muscle contraction
-          Requires more ATP
-          Need to increase respiration (aerobically)
-          Need more oxygen, therefore need to increase breathing rate!
-          Because of increased respiration, more CO2 produced, need to exhale Co2.

 Increased Heart Rate

-          More muscle contraction
 -          Need to increase rate of aerobic respiration
-          Needs more ATP.
-          Need more oxygen delivered to muscles
-          So heart rate (no. of beats per min.) increases!

Anaerobic respiration = Respiration without oxygen! Glucose is broken down to form lactic acid, water and a small amount of energy. Sprinters run off their anaerobic system.

 Muscle Fatigue = Muscles become fatigued after long periods of use. This means they stop contracting efficiently. At this stage they are short of oxygen and respire anaerobically.

Lactic Acid = Lactic acid is a product of anaerobic respiration. Glucose is broken down into lactic acid and ATP (energy.) Lactic acid builds up in the muscles.

Oxygen Debt = The additional oxygen that must be taken into the body after vigorous exercise to return all systems to a normal rate.

Essential to look at a diagram and learn the parts... Test yourself, what is a sphincter? What is the ureter? What is the medulla?

 Kidneys filter the blood in the body to remove urea and other waste products in solution. They also remove excess water, and excess mineral ions, but conserve when needed. This helps maintain homeostasis, and an osmotic balance.The kidneys filter blood so glucose, mineral ions, amino acids and water move into the kidney tubules by diffusion down and concentration. It is forced in by pressure.

Blood cells behind because they are too large to enter the tubules. Everything the body needs is reabsorbed into the blood!

•      All the glucose and amino acids are reabsorbed by active transport against a concentration gradient.
•       Only selective water and mineral ions are reabsorbed.

 Urine

 Ø      Clear yellow liquid. Produced by kidneys, stored in bladder.

 Ø      Contains: water, urea, mineral ions and other waste produced.

 Ø      Urea: produced by: breakdown of excess amino acids in liver.

 Ø      Volume of urine produced depends on the amount of water taken in and the amount of water lost through sweating and breathing.

Dialysis

 Dialysis replaces kidney function; it filters and cleans the blood. A fistula (permanent access point artery) is grafted in the arm, for haemodialysis, or if peritoneal, a permanent catheter is inserted into the abdomen and left protruding.

It depends on diffusion along a concentration gradient from blood to dialysis fluid.

Effects of Dialysis (process on next card).

Dialysis, whether peritoneal or haemodialysis, is a major tie to a medical institution.

1. A thin layer of natural tissue (in Peritoneal Dialysis) or of synthetic plastic (in Haemodialysis), known as the dialysis membrane, keeps the blood apart from the dialysis solution (also called the dialysis fluid, or the dialysate).

2.   Blood cells are too big to pass through the dialysis membrane, but wastes and water can diffuse through it into the dialysis solution.

3.  Diffusion is complete. Body wastes have diffused through the membrane. There are equal amounts of waste in the blood and the dialysis solution.

4.  Wastes are removed by removing the dialysis fluid.

In extreme cases, or after the patient has been on dialysis for what is considered too long, a transplant may be their only option.

> The old kidneys are left in. A new kidney is inserted via keyhole surgery to just above the groin area.
> The new kidney is attached by a tube to the bladder. (you only need one functioning kidney in your body! :)
> Transplants give a patient a new lease of life, and freedom from the dialysis machine.
> However there is a strong risk of rejection from the immune system ,and immuno-surpressant drugs must be taken daily.
> Transplanted organs don't last forever, 9 years is around normal.
> The donor can be recently dead (of natural causes so the organ is still healthy), alive and related, or alive and unrelated, depending on the best match!