Chapter 8 Flashcards
Describe the need to transport substances into and out of a range of organisms
Oxygen and Carbon dioxide for respiration and photosynthesis.
Water for plants and lungs
Dissolved food molecules for digestion and energy
Mineral ions in the blood and for plants via osmosis
Urea to get transported to kidneys
What does the blood transport
Disolved substances
Explain the need for exchange surfaces and a transport system in multi cellular organisms
As size of an organism increases, its surface area to volume ratio decreases. Therefore rate of diffusion wont be fast enough for cells to function. Large multi cellular organisms therefore cannot rely on diffusion alone to supply their cells with substances such as food, oxygen and waste products. Large multi cellular organisms require specialized transport systems.
Eg- the heart uses blood vessels to transport these substances around the body
How are alveoli adapted for gas exchange by diffusion between air in the lungs and blood in the capillaries.
They give lugs a large surface area
They have moist, thin walls.
They have lots of tiny blood vessels called capillaries.
What factors affect the rate of diffusion,
surface area, concentration gradient and diffusion distance.
How does concentration gradient effect rate of diffusion
rate of diffusion will increase when concentration gradient increases
How does Distance effect rate of diffusion
Rate of diffusion increases when distance is decreased
How to calculate rate of diffusion using Flicks law
Rate of diffusion= surface area x concentration difference / thickness of membrance
Explain how the structure of the blood is related to its function - RED BLOOD CELLS (erythrocytes)
The red blood cells transport oxygen, it has a bi concave shape which increases surface area- increases rate of diffusion. Doesn’t have a nucleus- more room for haemoglobin. Small size to pass through narrow capillaries.
Explain how the structure of the blood is related to its function- WHITE BLOOD CELLS (Phagocytes and lymphocytes)
White blood cells protect against disease.
They are adapted to change shape which allowes them to wrap around microbes in body and ingest them. They produce antibodies to destroy pathogens and produce antitoxins that neutralize the toxins released by pathogens.
Explain how the structure of the blood is related to its function- PLASMA
Plasma transports dissolved substances around the body including- Hormones, antibodies, nutrients and waste substance. Its a good solvent
Explain how the structure of the blood is related to its function- PLATELETS
Platelets help the blood to clot by clumping together and prevents bleeding, they are small fragments of cells and dont posses a nucleus
How is the structure of the blood vessel- ARTERY adapted to its function
Thick, elastic, muscular walls to withstand pressure so it can carry blood away from heart at high pressure.
How is the structure of the blood vessel- Capillary- adapted to its function
Thin permeable walls to allow exchange of materials between blood and tissues.
How is the structure of the blood vessel- vein - adapted to its function
Large diameter to offer least flow resistance. Valves to prevent black flow so it can return low pressure blood to the heart.
How is the structure of the heart and circulatory system related to its function
Thickness of chamber walls
The right side pumps blood to lungs and the left side pumps blood to rest of the body- thicker muscle wall
The semilunar, tricuspid and bicuspid valves.
The 4 main blood vessels of the heart
What are the 4 main blood vessels of the heart and what do they do
Aorta- the left side of the heart pumps oxygenated blood from the lungs, through the aorta to the body tissues.
Vena cava- deoxygenated blood returns from the body tissues to the right side of the heart, via the vena cava.
Pulmonary artery- it is then pumped into the lungs via the pulmonary artery where it is oxygenated
Pulmonary vein-Blood returns to the left side of the heart, via the pulmonary vein and is pumped to the body tissues again.
State function of Atria, ventricles and valves in heart
Left and right atria receive blood from veins
Left and right ventricles pump blood into arteries
The valves stop the blood flowing backwards when the heart relaxes
Describe cellular respiration
An exothermic reaction which occurs continuously in living cells to release energy for metabolic processes, including aerobic and anaerobic respiration.
What is anaerobic respiration
Anaerobic respiration doesn’t need oxygen, instead is the release of a relatively small amount of energy in cells by the breakdown of food substances and happens in muscles during hard exercise.
Glucose- Lactic acid
Glucose isn’t completely broken down therefore much less energy is released than during aerobic respiration. The lactic acid needs to be oxidised to co2 and water later.
What is aerobic respiration
The form of respiration which uses oxygen. Aerobic respiration happens all the time in+ cells of animals and plants and mostly occurs inside mitochondria, the reactions are controlled by enzymes.
Glucose and oxygen are used up and carbon dioxide and water are produced as waste products.
Glucose+oxygen— Carbon dioxide+Water(+energy)
Formula triangle for heart rate, stroke volume and cardiac output
C
S H
What is coronary heart disease
The coronary arteries supply blood to the heart muscle. These become blocked by a build-up of fatty plaques containing cholesterol. These causes high blood pressure and restricts blood flow to heart.
How can coronary heart disease cause a heart attack
Fatty deposits build up in the coronary arteries
A blood clot can form on a fatty deposit
The blood clot can block a coronary artery
Some heart muscle cells don’t get the oxygen and nutrients they need
These cells start to die
ALSO
If the coronary artery is blocked, the blood supply to part of the heart muscles is cut off. That part of the heart cannot continue to contract and causes a heart attack
Factors increasing risk of heart disease
Smoking
High blood pressure
High levels of salt in the diet
High levels of saturated fat in the diet
Fixing problems with the heart.
What are the options?
Placing stents in coronary artery, stents are metal grids which are inserted in arteries to keep artery open and increase blood flow.
Bypass surgery involves transplanting a vein from the keg to provide a route past the blockage
Artificial valve to replace faulty one
Heart transplant- need someone same age, health and blood type
How do you insert stents
A catheter with a balloon attached to it is inserted into the blood vessel in the leg. The balloon with the metal stent of it is directed to the coronary artery, when the narrowed section is found in the balloon is inflated which causes the stent to expand and it become lodged in the artery.
What is produced by the digestion of carbohydrates and needed for respiration
Glucose
What’s a mitochondrion
A sub- cellular structure (organelle) in the cytoplasm of eukaryotic cells, where aerobic respiration occurs (plural is mitochondria)
What does soda lime do
Absorbs CO2 to see how much oxygen is used up
Why when someone stands up does blood tend to collect in veins nearer the feet
Gravity pulls blood down towards feet, she lying down there is a lower pressure in the veins- blood flows more easily
Compare aerobic and anaerobic (time)
Anaerobic- short term energy production
Aerobic- long term energy production
Describe what may happen to the flow of blood in the left side of the hart if the bicuspid valve didn’t function properly
Less oxygenated blood would be being pumped to the body and blood would flow backwards from ventricle to the atrium
Compare and contrast circulatory system of fish and human circulatory system
- fish Heart has 2 chambers rather than 4
- fish only has 1 ventricle and 1 atrium rather than 2 ventricles and 2 atria
- only oxygenated blood flows through fish heart
- fish heart shows a single circulatory system rather than a double
