Unit 15: Transport System in Living Things Flashcards
Main Topics
- Circulation of Blood
- Pulmonary (to lungs)
- Coronary (to heart)
- Systemic (to rest of body)
- Structure of the Heart
- Blood vessels associated with the Heart
- Pathway of blood through the Heart
- Cardiac Cycle
- Blood Vessels
- Diffusion b/w body cells and blood capillaries
- Arteries (away from heart)
- Veins (to heart)
- Capillaries (where diffusion takes place)
- Blood & its Components
- Plasma
- Red Blood Cells
- White Blood Cells
o Lymphocytes & Phagocytes - Platelets
- Diffusion & Osmosis
- Transport System in Plants
- Diffusion & Osmosis in Plants (Photosynthesis, Respiration and Absorption of water from roots)
- Health, Social & Ethical Issues
- Coronary Heart Disease
Circulation of Blood
5pt - paths
- Blood circulates in three paths – Pulmonary, Systemic and Coronary Circulation
- Pulmonary: from the heart to the lungs and back to the heart
- Systemic: from the heart to the rest of the body and back to the heart
- Coronary: from the heart to the tissues of the heart and back to heart
- In the lungs, blood collects oxygen and releases carbon dioxide. The blood is now rich in oxygen and is called oxygenated blood (red).
- Blood carries oxygen to the rest of the body. After giving up its oxygen
to all the cells, it has little oxygen. This blood is called deoxygenated blood (blue).
Coronary Circulation 1pt
- The right and left coronary arteries branch off from the aorta to carry oxygen and glucose to the heart muscles (cardiac muscles).
Circulatory System
4pt
- The circulatory system works with other body systems such as the digestive and respiratory system.
- Food passes from the digestive system into the blood.
- Oxygen is taken in by the lungs (the main organs in the respiratory system) and enters the blood.
- The circulatory system carries the food and oxygen to all cells of the body.
- Blood passes through the heart twice as it moves from the pulmonary circulation (between the heart and lungs) and into the systemic circulation (between the heart and the rest of the body).
- This is a double circulation.
Types of veins:
Pulmonary Vein (from lungs to heart)
Vena Cava (main vein, from cells t/w heart)
Types of arteries:
Pulmonary Artery (frm heart t/w lungs)
Aorta (from heart t/w cells; biggest blood vessel)
Blood Vessels
3-4pt
- Blood circulates through the circulatory system in tubes known as the blood vessels.
- There are 3 types of blood vessels:
- Arteries carry blood away from the heart.
- Veins carry blood to the heart.
- Capillaries are fine network of tiny tubes linking arterioles and venules.
- Artery branches into numerous arterioles (smaller arteries).
- Arterioles branch into a network of smaller vessels known as capillaries.
- Food and oxygen pass from capillaries to the cells.
- Carbon dioxide and other waste substances pass from the cells to the capillaries.
- The capillaries drain the blood into venules (smaller veins) and these venules join to form veins.
Diffusion between body cells and blood capillaries
2-3pt
- Arterial blood – has oxygen and food
- Venous blood – has CO2 and waste products
- Tissue fluid is a colourless fluid found in the tiny spaces between cells.
- Digested food molecules, such as glucose and amino acids, and oxygen move from blood in blood capillaries into tissue fluid into cells by diffusion.
- Waste products, such as carbon dioxide and urea released by cells move into the tissue fluid by diffusion through the capillary walls into blood carried to excretory organs for removal.
- Capillary network made of capillaries increases surface area for more efficient exchange of substances between blood and cells.
Blood Vessels
types of blood vessels
3pt
- There are 3 types of blood vessels:
- Arteries: carries blood away from the heart
- Veins: allows for the exchange of materials between blood and tissue
- Capillaries: carries blood towards the heart
- Blood leaving the heart is under very high pressure. By the time the blood has reached the capillaries it is under very much lower pressure.
- The differences in blood pressure account for the differences in the wall structure of arteries and veins.
- Both arteries and veins have walls made of muscular and elastic tissues but the walls of arteries are very much thicker than those of the veins.
- Veins have valves at regular interval to prevent back flow of blood.
- Capillaries consist of a single layer of cells and they are tiny in cross section when compared with the arteries and veins.
Arteries (3pt)
Arteries
* Transport oxygenated blood from the heart to other organs in the body (aorta - main artery).
* Have thick muscular walls to withstand the high pressure of blood coming from heart
* Thick muscles contract and relax to cause constriction and dilation of the artery respectively to control the high blood flow.
Veins (3pt)
Veins
* Transport deoxygenated blood from other organs back to the heart (vena cava - main vein)
* Have relatively thin muscular walls as flow of blood is slower and hence blood pressure is lower compared to arteries.
* Veins have valves to prevent blood from flowing backwards (backflow).
- Valves are foldings of the inner walls of the veins.
Capillaries (3pt)
- The wall consists of a single layer of cells and the walls are selectively permeable.
- Capillary network increases surface area and total cross sectional-area for more efficient exchange of substances between blood and cells.
- Refer to diffusion b/w body cells and blood capillaries for the exchange of materials!
Artery Function
1pt
- Carries blood away from the heart
Artery Structure
3pt
thickness of wall, lumen & valves
- Thick muscular wall
- Small lumen
- Valves are absent
Artery Blood Pressure & Speed of Blood Flow
2pt
- Highest pressure
- Blood flows rapidly (fastest)
Artery
How the structure is related to its function
2pt
- Thick muscular walls allows the arteries to withstand the high pressure of blood flowing through it
- Elastic wall to push blood in spurts along the artery & give rise to the pulse
Vein Function
1pt
- Carries blood towards the heart
Vein Structure
3pt
thickness of wall, lumen & valves
- Thin muscular wall
- Large lumen
- Valves are present
Vein Blood Pressure & Speed of Blood Flow
2pt
- Lowest pressure
- Blood flows slower than artery; higher than capillary
Vein
How the structure is related to its function
2pt
- Muscular wall is thinner than arteries as blood is carried at low pressure
- Valves are present to prevent backflow of blood & to maintain blood flow in 1 direction
Capillary Function
2pt
- Allows the exchange of substances between blood and body cells via diffusion
- Links arteries and veins
Capillary Structure
3pt
thickness of wall, lumen & valves
- One-cell thick wall
- Lumen is narrow, the size of 1 RBC
- Valves are absent
Capillary Blood Pressure & Speed of Blood Flow
2pt
- Lower pressure than artery; higher than vein
- Blood flows slowly
Capillary
How the structure is related to its function
1pt
- One-cell thick wall allows efficient exchange of substances between the blood and the body cells via diffusion
Blood and its Components
4-5pt
- Blood acts as a transport medium carrying various substances:
soluble food substances, waste products (e.g. urea and carbon dioxide), hormones, thermal energy and oxygen. - Blood contains red blood cells, white blood cells and platelets. These are suspended in a pale-yellow liquid called plasma.
- Red blood cells (role of haemoglobin in oxygen transport)
- Plasma (transport of blood cells, ions, soluble food substances, hormones, carbon dioxide, urea, vitamins and plasma proteins)
- White blood cells (role in phagocytosis, antibody formation and tissue rejection)
- Platelets (role in blood clotting)
- White blood cells & plasma (antibodies) help in the protection of cells!
Transport of Oxygen to body cells
4pt
- Blood passes through lungs, oxygen diffuses from the air sacs in the lungs into the blood.
- Haemoglobin combines with oxygen to form oxyhaemoglobin.
- Blood transports oxygen to all the tissues of the body.
- At the tissue cells, oxyhaemoglobin releases the oxygen.