Transport In Animals Flashcards
What will an effective transport system include?
Fluid/medium to carry nutrients, oxygen and waste around the body (blood)
Pump create pressure that will push fluid around body (heart)
Exchange surfaces that enable substances to enter blood and leave it again where they are needed these are capillaries
Tubes/vessels to carry blood by mass flow
Two circuits one to pick up oxygen and another to deliver oxygen to the tissues
Single and double circularity system?
Single
Blood flows through heart once for each circuit of body
Heart-> gills-> body-> heart
Double
Blood flows through heart twice for each for each circuit of body
Heart -> body-> heart-> lungs-> heart
Disadvantages of single circulatory system in fish
Blood pressure drops as blood passes through tiny capillaries if gills
Blood has low pressure as flows towards body won’t flow quickly
Rate of oxygen and nutrients delivered to respiring tissues and carbon dioxide and urea are removed is limited
Disadvantage of double circularity of mammals
Blood pressure must not be too high in pulmonary circulation otherwise may damage delicate capillaries in lungs
Heart can increase pressure of blood after passed through lungs so blood is under higher pressure as flows to body and flows more quickly
Systemic circulation can carry blood at higher pressure than pulmonary circulation
Open and closed circulatory system
Open- one in which the blood is not held in vessels
Closed- one in which the blood is held in vessels
Disadvantages of open circularity systems
Blood pressure is low and blood flow is slow
Circulation of blood may be affected by body movements or lack of body movements
Advantages of closed circularity system?
High pressure so blood flows quicker
More rapid delivery of oxygen and nutrients
More rapid removal of carbon dioxide and other wastes
Transport is independent of body movements
Types of blood vessels
Artery Arterioles Capillary Venules Veins
Artery
Carry blood from heart
Thick and muscular elastic walls to stretch and recoil as heart beats helps maintain high pressure
Inner endothelium folded allowing artery to expand helps maintain high pressure
Artery carry oxygenated blood except pulmonary artery
What is the need for transport system affected by?
Size
Surface area to volume ratio
Level of metabolic activity
Arterioles
Artery branches into Arterioles
Much smaller than arteries
Have layer of smooth tissue less elastic tissue
Smooth muscle allows them to expand/contract controlling amount of blood following to tissues
Capillaries
Smallest blood vessels
Substances like glucose and oxygen exchanged between cells and capillaries
Adapted for efficient diffusion
Walls one cell thick
Capillaries walls properties are
Single layer of flattened endothelial cells, reduces diffusion distance for materials being exchanged
Leaky allow blood plasma and dissolved substances to leave blood
Venules
Very thin walls contain muscle cells
Join together to form veins
Veins
Take blood back to heart under low pressure
Very little elastic/ muscle tissue
Contain valves stop blood flowing backwards
Blood flowed through vein helped by contractions of body lurked surrounding them
Carry deoxygenated blood except pulmonary veins carry oxygenated blood to heart from lungs
What is blood plasma?
Fluid that our blood is held in
What does the plasma contain?
Oxygen, carbon dioxide, minerals, glucose, amino acids, hormones and plasma proteins
Cells include erythrocytes and leucocytes and platelets
What are erythrocytes and leucocytes
Erythrocytes are red blood cells
Leucocytes are white blood cells
Features of tissue fluid
Doesn’t contain most of cells found in blood or plasma proteins
Formed by plasma leaking from capillaries
Surrounded by cells in tissue and supplies them with oxygen and nutrients they require
Blood plasma leaks from capillaries carries all dissolved substances into tissue fluid
Movement called mass flow
Waste products from cell metabolism carried back into capillary as some of tissue fluid returns to capillary
Making of tissue fluid first two steps
When artery reaches tissue branches off into smaller Arterioles and then into capillaries leading to Venules to carry blood back to veins, blood flowing into organ/ tissue is contained in capillaries
At end of arterial end of capillary blood at relatively high hydrostatic pressure which pushes blood fluid out of capillaries through capillary wall, fluid can leave through tiny gaps in capillary wall
Making tissue fluid last two steps
Fluid leaves blood consists of plasma with dissolved nutrients and oxygen all red blood cells, platelets, plasma proteins and most white blood cells remain in blood as too large to be pushed out of gaps of capillary wall
Tissue fluid surrounds body cells so exchange by diffusion, facilitated diffusion and active uptake. Oxygen and nutrients enter cells carbon dioxide and other wastes leave cells
Hydrostatic pressure
Pressure that fluid exerts when pushing against sides of a vessel or container
How does some of the tissue fluid return to capillary
Blood pressure at venous end of capillary is much lower
What else happens to tissue fluid after leaving blood?
Some is directed into lymph system or lymphatic system
Drains excess fluid of tissues and returns to blood systems in subclavian in chest
Lymph in lymphatic system composed of similar composition to tissue fluid but contains more lymphocytes as produced by lymph nodes
Where are lymph nodes found?
Swellings found at intervals along lymphatic system have important part to play in immune response
Lymph
Fluid held in lymphatic system
What is the lymphatic system?
A system of tubes that return excess fluid to blood system
What is oncotic pressure?
Pressure created by osmotic effects of solutes
What is the hydrostatic pressure if blood plasma, tissue fluid and lymph?
Blood plasma- high
Tissue fluid- low
Lymph- low
What is the oncotic pressure of blood plasma, tissue fluid and lymph?
Blood plasma- more negative
Tissue fluid- less negative
Lymph- less negative
Cells found in blood plasma, tissue fluid and lymph?
Blood plasma- red blood cells- neutrophils, lymphocytes
Tissue fluid- some neutrophils especially in infected areas
Lymph- lymphocytes
Proteins in blood plasma, tissue fluid and lymph?
Blood plasma- plasma proteins
Tissue fluid and lymph- few proteins
Fats blood plasma, tissue fluid and lymph?
Blood plasma- transported in lipoproteins
Tissue fluid- few fats
Lymph- more fats, especially near digestive system
Influences on movement of fluid
Tissue fluid has own hydrostatic pressures
Oncotic pressure of solutes
Hydrostatic pressure of blood
What does each influcence do?
Hydrostatic pressure of blood tends to push fluid out into tissues
Hydrostatic pressure of tissue fluid tends to push fluid tends to push fluid into capillaries
Oncotic pressure of blood tends to pull water back into blood
Oncotic pressure of tissue fluid pulls water into tissue fluid
What is the muscle called and like in texture?
Cardiac muscle
Firm dark red
Chambers of the heart
Right atrium Left atrium
Right ventricle Left ventricle
What are coronary arteries and why are these important?
The arteries over surface that supply oxygenated blood to heart muscle
If constricted causes restricted blood flow to heart muscle reduces delivery of oxygen and nutrients such as fatty acids and glucose
May cause angina or heart attack
Atrio-ventricular valves are?
Valves vetween atria and ventricles which ensure blood flow in correct direction
Semi lunar valves do what
Valves prevent blood reentering the heart from the arteries
Atria
Walls very thin
Don’t need much pressure
Function to receive blood from veins and push it into ventricles
Right ventricle
Thicker than walls of atria
Enables right ventricles to pump blood out of lungs
Left ventricle pumps deoxygenated blood to lungs
Alveoli in lungs very delicate and could be damaged by very high blood pressure
Left ventricle
Walls of left ventricle can be two or three times thicker than right ventricle
Blood pumped out through aorta and needs sufficient pressure to overcome systemic circulation
Stages of cardiac cycle
Ventricular systole
Diastole
Atrial systole
Ventricular systole
Right and left ventricles pump together
Contraction starts at base of heart so blood pushed upwards towards arteries
Diastole
Muscular walls of all four chambers relax
Elastic recoil causes chamber to increase in volume allowing blood to flow in from the veins
Atrial systole
Right and left atria contract together
Muscle in walls is thin so only small increase in pressure is created by contraction
Helps to push blood into ventricles stretching walls and ensuring they are full of blood