Circulatory system Flashcards
What is the function of Plasma
Transport of CO2, digested food, urea, mineral ions, hormones and heat energy
What is the function of red blood cells
Transport of oxygen in the form oxyhaemoglobin across the body
What is the function of white blood cells
Defend the body against pathogens by carrying out phagocytosis and antibody production
What do platelets do
Help blood to clot
What are red blood cells and where are they made
Highly specialized cell made in bone marrow
Name 4 adaptations of red blood cells and what are they used for?
Biconcave shape for high surface area to volume ratio to create fast and efficient diffusion of gases
Lacks a nucleus and other large organelles to give more space for haemoglobin so that more oxygen can be transported
Has Haemoglobin that combines with oxygen to form oxyhaemoglobin
Thin cell wall so that short diffusion distance to the centre of the cell
Name 2 types of white blood cells
Phagocytes and Lymphocytes
How can Phagocytes be recognized
Through their multi-lobed nucleus and granular cytoplasm
How can Lymphocytes be recognized
Through their large round nucleus and non-granular cytoplasm
What are 2 ways that Lymphocytes take action
By making antibodies stick to antigen and destroy the pathogen
Some Lymphocytes make memory cells without killing the pathogen. This allows the Lymphocytes to make specific antibodies when a re-infection takes place
Lymphocytes also produce _________ to neutralize _______ released by the pathogens
Lymphocytes also produce antitoxins to neutralize toxins released by the pathogens
What are antibodies
Y shaped proteins with a shape that are specific to the antigens on the surface of the pathogen
What is the primary immune response
Production of antibodies after the first exposure to a foreign antigen
Some Lymphocytes convert into memory cells without killing pathogens
How does the Lymphocyte destroy the pathogen by antibodies
Causing bacteria to stick together
Acting as a label so that the phagocyte can recognize it
Causing bacteria to burst open
Neutralizing poisons released by pathogens
What is the Secondary immune response
Memory cells recognize the microorganism that re-infects a person and starts to reproduce and produce a large number of antibodies rapidly
What happens through Vaccination
A person can be given artificial immunity through an agent that carries the same antigen as a specific pathogen
Lymphocytes recognizes the antigen and multiply exactly as if that microorganisms had entered the bloodstream, they produce memory cells and make the person immune to the diseases
If a person comes in contact with a real pathogen they will experience a secondary immune response
How does a blood clot form?
When the skin is cut, exposure to air stimulates the platelets and the damaged tissues to produce a chemical
This chemical causes fibrinogen (soluble plasma protein) to form fibrin (insoluble plasma protein)
Fibrin forms a network across the wound in which red blood cells become trapped
This forms a clot that turns into a scab
Name 5 things that arteries have or do
Carry blood at high pressure away from the heart
Carry oxygenated blood
Have a narrow lumen to maintain high blood pressure
Have thick walls containing elastic fibers to withstand and maintain high pressure of blood
The speed of blood flow is fast
Name 6 things that veins have or do
Carry blood at low pressure away from the heart
Carry deoxygenated blood
Have thin walls with fewer muscles and fibers
Large lumen so that blood pressure is slow so more volume of blood can be contained
Valves to prevent the backflow of blood
The speed of blood flow is slow
Name 5 things that capillaries have or do
Carry blood at low pressure within tissues/organs so that there is more time for an exchange
Carry both oxygenated and deoxygenated blood
Speed of blood flow is slow for better diffusion
Have one cell thick walls so that diffusion distances are shorter
Have ‘leaky’ walls for better exchange so that blood plasma can leak out and form tissue fluid surrounding cells
What is Lymph/Tissue fluid
Tissue fluid is a fluid surrounding the cells of a tissue.
It is leaked plasma - Plasma from the blood capillaries move to the tissue through gaps in the walls and become tissue fluid
Supplies cells with O2 and nutrients and takes away waste products such as CO2
The walls of the capillaries are so thin that water, dissolved solutes and dissolved gases easily leak out of them/pass through the walls from the plasma into the tissue fluid surrounding the cells
Cells exchange materials (such as water, oxygen, glucose, carbon dioxide, mineral ions) across their cell membranes with the tissue fluid surrounding them by diffusion, osmosis or active transport
More fluid leaks out of the capillaries than is returned to them, and this excess of leaked fluid surrounding the capillaries then passes into the lymphatic system, becoming lymph fluid
Why simple unicellular organisms can rely on diffusion for movement of substances in and out of the cell?
They have larger surface area to volume ratio than multicellular organisms
They can have more nutrients such as oxygen, glucose, that their volume demands through simple diffusion
Why large organisms are evolved with special gas exchange organs or circulatory system?
Surface area to volume ratio is low and their distance within the body is larger and diffusion is inefficient to transport materials in the body
Large organisms use special gas exchange organs and circulatory system that carry nutrients to each cell of the body
What are the differences in circulatory system between a human and a fish
Fish have a single circulatory system while humans have a double circulatory system
Fish: Blood pumps from heart –> Gas exchange organ (gills) –> rest of the body
Humans: Blood pumps from the heart–> lungs–>heart–>body
