Transport In Humans Flashcards
(16 cards)
Another name for Red blood cells
Erythrocytes
Structure of red blood cell + purpose
Contains haemoglobin → binds oxygen reversibly, allows red blood cell to transport oxygen from lungs to rest of the body
Biconcave disc shape → increase surface area to volume ratio, increase rate of diffusion in and out of cell
2 types of white blood cells
Lymphocytes, phagocytes
Another word for white blood cells
Leucocytes
Structure of lymphocytes
Large spherical nucleus, clear cytoplasm
Function of lymphocytes
• produce antibodies
• antibodies → foreign bodies: agglutinate for phagocytosis by phagocytes
Structure of phagocytes
Lobed nucleus, granular cytoplasm
Function of phagocytes
Perform phagocytosis: engulf, ingest digest foreign bodies
Is virus a cell? Why?
No.
Virus are molecules → do not reproduce
Why does the red blood cell bind to oxygen weakly and temporarily?
Oxygen needs to move out of the cell
Definition of pathogen
A bacterium, virus ur other microorganism → cause disease
Definition of antigen
Foreign substances that enters body, triggering an immune response
Structure of platelets
Membrane bound cell fragments
Function of platelets
Involved in the process of blood clotting
Platelets release thrombokinase → activates prothrombin in blood plasma into active form: thrombin
Thrombin → converts soluble fibrinogen in the blood plasma → insoluble fibrin threads
fibrin threads trap blood cells → form a blood clot
Blood clot prevents:
1. Further loss of blood
2. Entry of pathogens into the blood stream
Structure of plasma
Pale yellow liquid made of 90% water by volume
Function of plasma
Contains, transports blood cells and dissolved substances:
Nutrients e.g. Glucose, amino acids
Metabolic waste products eg. Urea, carbon dioxide (in the form at hydrogen carbonate ions)
Other useful substances eg. Hormones: insulin, vitamins, mineral salts, plasma proteins
