Blood tissue Fluid Lymph Flashcards
What is blood
Specialised transport medium that is also considered a special type of connective tissue.
How much blood on average do adults have
4-6 litres of blood
Functions of blood
Transport
Defence
Thermoregulation
Maintaining pH of body fluids
What makes up blood
Plasma 55%
Cells 45%
What is a monocyte
Longer life span than many WBC - Help break down bacteria
What are lymphocytes
Create antibodies to defend against bacteria, viruses and other pathogens
What are neurophils
Kill and digest bacteria and fungi by phagocytosis. First line of defense to infection
What are eosinophils
attack and kill parasites destroy cancer cells help with allergic responses
What are basophils
Secrete chemicals such as histamine, marker of allergic disease, that help control bodys immune response
What are macrophage
Type of phagocyte, responsible for detecting engulfing and destroying pathogens
Structure of Erythrocytes
Flattened, biconcave disc shape: Ensures large surface area:volume ratio for efficient gas exchange
Large amount of haemoglobin for O2 transport
No nucleus or organelles to make space for more haemoglobin
Diameter (6-8um) larger than capillary diameter: Slows blood flow to enable diffusion of oxygen
What are cells bathed in and why
Tissue fluid - enables substances to diffuse in and out
What is the blood like at the arterial end of the capillary
Relatively high pressure - forces water and small molecules out through the capillary wall by ultrafiltration
What happens to the tissue that doesnt return to the capillaries
Excess drains into the lymphatic system - forms lymph
What is lymph
Colourless/pale yellow fluid - Similar to tissue but contains more lipids
Where does the lymphatic system drain
into the ciruclatory system near the vena cavae via thoracic duct
What is the lymphatic system
secondary circulatory system - major part of the immune system
What does the lymphatic system contain
Lymphatic capillaries + Vein like lymph vessels containing valves
Lymph nodes
Lymphatic tissue in the spleen, thymus and tonsils
What are lymph nodes
Sac like organs that trap pathogens and foreign substances, contain large numbers of WBC
What is lymphatic tissue
Also contain large amounts of WBCs and involved in their development
What is Oedema
Accumulation of fluid in the tissue
What can cause Oedema
Lack of plasma protein
Right ventricular heart failure that prevents blood leaving heart efficiently
Blockages or poor circulation in the lymph vessel
