Circulatory System Flashcards
What is the circulatory system?
It’s the main internal transport system, linking cells with certain requirements to the environment outside the body that supplies those requirements.
Main function and other important functions of the blood are:
Transport link between the cells of all the body systems
Other important functions:
- Transporting oxygen and nutrients to all cells of the body.
- Transporting carbon dioxide and other waste products away from the cells.
- Distributing heat and maintaining body temperature.
- Clothing when vessels are damaged, preventing blood loss.
Structure of blood, what is it composed of?
Composed of
Plasma: The liquid part, making up around 55% of the blood volume.
Formed Elements: The non-liquid part, makes up 45% of the blood volume and consists of erythrocytes (red BLC), leukocytes (white BLC) and thrombocytes (platelets).
What is in the blood?
- Digested food
- White blood cells (4% includes platelets)
- Waste (urea)
- Platelets (4% includes white blood cells)
- Hormones
- Plasma (55%)
- Carbon Dioxide
- Oxygen
- Red blood cells (41%)
What is plasma?
It is a mixture of water with dissolved substances (sugars and salts).
What is the function of plasma?
To transport the components of blood, including cells, nutrients, wastes, hormones, proteins and antibodies throughout the body
What useful substances does plasma contain?
- Carbon dioxide
- Glucose
- Amino Acids
- Proteins
- Minerals
- Vitamins
- Hormones
- Waste materials like urea
What are erythrocytes?
Red blood cells
What is the function of erythrocytes?
Transports oxygen from the lungs to the cells throughout the body.
What do erythrocytes contain?
Haemoglobin (molecule specially designed to hold oxygen and carry it to cells that need it.)
What are Leucocytes?
White blood cells
What is the function of leucocytes?
To protect the body from infection
Describe types of leucocytes are there
Neutrophils - Are the most common type of leucocytes, they contain enzymes to digest pathogens.
Monocytes - form other cells; macrophages that engulf pathogens and aged or damaged cells by phagocytosis.
Lymphocytes - are involved in the immune response cell-mediated immunity uses T-lymphocytes, and antibody-mediated immunity uses B-lymphocytes.
Basophils - are responsible for allergic reactions, producing heparin and histamine to defend the body against parasites and bacteria.
Eosinophils - these lead to inflammatory responses; they respond to larger parasites such as worms.
What are thrombocytes?
They’re platelets
What do thrombocytes do?
Platelets (small fragments of cells) adhere to the lining of an injured blood vessel as they produce tiny fibrinogen fibres to form a net. This net traps other blood cells to form a blood clot.
