Module 1: Cardiovascular System Flashcards
What is the main role of blood?
Body’s transport/distribution medium that is continuously circulated via blood vessels
Is blood connective tissue? If so, why?
Yes; liquid CT, because it consists of cells, fibres, and amorphous ground substance (AGS)
3 main functions of blood?
- Regulation: monitors temperature, pH, water distribution
- Protection: houses immune system and facilitates immune communication
- Transportation: transports oxygen, nutrients, gases, hormones, metabolic wastes
Acronym: RPT
Consistency of blood?
Viscous and slightly sticky, because of RBCs and plasma proteins
3 main components of blood?
- Plasma
- Buffy coat
- RBCs
Temperature of blood in the body?
37-38°C
pH of blood in the body?
Alkaline, with a normal pH range of 7.35-7.45
Volume of blood in the body?
Variable according to size, etc.
Typically: 4-5L in females, 5-6L in males.
What percent of blood is plasma?
55%
What is plasma comprised of?
- 91% water
- 7% blood proteins
- 2% nutrients, hormones, and electrolytes
What percent of blood is buffy coat?
<1%
What is buffy coat comprised of?
WBCs and platelets
What percent of blood is RBCs?
45%
What is another name for RBCs?
Erythrocytes
What is another name for WBCs?
Leukocytes
Shape and size of erythryocytes?
Biconcave disc, diameter of 7-8µm
Structure of erythrocytes?
No nucleus or organelles; have cytosol packed with haemoglobin
Function of haemoglobin?
Oxygen transporting vehicle; carries oxygen from lungs and releases it to tissues
Where is haemoglobin synthesised? Why?
In immature RBCs, because maturation of these cells involves the loss of machinery (e.g. nucleus, organelles) for protein synthesis
What type of protein is haemoglobin (Hb)?
Metalloprotein
Structure of 1 haemoglobin molecule?
4 globulin proteins, each of which contains an Fe molecule. Each Fe binds 1 x O2 molecule, meaning Hb binds 4 x O2 molecules max.
Main role of leukocytes?
Part of the immune system, thus participate in immune responses to injury or pathogens
What are neutrophils?
- Type of leukocyte
- Engulf and destroy invading microorganisms by means of phagocytosis; capable of phagocytosis in low oxygen conditions
- Increase in bacterial infections
What are lymphocytes?
- Type of leukocyte; include T and B cells
- Responsible for antibody production, direct cell-mediated killing of virus-infected and tumour cells, and regulation of the immune response
- Bear receptors that bind to a specific antigen
What are monocytes?
- Type of leukocyte
- Differentiate into macrophages
- Responsible for phagocytosis and presentation of antigens to lymphocytes
What are eosinophils?
- Type of leukocyte
- Phagocytose Ag-Ab complexes, antigens, and release enzymes
- Increase in parasitic infections or allergies
What are basophils?
- Type of leukocyte
- Store heparin and histamine
What are platelets?
Fragments of megakaryocytic that are formed elements; not cells
Structure of platelets?
Disc-shaped; 2-4µm in diameter
Functions of platelets?
- Involved in blood clotting; upon activation, adhere a platelet plug
- Secrete: vasoconstrictors, clotting factors, growth factors, and chemical attractants
What proteins/clotting factors circulate in blood plasma, and what proportion do they make up? (3-4)
- Albumins: 54-60%
- Globulins: 36-38%
- Clotting proteins: 4-7%
- Other proteins: 1%
Role of albumins?
Primarily transport proteins; transport of steroid hormones, thyroid hormones. Also induce blood colloid osmotic pressure.