Blood vessels - Structure and function, Blood - Components, function and disease Flashcards
What are the main components of blood?
Plasma: 55% of blood; contains water (92%), plasma proteins (7%), and other solutes (1%).
Formed Elements: 45% of blood; includes red blood cells (95.8%), white blood cells (0.1%), and platelets (4%).
What are the primary plasma proteins and their functions?
Albumin: Maintains osmotic pressure.
Fibrinogen: Involved in blood clotting.
Globulins: Include immunoglobulins for immune defence.
What are the functions of red blood cells (erythrocytes)?
Transport oxygen via haemoglobin.
Lack nuclei, mitochondria, and ribosomes to maximize oxygen-carrying capacity.
What are the types of white blood cells and their functions?
Neutrophils: Phagocytosis of bacteria (pus formation).
Eosinophils: Allergic reactions, defense against parasites.
Basophils: Release histamine during inflammation.
Lymphocytes: Immune response (T and B cells).
Monocytes: Phagocytosis of large particles.
What are the functions of blood?
Transportation: Carries oxygen, nutrients, hormones, and removes waste.
Regulation: Maintains pH, fluid balance, and body temperature.
Protection: Defends against pathogens and prevents blood loss via clotting.
What are the phases of haemostasis?
Vascular Phase: Vasospasm and endothelial cell changes to reduce blood flow.
Platelet Phase: Platelets adhere to damaged vessels and aggregate.
Coagulation Phase: Cascade reactions convert fibrinogen into fibrin, forming a stable blood clot.
What are the three pathways in the coagulation phase?
Extrinsic Pathway: Triggered by external vessel wall damage.
Intrinsic Pathway: Activated within the bloodstream.
Common Pathway: Where extrinsic and intrinsic pathways converge to form a clot.
What is anaemia, and what are its causes?
Anaemia: A deficiency in hemoglobin or red blood cells.
Causes: Blood loss, inadequate RBC production, or excessive RBC destruction.
What is polycythaemia, and how does it differ from leukocytosis?
Polycythaemia: Abnormally high hemoglobin concentration.
Leukocytosis: Elevated white blood cell count, often due to infection or inflammation.
What are the common blood clotting pathologies?
Platelet deficiency or dysfunction.
Abnormal clotting factors (e.g., haemophilia).
What are the three main types of blood disorders covered in the document?
Anaemia: Low RBCs or hemoglobin.
Polycythaemia: Excess RBCs.
Leukocytosis and Leukopenia: High or low WBC counts.
How does blood regulate pH and temperature?
Maintains pH between 7.35 and 7.45 using buffers.
Removes excess heat from tissues, especially muscles.
What are the five main types of blood vessels?
Arteries: Conducting and distributing vessels.
Arterioles: Resistance vessels, regulate blood pressure.
Capillaries: Exchange vessels for gas, nutrients, and waste.
Venules: Collecting vessels returning blood from capillaries.
Veins: Capacitance vessels, return blood to the heart.
What are the three layers of a blood vessel wall?
Tunica Intima: Inner layer, lined by endothelium.
Tunica Media: Middle muscular and elastic layer.
Tunica Externa: Outer layer, provides support.
How do arteries differ from veins in structure and function?
Arteries: Thick, elastic walls to withstand high pressure; transport blood from the heart.
Veins: Thin walls with valves to prevent backflow; assist venous return using muscle and respiratory pumps.
What is the formula for blood pressure, and what factors influence it?
Formula: Blood Pressure = Cardiac Output × Peripheral Resistance
Influencing Factors: Cardiac output, peripheral resistance, and blood volume.
What is hypertension, and what are its risk factors?
Hypertension: Blood pressure >140/90 mmHg.
Risk Factors: Genetics, age, race, smoking, poor diet (high salt/fat), obesity, sedentary lifestyle, stress.
What are the types of arterial wall pathologies?
Arteriosclerosis: Hardening and loss of elasticity in arteries.
Arteriolosclerosis: Affects arterioles.
Atherosclerosis: Plaque buildup in arteries.
What are the consequences of atherosclerosis?
Thrombus: Blood clot formation.
Embolus: Dislodged clot that travels and blocks smaller vessels.
What is an aneurysm, and where is it commonly located?
Aneurysm: Localized enlargement of an artery due to a weakened wall.
Common Locations: Aorta and cerebral arteries.
What is deep vein thrombosis (DVT), and what are its symptoms?
DVT: Formation of a blood clot in a large vein.
Symptoms: Pain, swelling, discoloration, and positive Homan’s sign.
How does the skeletal muscle pump aid venous return?
Muscle contractions compress veins, pushing blood toward the heart.
One-way valves prevent backflow.
What are common causes of venous insufficiency?
Faulty Valves: Incompetent valves causing blood pooling.
Varicose Veins: Enlarged, twisted veins due to weakened walls.
How is hypertension managed?
Lifestyle Changes: Diet, exercise, weight management, quitting smoking.
Medications: ACE inhibitors, beta-blockers, calcium channel blockers, diuretics.
