Week 10 CVS blood part 1 Flashcards
Cardiovascular system
Consists of;
-Blood
-Blood vessels
-Heart
Role: These components ensure that the body receives the
necessary nutrients to function properly and that waste products are efficiently
removed
Blood
Blood is the fluid that circulates through the cardiovascular system
-It consists of;
->Red blood cells (which carry oxygen)
->White blood cells (which fight
infection)
->Platelets (which help with clotting)
->Plasma (the liquid component containing nutrients, hormones, and waste products)
Blood Vessels
->Arteries: These vessels carry oxygenated blood away from the heart to the body’s tissues -The largest artery is the aorta ->Veins: These vessels return
deoxygenated blood back to the heart -The largest veins are the superior and inferior vena cava –>Capillaries: These are small, thin-walled vessels where the
exchange of gases, nutrients, and waste products occurs between blood and tissues
Heart
-The heart is a muscular organ that pumps blood throughout the body ->The heart ensures continuous blood circulation, supplying oxygen and nutrients to tissues and removing carbon dioxide and waste products
Functions of Blood
Blood is a vital fluid that sustains life by performing essential functions, particularly in
the circulatory system (CVS)
It acts as a transport carrier, providing various critical
functions including; -transportation
-protection
-regulation
Transportation (O2 and CO2)
Oxygen (O2) and Carbon Dioxide (CO2) Movement:
->Oxygen Transport: Blood carries oxygen from the lungs to the tissues throughout the body via red blood cells (RBCs) bound to haemoglobin
->Carbon Dioxide Transport: Blood transports carbon dioxide, a waste product of metabolism, from the tissues back to the lungs for exhalation
Transportation (nutrients)
Blood distributes nutrients absorbed from the digestive system to all cells in the body, providing the necessary fuel and building blocks for cellular function
Transportation (electrolytes)
Blood carries electrolytes such as sodium, potassium, calcium,
and bicarbonate, which are essential for maintaining cellular
function, nerve transmission, and muscle contraction
Transportation (metabolic waste)
Blood transports metabolic waste products such as urea and
creatinine to the kidneys for excretion, thus helping to maintain homeostasis
Transportation (hormones and cytokines)
Blood delivers hormones and cytokines, which are signalling
molecules that regulate various physiological processes, including growth, metabolism, and immune responses
Protection (immune response)
->Antibodies and Complement Proteins: Blood contains antibodies (immunoglobulins) and complement proteins that help identify and neutralise pathogens such as bacteria, viruses, and toxins
->White Blood Cells (WBCs): Blood houses various types of white blood cells (e.g., neutrophils, lymphocytes, monocytes) that are crucial for the immune response, detecting, attacking, and destroying infectious agents
Protection (prevention of blood loss)
->Clotting Mechanism: Blood has platelets and clotting factors that
initiate clot formation to prevent excessive blood loss in the event
of injury
->Platelets: These cell fragments aggregate at the site of injury to
form a plug, while clotting factors activate a cascade leading to the formation of a stable fibrin clot
Regulation (body temperature)
->Heat Distribution: Blood absorbs and distributes heat throughout the body, helping to maintain a stable internal temperature
->Heat Exchange: Blood vessels can dilate (vasodilation) to release excess heat through the skin or constrict (vasoconstriction) to retain heat, thus regulating body temperature
Regulation (pH balance)
->Buffer Systems: Blood contains buffers such as bicarbonate (HCO3-) that help maintain the pH within a narrow range (around 7.35-7.45), crucial for normal cellular functions
->Acid-Base Balance: Blood transports carbon dioxide (a by-product of metabolism) to the lungs for exhalation and helps neutralise acids produced by metabolic processes
Regulation (Circulatory Body Fluid Volume/Concentration (Osmosis))
->Fluid Balance: Blood helps regulate the volume and concentration of body fluids through osmosis, ensuring that cells receive the proper amount of water
->Plasma Proteins: Proteins such as albumin in the blood plasma maintain oncotic pressure, which helps draw water into the bloodstream and maintain fluid balance
->Electrolyte Balance: Blood maintains the proper balance of electrolytes, such as sodium, potassium, and calcium, which are essential for various cellular processes and osmotic balance
Characteristics of blood
->Blood is a unique connective tissue and the only fluid tissue in the human body
->It has distinct physical and chemical properties that enable it to perform its vital functions
Physical characteristics (nature)
->Liquid Connective Tissue: Blood is a fluid connective tissue that circulates throughout the body within the cardiovascular system
->Sticky and Viscous: Blood is a sticky, viscous fluid due to the
presence of cells, proteins, and other substances
Physical characteristics (colour)
->Scarlet Red: Blood is bright red when it is oxygen-rich, typically
found in arteries
->Dark Red: Blood is darker when it is low in oxygen, typically found in veins
Physical characteristics (volume)
Total Blood Volume: Blood constitutes about 8-10% of an
individual’s body weight
Average Volume:
->Males: Approximately 5-6 litres
->Females: Approximately 4.5 litres
Composition of blood (plasma)
It is typically divided into three main components: plasma, the buffy coat, and red blood cells (RBCs)
->Plasma (55%): Liquid Matrix: Plasma is the liquid component of blood, constituting about 55% of its total volume
Composition of blood (buffy coat)
Buffy Coat (~1%):
->Leucocytes (White Blood Cells): Part of the immune system, involved in protecting the body against infections and foreign invaders ->Types of Leucocytes: Neutrophils, lymphocytes, monocytes, eosinophils, and basophils
->Platelets (Thrombocytes): Cell fragments that play a crucial role in blood clotting and preventing blood loss
Composition of blood (RBC)
Red Blood Cells (RBCs, ~44%):
->Erythrocytes: The most abundant cells in the blood, responsible for transporting oxygen from the lungs to the tissues and carbon dioxide
from the tissues to the lungs
Blood - plasma
->Plasma is the straw-coloured, sticky fluid component of blood, making up about 55% of its total volume
It consists primarily of water and contains various soluble
components crucial for maintaining homeostasis and supporting bodily functions