Blood and Transport Systems in Humans

Study Notes

Blood

Blood is a connective tissue, consisting of plasma and formed elements.
Plasma is the liquid component, largely water, containing dissolved proteins, nutrients, wastes, and hormones.
Formed elements include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes).
Erythrocytes transport oxygen and carbon dioxide.
Leukocytes are involved in the immune response, defending the body against pathogens.
Platelets play a crucial role in blood clotting.
Blood is essential for transporting nutrients, oxygen, hormones, waste products, and heat around the body.
Blood maintains a constant internal environment by regulating pH, temperature, and osmotic pressure.
Blood volume is maintained through fluid balance between blood and interstitial fluid.

Transport in Humans

Transport systems in humans are vital for distributing essential substances throughout the body.
The cardiovascular system is the primary transport system, consisting of the heart, blood vessels (arteries, veins, and capillaries), and blood.
The respiratory system works with the cardiovascular system to deliver oxygen and remove carbon dioxide.
The digestive system breaks down food and absorbs nutrients into the blood.
The excretory system removes waste products from the blood.
Hormones are transported in the bloodstream to regulate various bodily functions.
Nutrients are transported from the digestive tract to the liver and other tissues for use or storage, further distributed as needed.

Cardiac Cycle

The cardiac cycle is the sequence of events in one complete heartbeat.
It is comprised of two phases: diastole and systole.
During diastole, the heart relaxes and fills with blood.
During systole, the heart contracts and pumps blood out.
The cardiac cycle involves specific phases of atrial and ventricular contraction and relaxation.
The cycle is regulated by the sinoatrial (SA) node, the heart’s pacemaker.
Electrical impulses initiated by the SA node cause the atria and ventricles to contract in a coordinated manner.
Valves in the heart (atrioventricular and semilunar valves) ensure that blood flows in one direction throughout the cycle.
The cycle repeats continuously, regulated by a complex interplay of electrical and mechanical events.

Coronary Heart Diseases

Coronary heart disease (CHD) is a condition affecting the arteries supplying blood to the heart muscle.
CHD typically involves atherosclerosis, where plaque builds up in these arteries.
Plaque consists of cholesterol, fats, cellular waste products, and fibrous tissue.
Narrowed arteries reduce blood flow, potentially leading to ischemia (reduced blood supply) and damage to the heart muscle.
Risk factors for CHD include high blood pressure, high blood cholesterol, smoking, diabetes, obesity, lack of exercise, and a family history of CHD.
Symptoms of CHD can vary from angina (chest pain) to heart attack (myocardial infarction).
Treatments for CHD focus on managing risk factors, enhancing blood flow (medications, lifestyle changes), or surgery (angioplasty, bypass surgery) to address narrowed arteries.
Regular health checks and monitoring are significant to detect CHD early and adjust lifestyle habits.

Description

This quiz explores the essential components and functions of blood as a connective tissue, including plasma and formed elements. It also covers the vital transport systems in humans, particularly the cardiovascular system, which is responsible for distributing various substances throughout the body.