Introduction to Physiology Quiz

Study Notes

Physiology is the branch of biology studying the functions and activities of living organisms and their parts.
It examines all systems of the human body and their interactions.

The urinary (renal) system consists of two kidneys, ureters, bladder, and urethra.
The kidneys filter blood, regulating fluid osmolarity, electrolyte balance, acid-base balance, and blood pressure.

Regulation: Body fluid osmolarity and volume, electrolyte balance, acid-base balance, blood pressure.
Excretion: Metabolic products, foreign substances, excess substances (water, etc.).
Secretion: Erythropoietin, 1,25-dihydroxy vitamin D3 (vitamin D activation), renin, prostaglandin.

The cardiovascular system is responsible for transporting oxygen, nutrients, hormones, and cellular waste throughout the body.
It is powered by the heart, a muscular organ approximately the size of a closed fist.
At rest, the average heart pumps over 5 liters of blood throughout the body every minute.

The heart is a muscular pumping organ located medially within the thoracic cavity.
The apex (bottom tip) is turned to the left, with about two-thirds of the heart on the left side of the body.
The base (top of the heart) connects to major blood vessels (aorta, vena cava, pulmonary trunk, pulmonary veins).
The heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle.

Atrioventricular (AV) valves: Tricuspid valve (right side), Bicuspid (mitral) valve (left side).
Semilunar valves: Pulmonary semilunar valve (right side), Aortic semilunar valve (left side).

There are two primary circulatory loops:
- Pulmonary circulation: Transports deoxygenated blood from the right side of the heart to the lungs (to pick up oxygen) and returns oxygenated blood to the left side of the heart. Driven by the right atrium and ventricle.
- Systemic circulation: Transports highly oxygenated blood from the left side of the heart to all body tissues (except the lungs) to deliver oxygen and nutrients, and returns deoxygenated blood to the right side of the heart. Driven by the left atrium and ventricle.

Blood vessels (arteries, arterioles, capillaries, venules, veins) are the body's highways for blood transport.
Arteries carry blood away from the heart; veins carry blood toward the heart; capillaries facilitate exchange between blood and tissues.
Blood vessels have a hollow lumen for blood flow, with walls varying in thickness based on function (thin capillaries for exchange, thick arteries for pressure).

Blood (7-8% of human body weight) is a vital fluid for carrying out essential functions such as transporting oxygen and nutrients, removing carbon dioxide and waste products, maintaining temperature, and participating in immune responses.
Blood is composed of plasma (55%) and formed elements (45%): red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.

The nephron is the functional unit of the kidney.
It filters blood, regulates water and solute concentrations, and excretes waste products as urine.
The nephron consists of the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.