Written Potential

Muscle Contraction Process

Calcium binds to troponin, tropomyosin is removed, revealing actin binding sites, myosin binds to actin, followed by ATP breaking the myosin-actin bridge to relax the muscle.

Pathway of Deoxygenated Blood in the Heart

Deoxygenated blood enters the right atrium via the superior/inferior vena cava, flows through the tricuspid valve into the right ventricle, pumped through the pulmonic valve into the pulmonary artery to the lungs.

Oxygenated Blood Pathway

Oxygenated blood returns through the pulmonary veins into the left atrium, passes through the mitral valve into the left ventricle, and is pumped through the aortic valve into the aorta for distribution.

Innate Immune Response

Macrophages engulf pathogens, dendritic cells present antigen fragments to naive Helper T cells, activating them to release cytokines.

Acquired Immune Response

Naive cytotoxic T cells recognize infected cells and multiply; naive B cells undergo clonal selection to produce plasma B cells for antibodies and memory B cells for future infections.

Digestion Begins

Digestion begins in the mouth with chewing and salivary amylase facilitating starch digestion, forming a bolus.

Role of the Stomach in Digestion

Food is mixed with gastric juices containing hydrochloric acid and pepsin to break down proteins into chyme.

Nutrient Absorption in the Small Intestine

In the small intestine, villi and microvilli absorb carbohydrates, proteins, and fats, sending nutrients to the bloodstream.

Process of Waste Elimination

Remaining undigested material passes into the large intestine for water absorption, and waste is stored in the rectum before elimination.

Vascular Return to the Heart

Oxygenated blood from the lungs returns to the heart through pulmonary veins before being distributed throughout the body.