Written Potential

Written Questions Review


  1. Describe how a muscle contracts using the following terms: Troponin, tropomyosin, myosin (thick filament), actin (thin filaments), calcium, sarcoplasmic reticulum, ATP


Calcium binds to troponin. Troponin removes tropomyosin and reveals the actin binding site. Myosin then binds to actin, shortening the muscle to cause muscle contraction. ATP then breaks the myosin-actin bridge to relax the muscle.





  1. How does the blood flow through the heart to the rest of the body? Include 4 chamber, 4 valves, and 5 blood vessels



deoxygenated blood enters the right atrium through the superior and inferior vena cava. it flows through the tricuspid valve into the right ventricle. it is pumped through the pulmonic valve into the pulmonary artery, which carries the blood to the lungs. in the lungs, the blood becomes oxygenated and returns through the pulmonary veins into the left atrium. it passes through the mitral (bicuspid) valve into the left ventricle. the blood is pumped through the aortic valve into the aorta, which distributes oxygenated blood to the rest of the body.







  1. After a pathogen enters the body, what are the innate and acquired immune responses? Use all of the following keywords:

  • Macrophage, dendritic cells, pathogen, antigen, clonal selection, Helper T, Cytotoxic T, naive B, Plasma B, Memory B & T, antibodies, Regulatory T, secondary infection



macrophage engulf pathogen and dendrites (APC_ get fragments of antigens and present to naïve helper T and activate once they n they see the antigens and become helper t, then release cytokines to all other cells and then undergo clonal selection. Naïve cytotoxic recognize and start to activate and multiply to kill infected cells. Clonal selection also multiplies memory T which are used to recognize pathogen for future infection, simutaiouslyu helper t also activates previously naive B which undergo clonal selection with cells that have same antigens and bind to their receptors, this proliferates plasma B cells which make antibodies that neutralize and mark pathogens for the phagocytes to consume quicker. Clonal selection from naïve b can also produce memory B which can be used for future infection when they need antibodies quicker







  1. How is food broken down and absorbed into the blood starting the first bite?

Digestion begins in the mouth, where food is mechanically broken down by chewing and chemically broken down by saliva, which contains the enzyme amylase that starts digesting starches. The moistened food, now called a bolus, moves through the pharynx and esophagus by peristalsis into the stomach. In the stomach, it is mixed with gastric juices containing hydrochloric acid and pepsin, which help break down proteins while the stomach muscles churn the food into a semi-liquid substance called chyme. This chyme then enters the small intestine, starting with the duodenum, where it is mixed with enzymes from the pancreas and bile from the liver to finish digesting proteins, carbohydrates, and fats. In the jejunum and ileum, tiny structures called villi and microvilli absorb the nutrients: carbohydrates are broken into glucose, proteins into amino acids, and fats into fatty acids and glycerol. These nutrients are absorbed into the bloodstream or lymph and sent to the liver via the hepatic portal vein for processing and distribution throughout the body. Any remaining undigested material passes into the large intestine, where water and electrolytes are absorbed. Finally, the leftover waste is stored in the rectum and eliminated through the anus.