2024/2/15 Science Criterion A Prep: Human Body System

• What are feces?


  A combination of digestive waste products and indigestible molecules leftover in chyme
• What does the large intestine do?


  Reabsorbs water and stores and eliminates undigested food
• What does the duodenum do?


  It receives partially digested food (chyme) from the stomach and further breaks it down with the help of digestive enzymes from the pancreas and bile from the liver and gallbladder
• What does villi do?


  increase surface area absorption (has microvilli as well)

  they have capillaries running through them which transports the nutrients throughout the body

  
• What does the small intestine do?


  absorbs nutrients
• What are the three major parts of the small intestine?

  Duodenum, Je junum, Ileum
• What does the stomach do?


  breaks down food with acid, enzymes and its fast speed
• What does the epiglottis do?


  prevents food from entering the trachea (a flap)
• What does the esophagus do?


  transports food to stomach via peristalsis
• What does the teeth do in digestion?


  Mechanical Digestion. Breaks down food physically
• Digestive System


  Breaks down food into absorbable units that enter the blood for distribution to body cells
• What does the diaphragm do?


  It helps inhale and exhale air.

  When we inhale, the diaphragm contracts so the air can be filled. When we exhale, the diaphragm relaxes and expands so the air can be pushed out of the lungs
• Are carbon dioxide carried by the red blood cells?

  No, carbon dioxide is dissolve in the blood plasma
• How does the gas exchange occur?


  Deoxygenated blood (with CO2) in capillaries --> Alveoli (full of O2) --> Deoxygenated blood becomes oxygenated --> CO2 is diffused into the alveoli --> CO2 is breathed out of the lungs
• What does the bronchioles do?


  the small branches help deliver all of the air to the alveoli and cover the large surface area of the lungs
• What does the rings of cartilage do in the trachea & bronchus?


  They keep the trachea and the bronchus open (prevent stopping the air passageway)
• What does the alveoli do?


  where the gas exchange occurs

  capillaries are closely in touch with the alveolus where it delivers carbon dioxide and picks up oxygen
• What does the bronchi do?


  air passageways entering the lungs
• What does the trachea do?


  transports air to and from lungs
• What does the larynx do?


  Routes air and food into the proper channels and plays a role in speech
• What does the pharynx do?


  A common passageway for food and air
• What does the nasal cavity do?


  filters, warms, and moistens air
• What makes up the respiratory system?

  nose, pharynx, larynx, trachea, bronchi, lungs
• Respiratory System


  System responsible for taking in oxygen and releasing carbon dioxide using the lungs
• What is a septum?


  the wall that divides the two sides (right/left) of the heart
• What is the pathway of blood through the heart?

  Superior/inferior vena cava --> right atrium --> tricuspid valve --> right ventricle --> pulmonary valve --> pulmonary artery --> lungs (picks up O2 and get rid of carbon dioxide) --> pulmonary vein --> left atrium --> mitral (bicuspid) valve --> left ventricle --> aortic valve --> aorta --> body

  
• What does the left atrium do?


  Receives oxygenated blood from the lungs via the pulmonary veins and transfers to the left ventricle
• What does the right atrium do?


  Receives deoxygenated blood from the body via the interior vena cava and transfers to the right ventricle
• What do valves do?


  separates the chambers and prevent back flow of blood and maintain unidirectional flow of the heart (heart problems may occur when these valves don't work properly)

  
• What does the left ventricle do?


  pumps oxygen-rich blood to the body via the aorta (its muscle wall is much thicker as it requires much pressure to send it through the whole body)
• What does the right ventricle do?


  pumps deoxygenated blood to the lungs via the pulmonary artery (which is why its muscle wall is very slim as it doesn't require much pressure to pump it to the lungs)
• What are the four chambers of the heart?

  right atrium, left atrium, right ventricle, left ventricle
• What makes up the Circulatory/Cardiovascular System?

  Heart, blood vessels and blood
• What makes the shade of blood change?

  Different amount of oxygen present
• What are capillaries?


  Circulatory system

  Smallest, tiny blood vessels in which oxygen and nutrients from the blood can move through the walls into organs and tissues.

  It also carries the carbon dioxide to the lungs (so it can be exhaled out)
• What are veins?


  Circulatory system

  Blood vessels that carry blood back to the heart
• What are arteries?


  Circulatory system

  Blood vessels that carry blood away from the heart
• What does blood carry?

  Circulatory system

  The red blood cells carry gases like oxygen and nutrients and removes carbon dioxide
• Circulatory/Cardiovascular System


  a vital organ system in multicellular organisms that circulates and transports blood, nutrients, oxygen, carbon dioxide, hormones, and other substances throughout the body