Question

pigestive systems and Excretory Systems Watch the video review of digestion and excretion Linkedin Backboard and below) https://www.youtube.com/watch? ENDOMEU Practice Identify the following structures on the digestive system model Describe the function of anch structure: Esophagus Liver Stomach Gall bladder Pancreas Colon Rectum Small intestine Appendix

Answer 1

Esophagus Liver Stomach w stomach Gall bladder Pancreas esophagus Colon Rectum Small intestine Appendix pancrea liver - gall bladdder small intestine appendix colon rectum

functions:

1. esophagus: (also called food pipe) it transfer food from the pharynx to the stomach

2. liver: it produce bile ( sodium carbonate, sodium glycocholate, bilirubin, etc.), detoxification is done in liver.

3. stomach: it stores food for some time, partial digestion with gastric juice, production of HCl.

4. gall blader: temporary stores bile juice from liver

5. pancrease: produce prancreatic juice for digesion , production of hormones like insulin, etc.

6. colon: absorbtion of water and electrolytes and elimination of solid waste.

7. rectum: stores feces prior to defecation and helps in defecation by producing mucus.

8. small intestine: digestion and absorbtion are completed here

9. appendix: stores bacteria, but useless remnant after evolution.

# during inspiration ( when fresh air enter our lungs) a) the diaphragm becomes flat, b) external intercostal muscles contract to pull up the ribs to , c) the abdominal muscles relax. this is to increase the volume of the lungs, so that a higher pressure is created compared to air pressure present inside the blood for gas exchange (which is mainly CO2 and O2 exchange).

during expiration : a) diaphragm is relaxed making it convex, b) internal intercostal muscle contracts c) abdominal muscles contracts.

#

EXPIRED AIR INSPIRED AIR ALVEOLAR AIR PO2 = 104 mm Hg PCO2 = 40 mm Hg - ALVEOLUS OF LUNG Coz O2 CO2 O BLOOD ENTERING ALVEOLAR CAPILLARIES Po, 40 mm Hg Pco, 45 mm Hg PULMONARY ARTERIES - BLOOD LEAVING ALVEOLAR CAPILLARIES Po 95 mm Hg Pco, 40 mm Hg PULMONARY VEINS RIGHT ATRIUM - LEFT ATRIUM -LEFT VENTRICLE RIGHT VENTRICLE- SYSTEMIC VEINS - (CARRYING DEOXYGENATED BLOOD) HEART SYSTEMIC ARTERIES (CARRYING OXYGENATED BLOOD) BLOOD LEAVING TISSUE CAPILLARIES CO2 02 PO2 = 40 mm Hg PCO2 = 45 mm Hg BLOOD ENTERING TISSUE CAPILLARIES PO2 = 95 mm Hg PCO2 = 40 mm Hg cozz BODY TISSUE CELLS

there is direct connection between circulatory and respiratory system. when we inspire the partial pressure of O2 in alveolus is 104mm Hg and that of CO2 is 40 mm Hg while the partial pressure of O2 in the alveolar capillary is 40mm Hg and that of CO2 is 45 mm Hg. due to difference in partial pressure, O2 comes in from alveolus to blood capillary and CO2 goes out from capillary to the lungs. thats how O2 is taken up during inspiration and CO2 is expired out during expiration.