Digestive System
Functions
a. take in food
b. break down the food
c. absorb nutrients
d. eliminate waste
Oral cavity
> the oral cavity or the mouth is part of the digestive system bounded by the lips.
> tongue is a large, muscular organ that occupies most of the oral cavity.
> teeth play a vital role in mastication of the food.
> adult have 32 teeth.
Esophagus
> it is about 25 cm long
> the esophagus has thick walls consisting of the tunics: the mucosa, submucosa, muscularis, adventitia.
Stomach
> the opening from the esophagus to the stomach is called gastroesophageal.
> the secretion of the stomach are called gastric juice.
> as food enters the stomach, it is mixed with gastric juice to become a semifluid mixture called chyme.
> there are two types of stomach movement occurring: mixing waves and peristaltic waves.
> relatively weak contraction result in mixing waves.
> stronger contraction is peristaltic waves.
Small intestine
> consist of three parts: the duodenum, the jejunum, and the ileum.
> the entire small intestine i about 6 m long.
> the mucosa of the small intestine produces secretions that primary contain mucus, electrolytes, and water.
Liver and Gallbladder
>the liver is the largest internal organ of the body, weighing about 1.63 kg.
>the gallbladder is a small sac on the inferior surface of the liver that stores bile.
Fuctions of the liver
> bile production
> storage
> nutrient interconverion
> detoxification
> phagocytosis
> synthesis
Large intestine
> is the portion of the digestive tract extending from the ileocecal junction to the anus.
> its consist of cecum, colon, rectum, and anal canal.
Movement in the large intestine
> three to four time a day, the circular muscles in large parts of the transverse and descending colon undergo several strong peristaltic contraction called massmovement.
Anal canal
> the lat 2-3 cm of the digestive tract is the anal canal . it begins at the inferior end of the rectum and end in anus.
Walang komento:
Mag-post ng isang Komento