science

• digestive system has three main divisions:

  • Mouth region or oral cavity
  • Gastrointestinal tract
  • Accessory organs
• Lips - have sensory receptors

  that can detect the texture

  and temperature of food.
• palate - is the mouth’s

  upper boundary where food is

  pushed against when chewing.
• tongue - functions

  for tasting, mixing, and

  swallowing food.
• Papillae - are tiny bumps

  on the upper surface of

  the tongue that contain

  taste buds.
• teeth functions to physically

  break down the food.
• Incisors: cutting

  Canines: tearing

  Premolars: tearing, crushing

  Molars: grinding, crushing
• pharynx - connects the

  mouth to the esophagus.
• Nasopharynx: passage

  of air only

  Oropharynx: passage

  of food and air

  Laryngopharynx:

  passage of food only
• epiglottis - is a

  cartilaginous tissue that

  prevents the entry of food

  and water into the

  respiratory tract.
• esophagus - is a long

  muscular tube where food

  travels from the mouth to the

  stomach.
• Sphincters - prevent the

  backflow of food.
• stomach - is a hollow

  and curved organ that

  functions for the storage

  and breakdown of food.
• stomach - It produces acids, mucus,

  and enzymes that help in

  digestion.
• The inner walls of the stomach have folds

  known as rugae that allow the

  stomach to stretch to store

  large meals.
• The stomach has three

  sections: the cardia, the

  fundus, and the pylorus.
• The stomach has two

  sphincters that prevent the

  backflow of food.

  • Cardiac sphincter
  • Pyloric sphincter
• small intestine - is a long tube

  where the final digestion takes

  place.
• Duodenum - where chyme

  mixes with enzymes
• Jejunum - site of nutrient

  absorption
• Ileum - site of digestion and

  further absorption
• The large intestine - is the final

  organ of the digestive system. It is the site for vitamin and

  water absorption. It converts chyme into feces.
• Salivary glands - secrete saliva

  into the mouth that clean the

  teeth, lubricate the food, and

  allow chemical digestion.
• salivary gland consist of the parotid

  gland, submandibular gland,

  and sublingual gland.
• The liver, the second

  largest organ, produces bile

  which aids in lipid digestion.
• The gallbladder - stores and

  holds the bile until it is

  needed in the duodenum.
• pancreas - is a yellowish

  organ that secretes

  pancreatic juice.
• Pits - in the tooth crown

  develop as a result of the

  destruction of enamel.
• Decay - begins in the dentin

  layer of teeth when the acids

  leak into the pits creating a

  cavity.
• Plaques are bacterial films in

  the teeth where acids are

  produced, causing the tooth

  decay.
• Cavities - can be prevented by

  daily brushing, flossing, and

  using antibacterial

  mouthwash.
• gingivitis - This is an early stage of gum

  disease characterized by

  gum inflammation.
• The hardened plaques are

  called tartar, and these further

  collect bacteria.
• Constipation - is marked by

  irregular defecation or release

  of feces. The feces released is dry, making

  defecation hard and sometimes

  painful in the lower part of the

  abdomen
• Diarrhea - the opposite of

  constipation, is characterized

  by abnormally loose and wet

  feces. It is commonly caused by a

  viral or bacterial infection

  in the gastrointestinal tract.
• Peptic ulcers - are holes in the

  linings of the stomach or

  upper part of the small

  intestine caused by exposure

  to acids.
• Gastritis - involves mucosal

  inflammation.
• Indigestion (or dyspepsia) - is

  the recurring pain or

  discomfort in the upper

  portion of the abdomen. It is sometimes accompanied

  by chest pains called

  heartburn.
• Malnutrition - is the general

  term to indicate poor health

  due to a lack of certain

  nutrients. It is often due to improper

  food consumption and an

  unbalanced intake of

  nutrients.
• overnutrition - It is characterized by

  being overweight, and

  a high amount of fat

  evident in the body.