digestive system

100問 • 2年前

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breaks down the food you eat into nutrients needed for metabolic processes, such as making ATP, and rids the body of materials that cannot be used such as fiber.

digestive systmem

ANATOMY OF THE DIGESTIVE SYSTEM

Organs of the Alimentary Canal Accessory organs

Also called the "gastrointestinal (GI) tract" or gut, is a continuous, coiled, hollow muscular tube that winds through the ventral body cavity from the mouth to anus. It is approx. 9 meters (about 30 ft long), but in a living person, it is considerable shorter because of its muscle tone.

alimentary canal

ORGANS OF INHE ALIMENTARY CANAL

1. Mouth 2. Pharynx 3. Esophagus 4. Stomach 5. Small Intestine 6. Large Intestine

Food enters the digestive tract through the., a mucous membrane-lined cavity.

Mouth or oral cavity

part of the mouth which protect its anterior opening

lips or labia

part of the mouth which form its lateral walls;

hard palate

part of the mouth which forms its anterior roof and __ forms the its posterior roof.

hard palate, soft palate

a fleshy finger-like projection of the soft palate, which dangles from the posterior edge of the soft palate.

uvula

The space between the lips and cheeks externally and the teeth and gums internally is the

vestibule

occupies the floor of the mouth. The tongue has several bony attachments two of these are to the hyoid bone and the styloid processes of the skull.

muscular tounge

a fold of mucous membrane that secures the tongue to the floor of the mouth and limits its posterior movements

Lingual frenulum

small round mass of a substance, especially food that has been chewed to make it soft before it is swallowed.

bolus

Masses of lymphatic tissue which are part of the body's defense system. They become inflamed and enlarge, they partially block the entrance into the throat (pharynx), making swallowing difficult and painful.

tonsils

two types of tonsils

Palatine tonsils Lingual Tonsils

Food passes posteriorly into the oropharynx and laryngopharynx, both of which are common. passageways for food, fluids, and air.

pharynx

layers: The walls of the pharynx contain two (2) skeletal muscle

Longitudinal muscles Circular/constrictor muscles

Alternating contractions of these two (2) muscle layers propel food through the pharynx

inferiorly into the esophagus

Also known as the "gullet", runs from the pharynx through the diaphragm to the stomach (approx. 25 meters or 10 inches. long) It is an essential passageway that conducts food (by peristalsis) to the stomach (approx. 25m or 10in long) It is an essential passageway that conducts food (by peristalsis) to the stomach

esophagus

valve preventing backflow of food to esophagus

Esophageal sphincter

It is a digestive disorder that occurs when acidic stomach juices, or food and fluids back up from the stomach into the esophagus due to weakness: or unusual relaxation of the esophageal sphincter

GASTROESOPHAGEAL REFLUX DISEASE (GERD)

The main symptom of GERD is acid reflux which can cause an uncomfortable burning feeling in your chest often known as

heartburn

walls of alimentary canal

Mucosa Submucosa Muscularis externa Seresa

innermost layer of alimentary canal , moist mucous membrane lining the hollow cavities of the organ

mucosa

parts of alimentary canal which soft connective tissue containing blood vessels, nerve endings, and lymphatic vessels

Submucosa

muscle layer (circular and longitudinal smooth muscles)

Muscularis externa

-outermost layer of the alimentary canal

Seresa

parts of serosa which is organs

Visceral peritoneum

interior wall of the abdominal cavity of serosa

Parietal peritoneum

-fold of membrane that attaches the intestine to the abdominal wall and holds it in place of serosa

Mesentery

parts of serosa

Visceral peritoneum Parietal peritoneum Mesentery

The alimentary canal wall contains two (2) important intrinsic nerve plexuses:

1. Submucosal nerve plexus 2. Myenteric ("intestinal muscle") nerve plexus

These networks of nerve fibers are actual parts of the autonomic nervous system. They helps regulate the mobility and secretory activity of Gl tract organs.

Submucosal nerve plexus 2. Myenteric ("intestinal muscle") nerve plexus

a part of omentym which double layer of peritoneum from the liver to the lesser curvature of the stomach

Lesser Omentum

a part of omentum another extension of the peritoneum which covers the abdominal organs; contains macrophages and defensive cells

Greater Omentum

C-shaped and is located on the left side of the abdominal cavity, nearly hidden by the liver and diaphragm.

stomach

part of stomach that food anters from the esophagus

Cardial region or cardia

expanded part of the stomach

fundus

-midpartion of the stomach

body

terminal part continuous with the small intestine

pylorus

regions of the stomach

1Cardial region or cardia food 2. Fundus 3Body 4Pyloric antrum 5. Pylorus

-prevents backflow of food to the esophagus in the stomach part

Cardioesophageal sphincter

controls the outflow of gastric contents into the duodenum

Pyloric sphincter or pyloric valve

varies from 15 to 25cm (6-10in) in length, but its diameter and volume depends on how much food it contains

stomach

veries of ridges produced by folding of the walls of the stomach

rugae

Storage, mixing and breakdown of food (chemical breakdown of proteins)

stomach

variable mixture of water, hydrochloric acid, electrolytes (sodium, calcium, phosphate, sulfate, and bicarbonate), and organic substances (mucus, pepsins, and protein)

gastric juice

-openings leading to gastric glands that secrete gastric juice

gastric pits

hormone produced by "G"cells in the lining of the stomach; stimulates secretion of gastric juice

gastrin

It is a condition that inflames the stomach lining (the mucosa), causing belly pain, indigestion (dyspepsia), bloating and nouses. It is often caused by bacterial infection (Helicobacter pylori), excessive drinking or smoking, unhealthy diet or nutrient deficiencies, excessive spicy or acidic food, prolonged use of Non-Steroidal Anti- Inflammatory Drugs (NSAIDs).

gastritis

It can progress into an ___ or an open sare in the lining of the stomach

ulcer

gastritis Treatment

Antacids, Antibiotics. Proton pump inhibitors.

The body's "Major Digestive Organ" Longest section of the alimentary canal; It is a muscular tube hanging in sausage-like coils. extending from the pyloric sphincter to the large intestine

small intestine

small intestine Three (3) subdivisions:

. Duodenum 2. Jejunum. 3. Ileum

semifluid mass of partly digested food expelled by the stomach into the duodenum

chyme

contains digestive enzymes

Pancreatic Juice-

openings at the duodenum that lead into the pancreas.

Pancreatic ducts-

-fluid that breaks down fats into fatty acids

Bile

opening at the duodenum leading into the liver

Bile duct-

Nearly all nutrient absorption occurs in the ____ (water and electrolytes)

small intestine

-deep folds on the mucosa and submucosa layer

Circular Folds

-fingerlike projections of the mucosa with abundant capillaries

Villi

- "brush border"; tiny projections of the plasma membrane containing enzymes that complete digestion of proteins and carbohydrates

Microvilli

Three (3) structures absorption: pf small intestime

Circular Folds-deep folds on the mucosa and submucosa layer Villi-fingerlike projections of the mucosa with abundant capillaries Microvilli - "brush border"; tiny projections of the plasma membrane containing enzymes that complete digestion of proteins and carbohydrates

collections of lymphatic tissue in the submucosa

Peyer's Patches

Important part of the immune system by monitoring intestinal bacteria populations and preventing the growth of pathogenic bacteria in the intestines

Peyer's Patches

Also known as the "large bowel" -largest part of the digestive system Water absorption; elimination of residues

large intestine

Three (3) subdivisions: large intestine

1. Cecum 2. Colon-ascending, transverse, descending, Sigmoid colon 3. Rectum

-first part of the large intestine

CECUM

- narrow, finger-shaped pouch that projects out from the cecum

Appendix

It is an ideal location for bacteria to accumulate and multiply which can lead to

Appendicitis

- hast two valves that opens and closes the anus

Anal Canal

- voluntary skeletal muscle

External Anal Sphincter

involuntary smooth muscle of large intestine

Internal Anal Sphincter -

ACESSORY DIGESTIVE ORGANS

TEETH SALIVARY GLANDS PANCREAS LIVER AND GALL BLADDER

- chewing by opening and closing of jaws and moving from side to side while using our tongue and cheek muscles to keep food in between

MASTICATION

baby or milk teeth) begin to erupt around 6mos until a baby has a full set (20 teeth) by the age of 2 years

Deciduous teeth (

develops between the ages of 6-12 years old

Permanent teeth

(wisdom teeth) usually erupt between 17-25 years

Third molars

Overall, there are_____ set of teeth but there are times that wisdom teeth fail to erupt or sometimes completely absent

32 permanent full

-thick ceramic-like substance; hardest substance in the body which bears the force of chewing

Enamel

-bone-like material underlies the enamel and forms the bulk of the tooth

Dentin

-contains pulp (connective tissue, blood vessels, and nerve fibers)

Pulp cavity

extension of the pulp cavity which provides a route for blood vessels, nerves and the other pulp structures.

Root/Root Canal-

Three (3) pairs of salivary glands:

Parotid glands 2. Submandibular glands 3. Sublingual glands

mixture of mucus and serous fluids which moistens and helps to bind food together into a mass called a bolus.

Saliva

amylase enzyme that begins the process of starch digestion in the mouth Lysozyme and IgA antibodies that inhibit bacteria

Salivary

Largest gland in the body Located under the diaphragm at the right side of the body and overlies the stomach

liver

liver has four (4) lobes and is suspended from the diaphragm and abdominal wall by delicate mesentery cord, the

falciform ligament.

The ___has many critical metabolic and regulatory roles; however, its digestive function is to produce bile cells detoxify drugs and alcohol and degrade hormones

Liver

-a yellow-to-green, watery solution bile salts, bile pigments (bilirubin), cholesterol, phospholipids, and electrolytes

Bile

Bile salts physically break large fat globules into smaller ones Bile exits the liver via the

common hepatic duct

- an inflammation of the liver resulting from drinking contaminated water or transmitted in blood via transfusion or contaminated

Hepatitis

-chronic inflammatory condition in which the liver is severely damaged and becomes hard and fibrous; caused by excess alcoholic beverage consumption for many years

Cirrhosis

Small, thin-walled green sac in the inferior surface of the liver Bile enters the gall bladder via the __ duct where it is stored when food digestion does not occur While in the gallbladder, bile is concentrated by the removal of water.

gall bladder, cystic ducts

-crystalize cholesterol formed when bile is stored in the gall bladder for too long or when too much water is removed

Gall stones

The major functions of the digestive tract are usually summarized in two words-

digestion and absorption.

The essential activities of the Gl tract include the ff. six (6) processes

Ingestion 2. Propulsion 3. Food Breakdown: Mechanical breakdown 4. Food Breakdown: Digestion 5. Absorption 6. Defecation

It is an active, voluntary process where food is placed into the mouth First step to the digestive system process occurring in the oral cavity

ingestion

100

It is the process of propelling food from one organ to the next

propulsion

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Conan Clint · 100問 · 2年前

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