Digestive System Flashcards
The collection of organs concerned with ingestion and digestion of food; absorption of nutrients, propulsion of ingested food through the digestive tract, and defecation of indigestible substances
Digestive system
What two types of organs does the digestive system consists of?
Gastrointestinal tract (digestive tract) Accessory organs
A continuous tube through which food passes through directly
Alimentary canal
What does the alimentary canal consists of?
- oral cavity (mouth)
- pharynx
- esophagus
- stomach
- small intestine
- large intestine
Organs that are not part of the alimentary canal but assist in digestion in some type of way
Accessory organs
What does the accessory organs consists of?
- teeth
- tongue
- salivary glands
- liver
- gallbladder
- pancreas
What are the six basic processes that the digestive system must carry out?
- Ingestion
- Secretion
- Propulsion
- Digestion
- Absorption
- Defecation
A type of digestion where digestive organs physically break food down into smaller pieces via processes such as chewing and mixing food by moments by the muscles of the alimentary canal
Mechanical digestion
A type of digestion where enzymes secreted by digestive organs catalyze reactions that break the chemical bones within food particles until only small molecules remain
Chemical digestion
Rhythmic contractions of layers of smooth muscle that move material through a hollow organ
Peristalsis
The movement of a cell or tissue
Motility
A self-contained branch of the autonomic nervous system that extends from the esophagus to the anus and regulates secretion and motility of the digestive organs
Enteric nervous system
What are the four tissue layers of the alimentary anal?
- Mucosa
- Submucosa
- Muscularis externa
- Serosa (adventitia)
What are the layers of the mucosa in the alimentary canal?
- Epithelium
- Lamina propria
- Muscularis mucosae
What are the layers of the submucosa in the alimentary canal?
- Submucosal gland
- Blood and lymphatic vessels
- Submucosal plexus (Meissner’s plexus)
- Dense irregular connective tissue
What are the layers of the muscularis externa in the alimentary canal?
- Circular layer
- Myenteric plexus (Auerbach’s plexus)
- Longitudinal layer
What type of tissue is the serosa and adventitia in the alimentary canal composed of?
Serosa- simple squamous epithelial tissue and loose connective tissue
Adventitia- dense irregular tissue
What are the two layers that the peritoneal membrane (peritoneum) consists of?
- Parietal peritoneum (outer)
* Visceral peritoneum (inner)
What is the name of the cavity found between the to peritoneal layers?
Peritoneal cavity
What is the largest serous membrane in the body?
Peritoneal membrane (peritoneum)
Folds of visceral peritoneum that bind and support abdominal organs
Mesenteries
What are the two types of mesenteries?
- Greater omentum
* Lesser omentum
the blood vessels that supply and drain the abdominal digestive organs?
Splanchnic circulation
Where does the nerve supply of the abdominal digestive organs comes from?
Enteric nervous system and two branches of the autonomic nervous system
A moist chewed mass that comes from ingested food
Bolus
What are the three accessory organs that the oral cavity house?
Teeth
Tongue
Salivary glands
What are the four digestive processes that takes place in the oral cavity?
Ingestion
Secretion
Chemical and mechanical digestion
Propulsion
Posterior to the lips and cheeks
Gums (gingivae)
A narrow band of mucosa that attaches the internal surfaces of the upper and lower lips to the gums and midline
Labial frenulum
The narrow space between the teeth and gums and the internal surfaces of the lips and cheeks
Vestibule
The space posterior to the teeth and gums
Oral cavity proper
The superior boundary or roof of the mouth that consists of the hard and soft palate
Palate
The projection extending inferiorly from the soft palate
Uvula
Key organs of mechanical digestion (mastication) that are located in alveoli within the mandible and maxilla and held in place by periodontal ligament
Teeth
Chew ingested food grinding it into smaller pieces
Mastication
Which two muscles are involved in mastication?
Masseter muscle
Temporalis muscle
What are the three types of teeth?
- Incisors
- Canines
- Molars
Central teeth that are broad and flat with a narrow crown and are specialized for curing off pieces of food
Incisors
Teeth that are also known as cuspids that are on either side of incisors and are specie for ripping and tearing
Canines
Teeth posterior and lateral to canines that have broad crowns with rounded projections called cusps that are specialized for grinding
Molars
What is the name for the 20 baby teeth?
Primary dentition (deciduous teeth)
What is the name for the 32 permanent teeth?
Secondary dentition (permanent teeth)
What are the two components that a tooth consists of?
- Crown
* Root
The visible portion of the tooth that’s above the gum line
Crown
The part of the tooth that is embedded in the alveolus
Root
The hard outer layer of the tooth
Enamel
The soft inner gelatinous layer of the tooth
Pulp
The inner layer of mineralized tissue in both the root and crown composed of 70% calcium hydroxyapatite crystals
Dentin
The mineralized bonelike tissue on the outer portion of the root of the tooth
Cementum
Pulp becomes infected which results in inflammation that risks the health of the tooth
Root canal
This organ consists of skeletal muscle covered with stratified squamous epithelium that is involved in mechanical digestion, and it pushes the bolus posteriorly during swallowing
Tongue
A thin band that attaches the tongue to the floor of the oral cavity and prevents the tongue from moving too far posteriorly
Lingual frenulum
Small projections that the epithelium of the tongue is arranged into
Papillae
What are the four kinds of papillae?
- filiform papillae
- fungiform papillae
- circumvallate papillae
- foliate papillae
What is the only kind of papillae does not contain sensory receptors called taste buds?
Filiform papillae
What are the two groups of skeletal muscles that control tongue movement?
- Extrinsic muscles
* Intrinsic muscles
Muscles that control the position of the tongue
Extrinsic muscles
Muscles that control the shape and size of the tongue
Intrinsic muscles
A set of three pairs of glands around the oral cavity that secrete saliva into it
Salivary glands
A fluid secreted by the salivary gland into the oral cavity that contains water, mucus, salivary amylase, lysozyme, secretory IgA, and other solutes
Saliva
What are the three pairs of salivary glands?
- parotid glands
- submandibular glands
- sublingual glands
Glands over the masseter muscle
Parotid glands
Glands medial to the mandible
Submandibular glands
Glands under the tongue
Sublingual glands
What are the components of saliva?
- salivary amylase
- lysozyme
- secretory IgA
- bicarbonate ions
The process of secretion from the three pairs of salivary glands primarily controlled by the parasympathetic nervous system in the reflex arc
Salivation
The organ that sit posterior to the oral and nasal cavities and the primary function is propulsion in the form of swallowing (bolus passes through the pharynx into the esophagus)
Pharynx
What are the three divisions of the pharynx?
- nasopharynx
- oropharynx
- laryngopharynx
What are the three skeletal muscles that surround the pharynx and their functions?
Upper, middle, and lower pharyngeal constrictor muscles. Muscles contract sequentially during swallowing and propel the bolus inferiorly
A muscular tube about 25cm(10in) long found posterior to the trachea that transmits bolus from the pharynx to the stomach
Esophagus
A sphincter at the esophagus inferior end that regulates the passage of bolus into the stomach and prevents the contents of the stomach from re-entering the esophagus
Gastroesphageal sphincter
A specialized type of propulsion at pushes a bolus of food from the oral cavity through the pharynx and esophagus to e stomach
Swallowing (deglutition)
What are the three phases of swallowing?
- voluntary
- pharyngeal
- esophageal
During this phase of swallowing the tongue pushes the bolus posteriorly toward the oropharynx
Voluntary phase
During this phase of swallowing the bolus enters the oropharynx; the soft palate and epiglottis seal off the nasopharynx and larynx
Pharyngeal phase
During this phase of swallowing peristaltic waves move the bolus down the esophagus to the stomach
Esophageal phase
The J shaped organ located in the left upper quadrant
Stomach
What are the five anatomical regions of the stomach?
- cardia
- fundus
- body
- pyloric antrum
- pylorus
Region where the esophagus empties into the stomach
Cardia
The dome-shaped top of the stomach
Fundus
The largest portion of the stomach
Body
The inferior portion of the stomach
Pyloric antrum
The terminal portion of the stomach
Pylorus
A motion that pummels food into a liquid called chyme
Churning
Folds of the stomach mucosa that house gastric glands
Gastric pits
An acidic enzyme containing fluid secreted by exocrine cells into the lumen of the stomach
Gastric juice
A sphincter that regulates the flow of materials between the stomach and the small intestine
Pyloric sphincter
Folds in the interior stomach that allow the stomach to expand
Rugae
What are the four main cells in or near the gastric glands?
- mucous neck cells
- parietal cells
- chief cells
- enterendocrine cells
This type of cell secrete acidic mucus
Mucous neck cells
This type of cell secret hydrochloric acid and intrinsic factor
Parietal cells
This type of cell secrete the inactive precursor pepsinogin
Chief cells
This type of cell produce hormones
Enterendocrine cells
What are the processes that takes place in the stomach?
Secretion
Chemical digestion
Mechanical digestion
Propulsion
What are the three phases of acid secretion in the stomach?
Cephalic phase
Gastric phase
Intestinal phase
This phase of secretion is mediated by the sight, smell, taste, or even thought of food
Cephalic phase
During this phase of secretion food enters the stomach
Gastric phase
During this phase of secretion chyme enters the duodenum
Intestinal phase
A reflex that decreases vagal activity and acid secretion
Enterogastric reflex
What two hormones reduce acid secretion?
Secretin
Gastric inhibitory peptide (GIP)
A digestive disease in which acidic chyme from the stomach regurgitates into the esophagus
Gastroesophageal reflux disease
An unpleasant process caused by the stomach contents moving backward
Vomiting
What are the three actions that the stomach motility perform?
Receptive function
Churning function
Emptying function
During this action of stomach motility the stomach receives food from the esophagus
Receptive function
During this action of stomach motility the stomach churn the incoming bolus into chyme
Churning function
During this action of stomach motility the stomach control the rate at which chyme empties into the small intestine
Emptying function
When food or liquid is swallowed, the gastroesophageal sphincter and smooth muscle of the fundus and the body of the stomach relax to allow the stomach to fill
Receptive relaxation
What two hormones stimulate gastric motility?
Serotonin
Intestinal gastrin
This organ is the longest portion of the alimentary canal, 6 meters long (20ft)
Small intestine
What are the three divisions of the small intestine?
Duodenum
Jejunum
Ileum
The first segment of the small intestine that begins at the pylorus
Duodenum
The middle portion of the small intestine
Jejunum
The final portion of the small intestine
Ileum
Where the secretions from the gallbladder and pancreas enter the small intestine
Major duodenal papilla
Controls the movement of materials from the ileum into the cecum. Also prevents materials from the large intestine from flowing backward into the ileum
Ileum-cecal valve
This type of food is visible with the naked eye and involve the mucosa and submucosa of the small intestine
Circular folds
What are the two smaller folds that are not visible with the naked eye?
Villi
Microvilli
This structure is between villi and it houses glands
Intestinal crypts
Slow rhythmic contractions characterized by the small intestines motility between meals
Migrating motor complex
Also known as intestinal churning, involves contractions of only the circular layer of smooth muscle, which produces a squeezing motion
Segementation
What are the four main processes that occur in the small intestine?
Secretion
Digestion
Absorption
Propulsion
This organ runs along the border of the abdominal cavity, surrounding the small intestine and the other abdominal organs like a frame
Large intestine
Waste matter discharged from the bowels after food has been digested
Feces
What are the three segments that makes up the large intestine?
Cecum
Colon
Rectum
The first portion of the large intestine
Cecum
A small blind-ended pouch extended from its posteroinferior end
Vermiform appendix
The longest portion of the large intestine that’s divided into four portions
Colon
What are the four portions of the colon?
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
The portion of the large intestine that runs anterior to the sacrum and is retroperitoneal. Also a continuation of the sigmoid colon
Rectum
These valves allow the passage of flatus (gas) without risking the simultaneous passage of feces
Rectal valves
The last portion of the large intestine, where the rectum ends
Anal canal
What are the two sphincters of the anal canal?
Internal anal sphincter (involuntary)
External anal sphincter (voluntary)
What is the names of the bacteria found in the large intestine?
Normal flora
Gut flora
What are the functions of bacteria?
- Produce vitamins
- Metabolize undigested materials
- Deter the growth of harmful bacteria
- Stimulate the immune system
A type of motility in the proximal large intestine that causes a propulsive motion
Mass movement (mass peristalsis)
When mass movements force fecal material into the normally empty rectum
Defecation reflex
What are the functions of the large intestine?
Absorption
Propulsion
Secretion
Defecation
A gland with both endocrine and exocrine functions
Pancreas
A duct that receives secretions from acinar cells
Main pancreatic duct
Clusters where acinar cells are found
Acini
Collective secretions of the pancreatic acinar and duct cells
Pancreatic juice
A hormone produced by duodenal enterendocrine cells in response to the presence of lipids and partially digested proteins of the duodenum
Cholecystokinin (CCK)
A pyramid-shaped organ that is located in the right upper quadrant
Liver
A small sac on the posterior side of the liver
Gallbladder
Why are the four lobes of the liver?
Right lobe
Left lobe
Caudate lobe
Quadrants lobe
What is the liver main digestive function?
Production of bile
A liquid produced by the liver that contain water, electrolytes, and organic compounds
Bile
What are the other functions of the liver?
- Nutrient metabolism
- Detoxification
- Excretion
Where does the gallbladder receive bile from and store it for release?
Common hepatic duct
Bile leaves the gallbladder from this duct
Cystic duct
This duct empties into the duodenum
Common bile duct
This sphincter controls the emoting of bile and pancreatic fluids into the duodenum
Hepatopancreatic sphincter
The enzyme that helps with carbohydrate digestion in the small intestine
Pancreatic amylase
What are the brush order enzymes?
Lactase
Maltase
Sucrase
Glucose and galactose are transported across an enterocyte’s apical membrane using the secondary active transport
Na+/glucose cotransporter
Protein digestion begins in the stomach with this enzyme
Pepsin
A process in which an amphiphilic compound physically breaks lipids into smaller clusters through polar and nopolar interactions
Emulsification
An enzyme that catalyze lipid breakdown
Pancreatic lipase
After chemical digestion by lipase is complete, the bike salts stay together in these structures
Micelles
Vitamins that are polar molecules
Water-soluble vitamins
Vitamins that are lipid-based and mostly nonpolar
Fat-soluble vitamins
A condition that is caused when people lack the enzyme lactase and as a result cannot digest the milk sugar lactose
Lactose intolerance
A condition in which the appendix becomes inflamed from bacteria within the feces that multiply in the appendix and cause affection
Appendicitis
A condition caused by inflammation of the peritoneum when substances such as blood or the contents of an abdominal organ leak into the peritoneal cavity
Peritonitis
A large molecule composed of triglycerides packaged with cholesterol, other dietary lipids, phospholipids, and lipid-binding apoproteins that delivers dietary lipids to cells
Chylomicron
