Chap 16: Digestive System Flashcards
is a continuous tube extending from the mouth to the anus thru the thoracic and abdominoplevic cavities
GastroIntestinal Tract (Alimentary Canal)
These organs serve as passageway of food
GastroIntestinal Tract (Alimentary Canal)
This includes the mouth, most of the pharynx, esopahugs, stomach, small intestine, and the large intestine.
GastroIntestinal Tract (Alimentary Canal)
These are the organs the helps breakdown food by secreting fluids or providing mechanical means of digestion.
Accesory Organs
include the teeth, tongue, salivary glands, liver, gallbladder, and pancreas
Accesory Organs
The digestive tract consists of four major tunics, or layers
(1) the mucosa, (2) the submucosa, (3) the muscularis, and (4) a serosa or an adventitia
specific associated organs of the digestive system are
(1) the salivary glands, which empty into the oral cavity,
(2) the liver
(3) the pancreas.
The specific portions of the digestive tract include
(1) the oral cavity
(2) the pharynx (throat)
(3) the esophagus
(4) the stomach
(5) the small and large intestines
(6) the anus
is the movement of food from one end of
the digestive tract to the other
Propulsion
chewing
Mastication
is the consumption of solid or liquid
food, usually through the mouth
Ingestion
is the movement of food back and
forth in the digestive tract, which incorporates the digestive system’s many
secretions into the food
Mixing
is the breakdown of large organic
molecules into smaller molecules that can be absorbed
Digestion
is the addition of liquids,
enzymes, and mucus to the ingested food
secretion
is the movement of molecules out of the digestive
tract and into the blood or lymphatic system
Absorption
is the removal of undigested material, such as fiber
from food, plus other waste products from the body as feces
Elimination
loose connective tissues mucosa
lamina propria
the innermost tunic and it consists of three layers
mucosa
Musoca three layers
- inner mucous epithelium
- lamina propria
- muscularis mucosae
innermost layer of Mucosa
inner mucous epithelium
musoca thin outer layer of smooth muscle
muscularis mucosae
lies just outside the mucosa
submucosa
a thick layer of loose
connective tissue containing nerves, blood vessels, and small gland
submucosa
An extensive network of nerve cell processes forms a _____ within
the submucosa
plexus (network)
extremely important in
controlling movement and secretion within the tract
enteric plexus
In regions of the digestive tract not covered by peritoneum,
the connective tissue layer is called the
adventia
lies outside the submucosa.
muscularis
is the outermost layer of the digestive tract
serosa
the serous
membrane that covers the organs
Visceral Peritoneum or Serosa
a serous membrane that lines the
walls of the abdominal cavity and the abdominal
organs
Peritoneum
the serous membrane that
lines the wall of the abdominal cavity
Parietal Peritoneum
Consist of two layers of serous membranes with a
thin layer of loose connective tissue between them
MESENTERIES
general term referring to the serous
membranes attached to the abdominal organs
Mesentery
the mesentery associated with the small intestine
Mesentery proper
the mesentery connecting
the lesser curvature of the stomach to the liver and diaphragm
Lesser omentum
other abdominal organs that have
no mesenteries
Retroperitoneal
is the normal location for ingestion of
liquid and solid food
ORAL CAVITY
Form the lateral walls of the oral cavity
CHEEKS
the space between the lips or cheeks and the
teeth
vestibule
Are muscular structures, formed mostly by the orbicularis oris muscle
LIPS
lies inside the teeth
and houses the tongue
oral cavity proper
Located within the cheeks are the ______
buccinator muscles
A large, muscular organ that occupies most of the oral cavity
TONGUE
an anterior attachment to the floor of the
mouth by a thin fold of tissue called the
frenulum
Each tooth consists of three regions
- crown
- neck
- root
moves food in the mouth and holds the
food in place during mastication
tongue
A major sensory organ for taste, as well as one of the major organs of speech
tongue
visible portion of a tooth
crown
plays a major role in the process of
swallowing
tongue
how many teeth for adult
32
small region between the crown and
root
neck
largest region; anchors it in the bone of
the maxilla and mandible
root
Within the center of
the tooth is a hollow space called the
pulp cavity
The bulk of the tooth is formed by a living, cellular, calcified tissue called
dentin
the dentin of the tooth is covered by this hard cellular substance
enamel
The teeth are held in place within pockets in the bone, called
alveoli
surface of the dentin in the root is covered by this ; helps anchor the tooth
cementum
teeth in the middle
central and lateral incisor
road crowns and rounded suited for grinding
premolars and morals
conical fang like teeth
canine
roof of the oral cavity, separates the
oral cavity from the nasal cavity
palate
anterior part and contains bone
hard palate
Produces saliva
SALIVARY GLANDS
posterior part and consists of
skeletal muscle and connective tissue
soft palate
a posterior extension of the soft palate
uvula
boundary of oral cavity ; opening going thru the pharynx to throat
fauces
are located in the lateral posterior walls of
the oral cavity, in the nasopharynx, and in the
posterior surface of the tongue
Tonsils
They have branching ducts with clusters of alveoli at
the ends of the ducts
SALIVARY GLANDS
largest; serous glands located
just anterior to each ear
parotid glands
produce more serous
than mucous secretions
submandibular glands
smallest; produce primarily
mucous secretions
sublingual glands
mixture of serous and mucous fluids; have
multiple roles
saliva
roles of saliva
- Helps keep the oral cavity moist
- It has protective functions
- Begins the process of digestion
pharynx 3 parts
★ Nasopharynx
★ Oropharynx
★ Laryngopharynx
a digestive enzyme in the
serous part of saliva that breaks down starch
Salivary amylas
Connects the mouth with the esophagus
PHARYNX (THROAT)
for respiration only
Nasopharynx
digestive and respiratory function
Oropharynx
The
posterior walls of the oropharynx and laryngopharynx are formed by the
superior, middle, and inferior pharyngeal constrictor muscles
inferior pharynx
Laryngopharynx
transfers food from pharynx to stomach
esophagus
a muscular tube, lined with
moist stratified squamous epithelium, that extends from the pharynx to
the stomach
esophagus
located at the upper and lower ends of the esophagus,
respectively, regulate the movement of food into and out of the esophagus
esophageal sphincters
storage and mixing chamber
stomach
Transports food from pharynx to the stomach.
swallowing
swallowing phases
(1) the voluntary phase
(2) the pharyngeal phase
(3) the esophageal phase
a bolus, or mass of food, is formed in the mouth. The tongue pushes the bolus against the hard palate. This
forces the bolus toward the posterior part of the mouth and into the oropharynx
voluntary phase
This phase is initiated when a bolus of food stimulates receptors in the oropharynx to elevate the soft palate, closing off the nasopharynx
pharyngeal phase
is responsible for moving food
from the pharynx to the stomach
esophageal phase
stomach 4 regions
cardiac part
fundus
body
pyloric part
The part
of the stomach to the left of the cardiac part, the ______, is
actually superior to the cardiac opening.
fundus
The largest part of the stomach
body
helps regulate
the movement of gastric contents into the small intestine
pyloric sphincter
The body narrows to form the funnel-shaped _____ part of the stomach
pyloric part
The submucosa and mucosa of the stomach are arranged in large folds called
rugae
muscularis layers
(1) an outer longitudinal layer
(2) a middle circular layer
(3) an inner oblique layer
which produce regulatory hormones and paracrine signal
molecules
endocrine cells
The epithelial cells of the stomach can be divided into five groups
(1) surface mucous cells
(2) mucous neck cells
(3) parietal cells
(4) endocrine cells
(5) chief cells
which are found on the inner surface of the stomach
and lining the gastric pits. These cells produce mucus that coats and protects
the stomach lining
Surface mucous cells
which produce hydrochloric acid and intrinsic factor
parietal cells
which produce pepsinogen and pepsin
chief cells
major site of the nutrient absorption
duodenum and jejunum
body’s major digestive organ
small intestine
small intestine 3 divisions
- duodenum
- jejunum
- ileum
Tiny, fingerlike projections of the mucosa
Villi
The mucosa and submucosa form a series of circular folds
that run perpendicular to the long axis of the digestive tract
Circular folds
mucous glands in the
submucosa of the duodenum, which open into the
base of the intestinal glands
Duodenal glands
Most of the cells composing the surface of the villi have
numerous cytoplasmic extensions ; increase surface area
Microvilli
clusters of lymphatic nodules that
are common along the entire length of the digestive
tract and are numerous in the ileum
Peyer Patches
the site where the ileum
connects to the large intestine
Ileocecal junction
terminal portion of GI tract
large intestine
allow the
intestinal contents to move from the ileum to the
large intestine, but not in the opposite direction
Ileocecal sphincter and ileocecal valve
The proximal end of the large intestine where it joins
with the small intestine at the ileocecal junction
CECUM
formation of feces
large intestine
extends superiorly from the
cecum to the right colic flexure, near the liver,
where the colon turns to the left
Ascending colon
Attached to the cecum is a tube about 9 cm long
called the
appendix
extends from the right colic
flexure to the left colic flexure near the spleen,
where the colon turns inferiorly
Transverse colon
extends from the left colic
flexure to the pelvis, where the colon becomes
the sigmoid colon
Descending colon
forms an S-shaped tube that
extends medially and then inferiorly into the
pelvic cavity and ends at the rectum
Sigmoid colon
A straight, muscular tube that begins at the
termination of the sigmoid colon and ends at the
anal canal.
RECTUM
It begins at the inferior end of the rectum and ends
at the anus.
ANAL CANAL
largest internal organ of the body
liver
liver 2 major lobes
right and left lobe
liver 2 minor lobes
caudate and quadrate lobe
carries nutrient-rich blood
from the digestive tract to the liver
Hepatic Portal Vein
delivers oxygenated blood to
the liver
Hepatic Artery
inferior surface of the liver
gall bladder
functional cells of the liver
hepatocytes
both endorcine and exocrine tissues
pancreas
