Digestive Flashcards
Accessory Digestive Organs
Parotid salivary gland
Teeth
Tongue
Sublingual salivary gland
Submandibular salivary gland
Liver
Gallbladder
Pancreas
Gastrointestinal tract (digestive organs)
OPESSLA
Oral cavity
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
Anus
BASIC LAYERS OF THE DIGESTIVE SYSTEM
Mucosa
Submucosa
Muscularis Externa
Serosa
(3) MUCOSA (MUCOUS MEMBRANE)
Epithelium
Lamina propria
Muscularis mucosae
refer to all organized lymphoid tissue found in the intestines, including Peyer’s patches in small intestine and cecal patch in colonic
GALT - (gut-associated lymphoid tissue)
Loose connective tissue but denser and usually more abundant than lamina propria
SUBMUCOSA
Contains blood vessels that are larger than in lamina propria & GALT
SUBMUCOSA
Submucosa contains
submucous plexus of Meissner
MUSCULARIS EXTERNA
Two smooth muscle coats:
Inner coat
Outer coat
Circularly oriented muscle cells
Inner coat
Longitudinally oriented muscle cells
Outer coat
ICOL
Inner-Circular
Outer-Longitudinal
Autonomic nerve fibers & neurons
Pale areas in between muscle layers
Myenteric plexus (of Auerbach)
In esophagus, small and large intestines
Morphologically very similar to smooth muscle cells
Located between nerves and smooth muscle cells
Act as pacemaker for intestinal motility
Cells of Cajal (ICC)
NOTES:
When excited (diarrhea), peristalsis will be
Faster
- movement of food/substances inside the intestines forward to the anus
Peristalsis
Outermost histologic layer
Mostly connective tissue
ADVENTITIA OR SEROSA
In areas covered by peritoneum
With simple squamous epithelium (mesothelium)
Serosa
In areas with no peritoneal covering
Blends with surrounding connective tissue
Adventitia
NOTES:
NOT all of the digestive tract is covered with serosa, some are covered with
adventitia
= within/inside peritoneum
= retroperitoneal; outside/back of peritoneum
Serosa
Adventitia
Area anterior to teeth and gums
Space between teeth & lips
Vestibule
Oral cavity proper
- hard and soft palate
- tongue
Roof
Floor
The mucosa of the oral cavity is mostly non-keratinized except what part?
Hard palate
In the oral cavity, the submucosa is not well-delineated from lamina propria because there is no
no muscularis mucosae
Glands in the oral cavity (submucosa)
Labial glands (upper and lower lips)
Buccal glands (cheek)
Palatine glands (hard palate)
In the oral cavity, the muscularis externa is present in _____ and _____
Cheeks and tongue
In the oral cavity, the muscularis is atypical because its muscle type is
Skeletal muscle
Subcutaneous tissue between muscularis externa and skin
ADVENTITIA
In the oral cavity, why adventitia and not serosa
Because there is no peritoneum (only located sa tiyan)
3 different covered surface of the lips
Oral/ Internal surface
Vermilion zone (border)
Skin side/ external surface
Muscle in the lips
orbicularis oris
The palate is divided into:
Anterior hard palate
Posterior soft palate
Anterior hard palate (possessing a____ shelf in its core)
bony
Posterior soft palate (possessing _______ in its core)
skeletal muscle
stratified squamous parakeratinized to stratified squamous keratinized epithelium
ANTERIOR HARD PALATE
ANTERIOR HARD PALATE
contains_____ tissue (anteriorly) and minor_________(posteriorly) in the oral aspect of its mucosa.
adipose
mucous salivary glands
POSTERIOR SOFT PALATE
stratified squamous_______ epithelium
nonkeratinized
Tongue is composed of
Mucosa
Smooth in ventral aspect of tongue
Rough on dorsal aspect
Epithelium is stratified squamous
Muscle of tongue
Skeletal
Anterior and Posterior tongue is demarcated by
Sulcus terminalis
Inverted v-shaped shallow furrow
Demarcates anterior ⅔ from posterior ⅓
Sulcus terminalis
ANTERIOR TONGUE
Covered by_____ papillae
lingual
Contains lingual tonsils and lymph nodules
POSTERIOR TONGUE
Covers the anterior 2/3 of the tongue
Lingual papillae
Types of lingual papillae
Types:
Filliform
Fungiform
Foliate
Vallate
Most numerous
Lacking taste buds (taste buds - sensory part)
All over anterior tongue
Filiform Papilla
Filiform papilla is covered w/ stratified squamous epithelium (________tips)
keratinized
Histology of Filiform
Keratinising layer
Orthokeratinized epithelium
Connective tissue
Muscles of the tongue
Flattened surfaces
Broader than filiform papillae
Scattered among filiform papillae
Fungiform papilla
Fungiform papilla - Pinhead-sized red dots because core contains many
______
capillaries
Mushroom-shaped structures
Taste buds are occasionally present on surface
Fungiform
Several parallel ridges on each side of the tongue
Hallow, longitudinal furrows located on the lateral aspect of the posterior region of the anterior two thirds of the tongue
Foliate papilla
Taste buds degenerate shortly after the second year of life.
Foliate papilla
Papilla arranged in a “V” along the sulcus terminalis
Circumvallate papilla
Circular papillae, each of which is surrounded by a moat-like furrow.
Circumvallate papilla
Largest (1-3 mm in diameter)
Least numerous (just 6-14)
Papilla
Circumvallate papilla
Taste buds (200-300/ papilla) on sides (lateral)
Has the most numerous number of taste buds
Circumvallate
are minor salivary glands that deliver their serous secretion into the furrow surrounding each papilla, assisting the taste buds in perceiving stimuli.
Glands of von Ebner
- has lots of hydrogen
- has lots of glucose
- glutamate (amino acid)
Sour
Sweet
Umami
Organs of taste
Ovoid, pale structures
Taste buds
Has _____cells per taste bud
50-100
Nerve supply of taste buds
CN VII
CN IX
CN X
Supplies those on anterior tongue (anterior ⅔) ; sensory
Facial nerve (CN VII)
Supply those on posterior tongue and pharynx
Glossopharyngeal nerve (CN IX) and, to a small extent, vagus nerve(CN X)
Taste buds are pale ovoid structures within the stratified epithelium
located in
foliate, fungiform, and circumvallate papillae
3 main cell types in taste buds
Gustatory/Taste/ Neuroepithelial cells
Supportive/sustentacular cells
Basal cells/stem cells
Five basic taste sensations are:
- due to hydrogen
- due to metals (NaCl)
- due to OH (hydroxyls)
- due to glucose
- due to glutamate (e.g. MSG)
Sour
Salt
Bitter
Sweet
Umami
Serous glands in lamina propria in area of circumvallate papillae
Glands of von Ebner
In submucosa under apex of tongue
Mixed glands
Like von Ebner’s glands, branched tubuloalveolar glands
Anterior lingual glands of Nuhn and Blandin
2 types of teeth
Deciduous/Milk teeth/Primary: 20 teeth
Permanent/Secondary: 32 teeth
covers the crown
hardest component of the human body, consisting of 96% calcium hydroxyapatite
ENAMEL
ENAMEL is produced by
Ameloblasts
forms the majority of the tooth
consists of a calcified connective tissue that gives the tooth its basic shape and rigidity
70% calcium hydroxyapatite
DENTIN
DENTIN is produced by
Odontoblasts
covers the root of the tooth
attaches the root to the periodontal ligament
CEMENTUM
CEMENTUM is produced by
Cementoblasts
highly vascular and well-innervated
Becomes the “sensitive” part of the teeth
PULP CAVITY
extension of the pulp cavity that contains nerves and blood vessels
ROOT CANAL
opening at the base of a root canal through which blood vessels, lymphatic vessels and nerves enter a tooth
APICAL FORAMEN
fibrous connective tissue bundles of collagen fibers inserted into both the cementum and the alveolar bone
PERIODONTAL LIGAMENT
three paired exocrine glands:
Parotid
Submandibular, and
Sublingual
synthesize and secrete salivary amylase, lysozyme, lactoferrin, and a secretory component, which complexes with immunoglobulin A (IgA)
Salivary glands
Salivary glands are what type of glands?
tubuloacinar (tubuloalveolar) glands
Glands
- proteinaceous; pyramidal
- mucosal
Serous
Mucous
Mucous acini: may be overlain with a crescent-shaped collection of serous cells called
serous demilunes
consist of serous acini and are classified as serous
PAROTID GLANDS
consist mostly of mucous acini capped with serous demilunes.
They are classified as mixed
SUBLINGUAL GLANDS
consist of both serous and mucous acini (some also have serous demilunes).
They are classified as mixed
SUBMANDIBULAR GLANDS
