Week 12 GI Flashcards
What are the main components of the GI tract?
Oral cavity
Esophagus
Stomach
Small & large intestines
What are the 4 basic histological layers of the GI tract?
Mucosa
Submucosa
Muscularis externa
Serosa/Adventitia
Describe the gingiva
Gingiva = gums
Lightly keratinized stratified squamous epithelium
Richly vascularized lamina propria
What is the most common dental pathology in children and adults?
Gingivitis
Bacterial invasion results in accumulation of plasma cells/B cells in the lamina propria and destruction of collagen.
Describe oral mucosa
Stratified squamous epithelium
Basement membrane
Lamina propria
3 types:
Lining (lips, cheeks, soft palate)
Masticatory (gingiva, hard palate)
Specialized (dorsum of tongue)
What are the major salivary glands?
Parotid
Sublingual
Submandibular
Structure and function of salivary glands
Salivary glands are made up of serous and mucous cells surrounded by myoepithelial cells.
Striated ducts modify secretions by resorbing Na creating a hypotonic secretion.
What types of secretions come from the:
1. Parotid gland
2. Submandibular gland
3. Sublingual gland
- Totally serous
- Mostly serous
- Mostly mucous
What do glands secrete?
Amylase
Mucous
Bacterial lysozyme
Immunoglobulins
What is the 25 rule?
The GI tract is about 25 ft long
The esophagus is about 25 cm long
Discuss the structure of the esophagus
Mucosa
Submucosa
Muscularis externa
Adventitia
Mucosa: strat squam nonkeratinized epithelium, with underlying lamina propria and muscularis mucosae.
Small mucous glands release thin highly viscous mucous film to lubricate luminal surface.
Multilayer epithelium protects against abrasion. Renews 14-21 days.
Discuss the difference between the upper esophagus, middle esophagus, and lower esophagus
Upper: 2 layers of skeletal muscle
Middle: mixed skeletal and smooth muscle
Lower: 2 layers of smooth muscle
What delineates the esophagogastric junction?
Zigzag (Z) line: juncture of esophageal and gastric mucosa.
SSNKE transitions to simple columnar epithelium.
What are the anatomic regions of the stomach?
Cardia
Fundus
Body
Pylorus
What are the 4 layers of the stomach wall?
Mucosa
Submucosa
Muscularis externa
Serosa
What are the main cells types of the stomach?
Surface mucous cells
Mucus neck cells
Parietal cells
Chief cells
Enteroendocrine cells
What do parietal cells secrete?
HCl
Intrinsic factor
What do chief cells secrete?
Pepsinogen
Lipase
What is the proximal portion of the small intestine?
Duodenum
What sphincter controls the movement of chyme from stomach to small intestine?
Pyloric sphincter
Function of Brunner glands
Secrete alkaline mucous to neutralize acidic chyme.
What structure pierces the duodenum 2/3 of the way down?
Major duodenal papilla from common bile duct and main pancreatic duct.
What lines the villi of the duodenum?
Enterocytes
Goblet cells
What is the middle portion of the small intestine and what structures are show up?
Jejunum
Lymphatic lacteals
What is the distal portion of the small intestine and what new cells are present?
Ileum
Paneth cells that control bacteria are present at the base of intestinal glands (crypts)
List the sections of the colon
Cecum
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
What innervates the cecum to and including the transverse colon?
CNX
What innervates the descending colon to and including the rectum?
S2,3,4
Discuss the changes in the large intestinal wall.
Lacks villi
Contains intestinal glands
Numerous goblet cells
Fewer enterocytes
Lympohid nodules present
Discuss the anorectal junction
Transition from colonic mucosa to SSNKE
What plexi make up the enteric nervous system and what types of nerves are they?
Myenteric plexus - between inner circ and outer long muscularis externa layers.
Submucosal plexus - lies above submucosa.
Autonomic nerves, both sympathetic and parasympathetic.
What are considered constitutional symptoms?
Fatigue and weakness: ask about when it occurs (ie normal response to stress/work vs abnormal/out of character d/t depression, infection, endocrine, etc.)
Fever, chills, night sweats (recurrent chills - possibly systemic bact. infection. night sweats - menopause, TB, malignancy)
Weight change (unintended weight loss, rapid weight gain, meds, nutrition)
Pain
What are we routinely looking for in a general survey of a patient?
Height, weight, BMI, risk for obesity.
How do you assess the patient’s general appearance?
Apparent state of health: acutely or chronically ill, frail, fit, robust.
Level of consciousness: awake, alert, responsive.
Apparent state of discomfort or distress: cardiac or respiratory distress, pain, anxiety or depression, pallor, diaphoresis, fidgety, flat affect, eye contact.
Skin colour and obvious lesions: Pallor, cyanosis, jaundice, rashes, bruises, etc.
Dress, grooming, personal hygiene: suitable clothing for weather, quality of footwear may suggest calluses, bunions, piercings, fingernails, dementia.
Facial expression: Parkinsonian mask, hyperthyroidism, depression.
Body and breath odor: diabetes, alcohol, liver failure.
Posture, gait, motor activity
Height and weight
Vitals: BP, pulse, HR, RR, temp, pain, physical activity
List the head and neck lymph nodes to be assessed.
Occipital
Posterior auricular
Preauricular
Anterior superficial cervical
Posterior cervical
Tonsilar
Submandibular
Submental
Supraclavicular
Deep cervical
Common or concerning symptoms of the head and neck.
Neck mass or lump
Thyroid mass, nodule, or goiter
Neck pain
Headache
Key components of the head and neck exam.
Examine hair: quality, distribution, texture, patterns of loss.
Examine the scalp: scaliness, lumps, nevi, lesions.
Examine the skull: size, contour, deformities, depressions, lumps, tenderness.
Inspect the skin of head and face: expression, contours, asymmetry, involuntary movements, edema, masses.
Palpate the cervical lymph nodes: size, shape, delimitation, mobility, consistency, tenderness.
Examine the trachea: deviation, breath sounds over it.
Examine the thyroid gland: shape, size, consistency.
What is the significance of an enlarge supraclavicular lymph node, especially on the left?
Virchow’s node
Suggests possible thoracic or abdominal malignancy.
What is the protocol if enlarges or tender lymph nodes are found?
- Re-examine the regions they drain.
- Assess nodes in other regions to identify regional from general lypmphadenopathy.
Discuss examination of the thyroid gland
- Inspect region below cricoid cartilage and identify contours of the gland.
- Observe patient swallowing, watching for upward movement of all structures,
and symmetry. - Palpate thyroid while swallowing.
4.. Palpate the gland outlines, isthmus, and both lobe. - If there is tenderness listen for bruit over lateral lobes.
