GASTROINTESTINAL Flashcards
What is the alimentary canal?
Also called the GI tract- mouth to anus- plus accessory organs (teeth, tongue, salivary glands, liver, gallbladder, pancreas)
What are the walls of the GI tract?
Mucosa
Sub mucosa
Muscular is
Serous/adventita
What is mucosa?
Inner layer- has 3 distinct layers
Epithelium- epithelial cells- rapid renewal, comes into contact with digested food
Lamina propria- many blood vessels and lymph tissues MALT lives here
Muscularis mucosa- smooth muscle fibers, has many folds for better absorption especially in stomach and small intestines
What is submucosa?
Binds muscles to muscularis layers, many blood vessels and lymphatic vessels and a neural plexus called the sub mucosal plexus
What is the muscularis layer?
Muscle layers
Skeletal muscle (voluntary) in mouth, pharynx, esophagus and external sphincters
Smooth muscle ( involuntary) everywhere else, contains the Myentaric neural plexus, these muscles contract and relax to help break down food and mix it with secretions and propel it forward
Inner sheet of circular fibers
Outer sheet- of longitudinal fibers
What is the serous a/adventitia layer do?
Outermost layer
A serous membrane
Attaches organs to surrounding tissues in the abdominal cavity
Not found in esophagus
This layer is also called the visceral peritoneum
What does the salivary glands do-
Produce saliva or salivary amylase (breaks down carbs)
Begin the chemical breakdown of food
Controlled by parasympathetic of ANS
Where is the parotid gland?
In cheek
Where is submandibular?
Floor of mouth
Where is sublingual
Beneath the tongue
What kind of muscles does the tongue have?
Skeletal muscles covered by a mucus membrane
What are the tongues extrinsic muscles?
Originate outside the tongue, move food around to form a blus
Hat do the intrinsic muscles of the tongue do?
Originate inside the tongue, and changes shape
What does the surface of the surface of the tongue do/have?
Covered with papillae with taste buds
What does the lingual glands do?
Secrete mucus, lingual lipase (triglyceride digestion)
What does teeth do in digestion?
In sockets in mandible and maxilla bones held in by periodontal ligaments
What is the pharynx composed of and what does it contain?
Skeletal tissue and lined with mucus membranes
Nasophaynx
Orophayrnx
Larynfopharynx
Peritoneum- what is it and what are the 2 layers called?
Wraps around the abdonminopelvic organs
The largest serous membrane in the body
Made of large folds that bind organs together and bind them to the abdominal walls
2 layers filled with a lubricating serous fluid called
Parietal peritoneum- lines the walls of the abdominal cavity
Visceral- covers the alimentary canal and some organs in the abdominal cavity
The largest folds of the peritoneum have names- what are they?
Greater omentum
Lesser omentum
Mesentary
Mesocolon
Falciform ligament
What is the greater omentum
Largest peritoneum fold
Called the “fatty apron”
Drapes over the transverse colon and small intestines
Many blood vessels
Lymph nodes
Lymph nodes
Adipose tissue like a “beer belly”
What is in the retroperitoneal space?
Kidney and ureters
Most of the pancrease
Adrenal glands
Aorta (abdominal)
Inferior vena cava
Esophagus-what is its role?
Secretes mucus and transport food to stomach by peristalsis
What does the superior/upper 1/3?
Skeletal muscle (upper sphincter lives here)
Hat does the middle 1/3 esophagus consist of?
Both
Skeletal muscle
And
Smooth muscles
What does the inferior or lower 1/3 esophagus
Smooth muscles (lower sphincter lives here)
Pancreatic amylase
Carbohydrates digestion
Typsin (inactive form)
Protein digestion
Chymotrypsin (activated by ?)
Activated by trypsin
Protein digestion
Carboxypeptidase (activated by?)
Activated by trypsin
Digests protein
Elastase
Activated by trypsin
Protein digestion
Pancreatic lipase
Triglyceride digestion
Ribonuclease
RNA digestion
Deoxyribonuclease
DNA digestion
Salivary amylase
From salivary glands
Digests carbohydrates
Lingual lipase
Lingual gland
Digests triglycerides
Gastric juices
Pepsin
Stomach chief cells
Digests proteins into peptides
Gastric lipase
Stomach chief cells
Digest triglycerides
Pancreatic juices
[pancreatic amylase
Digests Carbohydrates
What do chief cells do- and where are they found?
Secrete pepsinogen and gastric lipase
Parties all cells in the stomach
Produce hydrochloric acid and intrinsic factor (for absorption of B12)
Stomach g-cells
Secretes a hormone called gastric
Stomach anatomy
Cardia
Fun days
Body
Pyloric antrum
Pylorus
Rugged- large folds in the mucosa that allow it to fully expand when full
Pyloric sphincter
Mucous neck cells
Secrete alkaline mucus (protective layer from acid)
What is the pancreas made up of?
99%
Clusters of cells called acini that secrete fluids and digestive enzymes called pancreatic juices
1%
Clusters of cells called pancreatic islet that secrete hormones (glucagon, insulin somatostatin, pancreatic polypeptide)
What is pancreatic juices?
Mostly
Water
Salts
Bicarbonate
Enzymes
Falciform ligament
Separates lobes
Coronary ligament
Attaches liver to diaphragm
Ligamentum teres
(Round ligament )
Forms part of the Falciform ligament and attaches liver to the umbilicus
What is the liver anatomy
Hilum
Capsules
Associated vessels
Canals
Ducts and
Ligaments
Emulsification means
Breaks down fats
Where are kupffer cells?
Liver
What are liver cells called?
Hepatocytes
Kupffer cells
Clean up crew- phagocytes
Hepatic portal vein
Brings deoxygenated blood that is fresh from the GI tract so it is nutrient rich but also may have drugs, toxins or possibly microbes that were digested
What is a portal triad made up of?
Bile duct
Portal vein
Hepatic artery
