Tour of the Alimentary Canal Flashcards
What are the 4 main aspects of the digestive system ?
Digestion
Secretion
Absorption
Motility
What physiological processes occur in the mouth ?
The saliva within the mouth breaks down large molecules into smaller more digestible ones.
What physiological processes occur in the stomach ?
Digestion of proteins, reduction of food to liquid form and storage of the digested materials.
Enzymes from the pancreas assist in digestion of ___, ____ and _____
fats, carbs and proteins
What is released from the gallbladder/liver to assist with digestion ? and where is this released ?
Bile salts
2nd part of the duodenum through the papilla
Where in the Alimentary system are 95% of nutrients absorbed ?
The small intestine
What physiological processes occur in the large intestine ?
Water absorption, bacterial fermentation and the formation of faeces
What are the four layers of the gut tube ?
Mucosa
Submucosa
Muscularis
Serosa
What is the histology of the mucosa layer ?
Stratified squamous epithelium
What kind of epithelium is found within the mouth, oesophagus & anal canal ?
Stratified squamous epithelium
What type of epithelium is found within the stomach, small intestine and large intestine ?
Columnar epithelium
In which layer of the gut tube are glands, nerves and the blood supply ?
Submucosa
Which layer of the gut tube is responsible for peristalsis ?
The muscularis layer
Where is the myenteric plexus found ?
Between the circular layer and the longitudinal layer of muscle within the wall of the gut tube
Where does parasympathetic input come from in the alimentary canal ?
The vagus nerve (Cranial nerve X)
What nerves control saliva secretion in parasympathetic input ?
The facial nerve (Cranial nerve VII) and the glossopharyngeal nerve (cranial nerve IX)
How is sympathetic input directed to the alimentary canal ?
Via splanchnic nerves
What happens to secretions and motility in sympathetic input within the alimentary canal ?
Sympathetic is inhibitory within the alimentary system therefore secretions decrease as does motility
What happens to secretions and motility in parasympathetic input within the alimentary canal ?
Parasympathetic is excitatory within the alimentary system therefore secretions will increase as does motility
What are the 3 main arterial branches that supply the gut ?
The celiac trunk
The superior mesenteric artery
The inferior mesenteric artery
How is the venous blood drained from the alimentary system ?
Through the portal system through the liver
Chewing is controlled by which 2 processes ?
Voluntary: Somatic nerves (skeletal muscles in the mouth and jaw)
Reflexes: Contraction of the jaw muscles and the mechanoreceptors that sense food within the mouth.
Sympathetic input to the saliva glands will produce what ?
A small amount of thick, viscous saliva.
High mucous and high amylase content
Parasympathetic input to the saliva glands will produce what ?
Profuse watery saliva
