Physiology Flashcards
What is the function of epithelial cells in the mucosa?
Absorption
What is the process of segmentation called in the large intestine?
Haustration
In swallowing, what happens to the larynx? Why?
Elevates to prevent food from entering the trachea
What is xerostomia?
Dry mouth syndrome due to inadequate production of saliva
Where does most mixing/churning of food take place in the stomach?
Antrum
What is the substance produced when food mixes with gastric secretions?
Chyme
What occurs in Retropulsion?
Peristaltic wave forces chyme against closed pyloric sphincter, so chyme bounces back and undergoes more mixing
Where is the oxyntic mucosa area located?
Fundus and Body
Which cells are contained in the pyloric gland area?
D cells
G cells
What do D cells secrete?
Somatostatin
What do G cells secrete?
Gastrin
Which cells are contained in the oxyntic mucosa?
Parietal cells
Enterochromaffin-like cells
Chief cells
What do ECL cells secrete?
Histamine
What do parietal cells secrete?
HCl
Intrinsic factor
What do chief cells secrete?
Pepsinogen
What is the role of intrinsic factor in the oxyntic mucosa?
Binds vitamin B12
What is the role of histamine in the oxyntic mucosa?
Stimulates HCl secretion
What is the role of gastrin in the pyloric gland area?
Stimulates HCl secretion
What is the role of somatostatin in the pyloric gland area?
Inhibits HCl secretion
What is the storage form of iron called?
Ferratin
What are the ranges for normal BMI?
18.5-25
What are the ranges for BMI classed as overweight?
25-29
What are the ranges for BMI classed as obese?
30-39
What are the ranges for BMI classed as morbidly obese?
Greater than 40
Define satiation
Feeling of fullness during/following a meal
Define satiety
Period from end of one meal to beginning of next
What effects do satiation signals have during a meal?
Increased signals limit meal size, i.e. you can’t eat anymore
What is ghrelin?
A hunger signal - levels increase before a meal and decrease after a meal
Which 2 hormones report the “fat status” of fat stores to the brain?
Leptin
Insulin
Reduced leptin mimics starvation. True/False?
True
Name a drug that can be prescribed to tackle obesity
Orlistat
Vomiting is due to stomach contraction. True/False?
False
Stomach, oesophagus + sphincters are relaxed
Describe haustration
Intermittent contraction of circular muscle in proximal colon at slow rate to allow contents to move but leave enough opportunity for reabsorption
Which nerve conveys efferents to cause either relaxation or contraction of the external anal sphincter?
Pudendal nerve
Where does blood from the hepatic artery and hepatic portal vein meet and mix in the liver?
Sinusoids (fenestrated capillaries that enable blood to leak out into space of Disse)