The digestive system Flashcards
What is the alimentary canal?
The continuous musclar tube running from mouth to anus
How long is the gastro intestinal tract?
5-7m
What is peristalsis?
The action that moves things through muscular tubes
Name component x:
Submucosal plexus (plexus of Meissner)
What is the submucosal plexus (plexus of Meissner)
A neural network located within the submucosa
What is component x?
Glands in the submucosa
What is component x?
The submucosa
What is component x?
Glands in mucosa
What is component x?
Lymphatic tissue
What is component x?
Lumen
What are components A, B & C?
A - Epithelium
B - Lamina Propria (areolar tissue)
C - Muscularis Mucosae
What is the serosa and what are its two components ?
Serous membrane (serosa) is smooth tissue membrane that secretes serous fluid. It consists of:
-Areolar connective tissue
-Epithelium
What is component x?
The myenteric plexus (Auerbach’s plexus)
What type of tissue is sub mucosa?
Dense irregular connective
What is component x?
Mesentery
Where is stratified squamous epithelium found within the alimentary canal?
-Mouth
-Oesophagus
-Oropharynx
-Anal canal
(because it is usually more protective)
What is interstitial fluid?
Fluid found in the spaces around cells. It comes from substances that leak out of blood. It helps bring oxygen and nutrients to cells and to remove waste products from them.
What happens to excess interstitial fluid around the cells?
It is drained away by lymphatic capillaries and into the lymphatic system to become lymph.
What does MALT stand for and why is it important?
Mucosa Associated Lymphoid Tissue
Reservoirs for the immune system. Once it has been introduced to a pathogen it remembers and retains it ready for the next encounter.
Where is the parotid salivary gland located?
In front of the ear
Where is the sublingual gland located?
Under the tongue (these glands produce around 70% of saliva)
Where is the submandibular gland?
Deep in the mouth, can be felt at the top of the neck.
Where is the uvula?
What are the gingivas?
The tissue around the base of the teeth (gums)
What are the labiums?
Lips
Where are the fauces?
Where are the frenulums?
What are vestibules?
Gap between the lips and cheeks, and the gums and teeth
At what point does the oesophagus enter the peritoneal cavity?
Level with the 10th thoracic vertebrae
What kind of muscular fibres are on the outer layer of the stomach?
Longitudinal fibres
What kind of muscular fibres are on the middle layer of the stomach?
Circular fibres
What kind of muscular fibres are on the inner layer of the stomach?
Oblique fibres
What are rugae?
Ridges formed inside the stomach
What are omenta?
Folds of peritoneum that connect the stomach to other viscera. Includes the lesser (double layer connecting the liver to the lesser curvature and duodenum) and greater (double layer spanning from the greater curvature to the transverse colon).
Where are mucous cells and what do they do?
A - They secrete mucous that protects the lining from acids, enzymes and abrasive materials
Where are parietal cells in the stomach lining and what do they do?
B - Responsible for gastric acid secretion (Including hydrochloric acid and intrinsic factor)
Where are chief cells in the stomach lining and what do they do?
C - The gastric chief cell (also known as a zymogenic cell or peptic cell) release proenzymes like pepsinogen and chymosin. Pepsinogen is activated into the digestive enzyme pepsin when it comes in contact with hydrochloric acid produced by gastric parietal cells.
Where are G cells in the stomach lining and what do they do?
D - G-cells are neuroendocrine cells responsible for the synthesis and secretion of gastrin, a peptide hormone that stimulates the parietal cells to secrete hydrochloric acid
What are the four main parts of the stomach?
-Cardia
-Fundus
-Body
-Pylorus