Digestive system Flashcards
1
Q
What does gastric secreation consist of?
A
- Acids
- Enzymes
- Hormones and factors
2
Q
What do the acids in the stomach mucosa cause?
A
- Release and activation of pepsin, an enzyme that digests proteins.
- Somatostatin release from D cells.
- Denatures proteins so increase accessible pepsin
- Kill bacteria and other ingested microorganisms.
- Inactivates salivary amylase, stopping carbohydrate digestion that began in the mouth
3
Q
Omeprazole and proton pumps
A
- Proton pump modulates the gastric secreation
- Omeprazole irreversibly inhibits the H+/ATPase pump
4
Q
Enzymes in Gastric acid
A
- Protien breakdown in the stomach into pepsinogens
5
Q
Macronutrients
A
- Fat and lipids
- Protien
- Carbohydrates and sugars
6
Q
Key functions of the digestive sytem
A
- Ingestion - Food intake
- Digestion - Via mechanicical or chemical
- Absorbtion
- Elimination
7
Q
Gastrointestinal tract
A
- Mouth oral cavity
- Oesphogus
- Stomach
- Small intestine
- Large intestine
- Rectum and anus
Long tubes alimentary canal
8
Q
Accessories components
A
- Teeth
- Tounge
- Salivary glands
- Liver
- Gall bladder pancreas
9
Q
Lumen
A
- Epithelial tissue which moves food from the mouth to the anus
10
Q
Mucosa
A
- Thin layers of epithelium such as lamina propria and smooth muscle - contraction when increased acid content to release mucus
- Secreation of mucus digestive enzymes and hormones
11
Q
Submucosa
A
- Thick layer of loose connective tissue that contains blood and lymphatic vessels and nerves
- Glands are in layer enabling perstalsis
12
Q
Circular muscle layer
A
- Oblique muscles surrounding the submucosa layer
- Blood vessel and nerve innovation
13
Q
Longditudinal muscle layer
A
- Blood vessel and nerve innovation
- Peristalsis which is the involentary contraction and relaxation for the movement of food
14
Q
Serosa
A
- Thin sheet of connective tissue that contains blood and lympatic vessels
- This is covered by the peritoneum which secretes serous fluid to allow lubrication and sliding movement between the opposing surfaces
15
Q
Peristaltic waves
A
- Moves the bolus (after rinding food in mouth) forward propulsively
16
Q
GI motility
A
- Prevention of food entering the airways instead enters the oesophogus via the sphincter (involentary contraction and relaxing
- Allows movement dynamically from mouth to stomach - peristalsis where the circular muscles contract and longditudinal
- Ajacent segment also contract and relax alternative muscle contract and relax
- Sphicter preventing backflow at the entery point to stomach
17
Q
Gut motility
Segmentation mechanism
A
- Takes place in small intestine and large intestine
- Each segment there is a backward motion when contraction occours at two adjacent side there is a possiblity of mixing of food e.g. digestive enzyme and bolus
- Occours parallely no alternation allowing moving forward of food
18
Q
Mechanical
Mouth digestion
A
- Food enters via ingestion
- Mastication occours - chopping and grinding of food
- Teeth and tounge aid physical breakdown
19
Q
Chemical
Mouth digestion
A
- Salivary glands in the mouth secrete the amylase enzyme to digest carbs to break down into simple smaller molecules - 0.5%
- Water in saliva makes the food moist and bolous so it is easy to swallow and passage to oropharynx - 99.5%
20
Q
Oesophagus
A
- Food swallowed passes into oesophogus via narrow tube from throat to abdomen
- Initially skeletal muscle but transition into smooth muscle two thirds of the way down
- Under conscious control when breathing, eating, belching and vomiting
21
Q
Digestion process in the stomach
Cardiac sphincters
A
- Thin ring like muscle helps preventing stomach contents from going back up into the oesophagus
- Vents out air during burping
22
Q
Digestion process in the stomach
Fundus, body and antrum
A
- 3 regions of the stomach that chyme by mixing the bolus with acid and enzymes
- Where some digestion and absorbtion occours
23
Q
Digestion process in the stomach
how does the Rugae help with digestion?
A
- Series of ridges folding the stomach walls containing secretory pits
- This provides large surface area and explansion for full capacity
24
Q
Digestion process in the stomach
Function of pylorus in disgestion
A
- Sphincter that connects the stomach to the small intestine
- Prevention of the backflow of contents from the small intestine to the stomach
25
Q
Small intestine digestion
Duodenum
A
- Mixes the chyme and the secretions from gal bladder and pancreas ducts
- Absorbtion of minerals, vitamins and other micronutrients occour here
26
Q
Small intestine digestion
jejunum
A
- Segmentation and mixing of chyme and secretions
- Absorbtion of minerals, vitamins, micronutrients such as digetsted carbs, fats and protiens
27
Q
Small intestine digestion
Ileum
A
- Several folds with thin wall which mixes the digested and non-digested secretions
- Absorbtion of leftover digested carbs fats and protiens from the jejunum
28
Q
Small intestine cells structure
A
- Contains intestinal mucosa and finger like projections (Villi) which are multi folded
- The invagations are known as crypt
29
Q
Large intestine digestion
Caecum
A
- Remaining filterate from small intestine enters
- Water and electrolytes are absorbed starting from the mixing of mucus to lubricate the faeces
30
Q
Large intestine digestion
Acending, transverse, devcending sigmoid colon
A
- Completes the absorbtion of nutrients via gastrocolic reflux
- Bacteria in the large intestine produce vitamin B12 thimin and K
31
Q
Rectum
A
Storage place of the faeces
32
Q
Anal sphincter
A
- Group of muscles at the end of the rectum that surrounds the anus and controls the release of stool
