phase 1

What is the alternative name for the digestive system

Alimentary system

What are the two main functions of the alimentary system

Digestion and reabsorption

What is are the main components to the digestive system

Oral tract

Hard palate

Soft palate

Pharynx

Oesophagus

Stomach

Small intestine

Large intestine

What are the accessory components of the digestive system

Liver

Pancreas

Salivary ducts

gall bladder

What is the function of the salivary glands

Buffer pH of the mouth

Protect mouth and gut

Taste

Antimicrobial action

What is the main function of the gallbladder

To store the bile that is produced by the liver

What is the opening and end to the alimentary canal

Mouth - opening

Anus - termination

What is the function of the pharynx

For air and food to pass through, it can either split into the trachea or the oesophagus

What is the oesophagus

A muscular tube which carried food from the pharynx into the stomach where it will be digested

What are the parts of the pharynx and where are they found

Nasopharynx - nasal/oral tract to the soft palate

Oropharynx - soft palate to the epiglottis

Laryngopharynx - epiglottis to the trachea/oesophagus

What is the action of digestion in the stomach

Churning

What is the product that is made after being churned in the stomach

Chyme - this is a mix of food with the acid and enzymes produced by the stomach to break it down.

What does the stomach secrete to help with churning

Acid and enzymes

What are the sphincters of the stomach called

Cardia sphincter

Pyloric sphincter

What does the cardia sphincter connect

The oesophagus to the stomach

What does the pyloric sphincter connect

The stomach to the duodenum of the small intestine

What are the regions of the small intestine called

Duodenum

Jejunum

Ileum

What are the regions of the large intestine

Caecum

Ascending colon

Transverse colon

Descending colon

Sigmoid colon

What is the sphincter called between the ileum and caecum

Ileocaecal sphincter

Where does bile and pancreatic juices enter

At the duodenum

Through the great duodenal papilla

And stops at the deodenojejunal junction

What is the role of bile

It aids in fat digestion

What is the role of pancreatic juices

Fat, protein, carbohydrate and starch digestion

and they also have bicarbonate ions which maintain the alkaline nature of the small intestine

What happens to the food that is not digested and absorbed at the ileum

It will pass through as faeces

What structures are found in the mucosa

epithelia

lamina propria

muscularis mucosa

What are the layers to the digestive system

mucosa

submucosa

muscularis externa

serosa/aventitia

What structures are found in the muscularis externa

longitudinal muscle

circular muscle

oblique muscle

What is the role of lamina propria

it lines the epithelia, it has inflammatory cells and also supports and provides nutrients for the epithelia

What is the role of the muscularis mucosa

it is a smooth muscle

What is an additional structure found in the small intestine and what are their role

Villi, their role is to increase surface area to aid with absorption

What is the role of the muscularis externa

This is a smooth muscle which aids in peristalsis

What is the nerve plexuses of the digestive tract

Meisseners and Auerbach plexus

What is the function of brunner glands

They secrete bicarbonate ions to neutralise the acidity of the stomach

What is the role of Peyer patches

they are lymphoid follicles which have an immune role and ensure that no dangerous bacteria grows

What are the regions of the stomach

Hypochondrium (left and right)

Lumbar (left and right)

Iliac fossa (left and right)

Epigastric

Umbilical

Supra pubis

What muscles are found in the oesophagus

Skeletal

Both

Smooth

What are the 3 separating lines of the abdomen

Misclavicular (x2)

Subcostal

Intertubecular

What is the structure called which connects the great curvature of the stomach to the transverse colon

Great omentum

What are the main gross structures of the stomach

The cardia

Cardia sphincter

Fundus

Body

Pylorus

Pyloric sphincter

What are the folds of the stomach called

Rugae

What are the muscular layers of the cell wall

Outer longitudinal

Inner circular

Innermost oblique

What is the function of the rugae folds

To increase the surface area

What are the cells of the stomach mucosa

endocrine

parietal

chief

mucous neck

What is the function of endocrine cells

They produce gastrin - gastrin is responsible for activating the parietal cells

What is the function of the parietal cells

They produce the hydrochloric acid and this converts the pepsinogen to pepsin

What is the function of the chief cells

They produce pepsinogen

What is the function of the mucous neck cells

they produce mucous and act as a stem cell for gastric epithelium, they protect the mucous membranes

What is the difference in the epithelium in the small intestine

It has small finger like projections called villi which help increase surface area to aid in absorption

Where do the bile and pancreatic ducts enter the duodenum

Through the great duodenal papilla

What is the role of Brunners glands

They secrete alkaline so that the mucosa is not damaged by the stomach acid

Where are brunner glands found

In the duodenum

What is the function of the pancreas

It has exocrine and endocrine functions

Exocrine has a function in digestion and endocrine is hormonal

What are the exocrine functions of pancreas

They produce bicarbonate ions which can neutralise the acidity from the stomach

They have enzymes which are essential in digestion

What are the endocrine functions of the pancreas

They produce insulin, glucagon and somatostatin.

Role of insulin

This converts glucose to glycogen and it can then be stored in the liver

role of glucagon

It converts glycogen to glucose for use

Role of somatostatin

Reduce acid secretion to decrease digestion

What is the role of islets of langerhans

They secrete hormones for glucose regulation

List the roles of the liver

Produce bile

Produce proteins for clotting factors

Hormone and drug metabolism

Detoxifies everything that passes though the GI tract

Glucose regulation

What are the blood supplies of the liver

Hepatic artery

Hepatic portal vein

Role of the hepatic portal vein

This takes blood from other organs and it can be processed in the liver

What is the blood supply of the GI tract

Coeliac artery - foregut

Superior mesenteric artery - midgut

Interior iliac artery - hindgut

Where is the foregut found

Oesophagus to half of the duodenum

Where is the midgut found

second half of duodenum to the 2/3 of the transverse colon

Where is the hindgut found

From the last 1/3 of the transverse colon to the rectum

What are the regions of the large intestine called

Ileocaecal valve

Caecum

Ascending colon

transverse colon

Descending colon

Sigmoid colon

rectum

What type of peritoneum are the regions of the colon

Caecum - intraperitoneal

Ascending - retroperitoneum

Transverse - intraperitoneum

Descending - retroperitoneum

What is the function of the ileocaecal valve

To prevent reflux from the large intestine

What are the arches of the large intestine called

Hepatic flexure

Splenic flexure

Where does the sigmoid colon descend to

S3

What is the incomplete layers of longitudinal muscle called in the large intestine

Taenia coli

What are the lump like structures called in the large intestine

Hastruations

What is the venous drainage of the GI system

Femoral - lower limbs

Internal iliac veins - pelvis

Renal veins - kidneys

Hepatic veins - liver

What are the pouches of fat in the transverse and sigmoid colon called

Appendice epiploice

What is the role of goblet cells

produce mucous

What are the branches of the abdominal aorta in order

Coeliac

Renal

Superior mesenteric

Gonadal x2 (one on each side)

Inferior mesenteric

Common iliac - this then branches into the external iliac and the internal iliac

What are the main components of the diet

Carbohydrate

Protein

Fat

Vitamins

Minerals

Fibre

Water

Function of carbohydrates

They form part of the proteoglycans

They are also an energy source

What is the function of proteins

they are used in repair and growth as they form enzymes and structural proteins

What is the function of fats

they are an energy store, they provide insulation and can be found in the plasma membrane

What are the functions of vitamins

Vitamin A - vision

Vitamin C - antioxidant

Vitamin D - calcium (bone resorption)

Vitamin K - clotting factors

What are the functions of minerals

Bone mineralisation - calcium

Oxygen and blood transport - iron

What is the role of fibre

it is an osmotic agent, meaning it absorbs water, when it does this it can produce more water in stools making them looser

What are proteins made up of

20 amino acid polymers joined by a peptide bond

what are essential amino acids

amino acids we must obtain from our diets

List the types of essential amino acids

Phenylanine

Valine

Lysine

Leucine

Isoleucine

Tryptophan

Threonine

Methoionine

Histidine

What are the three types of monosaccharide

glucose

fructose

galactose

What are the 3 types of disaccharide

Sucrose

maltose

lactose

What is maltose make due up of

glucose and glucose

what is sucrose made up of

glucose and fructose

What is lactose made up of

glucose and galactose

What type of bond holds together disaccharides and polysaccharides

glycosidic bond

What is the most common type of polysaccharide

starch - made up of all glucose molecules

What is the average recommended calories/energy for males and females

females 200kcal/day

males 2500kcal/day

Outline the breakdown process of a carbohydrate

Carbohydrate > disaccharide > monosaccharide

what are carbohydrates

Monosaccharides

Disaccharides

Polysaccharides

Outline the digestive process of a protein

Protein > peptide > amino acid

Outline the process of breakdown for a triacylglycerol

Triacylglycerol > free fatty acid, glycerol, diacylglycerol, monoacylglycerol

Why are carbohydrates broken down

they cannot be absorbed whole, so must be digested into a form where they can be absorbed into the body

What is the process of digestion in the mouth called

Mastication