Week 10 - Gastrointestinal System Flashcards
What is the muscular makeup of the external muscle of the oesophagus
Upper 1/3 - skeletal
Middle- skeletal and smooth
Lower 1/3 - smooth
What major organ does the oesophagus lay posterior to
Heart
What muscle does the oesophagus pierce through to get to the stomach
Diaphragm
Name of sphincter which prevents acid reflux
Cardiac/lower oesophageal sphincter
Incisura angularis
Divides the stomach into left and right sections
3 sections of stomach from top to bottom
Fundus
Body
Pyloric part
Stomach location
Mainly left hypochondrium and epigastric region of abdomen
Stomach abdo aorta major branch
Coeliac trunk
What different about layer of muscle in stomach
3 layers of muscle - extra internal layer of smooth muscle called oblique layer -> Circular muscle -> Longitudinal muscle
Function of the liver
Storage of glycogen
Release of glucose
Inactivation of hormones and drugs
Production of bile
Production of platelets
Production of clotting factors
Metabolism
Excretion of waste
Size, weight and location of spleen
1 inch thick, 3 inches wide, 5 inches long, 7 ounces in weight, between 9th and 11th ribs (1,3,5,7,9,11)
Why is the splenic artery so tortuous
to allow a continuous supply of blood instead of it being pulsatile
Function of the spleen
Identifies, removes and destroys old red blood cells
Stores RBCs and platelets
Can you live without your spleen
Yes but you require daily antibiotics
Large intestine specialisations
Omental appendages (fatty tags) (mostly in transverse+descending colon)
Haustrations - sacculations of bowel wall
Taeni coli - longitudinal band of muscle
What controls secretions into the cecum
Ileocecal valve (sphincter)
Role of cecum
Fibre fermentation commencement
Fart production
Fluid absorption
Synthesis of some vitamins
Path of food through large intestine
Cecum
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Anal canal
What does coeliac artery supply
Lower half of oesophagus -> upper half of duodenum
Liver
Spleen
What does superior mesenteric artery supply
Lower half of duodenum -> first 2/3 of transverse colon
What does inferior mesenteric supply
final 1/3 of tranverse colon -> rectum
What is the main function of the large intestine
Water absorption
4 main histological layers to the small intestine
Mucosa
Submocosa
External muscle
Serosa
Type of epithelium found in small intestine
Stratified columnar epithelium
Type of epithelium in stomach
Stratified columnar epithelium
Type of epithelium in oesophagus
Stratified (non-keratinised) squamous epithelium
Function of lamina propria
Thin layer of connective tissue which lies beneath epithelium.
> Inflammatory cells
> Provides support and nutrients to epithelium
Function of muscularis mucosae
Smooth muscle that sits beneath lamina propria
Function of submucosa
Dense irregular connective tissue containing:
> Blood vessels
> Nerves
> Lymphatic vessels
Function of muscularis externa
Inner circular layer and outer longitudinal muscle
Responsible for peristalsis
Serosa
Outer layer of connective tissue which reduces friction of GI tract.
Where is submucosal plexus
Between submucosa and circular muscle
Myenteric plexus
Between circular muscle and longitudinal muscle
What is a lacteal
A vessel that absorbs fat in the small intestine
Which 2 cell types make up the colonic glands
Absorptive cells and mucous secreting goblet cells
What are the exocrine secretions of the pancreas
Pancreatic enzymes - endopeptidases and exopeptidases
What are the endocrine secretions of the pancreas
Insulin, glucagon and somatostatin
Name of endocrine section of the pancreas
Islet of langerhan’s
What is the aterial supply to the gall bladder
Cystic artery which branches off the right branch of the proper hepatic artery
Which main blood vessel supplies the gall bladder
Coeliac trunk
What are gall stones
Crystalised masses that can contain cholesterol or pigment or both
