Gastrointestinal System Flashcards
What are our acessory digestive organs
> Liver
Pancreas
How long is the GI tract ?
Possible exam question
> 5-7 metres
REVISION CARD:
Any food is outside the body because it’s the eosophagus is open to the external environment meaning it’s NOT sterile !
Bugs can enter EASILY🫤
Accessory organs inside the alimentary canal?
Hint: it’s 2 of these
Salivary glands
Teeth
Tongue
Liver
Pancreas
Gall bladder
Teeth and tongue
Where does propulsion occur
Oesphagus
What are the steps to mechanical ingestion.
Chewing (mouth)
Churning (stomach)
Segmentation (stomach)
Since Propulsion means foods being pushed what other 2 things do humans do to push food down?
Swallowing
Peristalsis
What is segmentation
Constriction of muscles in rhythmic motion. Breaking food down into smaller particles. Mixes food with digestive juices
What process out of the 5 does enzymes secrete into the lumen of the canal
Chemical digestion
Which accessory organs severete digestive Tract lumen?
Pancreas
Gall bladder
Salivary glands
4 main layers of the GI tract
> Inner:
Mucosa
submucosa
Muscle
Adventitia
Outter
How many layers of mucosa
3
What 3 layers is the muscusa made of
> Inner:
Epithelium
Lamina propria
Muscularis mucosae
Outter
What does the mucosa secrete?
Hormones
Digestive enzymes
Mucus
Absorbs nutrients
Protects by kills pathogens & protects ingestion of its self
( Has a secretery function & absorption function )
Epithelium is where ?
Inner part of the lumen
The mouth, oesophagus, oropharynx & anal canal is surrounded by what type of epithelial tissue?
Stratified squamous epithelium
What is stratified squamous epithelium?
Short fat cells.
Where’ would you find stratified squamous epithelium ?
Mouth
Eosophagus
Oropharym
Anal canal
Where would you find culmner epithelium
Everywhere else
Where does this occur ? Enzyme secreting and hormone secreting ?
Stomach and small Intestines
The process of scretion of hormones & enzymes help the small intestine to produce what?
Serotonin
Is serotonin a happy or bad chemical..?
Happy as it makes us feel happy whilst eating !!!
Why is the digestive system a endocrine organ
Because it secretes hormones and Enzymes required for digestion !!
Lamina propria (is in the mucosa) has a lot of …….. what that allows the absorption & delivery of nutrients?
Capillaries
What else does the lamina propria contain
Lymphatic tissue
How thick is a wall of a capillary ?
Single cell layer thick
What does the lymphatic capillaries absorb ?
Muck & nasties
What organs are involed in lymphatic system
Lymph glands
Why do your lymph node/ glands swell up or become visibly big ?
In that area it works hard to flush away the nasty infection. Because they’re facilitating protecting you from infection !!
(Draining)
What system does the lymphatic vessels run in conjunction with
Cardiovascular system !!
So…why does the mucosa have lymphatic tissue in it?
Drains all nasty stuff away
Lymphatic Tissue is also called this. What does MALT Stand for ?
Mucosa associated lymphoid tissue
Why is MALT special
It’s because when you are introduced with a new pathogen it remembers what pathogen it is for the next encounter!!
What else does MALT have that’s important ?
Resevoirs for immune system
How many layers of muscles doe the GI tract have
2
How many layers of muscles does the stomach have ?
3
What are the muscles of the GI tract ?
Longitudinal muscle & circular
What muscle layer is on the outside
Longitudinal
What layer of muscle is on the inside ?
Circular muscle
Why do we have circular muscle ?
To push food down and break food down
Peristalsis and segmentation
Submucosa is made up of ———— and what other tissue is it?
1) Loose areolar connective tissue
((Connective (strong) tissue connects, binds etc)
2) areolar connective tissue bz it’s a loose tissue as it’s strong enough to bind tissues together and loose to provide flexibility and cushioning.
(
What does the submuscosa have I.e lymphoid tissue
Glands, blood vessels & lymph tissue …
What does the submicosa bind together what layers ?
Muscle layer & the mucosa
Revision card: submucosa has a lot of elastic in it due constant bulk
How many layers of muscles for the stomach
3
What’ are the muscle layers of the stomach ?
Outter to inner
Longitudinal muscle > circular > oblique
What supplies the Submucosa I.e type of plexus
> Submucosal plexus (plexus of meissner)
Function of this plexus that is on the submucosa ?
Responsible for regulating doegestive secretions and reacting to presence of food.
Revision NOTE:
We have the CNS and PNS (somatic and autonomic nervous system) the autonomic system regulates those things that are done automatically. Somatic vise versa (it’s continue control).
Sympathetic innervation: exited, hyped up, high adrenaline
Parasympathetic: viseversa
What layer covers all the body’s cavities ?
Serosa
What does the series create ?
Serous fluid
What’s the function of serous fluid?
Alubrication and allows movement !! Avoiding friction
Dilation of pupils is what system?
Parasympathetic or sympathetic system
Sympathetic
Accelaration of heart
Parasympathetic or sympathetic system
Sympathetic
Stimulates tears
Parasympathetic or sympathetic system
Parasympathetic
Strong stimulation of salivary flow ?
Parasympathetic or sympathetic system
Parasympathetic
Atrioles constrict
Parasympathetic or sympathetic system
Sympath
Constriction of bronchi
Parasympathetic or sympathetic system
Parasympathetic
Stimulation of digestion
Parasympathetic or sympathetic system
Parasym system
Ejaculation
Parasympathetic or sympathetic system
Sympathetic
Contraction of bladder ?
Parasympathetic or sympathetic system
Parasympathetic
Stimulation of stomach muscles (
Parasympathetic or sympathetic system
Parasympathetic
Stimulates pancreas ?
Parasympathetic or sympathetic system
Parasympathetic
Relaxation of bladder
Parasympathetic or sympathetic
Sympathetic
Revision card: sympathetic system dialates bronchi ? Why? ….
To get more oxygen in
Revision card: relaxes bladder do that it can fill up more too 😜
Revision card: in the parasympathetic division the bronchioles constrict as we don’t need all that oxygen coming in !!
What’ are the 3 types of glands we have in the mouth ?
Parotid gland
Submandibular gland
Sublingual gland
What’s mastication
Chewing
What does the toingue do?
Turns food into bolus to swallow!!
How many parotid glands do we have ?
2
Biggest glands in the mouth
Paratid
What does the paratid gland break down?
Carbohydrates
Paediatric
if the frenulum is torn what does this indicate?
Child abuse
Sexual abuse
Or force fed
What is gingivitis?
Gum disease
Superior vestibule in the mouth. Where is it?
Upper inner lip
Role of the uvula ?
Triggers the gag reflex & stops you swallowing anything too large ..
1) Oral phase
(controlled by the what system… SNS or ANS)
2) Oral pupulsive stage
(controlled by the what system… SNS or ANS)
3) Pharyngeal phase (involuntary phase)
4) oesophageal phase
1) voluntary (masticated & probed by tongue)
2) pushes bolus up and into the hard palate
3) it’s involuntary swallow. Vocal cords close. Larynx moves up and epiglottis covers it. (stroke patients - choke)
Pharyngeal phase of its impaired they can choke or nasal regurgitation(up the nose).
Aspiration pneumonia
4) oesophageal phase: good moves down into the oesophagus and peristalsis occurs!
What happend a in the impairement of the oesophageal stage is effected
Heart burn
Vomiting
Abdo pain
At what level does the oseohagus enter the diaphragm ?
10th thoracic vertabrae
How long is the oesophagus in a adult ?
25 cm
Diameter of oesophagus ?
2cm
What two sphincters do we have?
Revision: Ring of muscle
Upper oesophageal sphincter
Lower oesophageal sphincter
Incompitenence of lower oesophageal sphincter (cardiac sphincter) causes what?
Acid reflux
What is barrates eosophagus ?
Is a irreversible damage & is pre-cancerous
Why does the pyloric sphincter close tight when stomachs full
Hydrochloride acid won’t have the time to break down the food
Greater curvature is right or left
Left
What is the omenta & what does it play a good role in?
1) Fold of peritoneum that connects the stomach to another viscera
2) immune responses
Function of the omenta?
Immune regulation
Tissue regeneration
Name of the Ridges that are inside of stomach
Rugae
Why does the stomach have 3 layers of stomach ?
To churn food
what’s the inner oblique muscle layer made of?
Oblique fibres
What is the stomach lined with?
Simple columnar epithelium
Chief cells produce
Pepsinogen
What is pepsinogen converted into ?
Pepsin.
This is by the effects of HCL acid in the stomach
What cells scerete HCL?
Parietal cells
Function of mucus cells
Protects the lining of stomach from acids & makes sure stomach done digest itself
Gastric pits communicate with what cells?
Parietal cells and chief cells
What detects 🍔 entering the stomach?
Gastric pits
Name two gastric glands !
Parietal cells
Chief cells
G cells do what?
Monitor and make sure cells communicate with each other
Absorbtion begin where !
Duodenum
Revision:
Some lipid soluble drugs and alcohol don’t go straight to the liver but straight to the blood stream
(Why you can become drunk)
Intrinsic factor is essential why?
For us to absorb vitamin B12
Pernicious anemia is caused by?
Lack or unable to absorb vit B12
G cells secrete ?
Gastric
Gastrin (hormone) function?
Stimulates the glands to secret more juices
In order from stomach name sections of the small intestines!!
Duodenum > jejunum > illium
How long is the duodenum ?
25cm
What lines the small intestines
Villi
What do villi do to the chyme?
Absorbing nutrients
How thick is the wall of microvilli?
1 cell thick
What is covered by Simple columnar epithelial cells
Villi
What do lymphatic vessels absorb? In the same intestines??
Dietary fats
What is secreted by the intestinal glands ? They secrete a hormone ?
Hint: That makes u happy
Serotonin
Illium ends where?
Illieo secal valve
What joins to make the sphincter of hepatopancretic ampulla’? Where does it open into ?
Common bile duct
Pancreatic duct
& opens onto the duodenum
What’s a sphincter
Round or ring of muscle
Liver weighs?
1.5kg
What has Large left & right lobes, smaller caudate and quadrate lobes ?
Liver
Falciform ligament marks what?
The division on the liver
What is the name of the free border of the falciform ligament ?
Hint: the name is a shape
Round ligament
The hepatic portal vein supplies what % of the blood to the liver?
75
How much blood is supplied by the hepatic arteries ?
25%
What are the two blood supplies ?what vessels?
Hepatic artery & hepatic portal vein
Individual liver cells are called ?
Hepatocyte
LIVER STRUCTURE
Revision: even tho the hepatic portal vein and artery are supplying different perscentages they are infact only SUPPLYING 50% of the livers oxygen demand. Even tho the hepatic portal vein is giving the liver 75% of the livers blood supply
revision
Hepatocytes: arranged in lobules
Sinosoids: highly permeable capillaries
What does the branch portal vein bring into the liver ?
& from where does it bring all the nutrient rich blood from?
Yummy nutrients from the small intestines all all areas of the alimentary canal
Hepatic artery (what does that bring to the liver)?
Oxygenated blood
Mixed blood that comes into the liver is mixed up where?
Sinosoids
What do sinosoids do/allow to happen ?
Rapid transfer of the nutrients backwards and forwards into the cells
What do sinosoids do to glucagon?
Store it in the hepatocytes
(Because one function of the liver is storing nutrients)
Revision: in a fight or flight situation so when there is no meal that’s eaten, the brain will tell the hepatocytes to release nutrients into the blood !! So it can then go to the heart and go around the body !!
Hepatocytes store glycogen, for later use if the body is in high demand then it releases it out of the liver through the blood to the heart then it travels around the body !!
Fun FACT: Nutrients are absorbed from the intestines through the villi to the liver
Layered of the liver are called?
Lobules
What are the lobules made up of?
Hepatocytes
2 functions of the hepatocytes
> Absorb good nutrients from the blood
release nutrients to the bloodstream ONLY when the body needs them
Fun FACT: Sinosoids are one way flow towards the hepatic veins & central vein
Fun FACT! Endothelial cells line the sinosoids
Kupffer CELLS»_space;>
Revision: Kupffer cells are phagocitic meaning they engulf and destroy pathogens.
They are good and bad guys
Where are kupffer cells are Located in the liver
In the linen of the sinusoid near the portal areas!!
What else do they remove
Red blood cells (break them down) that releases Heam from heamglobin !!
(Simply breaks down RBC)
Revision:
kuppffer cells protects the body and secretes cytokines & kemokine - regulate and determine what the immune responses will be like
(Formulate an immune response )
Kupffer (bad guys)»_space;>
What happens when it repairs the liver
It scars the liver & isn’t stretchy
What kind of AGENTS cause kupffer cells to initiate the production of __?__ a connective tissue of the liver that leads to scarring
HINT: substance that is not stretchy & is found in skin.
Production of collagen
What happens when there’s too much scarring tissue in the sinosoid?
Sinosoid gets blocked
What confirm does scarring lead to?
Cirhosis
Fun fact: Hepatitis - causes liver cirhosis & non alcoholics can also get this too!!
When is bilirubin produced ? Break down of what?
Heme
What state is bilirubin? Conjugated or unconjicated
Unconjugated
How does bilirubin be some conjugated
It binds with albumin to be then carried into the liver!
Where is conjugated bilirubinexcreted through?
Urine & stools
Hepatocytes also onstantly produces what? - stored in the ———— ———————
Bile
Gallbladder
What is the bile canaliculous?
Bile travels through the bile canaliculous up the lobule and travels to the bile duct
Where does the bile duct go into
Gall bladder
Which duct enters directly into the gall bladder
Cystic duct
What is known as the sphincter of Oddi?
It’s either the following
Hepatopancreatic ampulla’ or
Hepatopancreatic sphincter/duct
Hepatopancreatic sphincter/duct
Broken down RBC is called what? What’s the substance called
Bilirubin
Revision : when bilirubin is released into the sinosoid it is unconjugated
Revision: enzymess in the liver allows that change from unconjugated to conjugated to occur
What gives bile it’s yellow color?
Bilirubin
Revision: 1% of conjugated bilirubin excreted by urine
High levels of bilirubin causes what? & what color is it?
Yellow
Jaundice
Unconjugated bilirubin cause skin yellow and very salty and when it tries to eliminate via skin ! The salt is sat in the sweat gland what does this cause???
Intense itching even if the patient isn’t yellow !!!
What hormone does the liver store ?
Glycogen (that tells the liver to release the sugars when needed)
Revision; liver also stores fatty lipids
What did the liver inactivate ? Starts with T
Toxins
What fat soluble vitamins are stored in the liver?
A, D, K, E
Paramedic fun stuff: if a patient is bleeding a lot you can start thinking does the patient have a good functioning liver as it is a iron reserve !!!
Revision:
Bile is synthesized & secreted into lime of duodenum
Why is vitamin A important ?
Healthy organs & is main component of the retina (bit A important for 👁️ sight)
Why is vitamin D important ?
Absorbtion of calcium
Why is vitamin K important
Supporting in clotting of BLOOD 🩸
> Fun fact: patients who have Overdosed on their anti-coagulants bccs it promotes the blood 🩸 clotting AGAIN!!
> Pre-term babies are given Vit K as they are prone to micro-Haemorhages in the brain 🧠 !!!
Why is vitamin E important ?
> > Because it’s involved in making up nerve cells so not enough of this cause nerve damage !! «
Revision: liver highly vascular as you can bleed out easily in major trauma
> > FUN FACT: If a patient has a lot of bruising under the skin and hasn’t been injured this could be related to liver
Revision:
> Liver Synthesizes (inactive hormone) angitensonigen
Angiotensinogen is invoked in maintenance of BP
Absorbs & breaks down circulating hormones & antibodies that are NOT NEEDED!!
What is Accronym that tells you the function of the liver ??
PUSHDoG
what does the (P)ushdog stand for ?
Protein synthesis
What does the p(U)shdog stand for ?
Urea production
What does the pu(S)hdog stand for
STORAGE !!!
What does the pus(H)dog stand for ?
Hormone synthesis
What does the push(D)og stand fior???
DETOXIFICATION
What does the pushdo(G) stand for
Glucose & fat metabolism
When the large intestine starts to form blushes what disease is this
Diverticuler disease
Pooo entering these holes can cause inflammation and redness causing infection called what!
Diverticulitis’
How does peritonitis occur ?
When the air pocket of poo pops
What is the largest most complex serous membrane in the body?
Peritoneum
How long is the appendix ?
9cm long
Revision: the appendix shrinks as you age
It’s a lymphatic organ !!
RECTUM:
Internal sphincter
» SMOOTH MUSCLE
» ANS
External sphincter (VERY VASCULAR)
» SKELETAL MUSCLE
» SNS
Revision:
SRectal dose of diazepam / midazolam can be administered safely someone having a seizure