stomach and spleen

Question 1

what important things do we need to know about organs ?

Answer 1

• size
• shape
• position
• relationship with organs organs
• their parts
• blood supply , venous + lymphatic drainage

Question 2

where is the stomach found ?

Answer 2

• between the esophagus + small intestine

- part of the epigastric umbilical + left hypochondria regions

Question 3

what happens if the stomach has to much tone ?

what is this known as ?

Answer 3

• stomach = shorter + flatter

- hypertonia

Question 4

what happens if the stomach doesnt have enough tone ?

what is this known as ?

Answer 4

stomach sacks into abdominal cavity

hypotonia

Question 5

what happens when there is a complete loss of tone ?

what is this known as ?

Answer 5

stomach sags into pelvis

atonia

Question 6

what else determines stomach shape ?

Answer 6

body shape

Question 7

what are the 5 regions of the stomach ?

Answer 7

• cardiac region
• fundus
• body
• antrum
• pylorus

Question 8

where is the cardiac notch found ?

Answer 8

angle between cardia and fundus

Question 9

where is the incisura angularis found ?

Answer 9

between the pyloric antrum + body of stomach

Question 10

what is the main role of the cardia ?

Answer 10

increase mucus secretion

reduce reflux of acid in esophagus

Question 11

what is an internal feature found in the cardia ?

Answer 11

• gastroesophageal junction

- where stratified squamous epithelium of esophagus turns into simple columnar of stomach

Question 12

what is the purpose of the fundus ?

Answer 12

fills with air

Question 13

what is the function of the body of the stomach ?

Answer 13

stores ingested food

Question 14

what are the 5 cells type found on the stomach wall ?

what do they produce ?

Answer 14

• goblet cells = mucus
• parietal cells = gastric acid + IF
• chief cells = pepsinogen
• D cells = somatostin
• G cells = gastrin

Question 15

what is the purpose of IF that paritetal cells secrete ?

Answer 15

absorbs vitamin B12

Question 16

what is pernicious anemia ?

what is it caused by ?

Answer 16

• failure to produce / utilize iF

- patients cant acquire energy from proteins or fats

Question 17

what is the average volume of the adult stomach ?

Answer 17

1000ml

Question 18

what can the stomach wall absorb ?

Answer 18

• water
• electrolytes
• alcohol
• aspirin

Question 19

what can absorbtion of asiprin cause ?

Answer 19

cause stomach wall to bleed + peptic ulcers

Question 20

what makes up the pyloric region ?

Answer 20

• pyloric antrum

- pyloris

Question 21

what happens in the antrum ?

Answer 21

lots of mixing + grinding of chyme

Question 22

what pushes chyme towards the pyloris ?

Answer 22

peristaltic waves

Question 23

what is the pyloric sphincter ?

where does it lead to ?

Answer 23

• ring of smooth muscle

- leads to pyloric canal

Question 24

what does contraction of the pyloric sphincter cause ?

Answer 24

• closure of sphincter = no food into canal

Question 25

how many layers is the wall of the stomach made up of ? | what are the layers ?

Answer 25

- 4 - mucosa - sub-mucosa - muscularis extrania - adventitia / serosa

Question 26

what makes up the mucosa ?

Answer 26

- gut epithelium - lamina propria - muscularis mucosa

Question 27

what does the muscularis mucosa do ?

Answer 27

controls contractions of the mucosa

Question 28

what glands are found in the mucosa ?

Answer 28

- ducts of the accessory glands e.g liver + pancreas - mucosal glands - sub-mucosal glands

Question 29

what does the sub-mucosa layer contain ?

Answer 29

contains submucosal plexus controls secretions of glands within submucosa + mucosa always controls contractions of the mucosa

Question 30

what is the submucosal plexus part of ? | what can it be influenced by ?

Answer 30

- enteric nervous system | - parasympathetic nerves of the vagus or pelvic splanchnic nerves

Question 31

what is found in the muscularis externa ?

Answer 31

- has 2 layers of muscle inner circular layer outer longitudinal layer - contains the Myentric plexus

Question 32

what is the purpose of the muscularis externa ?

Answer 32

generates peristaltic contractions controlled by myentric plexus

Question 33

what is the difference between adventitia / serosa ?

Answer 33

``` adventitia = retroperitoneal parts of the gut serosa = intraperitoneal parts of the gut ```

Question 34

what plexus are sensory nerves found in ? | what do they respond to ?

Answer 34

- myenteric plexus - responded to local factors in wall of gut -

Question 35

what layers of muscles make up the stomach ?

Answer 35

- inner oblique layer - middle circular layer - outer longitudinal layer

Question 36

what happens to the circular layer at the pyloric sphincter ?

Answer 36

increases | to control contractions of chyme

Question 37

what controls gastric secretions into the esophagus ?

Answer 37

muscle fibres of the diaphragm | angulation of cardia

Question 38

what do folds of the stomachs longitudinal layer make ? | what is there purpose ?

Answer 38

rugae | allow stomach to stretch after eating

Question 39

what is the key artery of the upper abdominal arteteries ? | where does it come from ?

Answer 39

- coeliac trunk | - aorta

Question 40

what are the 3 large branches of the coeliac trunk ?

Answer 40

- common hepatic artery to the right for the liver - splenic artery to the left for the spleen - left gastric artery at the top for the stomach

Question 41

what does the common hepatic artery give rise to ?

Answer 41

proper hepatic artery | divides into a right + left hepatic artery

Question 42

what arteries supply the stomach ?

Answer 42

- left gastric which supplies the lesser curvature - common hepatic = lower part - right gastroepiploic = greater curvature - splenic = upper part

Question 43

what is the route of lymphatic drainage ?

Answer 43

- nodes drain into the coeliac nodes - drain to para-aortic nodes - then into thoracic duct

Question 44

where does parasympathetic stimulation of the GI tract come from ?

Answer 44

- from vagus nerves | - from 10th cranial nerve

Question 45

where does the esophageal plexus come from ? | what do they give rise to ?

Answer 45

- branches from left + right vagus nerves | - becomes twisted around lower esophagus = anterior + posterior vagal trunks

Question 46

where does the coeliac + superior mesentry come from ?

Answer 46

fibres from the posterior vagal trunk

Question 47

where does sympathetic stimulation come from ? | what do these nerves cause ?

Answer 47

- greater splanchnic nerves at T6 + T9 - distributed via coeliac plexus - cause vasoconstriction

Question 48

what is another feature of sympathetic nerves ?

Answer 48

- inhibitory to intrinsic plexuses | - inhibit peristalsis

Question 49

how do sympathetic nerves reach the organs of the abdominal cavity ?

Answer 49

- preganglionic nerves synapse in ganglia at the root of the coeliac trunk - postganglionic neurons travel with blood vessels to its intended organ

Question 50

where is the spleen found ?

Answer 50

- in the upper left hypocchondrium - lies along axis of 10th rib - sit between 9-11th

Question 51

what is the purpose of macrophages in the spleen ?

Answer 51

to destroy aging red blood cells

Question 52

what does the spleen produce ?

Answer 52

- lymphocytes | - erythrocytes in infants

Question 53

what happens if the spleen enlarges ?

Answer 53

greater number of platelets in the spleen = less in blood = excessive bleeding

Question 54

what does the spleen respond to ?

Answer 54

- stimulation for sympathetic nerves | - adrenaline

Question 55

what attaches the spleen to the stomach ? | where else is the spleen attached to ?

Answer 55

- gastrosplenic ligament | - to the posterior abdominal wall + left kidney by lienorenal ligament

Question 56

what are the 2 boarders of the spleen ?

Answer 56

- notched one | - smooth one

Question 57

what are the 2 forms of splenic pulp ?

Answer 57

- red pulp 75% = RBC + macrophages | - white pulp 25% = lymphocytes

Question 58

what is the primary function of the red pulp ?

Answer 58

filter the blood | remove pathogens + old RBC

Question 59

what is found within the red pulp ? | what is there purpose ?

Answer 59

venous sinuses | filters out healthy RBC from old ones

Question 60

what is a splenomegarly ?

Answer 60

enlargement of the spleen due to immune hyperplasia (increased immune response ) can also be due to anemia