Anatomy + Physiology of GI Tract (Revision Session)

Question 1

What is the nervous system of the GI system?

Answer 1

enteric nervous system

Question 2

How many layers does greater omentum have?

Answer 2

4

Question 3

How many layers does the lesser omentum have?

Answer 3

2

Question 4

What are the 4 muscles of mastication?

Answer 4

-temporalis -masseter -medial pterygoid -lateral pterygoid

Question 5

What cranial nerve supplies the 4 muscles of mastication?

Answer 5

CN V3

Question 6

Which muscle is used to open the mouth?

Answer 6

Lateral pterygoid

Question 7

Where does the lateral pterygoid originate and where does it insert?

Answer 7

Originates at condyle of mandible and inserts at the pterygoid plates

Question 8

Where does the temporalis originate and where does it insert?

Answer 8

Originates at coronoid process of mandible and inserts at temporal fossa

Question 9

Where does the masseter muscle originate and where does it insert?

Answer 9

Originates from the angle of mandible and at zygomatic arch

Question 10

Where does the medial pterygoid originate and insert at?

Answer 10

Originates at the angle of the mandible and inserts at pterygoid plate

Question 11

At what joint does movement of the mouth occur?

Answer 11

Temporomandibular joint

Question 12

What is the temporomandibular joint made up of?

Answer 12

-mandibular fossa on temporal bone -articular tubercle on temporal bone -head of condylar process on mandible

Question 13

What nerve supplies the superior half of the oral cavity?

Answer 13

CN V2

Question 14

What nerve supplies the inferior half of the oral cavity?

Answer 14

CN V3

Question 15

What nerve supplies the orbicularis oris?

Answer 15

CN VII

Question 16

What nerves supply the gag reflex (motor and sensory)?

Answer 16

-Motor -> CN IX and CN X -Sensory -> CN IX

Question 17

What are the three salivary glands?

Answer 17

-parotid -submandibular -sublingual

Question 18

Where in the mouth does the parotid gland secrete saliva into?

Answer 18

Into mouth by upper 2nd molar

Question 19

What nerve supplies the parotid gland?

Answer 19

CN IX

Question 20

Where in the mouth does the submandibular gland secrete saliva into?

Answer 20

Secretes via the lingual caruncle and enters floor of the mouth

Question 21

What nerve supplies the submandibular glands?

Answer 21

CN VII

Question 22

Where does the sublingual gland secrete saliva into?

Answer 22

Via the lingual caruncle and other salivary ducts superior to the sublingual gland

Question 23

What nerve supplies the sublingual glands?

Answer 23

CN VII

Question 24

Where is the posterior third of the tongue located?

Answer 24

Vertically in the oropharynx

Question 25

What nerve supplies the posterior third of the tongue and what does it supply tongue for?

Answer 25

CN IX for taste and general sensation

Question 26

Where is the anterior two thirds of the tongue located?

Answer 26

In the oral cavity

Question 27

What nerve supplies the anterior two thirds of the tongue for general sensation?

Answer 27

CNV3

Question 28

What nerve supplies the anterior two thirds of the tongue for taste?

Answer 28

CNVII

Question 29

What are the 4 types of papillae on the tongue?

Answer 29

-filiform -fungiform -vallate -follate

Question 30

What is significant about filiform papillae?

Answer 30

They have no taste buds they just sense touch and temperature

Question 31

What do the intrinsic muscles of the tongue do?

Answer 31

-they change the shape of the tongue

Question 32

What do the extrinsic muscles do and list the 4 extrinsic muscles.

Answer 32

-they reposition the tongue -genioglossus -styloglossus -hyoglossus -palatoglossus

Question 33

What nerve supplies the muscles of the tongue and what is the exception?

Answer 33

CNXII supplies all muscles except the palatoglossus which is supplied by CN X

Question 34

What are the 3 types of tonsils?

Answer 34

- palatine - pharyngeal - lingual

Question 35

What muscles form the inner and outer layers of the pharynx and what is the function of each type?

Answer 35

inner: longitudinal -\> elevate the larynx, close the laryngeal inlet and shorten the pharynx to aid swallowing outer: constrictor -\> constrict sequentially to move food down the oesophagus

Question 36

Fill in the labels on this diagram.

Answer 36

Question 37

Which nerve supplies the constrictor muscles of the pharynx?

Answer 37

CNX

Question 38

At what level of the spine does the cricopharyngeus (UOS) sit at and what also sits at this level?

Answer 38

- C6 - thyroid

Question 39

What is the pharyngeal midline raphe?

Answer 39

tendinous line in the middle of the pharynx where the constrictor muscles on either side meet

Question 40

What two nerves supply the longitudinal muscles of the pharynx?

Answer 40

- CNX - CNIX

Question 41

At which vertebra does oesophagus pass through the diaphragm?

Answer 41

T10

Question 42

I ate 10 Eggs At 12 -\> explain this

Answer 42

I - Inferior vena cava - T8 E - (O)esohagus - T10 A - Aorta - T12

Question 43

What are the 4 layers of the digestive tract wall?

Answer 43

- mucosa - submucosa - muscularis externa - adventitia

Question 44

What muscles make up the upper 1/3 portion of the oesophagus and what makes up the lower 3/4?

Answer 44

Upper: skeletal lower: smooth

Question 45

What 3 layers make up the mucosa?

Answer 45

- epithelium - lamina propria - muscularis mucsoae

Question 46

What is the function of the muscularis mucosae of the gi tract?

Answer 46

thin layer of muscle that allows mucosa to move and fold

Question 47

What are the components of the submucosa?

Answer 47

-connective tissue containing arteries, veins, lymphatics and nerves

Question 49

What nervous system controls peristalsis?

Answer 49

enteric

Question 50

Where does the myenteric plexus sit?

Answer 50

in between the circular and longitudinal layers of the muscularis externa

Question 51

What cells are in the myenteric plexus?

Answer 51

interstitial cells of Cajal

Question 52

Through what do the interstitial cells of Cajal of the myenteric plexus and the smooth muscles connect?

Answer 52

Through gap junctions

Question 53

How do peristaltic contractions occur?

Answer 53

When enteric nervous system depolarises by opening Ca2+ channels to achieve threshold

Question 54

What determines the rate of peristaltic contraction?

Answer 54

Slow wave

Question 55

What do the circular muscles and longitudinal muscles do behind a bolus?

Answer 55

- Circular contract - longitudinal relax

Question 56

What do the circular muscles and longitudinal muscles do in front of a bolus?

Answer 56

- circular relax - longitudinal contract

Question 57

What is the peritoneum?

Answer 57

Continuous membrane that lines the abdominal cavity walls and organs

Question 58

What is the peritoneal cavity?

Answer 58

Space between the visceral and parietal perietal layers

Question 59

What neurotransmitters cause contraction and relaxation in peristalsis?

Answer 59

- Contraction: ACh - Relaxation: NO and VIP

Question 60

What are the two main differences between intraperitoneal and retroperitoneal organs?

Answer 60

- intraperitoneal: covered in visceral peritoneum + have minimal mobility - retroperitoneal: only has visceral peritoneum on anterior surface + have no mobility

Question 61

What are 6 examples of intraperitoneal organs?

Answer 61

- liver - gallbladder - stomach - spleen - transverse colon - small bowel

Question 62

What are 4 examples of retroperitoneal organs?

Answer 62

- kidneys - pancreas - ascending colon - descending colon

Question 63

What is the mesentery?

Answer 63

Where the visceral peritoneum folds over itself to form a double layer

Question 64

What does mesentery have a supply of?

Answer 64

Blood vessels lymphatics

Question 65

What is the mesentery attached to?

Answer 65

Posterior abdominal wall to small intestine, transverse and sigmoid colon

Question 66

List the names of the mesentery for the small bowel, large bowel and appendix?

Answer 66

- mesentery proper - mesocolon - mesoappendix

Question 67

What is the omentum in the abdominal cavity?

Answer 67

Fold of the visceral peritoneum

Question 68

Describe the greater omentum attachments.

Answer 68

Greater omentum hangs down like an apron from the greater curvature of the stomach, passes in front of small intestines, doubles back and attaches to transverse colon and then onto anterior abdominal wall

Question 69

Describe the lesser omentum attachments.

Answer 69

Extends from lesser curvature of stomach and the first part of duodenum to liver

Question 70

Where does the portal triad lie in relation to the lesser omentum?

Answer 70

In the free edge of the lesser omentum

Question 71

What two ligaments attach the lesser omentum to from the stomach to duodenum and liver and where are these located in relation to each other?

Answer 71

- hepatogastric ligament: medially - hepatoduodenal ligament: laterally

Question 72

What do the omentums divide the peritoneal cavity into and through what do these communicate?

Answer 72

- greater and lesser sacs - through omental foramen AKA foramen of Winslow AKA epiploic foramen

Question 73

What two recesses are within the greater sac?

Answer 73

- subphrenic recess (between diaphragm and liver) - hepatorenal recess (between right kidney and liver)