GI General Anatomy

Question 1

What are the GI components of the head?

Answer 1

Oral Cavity

Pharynx

Question 2

What are the GI components of the neck?

Answer 2

Pharynx

Oesophagus

Question 3

What are the GI components of the chest?

Answer 3

Oesophagus

Question 4

What are the GI components of the abdomen?

Answer 4

Stomach
Small intestine
Large Intestine
Most accessory organs of GI Tract

Question 5

What are the GI components of the pelvis?

Answer 5

Rectum

Anal Canal

Question 6

What are the GI components of the perineum?

Answer 6

Anus

Question 7

What are the 4 functions of the GI tract?

Answer 7

Mastication - chewing
Taste
Salivation
Deglutitation - swallowing

Question 8

Which muscles/joints/bones allow mastication?

Answer 8

Temporomandibular joint
Muscles of TMJ, Face and Tongue
Dentition (teeth)

i.e movement of the jaw and tongue

Question 9

Which muscles/joints/bones allow taste?

Answer 9

Mastication
Salivation
Tongue

Question 10

Which glands allow salivation?

Answer 10

Parotid gland
Submandibular gland
Sublingual gland
Minor glands

Question 11

Which muscles/joints/bones allow deglutitation?

Answer 11

Tongue
Palate
Pharynx
Oesophagus

Question 12

What is the Buccinator?

Answer 12

muscle inside cheek

- when food goes into the cheek it traps it

Question 13

Describe Adult Dentition?

Answer 13

32 teeth (all erupted by age 18)
 4 quadrants 
- upper right
- upper left
- lower right 
- lower left
Incisor = 1 and 2
Canine = 3
Pre molars = 4 and 5
Molards = 6, 7 and 8

Question 14

What are the 4 muscles of Mastication?

Answer 14

Lateral Pterygoid
Temporalis m.
Masseter m.
Medial Pterygoid

occurs at the TMJ

Question 15

What are the muscles of Mastication innervated by?

Answer 15

Cranial Nerve 3

Mandibular division of trigeminal nerve - CN V3

Question 16

Which muscle of mastication is the only one that opens the mouth?

Answer 16

Lateral Pterygoid

Question 17

What are the superior and inferior cavities of the TMJ for?

Answer 17

Superior cavity for translation

Inferior cavity for rotation

Question 18

Describe the route taken for the Mandibular division of the Trigeminal Nerve?

Answer 18

From pons
Out the skull through the foramen ovale
To muscles of mastication and sensory area

Question 19

Which tonsils are taken out?

when you get your tonsils taken out

Answer 19

Palatine tonsils

Question 20

Name the four types of papillae on the tongue? Which type does not have tastebuds?

Answer 20

Foliate
Fungiform
Vallate
Filiform - no tastebuds

Question 21

Outline the course of the facial nerve?

Answer 21

From Pontomedullary junction
Travel through temporal bone via internal acoustic meatus then stylomastoid foramen 
To supply
  - Taste anterior 2/3rds tongue 
  - Muscles of facial expression
  - Glands in floor of mouth

Question 22

What is the superior half of the oral cavity supplied by?

Answer 22

CN V2 - general sensation

Question 23

What is the inferior half of the oral cavity supplied by?

Answer 23

CN V3 - general sensation

Question 24

What nerves make up the sensory and motor components of the gag reflex?

Answer 24

sensory: nerve fibres within CN IX
motor: nerve fibres within CN IX and CN X

Question 25

What occurs during the gag reflex and what nerve controls this action?

Answer 25

pharynx constricts
(glossophyarngeal nerve CN IX)

Question 26

Outline the course of the Maxillary division of trigeminal nerve (CNV2)?

Answer 26

From pons
Through foramen rotundum
To sensory area (mid-face)

Question 27

Outline the course of the CN IX - Glossopharyngeal nerve?

Answer 27

From medulla
Through jugular foramen
To: 
posterior wall of oropharynx (sensory)
parotid gland (secretomotor) 
posterior 1/3rd Tongue (Sensation and Taste)

Question 28

Name the 3 pairs of salivary glands and how they secrete into the mouth?

Answer 28

Parotid Gland - Parotid duct crosses face secretes into mouth by upper 2nd molar

Submandibular Gland - Submandibular duct enters floor of mouth and secretes via lingual caruncle

Sublingual Gland - Lays in floor of mouth secretes via several ducts superiorly

Question 29

What are the 4 muscles of the tongue? what is the most important one?

Answer 29

Palatoglossus
Genioglossus - important
Hyoglossus
Styloglossus

Question 30

What are the muscles of the tongue (except palatoglossus) innervated by?

Answer 30

CNXII (Hypoglossal nerve)

Question 31

Outline the course of the Hypoglossal nerve?

Answer 31

From medulla
Through hypoglossal canal
To extrinsic and intrinsic muscle of tongue (except palatoglossus)

Question 32

What is the Pharynx innervated by?

Answer 32

CN X

Question 33

Describe the 4 steps of swallowing?

Answer 33

1. Close the lips to prevent drooling (orbicularis oris & cranial nerve VII)
2. The tongue (cranial nerve XII) pushes the bolus posteriorly towards the oropharynx
3. Sequentially contract the pharyngeal constrictor muscles (cranial nerve X) to push the bolus inferiorly towards the oesophagus
4. At the same time the inner longitudinal layer of pharyngeal muscles (cranial nerves IX & X) contracts to raise the larynx, shortening the pharynx and closing off the laryngeal inlet to help prevent aspiration
5. The bolus reaches the oesophagus

Question 34

Describe the Enteric Nervous System?

Answer 34

Extensive network of nerves, found only in walls of GI tract
Acts independently of other parts of nervous system, but can also be influenced by autonomic motor nerves
- Parasympathetics (speed up peristalsis)
- Sympathetics (slow down peristalsis)

Question 35

What level does the oesophagus start?

Answer 35

vertebral level C6

Question 36

Describe the nerve supply of the oesophagus?

Answer 36

Oesophageal plexus:

• runs on surface to supply smooth muscle within its walls (distally)
• contains parasympathetic nerve fibres (vagal trunks) and sympathetic nerve fibres

Question 37

Desribe the two oesophageal sphincters?

Answer 37

anatomical upper sphincter (cricopharyngeus) physiological lower oesophageal sphincter