Abdomen 1 - Gut divisions, Peritoneal Relations, Oral cavity (Mastication)

Question 1

sympathetic & parasympathetic innervation to the foregut?

Answer 1

sympathetic nerve = greater splanchnic nerve (T5-9)
parasympathetic nerve = vagus nerve

Question 2

sympathetic & parasympathetic innervation to midgut structures?

Answer 2

sympathetic = lesser splanchnic nerve (T10-11)
parasympathetic = vagus nerve

Question 3

sympathetic & parasympathetic innervation to hindgut structures?

Answer 3

sympathetic = lumbar splanchnic nerves (L1-4)
parasympathetic = pelvic splanchnic nerves (S2-4)

Question 4

layers of the GI tract (outer to inner)?

Answer 4

1. serosa
2. muscularis externa - outer longitudinal; inner circular layers
   3, submucosa - contains submucosal glands
3. mucosa - muscularis mucosa, lamina propria, epithelium

Question 5

where is the myenteric (Auerbach’s) plexus located? function?

Answer 5

located between the longitudinal & circular muscle layers; controls gut motility

Question 6

where is the submucosal (Meissner’s) plexus located? function?

Answer 6

within the submucosal layer; regulates secretions & blood flow

Question 7

the myenteric & submucosal plexuses are part of WHAT nervous system?

Answer 7

enteric nervous system

Question 8

what is meant by intraperitoneal?

Answer 8

an organ completely covered by visceral peritoneum - attaches to abdominal wall/other organs by double folds of peritoneum

Question 9

what is meant by extraperitoneal?

Answer 9

an organ not fully covered by peritoneal (only partly); lies outside peritoneal cavity

Question 10

what is meant by retroperitoneal?

Answer 10

covered by peritoneum only on the anterior wall (plastered surface on posterior surface)

Question 11

what innervates parietal peritoneum? how sensitised is parietal peritoneum to pain?

Answer 11

innervates by somatic nerves

well-localised pain sensations (sensitive to pain, temperature, touch and pressure)

Question 12

what innervates visceral peritoneum? how sensitised is visceral peritoneum to pain?

Answer 12

innervated by autonomic afferents (travel with organ nerves)

vague/dull, poorly-localised pain sensations - referred pain sensations with stretch and tearing

Question 13

what are the 3 divisions of the pharynx?

Answer 13

nasopharynx
oropharynx
laryngopharynx

Question 14

what are the two main divisions of the oral cavity?

Answer 14

1. oral vestibule (space between teeth and cheeks)
2. oral cavity proper (behind teeth)

Question 15

what is the roof, floor & lateral walls of the oral cavity?

Answer 15

roof = hard and soft palate
floor = tongue & muscular diaphragm of mylohyoid & geniohyoid
lateral walls = buccinator muscle (cheeks)

Question 16

the hard palate is formed by WHAT two bones?

Answer 16

palatine process of maxilla
horizontal plate of palatine bone

Question 17

sensory innervation to the roof of the oral cavity? (the hard & soft palate)

Answer 17

maxillary division of trigeminal nerve (CNV2)

Question 18

sensory innervation to the floor & lateral walls of the oral cavity?

Answer 18

mandibular division of trigeminal nerve (CNV3)

Question 19

what is the difference between the hard & soft palate?

Answer 19

hard palate - bony hard structure, more anterior
soft palate - soft, consists of muscles, more posterior

Question 20

what 5 muscles does the soft palate consist of?

Answer 20

muscularis uvulae
palatoglossus
palatopharyngeus
tensor veli palatini
levator veli palatini

Question 21

what is the name of the leaf-shaped cartilage located at the base of the tongue?

Answer 21

epiglottis

Question 22

what is the function of the epiglottis?

Answer 22

prevents food entering the airway during swallowing; closing over the laryngeal inlet – directs food to oesophagus

Question 23

what happens to the epiglottis during breathing?

Answer 23

remains open; allows airflow into the trachea

Question 24

what soft palate muscle is the only one not innervated by the vagus nerve?
A: muscularis uvulae
B: palatoglossus
C: palatopharyngeus
D: tensor veli palatini
E: levator veli palatini

Answer 24

D: tensor veli palatini - innervated by CNV3

Question 25

action of the levator veli palatini?

Answer 25

1. elevates soft palate - closes off nasopharynx during swallowing 2. helps open auditory tube (for pressure equalisation in middle ear)

Question 26

action of the muscularis uvuale?

Answer 26

elevates & retracts uvula - contributes to gag reflex

Question 27

action of the tensor veli palatini?

Answer 27

tenses soft palate helps open auditory tube

Question 28

action of palatoglossus?

Answer 28

depresses soft palate elevates tongue

Question 29

action of palatopharyngeus?

Answer 29

depresses soft palate elevates pharynx during swallowing

Question 30

which two muscles of the soft palate originate from the palatine aponeurosis? A: muscularis uvulae B: palatoglossus C: palatopharyngeus D: tensor veli palatini E: levator veli palatini

Answer 30

B: palatoglossus C: palatopharyngeus

Question 31

which two muscles of the soft palate are involved in pressure equalisation of the middle ear? A: muscularis uvulae B: palatoglossus C: palatopharyngeus D: tensor veli palatini E: levator veli palatini

Answer 31

D: tensor veli palatini E: levator veli palatini - both open up the auditory tube

Question 32

which muscle of the soft palate is involved in the gag reflex? A: muscularis uvulae B: palatoglossus C: palatopharyngeus D: tensor veli palatini E: levator veli palatini

Answer 32

A: muscularis uvuale

Question 33

general innervation to muscles of the soft palate? which muscle is the exception?

Answer 33

vagus nerve; tensor veli palatini is the exception - innervated by CNV3 (mandibular division)

Question 34

the floor of the oral cavity is formed by a muscular diaphragm, which is supported by TWO muscles. what are they?

Answer 34

mylohyoid geniohyoid

Question 35

actions of mylohyoid?

Answer 35

1. depresses mandible (helps gravity) 2. elevates hyoid bone & tongue during swallowing - forms main floor of mouth

Question 36

innervation to mylohyoid?

Answer 36

CNV3 via nerve to mylohyoid

Question 37

action of geniohyoid? innervation?

Answer 37

1. helps depress mandible (with gravity) 2. widens pharynx during swallowing 3. elevates hyoid bone CN12 via cervical nerve 1 (C1)

Question 38

what muscle mainly constitutes the lateral walls of the oral cavity?

Answer 38

buccinator muscle

Question 39

function of buccinator muscle?

Answer 39

1. tenses cheek 2. moves food from oral vestibule to oral cavity proper

Question 40

innervation to buccinator muscle?

Answer 40

CN7 (facial nerve)

Question 41

what occurs as a result of weakness of the buccinator muscle?

Answer 41

food accumulation in the oral vestibule – affects chewing

Question 42

the pterygomandibular raphe is a fibrous connective tissue band that serves as an attachment point for two muscles:

Answer 42

superior pharyngeal constrictor buccinator

Question 43

what are the 3 major salivary glands?

Answer 43

parotid gland submandibular gland sublingual gland

Question 44

the parotid gland is over WHAT muscle? A: buccinator B: temporalis C: orbicularis oris D: masseter

Answer 44

D: masseter

Question 45

the temporomandibular joint is formed by the articulations between WHAT three surfaces?

Answer 45

head of mandible mandibular fossa articular tubercle of temporal bone

Question 46

surfaces of the temporomandibular joint don't come into contact with each other as they're separated by...

Answer 46

an articular disc of fibrocartilage

Question 47

what nerve innervates all muscles of mastication?

Answer 47

CNV3 (mandibular division of the trigeminal nerve)

Question 48

what structure divides the tongue into its two parts?

Answer 48

terminal sulcus - divides tongue into anterior 2/2 and posterior 1/3

Question 49

general sensory innervation to the tongue - anterior & posterior parts?

Answer 49

anterior - CNV3 (mandibular division) posterior - CN9 (glossopharyngeal)

Question 50

special sensory innervation to the tongue - anterior & posterior parts?

Answer 50

anterior - CN7 (facial - via chorda tympani branch) posterior - CN9 (glossopharyngeal)

Question 51

what structure divides the upper & lower GI tract?

Answer 51

suspensory ligament of duodenum (between duodenum & jejunum)

Question 52

masseter - action? innervation?

Answer 52

elevates mouth; CNV3

Question 53

temporalis - action?

Answer 53

elevates & retracts mouth

Question 54

lateral pterygoids - action?

Answer 54

lateral movement protrusion elevation of the mouth

Question 55

medial pterygoids - action?

Answer 55

protrusion elevation some lateral movement of the mouth

Question 56

innervations to the oropharynx?

Answer 56

glossopharyngeal nerve (CN9) maxillary division of trigeminal nerve (CNV2)