GI General Anatomy Flashcards
What are the GI components of the head?
Oral Cavity
Pharynx
What are the GI components of the neck?
Pharynx
Oesophagus
What are the GI components of the chest?
Oesophagus
What are the GI components of the abdomen?
Stomach
Small intestine
Large Intestine
Most accessory organs of GI Tract
What are the GI components of the pelvis?
Rectum
Anal Canal
What are the GI components of the perineum?
Anus
What are the 4 functions of the GI tract?
Mastication - chewing
Taste
Salivation
Deglutitation - swallowing
Which muscles/joints/bones allow mastication?
Temporomandibular joint
Muscles of TMJ, Face and Tongue
Dentition (teeth)
i.e movement of the jaw and tongue
Which muscles/joints/bones allow taste?
Mastication
Salivation
Tongue
Which glands allow salivation?
Parotid gland
Submandibular gland
Sublingual gland
Minor glands
Which muscles/joints/bones allow deglutitation?
Tongue
Palate
Pharynx
Oesophagus
What is the Buccinator?
muscle inside cheek
- when food goes into the cheek it traps it
Describe Adult Dentition?
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
What are the 4 muscles of Mastication?
Lateral Pterygoid
Temporalis m.
Masseter m.
Medial Pterygoid
occurs at the TMJ
What are the muscles of Mastication innervated by?
Cranial Nerve 3
Mandibular division of trigeminal nerve - CN V3
Which muscle of mastication is the only one that opens the mouth?
Lateral Pterygoid
What are the superior and inferior cavities of the TMJ for?
Superior cavity for translation
Inferior cavity for rotation
Describe the route taken for the Mandibular division of the Trigeminal Nerve?
From pons
Out the skull through the foramen ovale
To muscles of mastication and sensory area
Which tonsils are taken out?
when you get your tonsils taken out
Palatine tonsils
Name the four types of papillae on the tongue? Which type does not have tastebuds?
Foliate
Fungiform
Vallate
Filiform - no tastebuds
Outline the course of the facial nerve?
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
What is the superior half of the oral cavity supplied by?
CN V2 - general sensation
What is the inferior half of the oral cavity supplied by?
CN V3 - general sensation
What nerves make up the sensory and motor components of the gag reflex?
sensory: nerve fibres within CN IX
motor: nerve fibres within CN IX and CN X
What occurs during the gag reflex and what nerve controls this action?
pharynx constricts (glossophyarngeal nerve CN IX)
Outline the course of the Maxillary division of trigeminal nerve (CNV2)?
From pons
Through foramen rotundum
To sensory area (mid-face)
Outline the course of the CN IX - Glossopharyngeal nerve?
From medulla Through jugular foramen To: posterior wall of oropharynx (sensory) parotid gland (secretomotor) posterior 1/3rd Tongue (Sensation and Taste)
Name the 3 pairs of salivary glands and how they secrete into the mouth?
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
What are the 4 muscles of the tongue? what is the most important one?
Palatoglossus
Genioglossus - important
Hyoglossus
Styloglossus
What are the muscles of the tongue (except palatoglossus) innervated by?
CNXII (Hypoglossal nerve)
Outline the course of the Hypoglossal nerve?
From medulla
Through hypoglossal canal
To extrinsic and intrinsic muscle of tongue (except palatoglossus)
What is the Pharynx innervated by?
CN X
Describe the 4 steps of swallowing?
- Close the lips to prevent drooling (orbicularis oris & cranial nerve VII)
- The tongue (cranial nerve XII) pushes the bolus posteriorly towards the oropharynx
- Sequentially contract the pharyngeal constrictor muscles (cranial nerve X) to push the bolus inferiorly towards the oesophagus
- 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
- The bolus reaches the oesophagus
Describe the Enteric Nervous System?
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)
What level does the oesophagus start?
vertebral level C6
Describe the nerve supply of the oesophagus?
Oesophageal plexus:
- runs on surface to supply smooth muscle within its walls (distally)
- contains parasympathetic nerve fibres (vagal trunks) and sympathetic nerve fibres
Desribe the two oesophageal sphincters?
anatomical upper sphincter (cricopharyngeus) physiological lower oesophageal sphincter
