Week 1/2 - A(1) - Anatomy 1&2 - Mastication, oral cavity, Pharynx, stomach, fore/mid/hindgut, abdo muscles/autonomics, peritoneum Flashcards
Where does jaw opening and closing occur at? What are the muscles that control these movements? What is the nerve supply of these muscles?
Jaw opening and closing occurs at the temperomandibular joint (TMJ) - all supplied by mandibular division of trigeminal nerve (CN V3) Jaw opening - * lateral pterygoid Jaw closing * Masseter * Medial pterygoid * Temporalis
Which muscles are felt when you clench your jaw? What is their attachments?
Masseter - attaches from the zygomatic arch to the lateral ramus (external)of the mandible Temporals - attaches from temporal fossa/fascia to coronoid process and anterior border of the ramus of the mandible
What is the attachment of the medial and lateral pterygoid muscles? Which opens the jaw again?
Medial pterygoid - angle of mandible (medial side) to pterygoid plates of sphenoid bone Lateral pterygoid - opens jaw - condylar head of mandible to pterygoid plates of sphenoid bone
What are the divisions of the trigeminal nerve? What are their foramen? Which are sensory and which provide motor innervation?
CNV1 - Ophthalmic division - superior orbital fissure CN V2 - Maxillary division - foramen rotundum CN V3 - Mandibular division - foramen ovale CN V1&2 are only sensory CNV3 - provides sensory and motor
How many adult teeth are there in total? What are the adult teeth? Which are known as the wisdom teeth?
32 adult teeth in total There are upper/lower right and left dental arches Dental arch consists of * Incisors - 1&2 * Canines - 3 * Pre-molars - 4&5 * Molars - 6,7&8 - third molar , tooth 8) is referred to as the wisdom teeth
What provides general sensation to the superior (gingiva and palate) and inferior halfs (gingiva and floor) of the oral cavity?
General sensation to the superior half of the oral cavity - maxillary division of CN V General sensation to the inferior half of the oral cavity - mandibular division of CN V
What is the protective reflex that prevents foreign bodies from entering the pharynx or larynx? Which nerves govern this reflex? When spraying a local anaesthetic eg for upper endocscope, the sensory action potential in what nerves will be blocked?
Gag reflex - protective reflex * Sensory part or afferent limb - fibres within CN IX (glossopharyngeal) * Motor part of efferent limb - fibres within CN IX and CN X (vagus) - constrict the pharynx Local anaesthetic will block sensory action potentials in * CN V2, V3, VII and IX
What innervates the tongue with general sensory and special sensory fibres? What is the special sensation?
Anterior 2/3rds of the tongue General sensory - CN V3 Special sensory - chorda tympani branch of facial nerve Posterior 1/3rd of the tongue General and special sensory - all CN IX
What modalities does the facial nerve provide? What is the route of the facial nerve?
CN VII provides general and special sensory, motor and parasympathetics Emerges at the pontomedullary junction - into the temporal bone through the internal acoustic meatus - through temporal bone within the facial canal - exits the temporal bone through the stylomastoid foramen
What are the three salivary glands? Where do they secrete? What is the most common tumour of the salivary glands?
Parotid gland - secretes opposite the upper 2nd molar Sublingual gland - secretes under the tongue in the sublingual folds Submandibular gland - floor of mouth via sublingual caruncle Pleomorphic adenomais the most common type of salivary gland tumor
What modalities does CN IX carry? What is the course of CN IX?
CNIX carries * general sensory - to posteiror wall of oropharynx and posterior 1/3rd of the tongue * Special sensory to posterior 1/3rd of the tongue * Parasympathetic to the paratoid gland It arises at the medulla and exits the skull through the jugular foramen
The extrinsic muscles of the tongue originate outside the tongue and embed into the tongue * What are the four extrinsic muscles? * What is the attachments of the extrinsic muscles of the tongue?
All insert into the tongue Genioglossus arises from superior genial tubercles of the mandible Hyoglossus -arises from the hyoid bone Styloglossus - arises from styloid process of temporal bone Palatoglossus - arises from the palatine aponeurosis of soft and hard palate
What is the function of the extrinsic muscles of the tongue? What is the nerve supply?
Palatoglossus Styloglossus Hyoglossus Genioglossus * Function - change the position of the tongue during mastication, swallowing and speech * All innervates by the hypoglossal nerve (CN XII) except palatoglossus which is innervated by CN X
What is the function of the intrinsic muscles of the tongue? What are they?
The intrinsic muscles of the tongue modify the shape of the tongue for function. They are named according to the direction in which they travel and originate / insert in the tongue: * Superior longitudinal * Transverse muscles * Vertical muscles * Inferior longitudinal
What is the nerve supply to the intrinsic muscles of the tongue? What is the modalities of this nerve? Where does it arise and how does it exit the skull?
The hypoglossal nerve provides motor innervation only It supplies all the intrinsic muscles of the tongue It supplies all the extrinsic muscles of the tongue (except palatoglossus - CN X) It arises at the medulla and exits the skull through the hypoglossal canal
What innervates the different regions of the pharynx? What level is the upper oeseophageal sphincter and what is it also known as? Which muscle forms it?
Nasopharynx - CN V2 Oropharynx - CN IX Laryngopharynx - CN X Upper oesophageal sphincter aka cricopharyngeus is at C6 - (pharynx becomes oesopagus) - formed from the lower fibres of the inferior constrictor muscles of the pharynx
What muscles are on the inner and external layers of the pharynx? What is the function of the layers of muscles?
Inner layer of pharynx - longitudinal muscles - elevate the pharynx and larynx, contract to shorten the phaynx - Raise the larynx to close over laryngeal inlet during swallowing External layer - constrictor muscles - - contract sequentially to propel food bolus
What is the little piece of elastic cartilage that will bend and close the laryngeal inlet when a bolus of food comes into contact with it?
This is the epiglottis
Is the lower oeseophageal sphincter a phsyicological or anatomical sphincter? What contributes to the lower oesophageal sphincter? What does the sphincter help to prevent?
Lower oeseophageal sphincter is physiological rather than an anatomical sphincter. Contributing: -Contraction of diaphragm intrabdominal pressure - Slightly higher than intragastric, - oblique angle of which oeseophagus enters the cardia of the stomach Sphincter helps to prevent gastrooeseopeal reflux
What are the four parts of the stomach? What is the small notch on the lesser curvature of the stomach? What is the rugae in the stomach?
Stomach fundus (often gas filled), cardia (opening), body (central portion), pylorus (antrum, canal and sphincter) Small notch is known as the incisura angularis Rugae are the visible folds in the stomach that allow for increased surface area and hence increased absorption
Approximately how long is the small intestine? What are the different regions from proximal to distal? What are the different regions of the large intestine?
Small intestine is around 7m long - duodenum, jejunum, ileum Large intestine from - The colon - caecum, appendix, ascending, transverse, descending, sigmoid The rectum The anal canal The anus
The abdominal organs can be described in 3 parts depending on their embryological origin * Foregut * Midgut * Hindgut Name the organs in each and where each section starts/ends
Foregut - oeseophagus to mid-duodenum (includes liver, gallbladder, spleen, 1/2 of pancreas) Midgut - mid-duodenum to proximal 2/3rds transverse colon (includes 1/2 of pancreas) Hindgut - distal 1/3rd of transverse colon to proximal 1/2 of anal canal
The abdominal cavity can be divided into regions and quadrants What are the 9 regions and what lines divide it?
9 regions Right/left hypochondrium Epigastric Right/left flank/lumbar Umbilical Right/left iliac fossa/inguinal Suprapubic/hypogastric Divided along mid-clavicular line, subcostal and transtuberulcar planes
What are the 4 quadrants and what divides them?
Right / left upper quadrant Right/left lower quadrant Divided by median plane and trans-umbilical plane
What are the muscles of the anter-lateral abdominal wall?
Rectus abdominus External oblique Internal oblique Transversus abdominus (then the parietal peritoneum)
What is the rectus sheath formed by? What does the rectus sheath contain? When does it change from being anterior/posterior?
The rectus sheath is formed by the aponeuroses of the external/internal oblique and transverse abdominal muscles. It contains the rectus abdominis and pyramidalis muscles. Can be divided into anterior and posterior laminae. Below the arcuate line, (1/2 from umbilicus to pubic crest) the rectus sheath is only anterior
What are the fibrous tendinous intersections surrounding the semilunaris? What is the fibrous structure that runs down the midline of the abdomen? What is it formed from?
Tendinous intersections of rectus abdominus - - Transverse tendinous intersections - Linea semilunaris - the curved intersection either side of rectus abdominus Linea alba - FIbrous midline structure formed from the aponeurosis of the anterolateral abdominal wall muscles
What is a mesentery and how is it formed?
Mesentery is a double layer of peritoneum Formed by the visceral peritoenum wrapping behind the organ to form a double layer - therefore suspending the organ from the posterior abdominal wall - very mobile eg small intestine
The mesentery of the small intestine is simply called ‘the mesentery’. Mesentery related to other parts of the gastrointestinal system is named according to the viscera it connects to What is the mesentery connected to the transverse, sigmoid colon and appendix called?
The transverse and sigmoid mesocolons The mesoappendix
What is the omentum and what does it do? Where are the lesser and greater omentum found?
The omentum is formed from folds of peritonem connecting the stomach with other organs The omenta divided the peritoneal cavity into a greater and lesser sac The lesser & greater omentum are found at the lesser& greater curvature of the stomach respectively
How do the greater and lesser sacs communicate? Where does the portal triad lie? - what is in the portal triad?
The greater and lesser sacs communicate through the omental (epiploic) foramen The portal triad is found in the free edge of the lesser omentum (aka the hepatoduodenal ligament) * Proper hepatic artery * Hepatic portal vein * Common bile duct
The peritoneum at its inferior aspect drapes over the superior aspect of the pelvic organs What are the pouches that are formed? What is the most inferior part of the peritoneal cavity when standing in females?
Peritoneum forms pouches when draping over the superior aspect of pevlic organs Males - rectovesical pouch Females - Rectouterine pouch aka pouch of Douglas - most inferior part of abdo cavity in female when standing Vesico-uterine pouch
What must be carefully avoided during paracentesis? Where does this structure arise?
During the procedure, needle must be placed lateral to the rectus sheath to avoid the inferior epigastric artery The inferior epigastric artery arises from the external iliac artery just medial to deep inguinal ring
Where do the sympathetic nerves leave the spinal cord to get to the abdominal organs? Where do they synapse? What is the exception?
Sympathetic outflow to the abdominal organs - enter sympathetic chain bilaterally and leave in abdominopelvic splanchnic nerves between T5 and L2 They synapse at prevertebral ganglia except the sympathetic to adrenal gland which synapses essentially on the organ
How do the post-sympathetic nerve fibres get from the prevertebral ganglia to the abdominal organs? What spinal cord level does the sympathetics to the adrenal gland arise from and where do they synapse?
Hitch a ride on surface of arterial branches leaving the abdominal aorta Sympathetics for adrenal gland leave spinal cord at T10-L1 to the sympathetic chain –> abdominopelvic splanchnic nerves, DOES NOT synapse, is carried with the periarterial plexuses to synapse directly at the adrenal cells
How do the parasympathetics from the vagus nerve reach the organs?
Vagus nerve presynaptic parasympathetic fibres enter abdominal cavity on surface of oesopagus and travel into periarterial plexuses around the aorta Carried to walls of organs where they synapse on ganglia
Where do visceral afferent (sensory) fibres travel to spinal cord from * Foregut structures * Midgut structures * Hindgut structures Where does pain tend to be felt from these structures?
Foregut structures - T6 to T9 - pain tends to be felt in epigastric region Midgut structures - T8-T12 - pain tend to be felt in umbilical region Hindgut structures - T10-L2 - pain tends to be felt in the suprapubic region
The somatic motor, somatic sensory and sympathetic nerve fibres supplying the structures of the abdominal part of the “body wall” travel within which nerves?
The thoracoabdominal nerves - 7th to 11th intercostal nerve Subcostal nerve (T12 anterior rami aka 12th intercostal nerve) L1 anterior rami * Iliohypogastric * Ilioinguinal
