Anatomy 1 (Lectures 1 and 2) Flashcards
Parts of the GI tract (11)
Oral cavity
Pharynx
oesophagus
stomach
small intestine
large intestine (including rectum and anal canal)
accessory organs (tongue, salivary glands, pancreas, liver, and gallbladder)
What joint is involved in opening the mouth
The temperomandibular joint (TMJ)
3 pairs of jaws “closing” muscles names?
Masseter
Temporalis
Medial pterygoid
Where does the masseter stretch?
From angle of mandible to zygomatic arch
Where does the temporalis run?
From coronoid process of mandible to temporal fossa
Where does the Medial Pterygoid run?
From angle of mandible (medial side) to pterygoid plates of sphenoid bone
What is the 1 pair of jaw opening muscle and where does it run
lateral pterygoid
Condyle of mandible to pterygoid plates of sphenoid bone
What supplies all the jaw muscles
Mandibular division of trigeminal nerve - CN V3
What cranial nerve number is the trigeminal nerve and what division is the mandibular division?
CN 5
3rd division
CN V3 course: CNS part Intracranial part Base of skull foramen part Extra-cranial part of course
Pons
Inferior to the edge of the tentorium cerebelli between the posterior and middle cranial fossa
foramen oval of sphenoid bone
From foramen oval towards structures they supply
What part of the mouth is particularly sensitive to touch
the posterior wall of the oropharynx
What is aspiration?
Inhalation of liquid or solid matter into the lungs (different from choking)
What are the arches of the soft palate made from?
Skeletal muscle covered in mucosa
Surface anatomy of the mouth (8)
Hard palate Soft palate (made up of arches) Upper dental arch Lower dental arch Palatine tonsils tongue uvula gingivae
What 2 parts can the tongue be divided into and how much of each tongue is classed as what
Anterior 2/3rds (horizontal and in oral cavity)
Posterior 1/3rd (vertical and not in oral cavity)
What supplies the:
general sensory parts of the tongue?
Special sensory areas of the tongue
general and sensory supply of posterior 3rd of tongue
CN V3 (3rd division of trigeminal nerve) CN VII (facial nerve) CN IX (glossopharyngeal)
What gives general sensation to the gingiva of oral cavity and palate (superior half)
CN V2
What gives general sensation to the gingiva of oral cavity and floor of mouth (inferior half)
CN V3
What is the gag reflex
A protective reflex that prevents foreign bodies from entering the pharynx or larynx
Sensory part of gag reflex
CN IX
Motor part of gag reflex
CNIX and CNX
What CN’s does spraying a local anaesthetic block the sensory action potentials of
CN V2, CN V3, CN VII and CN IX
What does the gag reflex cause that helps close off the entry to the body
Constrict the pharynx
CN V2 course: CNS part Intracranial part Base of skull foramen part Extra-cranial part of course
Pons
Inferior to the edge of the tentorium cerebella between the posterior and middle cranial fossae
Formane rotundum in sphenoid bone
From foramen rotunda towards structures they supply
CN VII course (special sensory, sensory, motor and parasympathetic): CNS part Intracranial part Base of skull foramen part Extra-cranial part of course
junction between the pons and medulla
Directly into internal acoustic meatus in the posterior cranial fossa
Passes through the temporal bone through the internal acoustic meatus and stylomastoid foramen
most fibres pass through he stylomastoid foramen
What branch of CN VII connects to the lingual nerve branch of CN V3?
The chorda tympani
What does the chorda tympani contain?
Taste axons for the anterior 2/3rds of the tongue
Parasypathetic axons for salivary glands
where does the chorda tympani branch off of CN VII
At the stylomastoid foramen
CN IX course (special sensory, sensory, motor, visceral afferent and parasympathetic): CNS part Intracranial part Base of skull foramen part Extra-cranial part of course
Medulla
Directly towards jugular foramen in the posterior cranial fossa
Jugular foramen at the junction between the temporal bone and occipital bone
Axons mainly pass to or from the tongue and palate
posterior wall of oropharynx
parasympathetic secretomotor to parotid salivary glands
3 pairs of salivary glands
Parotid
Submandibular
Sublingual
4 pairs of extrinsic muscles of the tongue?
Palatoglossus
Styloglossus
Hypoglossus
Geniolossus (check powerpoint for positions of these)
What is the function of the extrinsic muscles of the tongue
To change the position of the tongue during mastication, swallowing and speech
How many intrinsic muscles does the tongue have and what do these do?
4
Modify the shape of the tongue during function
What CN are the muscles of the tongue supplied by
CN XII (except palatoglossus)
CN XII course (motor): CNS part Intracranial part Base of skull foramen part Extra-cranial part of course
Medulla
Passes anteriorly towards hypoglossal canal in the posterior cranial fossa
Hypoglossal cancal (anterior wall of formate magnum)
Descneds in neck lateral to cartoid sheath
At level of hyoid bone it passes anteriorly towards the lateral aspect of the tongue
Supplies most of the muscles of the tongue
What muscles form the external layer of the pharynx
what type of muscles are these
Superior, middle and inferior constrictor (circular)
Skeletal (and striated) - we decide we want to swallow but once we have made that decision, we cannot control the muscles
What nerve supplies the pharynx
CN X
Look at diagram of the pharynx (posterior and anterior)
…
What muscles make up the inner layer of the pharynx
Longitudinal muscles
What is the purpose of the longitudinal muscles of the pharynx
To elevate the larynx and pharynx (attach to larynx, contract to shorten pharynx, raise the larynx close to the laryngeal inlet)
What are the steps of swallowing a food bolus?
Tongue pushes bolus of food towards oropharynx (voluntary)
Soft palate elevated, larynx elevated (involuntary skeletal muscles)
Circular layer of pharyngeal constrictor muscles contracts (involuntary)
Bolus of food enters oesophagus and travels inferiorly by peristalsis (involuntary)
What is the inferior pharyngeal constrictor called?
Cricopharyngeus (forms the upper oesophageal sphincter)
what muscle and what relevant cranial nerve prevents drooling
Orbicularis oris
CN VII
What type of muscles are the muscles involved in swallowing (orbicularis Doris, tongue muscles, pharyngeal constrictor muscles, longitudinal layer of of pharyngeal muscles)
Skeletal muscles
The initiation of swallowing is voluntary
On a barium swallow, what would causes a cervical constriction
Contraction of the cricopharyngeus
At what spinal feel is the cricopharyngeus muscle?
C6
What type of sphincter is the upper and lower (out of physiological or anatomical)
Upper = anatomical Lower = physiological (isn't actually anatomically there although a number of factors combine to create a sphincteric effect)
Is the oesophagus anterior/ posterior to the heart
Posterior
On a barium swallow, what causes thoracic constriction(s) of the oesophagus
Arch of aorta
Left main bronchus
On a barium swallow, what causes the diaphragmatic construction of the oesophagus
Result of passing through the diaphragm
Lower oesophageal sphincter
What leads to the lower oesophageal sphincter
Contraction of diaphragm
intrabdominal pressure slightly higher than intragastric pressure
Oblique angle at which the oesophagus enters the cardia of the stomach
What does the oesophageal sphincter help reduce the occurrence of
Reflux (presence of a hiatus hernia will reduce effectiveness and can lead to symptoms of reflux)
Where does the lower oesophageal sphincter lie
Immediately superior to gastro-oesophageal junction (here there will be an abrupt change in type of mucosa lining the wall causing the z-line)
What regions of the abdomen does the stomach mainly lie in when the patient is supine
Th left hypochondrium, epigastric and umbilical regions
Parts of stomach
Cardia Fundus Body Pyloric antrum pylorus
Name for series of ridges in stomach
Rugae
What notch marks the dividing line between the body of the stomach and pyloric antrum
Incisura angularis
Parts of the small intestines?
Duodenum (short), jejunum (about 3m), ileum (about 4m)
Parts of the large intestine
Colon (caecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon)
Rectum
Anal canal
Anus
Name for turn between the transverse and ascending colon?
Turn between transverse and descending colon?
Hepatic flexture
Splenic flexture
What are the 3 parts the abdominal organs are split into
Foregut
Midgut
Hindgut
(based on embryological origins)
Organs of the foregut
Oesophagus to mid-duodenum liver gallbladder spleen 1/2 of pancreas
Organs of midgut
Mid-duodenum to proximal 2/3rds of transverse colon
1/2 of pancreas
Organs of the hindgut
distal 1/3rd of the transverse colon to proximal 1/2 of the anal canal
What are all the organs in each of the regions of the abdomen (divided best on embryological origin) supply by the same
Arterial blood from common artery
Venous drainage from common vein
Lymphatic drainage from shared route
Nerve supply via common route
9 regions of the abdomen
Right/ left hypochondrium Epigastric Right/ left lumbar (flank) Umbilical Right/ let inguinal (iliac fossa) Pubic (suprapubic)
Where are the lines drawn to divide the abdomen into 9 regions
Mid-clavicular
Subcostal
Trans-tubercular
4 quadrants of the abdomen
UQ
LUQ
RLQ
LLQ
Muscles of the abdomen (4)
Rectus Abdominis External oblique Internal oblique transversus abdominis parietal peritoneum
When do the abdominal muscles contract to “guard”
to protect the abdominal organs when injury threatens
Peritonitis
2 parts of the peritoneum
Parietal
Visceral (both parts are continuous with each other)
Does peritoneum contain nerves
Yes, also secretes a small amount of lubricating fluid
In terms of the peritoneum,how are organs classified?
Intraperitoneal (almost completely covered in visceral peritoneum, minimally mobile) e.g. liver
Retroperitoneal e.g. pancreas and kidneys (only has visceral peritoneum on its anterior surface - located in the retroperitoneum)
With a messentery (e.g. parts of intestines, covered in visceral peritoneum which wraps itself behind the organ to form a double layer, mesentery suspends the organ fro the posterior abdominal wall = very mobile)
What is are the name of 3 condensations of the peritoneum?
Greater omentum
Lesser omentum
Messentery
(double layers that attach organs to each other and to the abdominal wall)
What do the omenta do?
Divide the peritoneal cavity into a greater sac and a much smaller lesser sac
How do the 2 peritoneal sacs communicate
throughs the omental foramen
What lies on the free edge of the lesser omentum
The portal triad
What pouches (which are part of the greater sac) are formed when the inferior aspect of the peritoneum “drapes over” the superior aspect of the pelvic organs?
Rectovesical (in males)
Rectouterine (pouch of douglas) and uterovesical (In females)
Ascites
Excess fluid within the peritoneal cavity
How is ascites fluid drained
Through paracentesis/ abdominocentesis
During paracentesis, where is the needle placed and why?
Lateral to the rectus sheath to avoid the inferior epigastric artery which ascends deep to the rectus abdomens after it iris from the external iliac just medial to the deep inguinal ring)
What are the characteristics of visceral pain
Hard to localise and dull, achy and nauseating (visceral includes visceral peritoneum)
Characteristics of somatic pain
Easier to localise and sharp and stabbing
What may colicky pain be caused by
A GI obstruction as peristalsis comes in waves
How do the sympathetic nerves get from the CNS to the abdominal organs
Leave the spinal cord between levels T5 and L2 and enter the sympathetic chains (but don’t synapse)
Leave the sympathetic chains within the abdominopelvic splanchnic nerves
Synpase at prevertebral ganglia which are located anterior to the aorta at the exit points of the major branches of the abdominal aorta
Where does the postsynaptic sympathetic nerve fibres pass?
What do they form along with other nerve fibres?
From the prevertebral ganglia onto the surface of the arterial branches leaving the abdominal aorta
They form periarterial plexuses as they hitch a ride with the arteries and their branches towards (or away from) the smooth muscles and glands of the organs
What is the course of the sympathetic nerves that supply the adrenal gland
Leave the spinal cord at T10-L1
Enter the abdominopelvic splanchnic nerves (do not synapse at the prevertberal ganglia) and instead are carried with periarterial plexuses to the adrenal gland and synapse directly onto cells
What are the 2 ways by which the parasympathetic nerves get from the CNS to the abdominal organs
How much of the digestive tract does each supply?
CNX (vagus nerve) - up tot he distal end of the transverse colon
Pelvic Splanchnic nerves (S2,3,4) - smooth muscle/ glands of the descending colon to anal canal
How does the vagus nerve provide parasympathetic nerve fibres to the abdominal organs
presynaptic parasympathetic nerve fibres enter abdominal cavity on surface of the oesophagus (“vagal trunks”)
travel into the periarterial plexuses around the abdominal aorta
carried to the walls of the organs where they synapse in ganglia
Where does pain from the foregut, midgut and handgun tend to be felt
Foregut = epigastric region Midgut = umbilical region Hindgut = pubic region
How do visceral afferent nerve fibres get from the abdominal organs to the CNS
Pain fibres from the bast majority of the abdominal organs run alongside sympathetic fibres back to the spinal cord
Where do visceral afferent nerve fibres from the foregut structures enter the spinal cord
At approx. T6-T9
Where do visceral afferent nerve fibres from the midgut structures enter the spinal cord
T8-T12
Where do visceral afferent nerve fibres from the hindgut structures enter the spinal cord
T10 - L2
Where does pain from the organs tend to be perceived
In the dermatomes of the levels at which they enter the spinal cord (bit of overlap) - type of referred pain
What pain can be felt in the right shoulder
Liver/ gallbladder pain
What pain can be felt in the centre of the back
Stomach pain/ pancreatic pain
Where is kidney and ureter pain felt
From groin right up back
Where is appendicitis pain felt
In centre and then travels to right bottom corner as it irritates the peritoneum
Where areThe somatic motor, somatic sensory and sympathetic nerve fibres supplying the structures of the abdominal part of the “body wall” are conveyed within?
The thoracoabdominal nerves (7th - 11th intercostal nerves -Travel anteriorly, then leave the intercostal spaces, travel in the plane between the internal oblique and transversus abdominis, as thoracoabdominal nerves) Subcostal nerve (T12 anterior ramus) Iliohypogastric nerve (half of L1 anterior rams) Ilioinguinal nerve (other half of L1 anterior ramus)
