Anatomy Flashcards
which joints controls jaw opening and closing?
the temporomandibular joints
name the 3 pairs of jaw closing muscles.
masseter
medial pterygoid
temporalis
name the pair of jaw opening muscles.
lateral pterygoid
which nerve supplies the muscles of mastication?
CN V3 (mandibular division of the tirgeminal nerve)
which feature of the skull prevents jaw dislocation?
articular tubercle
Describe the course of CN V3 (mandibular division of the trigeminal nerve) AND what type of fibres it contains.
Course: from pons, through foramen ovale to muscles of mastication and sensory area
Contains sensory AND motor fibres
Name the teeth in the mouth and their numbers.
Inscisors (1&2)
Canine (3)
Premolars (4&5)
Molars (6, 7, 8)
Name the 3 main pairs of salivary glands
Sublingual
Submandibular
Parotid
Which nerve supplies general sensation to the top and bottoms halfves of the mouth.
Top = CN V2 Bottom = CN V3
Describe the course and contents of CN V2 (maxillary division of trigeminal nerve)
Course: from pons, through foramen rotundum to the sensory area (mid-face, inc upper mouth)
Contains sensory fibres
which nerves govern the gag reflex?
Sensory part is CN IX
Motor part is CN IX and CN X
Spraying a local anaesthetic at the back of the mouth blocks senosry action potentials in which nerves?
CN V2, CN V3 (top and bottom of mouth), CN VII (anterior tongue) and CN IX (posterior tongue)
Which nerves supply the anterior 2/3rds of the tongue and what do they contain?
CN V3 = general sensory
CN VII = special sensory (taste)
Which nerve supplies the posterior 1/3rd of the tongue and what does it contain?
CN IX = general and special sensory
what divides the anterior tongue from the posterior tongue?
terminal sulcus
Describe the course of CN VII and what it contains.
Course: from pontomedullary junction, through the temporal bone via internal acoustic meatus THEN stylomastoid foramen WHERE part breaks off (chorda tympani - joins with CN V3 to contain taste axons - tongue - and parasympathetic axons - for salivary glands) The remaining part supplies the muscles of facial expression (as is only motor at this point)
Contains special sensory, sensory, motor and parasympathetic
What does CN VII supply?
REMEMBER = Facial nerve
Taste in the anterior 2/3 of tongue
Muscles of facial expression
Glands in the floor of the mouth
Describe the course of CN IX and what it contains
Course: from medulla, through jugular foramen, to supply area
Contains: special sensory, motor, visceral afferent and parasympathetics
Where does CN IX supply?
Posterior wall of oropharynx (sensory)
Parotid gland (secretomotor)
Posterior 1/3rd tongue (sensation and taste)
Name the 4 pairs of extrinsic tongue muscle.
Palatoglossus
Styloglossus
Hyoglossus
Genioglossus
What are the functions of the extrinsic and intrinsic muscles of the tongue?
Extrinsic: change the postition of the tongue during mastication, swallowing and speech
Intrinsic: modify the shape of the tongue during function
What supplies all the muscle of the tongue except the palatoglossus muscle?
CN XII (hypoglossal nerve)
Describe the course and contents of CN XII.
Course: from medulla, through hypoglossal canal, to extrinsic and intrinsic muscles of tongue (except palatoglossus)
Contains: motor
At what level does the oesophagus begin?
C6
what are the circular constrictor muscles of the pharynx innervated by?
CN X (contract sequentially)
what supplies the longitudinal muscle inner layer in the pharynx?
CN X and CN IX
describe the process of swallowing, highlighting which parts are voluntary and which aren’t AND the innervation.
Lips close to stop drooling (orbicularis oris and CN VII)
Tongue pushed food towards oropharynx (CN XII -voluntary).
Soft palate and larynx elevate (longitudinal muscle contracts) to close the nasal cavity (CN IX and X- involuntary)
At the same time circular layer of pharyngeal constrictor muscles contract (CN X -involuntary)
Bolus enters oesophagus and travels by peristalsis (involuntary)
What controls closing of the lips?
orbicularis oris and CN VII
Which muscle creates the UOS?
cricopharyngeus (at C6)
At which level does the oesophagus begin?
C6
How is the oesophagus innervated?
By the oesophageal plexus which runs on its surface supplying smooth muscle.
Contains para via vagal trunks and symp nerve fibres, these influence the ENS to slow or speed up peristalsis
How is the LOS created (remember it is physiological, NOT anatomical)?
Contraction of diaphragm
Intrabdominal pressure is slightly higher than intragastric pressure
Oblique angle at which it enters the stomach
What is the Z-line?
Describes the aprupt change from non-keratinised stratified squamous epithelium to simple columnar epithelium
Where is the pyloric sphincter?
Between the stomach and duodenum
The lesser omentum attaches to the _________. The greater omentum attaches to the _________.
Lesser curvature
Greater curvature
Which organs are in the foregut?
Oesophagus, stomach, mid-duodenum, liver, gallbladder, spleen and 1/2 of pancreas
Which organs are in the midgut?
2nd half of duodenum, rest of small intestine, large intestine up to 2/3rd of transverse colon AND 1/2 of pancrease
Which organs are in the hindgut?
Distal 1/3rd of transverse colon, rest of colon, rectum and proximal half of anal canal
what are the 9 abdominal regions?
Left and right hypochondrium
Epigastric
Left and right lumbar/flank
Umbilical
Left and right iliac fossa
Pubic/suprapubic/hypogastric
Which 3 line separate the abdomen into its 9 segments?
midclavicular
subcostal (under ribs)
trans-tubercular (across bony hib bit)
which 2 lines divide the abdomen into quadrants?
median and trans-umbilical
which layers of muscle make of the abdominal wall?
rectus abdominis (vertical) external oblique (hands in pockets) internal oblique (opposite - so up and in) transversus abdominis (horizontal)
what is the peritoneum?
a thin, transparent, semi-permeable serous membrane which lines the walls of the abdominopelvic cavity and organs (has parietal and visceral part)
what are the three ways that organs can be arranged within the peritoneum?
intraperitoneal (eg: liver)
retroperitoneal (eg: pancreas - as only the front is coated by it)
with a mesentery (eg: intestines)
what is the falciform ligament?
a ligament which attaches the liver to the front body wall, and separates the liver into the left medial lobe and left lateral lobe.
where do the two omental sacs communicate between?
the omental foramen
where does the portal triad lie in relation to the omentum?
on the free edge of the lesser omentum
which pouches are formed by the inferior aspect of the peritoneum in males and females?
Males: rectovesical (between bladder and rectum)
Females: vesico-uterine (between bladder and uterus) and recto-uterine/Pouch of Douglas (between uterus and rectum) pouches
what procedure is used to drain ascitic fluid from the peritoneal cavity?
paracentesis
where must the needle be inserted during paracentesis and why?
lateral to the rectus sheath to avoid the inferior epigastric artery
where does the inferior epigastric artery arise from?
the external iliac just medial to the deep inguinal ring
which types of nerves supply organs within the abdominal cavity?
visceral afferents (sensory)
parasympathetic
sympathetics
ENS
which types of nerves supply the abdominal wall?
somatic sensory
somatic motor
sympathetics
To supply abdominal organs:
Sympathetics leave the spinal cord between 1.
They then enter ___2____ but do not ___3___.
They leave the chains within _______4_______ nerves.
They synsapse at ____5____ which are found ____6____
Postsynaptic fibres then travel on the surface of _7__ in ___8___ to reach the smooth muscle and glands of the organ
- T5-L2
- sympathetic chains
- synapse
- abdominopelvic splanchnic
- prevertebral ganglia
- anterior to the aorta at exit points of major bracnes of the abdominal aorta
- arterial branches leaving the abdominal aorta
- periarterial plexuses
How do sympathetics get to the adrenal gland (doesn’t follow normal route)?
- Leave spinal cord at T10-L1
- Enter abdominopelvic splanchnic nerves
- DO NOT synapse at prevertebral ganglia, instead travel with periarterial plexuseese and synapse directly onto cells
Where does the parasympathetic innervation of abdominal organs originate from?
CNX (vagus nerve) AND pelvic splanchnic nerves (S2, 3, 4)
Supplying abdominal organs:
The vagus nerve (presynaptic fibres) enters the abdominal canvity on the surface of the ___1__ in __2__.
It then travels into the __3__ around the abdominal aorta
It is carried to the __4__ where they __5__ in ganglia.
- oesophagus
- vagal trunks
- periarterial plexuses
- walls of the organs
- synapse
Where does the vagus nerve supply and where do the pelvic splanchnic nerves supply?
Vagus supplies: GIT and abdominal organs up to the distal end of the transverse colon
Pelvic splanchnic nerves supply: descending colon to anal canal
Pain in the foregut tends to be felt in __1__
Pain in the midgut tends to be felt in ___2___
Pain in the hindgut tends to be felt in __3__.
- epigastric
- umbilical
- pubic
Visceral afferents get from the abdo organs to the CNS by travelling alongside __1__ back to the spinal cord.
Those from foregut structures enter at 2
Those from midgut enter at __3__
Those from hindgut enter at __4__
- sympathetic fibres
- T6-T9
- T8-T12
- T10-L2
Pain from the liver or gallbladder can be referred to 1
Pain from the stomach can be referred to 2
Pain from the pancreas can be referred to 3
- right shoulder
- inbetween the shoulder blades
- mid back
which nerves supply the abdominal body wall?
thoracoabdominal nerves
subcostal nerve
iliohypogastric nerve
ilioinguinal nerve
The thoracoabdominal nerves were origionally the 1 intercostal nerves which have left the intercostal spaces and travelled between 2
The subcostal nerve originated from 3 ___ ramus
The iliohypogastric nerve originated from half of 4 ___ ramus
The ilioinguinal nerve originated from the other half of 5 ___ ramus
- 7th-11th intercostal nerves
- the internal oblique and transversus abdominis
- T12 anterior ramus
- half of L1 anterior ramus
- other half of L1 anterior ramus
what is the portal triad made up of?
hepatic artery (blood supply to)
hepatic portal vein (drainage to)
common bile duct
nerves and lymphatics
at what level does the celiac trunk arise?
T12
Which arteries supply the foregut, midgut and hindgut
Foregut: celiac trunk
what does the celiac trunk trifurcate to produce?
splenic, hepatic and left gastric arteries
which ribs protect the pancreas?
9-11