Anatomy Flashcards
What muscle forms the floor of the oral cavity?
Mylohyoid muscle
What bone form the hard palate of the roof of the mouth cavity?
Maxilla and palatine bone
How many teeth in primary dentition?
20
incisors, canines, pre-molars and molars in each quadrant?
2 Incisors, 1 canine, 2 premolars, 3 molars
What is the space between cheeks and teeth and what muscle normally keeps it closed?
Vestibule, buccinators
Where do the buccinators attach and what is its nerve supply?
Maxilla and mandible, supplied by facial nerve
Extrinsic muscles of the tongue
Genioglossus (from mandible)
Hyoglossus (from hyoid bone)
Styloglossus
Palatoglossus
Nerve and blood supply of the tongue
Motor: hypoglossal (12) supplies all except palatoglossus
Sensory: general for A = lingual (mandibular from V)
general for P = glossopharyngeal (X)
Taste
A - facial via chord tympani
P - glossopharyngeal
Location of pharynx
Begins at the base of skull —> vertebra C6
Segments of the pharynx and their locations
- Nasopharynx (posterior to nasal cavity)
- Oropharynx (posterior to mouth cavity)
- Hypopharynx/laryngopharynx (post to larynx)
Origins of superior, middle and inferior constrictors of pharynx
S - Pterygomandibular origin
M - Hyoid origin
I - Laryngeal origin (Thyropharyngeus + Cricopharyngeus)
3 longitudinal muscles of the pharynx
- stylopharyngeus
- Salpingopharyngeus
- Palatopharyngeus
Which sphincter is involved in swallowing?
Crico-oesophageal sphincter
3 planes of reference for the abdominal regions
- mid-clavicular (vertical)
- Transpyloric (L9/9th costal cartilage)
- Transtubercular (tubercles of iliac crests)
External oblique location and aponeurosis
Location: ribs 5-12 –> iliac crest, downward and medial
Aponeurosis - inguinal ligament
Internal oblique location
Iliac crest inguinal ligament –> ribs 9-12
travels up and medial
Transversus abdominis location
ribs 7-12 lumbar fascia of iliac crest –> midline
travels horizontally
Rectus abdominis location
Too of pubis –> ribs costal cartilages 5,6,7
What is the linea alba?
Where three lateral aponeuroses meet in the midline to form a white fibrous structure
What 3 lateral aponeuroses form the linea alba?
- external obliques
- internal obliques
- transversus
Which blood vessels anastomose within the rectus sheath?
Superior epigastric (from S.C. to intern. thoracic) and inferior epigastric (from external iliac)
Differences between simple and compound gland
Simple - single unit, micro, part of an organ
Compound - branched ducts, its an organ
Histological pattern of serous units
- round nuclei (euchromatic)
- basal cytoplasm blue (rER)
- apical cytoplasm usually pink
Mucous units (acini) histology
- cytoplasm pale
- nuclei flat and peripheral
Predominant acini present in parotid, submandibular and sublingual gland?
Parotid - mainly serous
Submandibular - mixed
Sublingual - mostly mucous
In what tissue are glands commonly located? and less commonly?
Mostly limited to lamina propria (glands in mucosa)
Some pass through the muscular mucosae (in submucosa)
What is the muscle organisation in the oesophagus?
Upper - Musculares externa - skeletal
Lower oesophagus - smooth muscle
Middle part - mixture
Regions of the stomach
oesophagus - Fundus, body, pyloric antrum, pyloric canal - duodenum
What makes up the fundic, and pyloric part of the stomach?
Fundic part = fundus + body (acid secreting)
Pyloric part = pyloric antrum and canal (non-acid producing)
What cells are present in the glands in the lamina propria of the fundic part?
Chief cells - enzyme producing
Parietal cells - large pink (external side of gland)
Endocrine cells
Two mesenteries and what they connect?
Lesser momentum - connects lesser curvature of the stomach to the liver
Greater omentum - from greater curvature
2 sphincters of the stomach
Cardiac/lower eosophageal - no anatomical thickening, prevents reflux
Pyloric sphincter - thickening of circular smooth muscle
Blood supply to the abdominal GIT
- coeliac
- superior mesenteric
- inferior mesenteric
Which fibres carry normal sensation and warning sensation in the abdomen?
Normal sensations - parasympathetic
Warning - sympathetic
Epithelium of oesophagus
Stratified squamous epithelium (non keratinised)
Cells in the glands of the lamina propria in the stomach
- chief cells
- parietal cells
- endocrine cells
What contributes to the great surface area of the SI?
- Semicircular folds - pilae circularis
- villi with microvilli brush border
- intestinal glands/crypts
What is in the core of a villus?
Lamina propria (loose CT) which contains blood vessels and lacteals
Where are the paneth cells in the small intestine?
At the base of a crypt = phagocytic
Most characteristic feature of duodenum
Glands are in the submucosa (mucous glands = Brunner’s glands)
Where are Peyer’s patches?
Ileum (SI)
Structural differences between appendix and colon
- No taeniae – continuous longitudinal coat
- Small lumen
- Few glands
- Massive ring of lymphoid tissue
- Unknown function
Location of liver
Right hypochrondrium and epigastrium
What does the falciform ligament connect the liver to?
Anterior abdominal wall
What does the triangular ligament connect the liver to?
Diaphragm and abdominal wall
What does the dual blood supply to the liver consist of?
Hepatic artery and portal vein
What divides the liver into anatomical L + R lobes?
- falciform ligament
- ligamentum teres
- lesser omentum
Which lobe of the liver do the caudate and quadrate belong to?
Left lobe
In each lobe of the liver, there are several segments. What 3 structures are in every segment?
- portal vein
- hepatic artery
- bile duct
What is the portal vein formed by?
Splenic and superior mesenteric veins (inferior mesenteric joins the splenic)
What are the 2 main branches of the portal vein and what do they supply?
Left: segments 1-4 (L functional lobe)
Right: segments 5-8 (R functional lobe)
Where is the fossa of the gall bladder impressed on the liver?
Visceral surface, to the right of the quadrate lobe
What is hartmann’s pouch?
Slight dilatation at the neck of the gall bladder
What is the Phyrgian cap?
Folding of the fundus on the body of the gall bladder
What blood supply does the pancreas receive?
- Superior mesenteric artery
- Coeliac
Which part of the duodenum contains the sphincter of Oddi and what is its function?
The 2nd part (vertical), its a sphincter for the combined duct
Location of the spleen
Along ribs 9-11, rather posterior
What is the functional advantage of portal drainage in the spleen?
Haemoglobin metabolism
What is a portal triad?
Portal vein, hepatic artery and bile duct in a lobule of the liver
What is on the sinusoidal surface of hepatocytes?
Microvilli
What does the head-tail fold of the trilaminar embryo result in?
Formation of the endodermal tube - has three parts (foregut, midgut and hindgut)
Which future openings have endoderm and ectoderm in contact?
- Oral membrane
- Anal membrane
Consequence of lateral folds in the development of the GIT
- complete the tube formation
- coelomic/peritoneal cavity formed
- endoderm is the epithelial lining of the GI tract
- wall of the tube = muscle/CT = mesodermal
What forms the vitello-intestinal duct?
Yolk sac communication with midgut lumen
What are the foregut mesenteries composed of?
Ventral mesentery - has a free margin and the umbilical vein runs in it
Dorsal mesogastrium - continuous with the dorsal mesentery of midgut and hindgut
Foregut derivatives
- abdominal oesophagus
- stomach
- cranial half of duodenum
Rotation and development of the stomach during foetal life
Stomach:
- initially in sagittal plane, ventral curve is lesser, dorsal curve is greater
- rotation during development
- lesser curvature = right
- greater curvature = left
Development of liver
Liver develops within ventral mesogastrium
- the falciform ligament connects liver to diaphragm and anterior wall
- lesser omentum connects liver to lesser curvature of stomach
- liver grows up to the diaphragm, separating two layers of LO
Where does the spleen develop?
Within the dorsal mesogastrium
What is the upper limit of the true pelvis?
Pelvic brim
What is the pubis symphysis composed of?
White fibrocartilage disc and superior and inferior ligaments
What movement does the sacroiliac joint permit?
Slight movement, mostly passive - when standing up and weight bearing and during childbirth
The levator ani is a broad sheet of muscle. It is composed of three separate paired muscles, called:
the pubococcygeus, puborectalis and iliococcygeus.
Puborectalis location and function
The puborectalis muscle is a U-shaped sling, extending from the bodies of the pubic bones, past the urogenital hiatus, around the anal canal. Its tonic contraction bends the canal anteriorly, creating the anorectal angle (90 degrees) at the anorectal junction (where the rectum meets the anus).
The main function of this thick muscle is to maintain faecal continence – during defecation this muscle relaxes.
Describe the anatomy of the apex, body, fundus and neck of the bladder
Apex – This is located superiorly, pointing towards the pubic symphysis. It is connected to the umbilicus by the median umbilical ligament (a remnant of the urachus).
Body – The main part of the bladder, located between the apex and the fundus
Fundus (or base) – Located posteriorly. It is triangular-shaped, with the tip of the triangle pointing backwards.
Neck – Formed by the convergence of the fundus and the two inferolateral surfaces. This structure joins the bladder to the urethra.
What is the trigone?
The triangular area marked by the ureters and urethra
Which muscle and sphincters are involved in bladder contraction during micturition?
Detrusor muscle: contains fibres in all three directions to maintain structural integrity and is innervated by sympathetic and parasympathetic fibres
Internal sphincter
o Male – consists of circular smooth fibres, which are under autonomic control. Blends with muscle in prostate
o Females – thought to be a functional sphincter (i.e. no sphincteric muscle present). It is formed by the anatomy of the bladder neck and proximal urethra.
External urethral sphincter – around proximal urethra and has the same structure in both sexes. It is skeletal muscle, and under voluntary control. During micturition, it relaxes to allow urine flow.
Blood supply/venous drainage to the bladder
Internal iliac vessel and vesical venous plexus
Males: arterial supply supplemented by superior vesicle artery
Females: inferior vesical artery
Retroperitoneal organs
Pancreas Ureters Colon Kidneys Esophagus Rectum
Duodenum is mostly retroperitoneal
Muscles of mastication
Medial and lateral pterygoids
Masseter
Temporalis
Prominent feature of the nasopharynx
Opening of the pharyngotympanic tube - eustachian tube
What connects the tongue to the epiglottis?
Median glosso epiglottic fold - on either side of the fold is a tiny depression called vallecula
During swallowing, food passes ________
Down either side of the laryngeal inlet, through the piriform recess
Attachments of the digastric muscle
Proximal - medial side of the mastoid
Distal - anterior end of the mandible
Histology of the fund part of the stomach
Simple columnar cells - mucous secreting
What does the transpyloric and trans tubercular plane pass through ?
TP - L1 (cartilage of 9th rib meets 8th rib)
TT - tubercles of iliac crest
Where does the jejunum begin?
Below the transverse colon, to the left of the midline
What are the anatomical differences between the jejunum and ileum?
The jejunum is thicker and has thicker plicae circularis than the ileum
What are haustrations and taenia coli?
H - sac like pouches of the colon forming the tube
TC - longitudinal muscle condensed into 3 bands in the colon
Branches of the superior mesenteric artery
Ileocolic artery
Right colic artery
Middle colic artery
Branches of the inferior mesenteric artery
Left colic artery
Sigmoid arteries
Superior rectal artery
Which parts of the colon are retroperitoneal
ascending and descending
Where is the quadrate lobe located
Between the gall bladder and ligamentum teres
Stomach blood supply
All branches of the coeliac artery
Lesser curvature - R+L gastric
Greater curvature - R+L gastroepiploic
Fundus - short branches from splenic
Course of porta hepatis
Begins behind neck of pancreas then travels in oblique course, retroduodenal, then in the lesser omentum
Where do the lateral and medial pterygoid muscles attach
Lateral pterygoid plate
What muscle does the parotid gland sit on top of?
Masseter
Which muscles are supplied by the facial nerve?
Buccinator and platysma - both are not for mastication (little or no action on temporomandibular joint)
