Embryology Flashcards
Fill in the blanks. “The pancreas is formed by ___________ of ___________.”
2 pancreatic buds of Endodermal cells
What are the 2 pancreatic buds that form the pancreas?
Dorsal & Ventral buds
What are the relations to the Dorsal pancreatic bud?
Dorsal mesentery
Ligament of Treitz
Larger & slightly cranial to ventral bud
What are the relations to the Ventral pancreatic bud?
Close to the bile duct
Ventral mesentery
At what time during embryonic development do the dorsal and ventral pancreatic buds develop?
5 th to 8th week
What structures of the pancreas is formed by the ventral bud?
Forms the uncinate process and inferior part of the head.
What structures of the pancreas is formed by the dorsal bud?
Forms the upper part of the pancreatic head , neck , body and tail
Fill in the blanks. “ The main pancreatic duct of Wirsung is formed by _____.”
- Distal part of the dorsal pancreatic duct.
- Entire ventral pancreatic duct.
Fill in the blanks. “The accessory pancreatic duct of Santorini is formed by ________.”
The proximal part of the dorsal pancreatic duct .
What is the name of the condition given when the pancreatic duct system fails to fuse?
Pancreas Divisium
What happens in the Annular pancreas?
This is a congenital abnormality resulting from the a bifid ventral pancreatic duct. During the rotation of the duodenum, one limb fails to to rotate or may grow in the opposite direction to encircle the duodenum.
The first pharyngeal arch gives rise to what bony structures?
Malleus
Mandible
Maxilla
Incus
Sphenomandibular ligament
Squamous part of Temporal bone
Zygoma
Anterior ligament of malleus
Greater wing of sphenoid bone
1 st arch - MISS ZAG
What structures does the second pharyngeal arch give rise to?
Lesser cornu(horn) of hyoid bone
Upper part of body of hyoid bone
Stapes
Styloid process
Stylohyoid ligament
Second- LUSS
The greater cornu(horn) of the hyoid bone and lower part of the body of hyoid bone arises from what pharyngeal arch?
Third pharyngeal arch
Fill in the blanks. “ During the development of the third week, differentiation of the mesodermal layers forms _____, _______& ______.”
Para axial Plate
Intermediate Plate
Lateral Plate
A split in the lateral plate mesoderm, leads To development of the ___________.
Intra Embryonic coelom
Fill in the blanks. “At the end of the third week, Later, intra and extra embryonic coelom unite to form ________.”
Pleuroperitoneal cavity
True or False? Intra embryonic somatic mesoderm lines the the body wall while the Intra embryonic splanchnic mesoderm lines the gut tube and developing heart.
TRUE!!
What is the name of the the structure that shifts caudally to form the Stomadeum?
The buccopharyngeal membrane
The skeletal muscles and vascular component of the pharyngeal arches are derived from?
Splanchnic Mesoderm
What are the motor nerves of the Pharyngeal arches?
I - Trigeminal nerve ( That)
II- Facial nerve ( Food)
III- Glossopharyngeal nerve ( Gave)
IV- Vagus ( Pharyngeal plexus) (Very)
VI- Vagus ( Vagal Plexus) (Vegan)
“That Food Gave Very Vegan”
Fill in the blanks. “ The mandible develops by intra-membranous ossification around ______________.”
Mechel’s cartilage
M for mandible , M for Mechels
What are the muscle derivatives for the 1st Pharyngeal arch?
Masseter
Mylohyoid
Medial & lateral pterygoids
Anterior belly of digastric muscle
Tensor tympani
Temporalis
MMMATT muscles came 1st
What are the muscles of the Second arch derivatives?
Posterior Belly of Digastric
Muscles of facial expression
Stylohyoid
Stapedius
What is the nerve of the 1st pharyngeal arch?
Mandibular branch of Tigeminal
True or False? Third arch derivatives includes the greater horn of the hyoid bone, lower part of the body of hyoid bone, styloglossus, and the nerve is glossopharyngeal nerve.
FALSE!!
Bones
- Greater horn of hyoid bone
-Upper part of body of hyoid bone
Muscle
- STYLOPHARYNGEOUS muscle
Nerve
- Glossopharyngeal nerve
At what time does the tongue begin to form?
At the end of the fourth week
What are the structures that give rise to the tongue that derive from the first pharyngeal arch?
Body ( Anterior 2/3)
Lateral lingual swellings
Medial lingual welling ( tuberculum impar )
The copula ( Posterior part of tongue) and epiglottis which gives rise to the tongue are derived from which arches?
Second, Third and Fourth arch
What are the Fourth Pharyngeal arch derivatives?
Bone - Thyroid Cartilage
Muscle-
P- Palatopharyngeous
P- Palatoglossus
P- Pharyngeal constrictors
L- Levator ani muscle
S- Salpingopharyngeous
” PPPLS let remember the 4 th arch derivatives”
What are the 6th Pharyngeal arch derivatives ?
Striated muscles of the oesophagus.
Cricopharyngeus
Upper 2/3 of esophageal muscle
Intrinsic muscles of larynx
- Cricoarytenoideus ( posterior and lateral )
- Arythenoideus ( Transverse and oblique )
- Aryepiglotticus
- Thyroarytenoideus
- Thyroepiglotticus
Fill in the blanks. “The thymus is derived from the ________ pouch.”
Third pharyngeal- ventral part
The tonsillar fossa with tonsillar crypts arises from which Pharyngeal pouch?
Second Pharyngeal pouch
The tubotympanic recess is apart of which pharyngeal pouch?
The 1st pouch
Contains- Pharyngotympanic tube
Tympanic cavity and mastoid antrum
Inner layer of the ear drum
The 5th pharyngeal pouch gives rise to what structure?
Ultimopharyngeal body
- The parafollicular C cells migrate to the thyroid gland which produce calcitonin
What is the ONLY pharyngeal membrane to persists?
The tympanic membrane.
What is the name of the structure that covers 2nd 3rd and 4th pharyngeal clefts ?
Cervical mantle
What structures are apart of the 1st Pharyngeal cleft?
External auditory meatus
Outer layer of tympanic membrane
When does the Oropharyngeal membrane in the stomodeum rupture?
Between 4th & 5th
When does the oesophagus reaches its final relative length?
By the 7th week of Gestation
The lower 1/3 smooth muscular coat of the oesophagus is developed from?
Splanchnic mesochyme
What are the somatic and splanchnic sphincters of the oesophagus?
Somatic( Voluntary) - Cricopharyngeus muscle)
Splancnic ( Inoluntary) - Lower third of esophagus
Cardio-esophageal junction
Which congenital abnormality arises form a sponataneous deviation of trachea-oesophageal septum?
Tracheoesophageal fistula
‘ spoilt zip’
The are of communication between the midst section and a yolk sac represents the?
Vitilline duct
What is the degree for the first rotation of the stomach?
90 degrees
Fill in the blanks. “Due to the rotation of the stomach , the left vagus nerve becomes _______ and the right vagus nerve becomes __________.”
Left becomes Posterior ( LP)
Right becomes Anterior ( RA- Right Angle )
Which embryological structures forms the duodenum?
The duodenum is formed from the distal foregut and proximal midgut
When does bile formation begin?
In the 12th week
What process leads to the formation of the Trilamnar disc?
Gastrulation
In the lower GIT, what structures separate the caudal end of the notochord from the cloacal membrane?
Primitive node & Primitive streak
Fill in the blanks. “ The base of the Vitilline duct will later develop into ________.”
The bladder
What structures do the Proximal limb of the bowel loop give rise to?
Distal duodenum
Jejunum
Proximal ilium up to Meckel’s diverticulum
What structures dies the distal limb of the bowel loop give rise to?
Distal ilium
Ascending colon
Proximal 2/3 of transverse colon
At what time does the Mesodermal ridge between allantois and hindgut ( urorectal septum )start its descent towards the cloacal membrane?
4th week
True or False? The urorectal septum meets the cloacal membrane during the 6th week.
FALSE!! During the 7th week.
What happens during the 5th week of the development of lower GIT?
A common passage cloaca is shared between the primitive urogenital sinus anteriorly and the hindgut posteriorly.
Fill in the blanks. “ The tip of the urorectal septum where it meets the cloacal membrane becomes the _______.”
Perineal membrane
Fill in the blanks.” The upper 2/3 of the anal canal is of ____________ origin and supplied by the ____________.”
Endodermal origin and supplied by the inferior mesenteric artery.
The lower 1/3 of the anal canal is of ______ origin and supplied by the __________ ( systemic )
Ectodermal (Proctodeum) origin and supplied by the inferior rectal artery
The urogenital membrane persists in women as the __________?
Hymen
