Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

43 Cards in this Set

  • Front
  • Back
Branchial Appartus
**Composed of branchial clefts (grooves) + arches + pouches

Clefts --> derived from ectoderm

Arches --> derived from mesoderm and NC

Pouches --> derived from endoderm

Branchial Arch 1 Derivatives
Meckel's Cartilage:
=Mandible, Malleus, Incus, sphenoMandibular ligament

=Muscles of mastication (temporalis, Masseter, lateral + medial pterygoid), Mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini, anterior 2/3 of tongue

Nerve = CNV2 and CNV3
Branchial Arch 2 Derivatives
**Reichert's Cartilage
=Stapes, Styloid process, Lesser horn of the hyoid, Stylohyoid ligament

=muscles of facial expression, Stapedius, Stylohyoid, posterior belly of the diagastric

Nerve = CNVII
Branchial Arch 3 Derivatives
**Cartilage = greater horn of the hyoid


Branchial Arch 4-6 Derivatives
=thyroid, cricoid, arytendoids, corniculate, cuneiform

Muscles--4th Arch:
=most pharyngeal constrictors, cricothyroid, levator veli palatini

Muscles--6th Arch:
=all intrinsic muscles of the larynx EXCEPT CRICOTHYROID

4th Arch --> CNX (superior laryngeal branch
6th Arch --> CNX (recurrent laryngeal branch)
What forms the posterior 1/3 of the tongue?
**Arches 3 and 4
Contributions of arch 5?
Branchial Arch Innervation
Arch I --> CN V2 and V3

Arch II --> CN VII

Arch III --> CN IX

Arch IV and VI --> CN X
Tongue Development
**1st branchial arch forms the anterior 2/3
=sensation via CNV3
=taste via CN7

**3rd and 4th arches form the posterior 1/3
=sensation and taste mainly from CNIX
=the EXTREME posterior from CNX

**Motor innervation = CNXII
Branchial Cleft Derivatives
**1st cleft --> external auditory meatus

**2nd-4th clefts --> temporary cervical sinuses
=eventually obliterated by proliferation of 2nd arch mesenchyme
So what can a peristent cervical sinus lead to?
=branchial cyst in LATERAL neck

recall: thyroglossal duct cyst in MIDLINE neck
1st arch
2nd arch
Tensor tympani

=1st arch

2nd arch
External auditory meatus
1st cleft
Eardrum, eustachian tube
1st branchial membrane

=branchial membranes located at juncctions of clefts w/ pouches
1st Pouch
=middle ear cavity
=eustachial tube
=mastoid ear cells

**1st pouch contributes to endoderm-lined structures of ear
2nd Pouch
=epithelial lining of palatine tonsil
3rd Pouch
**3rd pouch contributes to 3 structures

DORSAL WINGS --> inferior parathyroids

4th Pouch
**Superior parathyroids
Abberant Development of the 3rd and 4th pouches?
=DiGeorge Syndrome

**T-cell deficiency (=thymic aplasia) + hypocalcemia (=failure to parathyroid development--i.e. tetany)
Thyroid Development
**Thyroid diverticulum arises from the floor of hte primitive pharynx
=descends into neck CONNECTED to the tongue by the thyroglossal duct (normally disappears BUT may persist as a pyramidal lobe of the thyroid)
What is a NORMAL remnant of the thyroglossal duct?
=Foramen ceccum
Most common ectopic thyroid tissue site?
Cleft Lip
**Failure of fusion of the maxillary and medial nasal processes (=formation of primary palate)
Cleft Palate
**Failure to fusion of the lateral palatine processes, the nasal septum and/or the median palatine process (=formation of the SECONDARY palate)
What is the DIAPHRAGM derived from?
**Several Parts Build Diaphragm:

1) Septum transversum
2) Pleuroperitoneal folds
3) Body wall
4) Dorsal mesentary of the esophagus
Innervation of the Diaphragm
C 3, 4, 5
Devevlopment of the Pancreas
**Pancreas is derived from foregut
What does the VENTRAL pancreatic bud become?
=pancreatic head
=uncinate process (lower half of head)
=main pancreatic duct
What does the DORSAL pancreatic bud become?
**everything else
=accessory pancreatic duct
Spleen Development
**Arises from dorsal mesentery but is supplied by the artery of the foregut
What is annular pancreas?
**Ventral and dorsal pancreatic buds abnormally encircle the duodenum
=forms a ring of pancreatic tissue that may cause duodenal narrowing
What defines the foregut?
Pharynx to duodenum
duodenum to transverse colon
distal transverse colon to rectum
Kidney Embryology Timeline
1) Pronephros = week 4
2) Mesonephros = 1st trimester
3) Metanephros = permanent
Genital Ducts
1) Mesonephric (Woffian) Duct

2) Paramesonephric (Mullerian) Duct
Mesonephric Duct
**Develops into SEED
=seminal vesicles
=ejaculatory duct
=ductus deferns
Paramesonephric Duct
**Develops into:
=fallopian tube
=part of vagina
What is secreted in males that will form their final genitalia?
1) MIF
=secreted by TESTES --> supresses development of paramesonephric ducts in males

2) Increased androgens cause development of mesonephric ducts
Male/Female Genital Homologues