EmbryologyLecture-Exam II Flashcards
What two layers make up the bilaminal disc?
Epiblast and Hypoblast
What are the three layers of the trilaminar disc?
Ectoderm, Intraembryonic Mesoderm, Endoderm
How is the intraembryonic mesoderm formed? Start from the primitive streak, use 3 steps
- Primitive Streak is formed 2.Cells move to primitive streak 3. Epiblast cells migrate down to make both endoderm and i.e. mesoderm
What is formed from epiblast->ectoderm?
nervous system, skin
What is formed from intraembryonic mesoderm?
body wall structures
What is formed from hypoblast->endoderm?
digestive system, respiratory system, urogenital system, PHARYNGEAL POUCHES
What are the two parts of the Lateral Mesoderm? Think linings!!
Parietal (Somatic) Layer-lining of body & Visceral Layer-lining around each organ
What does the Intermediate Mesoderm form?
Urogenital Structures
What type of Mesoderm forms the Somites and Pharyngeal Arches?
PARAXIAL mesoderm
What four items are in each somite?
1.Sclerotome(cartilage/bone) 2.Dermatome (Dermis of skin) 3.Myotome (Muscle) 4. A Nerve
Which somites become branchial arches?
1-7
What 4 items does every branchial arch contain?
A CRANIAL nerve, Artery, Cartilage, Branchial Muscle
What nerve is associated with Branchial Arch I? What cartilage and bones?
Trigeminal V….Meckel’s Cartilage, Malleus, Incus Bones
What nerve is associated with Branchial Arch II? What Bone, Process, and ligament?
Facial VII….Stapes, Styloid Process, and Stylohyoid Ligament
What nerve is associated with Branchial Arch III? What bone?
Glossopharyngeal IX….Hyoid Bone
What nerve is associated with Branchial Arch IV? What cartilage?
Vagus X SUPERIOR Laryngeal….Thyroid Cartilage
What nerve is associated with Branchial Arch VI? What cartilage?
Vagus X RECURRENT Laryngeal….Cricoid Cartilage
THROWBACK which pouch does the INFERIOR Parathyroid gland come from?
3rd pouch
Throwback: which pouch does the Superior Parathyroid gland come from?
4th Pouch
What comes from the 2nd Pouch? YOU MISSED THIS ON THE EMBRYO TEST
Palatine Tonsils (TWO of them remember?)
What arises out of the 1st cleft?
External Auditory Meatus
What arises from the 1st pouch?
Auditory tube, remember 1st pouch and 1st cleft join to make the tympanic membrane?!
Which pouch does the thymus arise from?
III
What structure and formen does the Thyroid Gland arise from?
The tongue and the foramen cecum
What three structures give rise to the anterior 2/3s of the tongue? What arch are they from?
The two lateral swellings and the tuberculum impar…1st arch…V get it?!
What structure gives rise to the posterior 1/3 of the tongue? What arch?
the COPULA in the 3rd arch…IX get it?!
What arch gives rise to the epiglottis?
The 4th arch…X get it?!
Are the tongue muscles SM or BM?
Somatic Motor from Occipital Somites
What two arches yield the Hyoid bone?
VII lesser horn and upper body and IX greater horn/ lower body
