07/25/2017

EMBRYOLOGY mci screening test and indian medical pg examz high yield important topics study tips

By Live Dr - Wed Feb 11, 3:46 am

EMBRYOLOGY

EMBRYONIC DERIVATIVES

STRUCTURE MALE FEMALE
Urogenital sinus Prostrate

Bulbourethral gland

Urethra and paraurethral glands

Vagina, Bartholin’s glands

Parmesonephric duct Appendix testis Uterus, fallopian tubes, Hydatid of Morgagni,
Mesonephric duct Trigone of bladder,

Epididymis, appendix of epididymis. Seminal vesicles, ductus deference

Trigone of bladder,

Epoophoron, Paroophoron

Gartner’s duct

Gubernaculums Gubernaculums Round and ovarian ligaments.

ANALOGOUS STRUCTURES IN MALE AND FEMALE GENITALIAE

Labia majora Scrotum
Labia minora Ventral aspect of penis
Clitoris Penis
Vestibular bulb Corpus spongiosum
STRUCTURE DERIVATIVE
The extra hepatic portion of umbilical vein The round ligament of the liver (ligamentum teres hepatic), which lies in the free edge of the falciform ligament
The intrahepatic portion (ductus venosus) Ligamentum venosus
Closure of ductus arteriosus Ligamentum arteriosum
Closure of distal part of umbilical arteries Medial umbilical ligament
Proximal part of umbilical artery Superior vesical artery

TWINS

Within 72 hrs Diamniotic dichorionic
4-8 days Diamniotic monochorionic
> 8 days Monoamniotic monochorionic
> development of embryonic disc Conjoined twins

QUOTE CORNER

Education is what remains after one has forgotten what one has learned in school. -Albert Einstein

ELEVENTH HOUR EMBRYOLOGY                                                                                                           14

ARCH NERVE AND ATERRIES MUSCLES BONES/ CARTILAGE.
First

(Mandibular)

Mandibular division of trigeminal nerve

maxillary remnant of 1st arch of aorta

Muscles of mastication, anterior digastric, tensor tympani, tensor palatii Quadrate cartilage, Malleus, Incus, Meckel’s cartilage, sphenomandibular ligament, mandible.
Second

(Hyoid)

Facial  nerve

stapedial remnant of dorsal part of 2nd arch of aorta

Facial muscles, posterior digastric, Stapes superstructure, styloid process, stylohyoid ligament, lesser horn and upper body of hyoid.
Third Glossopharyngeal nerve

internal carotid remnant of dorsal 3rd aortic arch and common carotid remnant of ventral 3rd aortic arch

Stylopharyngeus Greater horn and lower body of hyoid
Fourth Superior laryngeal nerve

1st part of Subclavian artery on right side

main part of aortic arch on left side

Cricothyroid, levator palatine, constrictor of pharynx, Laryngeal cartilages
Sixth recurrent laryngeal

main part of pulmonary artery on ventral side

muscles of larynx Laryngeal cartilages

Pharyngeal pouches-

1-      Middle ear, Eustachian tube.

2-      Tonsil

3-      Upper- inferior parathyroid

Lower-thymus

4- upper- superior parathyroid

Lower- ultimobranchial body

TRIVIAL TRUTH

In Persian mythology, Rudaba’s labour of Rostam was prolonged due to the extraordinary size of her baby. Zal, her husband, summoned the Simurgh, who instructed him upon how to perform a caesarean section, thus saving Rudaba and the child, who later on became one of the greatest Persian heroes.

ELEVENTH HOUR EMBRYOLOGY                                                                                                           15

Pharyngeal clefts-

1-      external auditory canal

2, 3, 4- cervical sinus

STRUCTURES DERIVED  FROM NEURAL CREST
Pia mater

Dental papillae

Adrenal medulla

Shwann cell

Melanoblasts

Dorsal root ganglia

Autonomic ganglia

Cells belonging to APUD series

Bones and connective tissues of craniofacial structures

Cells of truncoconal; cushions of heart

*At birth there are 2 million primary oocytes in the dictyotene (resting phase), arrested in the first meiotic division.

By puberty, 4 lac remain.

400 ovulate during reproductive period.

Just prior to ovulation, the primary oocyte enters and completes 1st meiotic division.

The 2nd meiotic division is completed after fertilization.

*During first 24 weeks, there is only fetal hemoglobin; after which adult type Hb appears,

At term, 75-80% Hb is of fetal type.

It is completely replaced by 4 months of age.

*Earlier weeks of gestation, primitive nucleated RBC s are produced in yolk sac.

In middle trimester, liver is the main organ along with spleen and lymph nodes.

*Order of development of paranasal sinuses.

Maxillary-ethmoid-frontal-sphenoid.

Occurrence of acute sinusitis and carcinoma-maxillary-ethmoid -frontal-sphenoid.

*Accutane embryopathy- isotretinoin teratogenicity.

*The anti epileptic least like to cause malformation is Phenobarbitone.

*HCG is produced from syncytiotrophoblast.

QUOTE CORNER

The greatest barrier to success is the fear of failure.- Sven Goran Eriksson

ELEVENTH HOUR EMBRYOLOGY                                                                                                           16

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