Systemic Embryology Flashcards
The pharyngeal apparatus is made up of what components?
Pharyngeal arch
Pharyngeal pouch
Pharyngeal cleft
Pharyngeal membrane
The pharyngeal apparatus plays an important role in the development of the ________________ region of the fetus
Head and neck
Pharyngeal arches appear at the ______ week of embryonic development
4th
What are the components of a pharyngeal arch?
Cartilage
Muscle
Artery
Nerve
What is the nerve of the first pharyngeal arch ?
Trigeminal nerve (Mandibular and maxillary branches)
What is the nerve of the 2nd Pharyngeal arch?
Facial nerve
What is the nerve of the 3rd Pharyngeal arch?
Glossopharyngeal nerve
What is the nerve of the 4th Pharyngeal arch?
Superior laryngeal branch of the vagus nerve
What is the nerve of the 6th Pharyngeal arch?
Recurrent laryngeal branch of the Vagus nerve
Another name for the cartilage of the 1st pharyngeal arch is ______________
Meckel’s cartilage
Another name for the cartilage of the 2nd Pharyngeal arch is ______________
Reichert’s cartilage
The superior parathyroid gland is derived from the ________________
Dorsal wing of the 4th pharyngeal pouch
The inferior parathyroid gland is derived from the ______________
Dorsal wing of the 3rd pharyngeal pouch
The _____________ wing of the ____________ pharyngeal pouch develops into the Thymus
Ventral wing of the 3rd pharyngeal pouch
Treacher Collins syndrome
Di Guerre syndrome
Pierre robin syndrome
The above are syndromes for which pharyngeal arch?
First
What is the artery of the 1st Pharyngeal arch?
Maxillary artery
What are the arteries of the 2nd Pharyngeal arch?
Hyoid artery
Stapedial artery
_______________ and _____________ are the arteries of the 3rd pharyngeal arch
Common carotid artery
Internal carotid artery
________________ and ______________ are the arteries of the 4th pharyngeal arch
Aortic arch
Subclavian artery
What artery of the 4th Pharyngeal arch supplies the left side?
Aortic arch
___________ and ____________ are the arteries of the 6th Pharyngeal arch
Ductus arteriosus
Pulmonary artery
What artery of the 6th pharyngeal arch supplies the right side?
Pulmonary artery
Cartilages of the pharyngeal arch are _________________ shaped
Horseshoe
Malleus
Incus
Sphenomandibular ligament
Spine of sphenoid bone
The above structures are derived from the cartilage of the ___________ Pharyngeal arch
1st
What structures are derived from the cartilage of the 2nd pharyngeal arch?
Stapes bone
Lesser horn of the hyoid bone
Styloid process of the temporal bone
Upper part of the hyoid bone body
What structures are derived from the cartilage of the 3rd pharyngeal arch?
Greater horn of the hyoid bone
Lower part of the hyoid bone body
All cartilages of the larynx are derived from the 4th & 6th cartilage except ________________
Epiglottis
3 muscles of the 1st Pharyngeal arch
Muscles of mastication
Tensor palati muscle
Tensor tympani muscle
Mylohyoid
Anterior belly of the digastric muscle
3 muscles of the 2nd pharyngeal arch
Posterior belly of the digastric muscle
Stylohyoid muscle
Muscles of facial expression
Stapedius muscle
What is the muscle of the 3rd Pharyngeal arch?
Stylopharyngeus muscle
2 muscles of the 4th pharyngeal arch
Constrictors of the pharynx
Levator veli palati
Cricothyroid
What muscles arise from the 6th Pharyngeal arch?
Intrinsic muscles of the larynx
What is the fate of the 1st to 4th pharyngeal clefts?
1st pharyngeal cleft gives rise to the Ear canal
All other Pharyngeal clefts are obliterated
____________________ is an autosomal recessive disorder characterised by cleft palate, small mandible (micrognathia) and a posteriorly placed tongue (glossoptosis)
Pierre Robins syndrome
________________ is an autosomal dominant disorder characterised by molar and mandibular hypoplasia, deformed external ear and depressed palpebral fissure.
Treacher Collins syndrome
Treacher Collins syndrome is otherwise called ______________
Mandibulofacial dysostosis
Which Pharyngeal arch disorder is as a result of the microdeletion of Chromosome 22?
DiGeorge syndrome
______________ is the most severe disorder relating to the pharyngeal arches
DiGeorge syndrome
The urogenital system is functionally divided into _______________ and _______________
Urinary system
Genital system
3 kidney systems are formed during intrauterine life. They are _______________, _________________ and ________________
Pronephros
Mesonephros
Metanephros
The 3 kidney systems are formed in a _______________ sequence
a. Caudal to Cranial
b. Lateral
c. Cranial to caudal
Cranial to caudal
Which of the kidney systems in Nonfunctional?
Pronephros
Which of the kidney systems forms the permanent kidney?
Metanephros
The mesonephros is functional throughout gestation.
True/False
False
The mesonephros is only functional for a short time during early fetal period
The pronephros is represented by __________ solid cell groups in the Cranial region
7-10
All signs of the pronephric system disappear by the end of the _________ week
4th
The mesonephros is derived from the _________________ germ layer
Intermediate mesodermal
The first excretory tubule of the mesonephros appears early in the ________ week
4th
The mesonephric duct is also called ____________
Wolffian duct
The mesonephros lengthens and form an S-shaped loop that forms the ___________________
Glomerulus
_____________ and _____________ are attached to the posterior abdominal wall by a broad urogenital mesentery
Mesonephros
Gonads
The mesonephros forms a large ovoid organ on each side of the midline. This occurs at what time?
Middle of the second month
The mesonephric duct runs __________ to the mesonephros
a. Anterior
b. Lateral
c. Posterior
d. Medial
Lateral
The metanephros appears in the _______ week
5th
Collecting ducts of the permanent kidney develop from the ________________
Ureteric buds
The ureteric bud penetrates the metanephric tissue to form the _______________
Primitive renal lelvis
The primitive renal pelvis splits into two portions. ________________ and _______________
Cranial
Caudal
Ureter
Renal pelvis
Major and minor calyces
1-3 million collecting tubules
The above structures are derived from the ______________
Ureteric buds
The kidney develops from 2 sources which are _________________ and _______________
Metanephric mesoderm
Ureteric buds
Urine production begins around what time of gestation?
10th week
A congenital disorder where the ureter does not connect with the bladder and drains somewhere else is called _____________
Ectopic ureter
Name 2 sites of ectopic ureteral opening
Vagina
Urethra
Vestibules
The kidney is initially positioned in the _____________ region
Pelvic
A clinical condition where the Ascension of the kidney into the abdominal region is obstructed by the root of the inferior mesenteric artery is called ______________
Horseshoe kidney
A clinical condition where the kidney fails to ascend into the abdominal region is called ______________
Pelvic kidney
Excretion of waste product during fetal life is carried out by the _______________
Placenta
Kidney formed by the metanephros becomes functional during the _______ week
12th
The cloaca divides into the _____________ and _______________
Urogenital sinus
Anal canal
Division of the cloaca occurs during the ____________ week
4th to 7th
________________ is a layer of mesoderm between the primitive anal canal and urogenital sinus
Urorectal septum
The perineal body is formed from the tip of the ________________
Urorectal septum
The urogenital sinus breaks up into 3 portions. Name them
Phallic part
Pelvic part
Urinary bladder
The urachus connects the apex of the bladder to the ________________ upon destruction of the allantois
Umbilicus
The urachus is known as the ___________________ in adults
Median umbilical ligament
The pelvic part of the urogenital sinus gives rise to the __________________ and ______________ urethra
Prostatic
Membranous
The prostate gland is formed by buds from the ______________
Urethra
Seminal vesicles are formed from buddings of the _______________
Ductus deferens
The epithelium of the urethra originates in the _________________ germ layer
Endodermal
In females, the urethral and paraurethral glands are derived from the ___________ part of the urethra
a. Lateral
b. Caudal
c. Cranial
d. Medial
Cranial
____________________ is a ventral body wall defect where bladder mucosa is exposed to the outside
Exstrophy of the bladder
__________________ is a ventral body wall defect in which migration of mesoderm to the midline is inhibited and the tail fold fails to progress
Exstrophy of the cloaca
What urogenital defect is associated with amniotic rupture?
Exstrophy of the cloaca
The nervous system develops from the ______________
Neural plate
The neural plate is found in what germ layer?
Ectodermal germ layer
The neural plate forms 4 components. Name them
Neural Crest
Neural Tube
Neural Groove
Neural Fold
Neural crest cells form the ___________ and ____________
Peripheral nervous system
Autonomic nervous system
The neural tube differentiates into the __________________
Central nervous system
The Cranial opening of the neural tube is called ________________
Rostral neuropore
The caudal opening of the neural tube is called _________________
Caudal neuropore
During the 3rd to 4th weeks, the walls of the neural tube thicken to form the _____________ and _______________
Brain
Spinal cord
Development of the brain starts with 3 primary vesicles which are:
Prosencephalon
Mesencephalon
Rhombencephalon
The prosencephalon gives rise to the ______________ and _______________
Telencephalon
Diencephalon
The Rhombencephalon gives rise to the _________________ and ________________
Metencephalon
Myelencephalon
The prosencephalon oversees the development of what region of the brain?
The forebrain
The mesencephalon oversees the development of what region of the brain?
Midbrain
The rhombencephalon oversees the development of what region of the brain?
Hindbrain
The telencephalon gives rise to the _____________
Cerebrum
The diencephalon gives rise to the ___________________
Thalamus
Hypothalamus
Epithalamus
Eye cup
The mesencephalon gives rise to the ___________
Midbrain
The metencephalon gives rise to the ___________________
Pons
Cerebellum
The myelencephalon gives rise to the __________________
Medulla oblongata
The lateral ventricles are formed from the _________________
Telencephalon
The third ventricle is formed from the _________________
Diencephalon
The rostral fourth ventricle is formed from the _______________
Metencephalon
The caudal fourth ventricle is formed from the ____________________
Myelencephalon
The walls of the neural tube are lined with _____________________ epithelium
Pseudostratified columnar
Neuroepithelium/neural tube epithelium cells constitute 3 zones which are
Ventricular zone
Intermediate zone
Marginal zone
All neurons and macroglial cells in the spinal cord are found in what neuroepithelial zone
Ventricular zone
The neuroepithelial zone formed by neuroblasts is called the ____________________
Intermediate zone
What neuroepithelial zone becomes the white matter?
Marginal zone
What neuroepithelial zone becomes the grey matter?
Intermediate zone
The respiratory system originates from which germ layer?
Endodermal layer
The epithelial lining of the trachea, lungs, bronchii and larynx are derived from what germ layer?
Endodermal layer
Cartilages, muscles and connective tissue of the respiratory system originate from which germ layer?
Splanchnic mesodermal layer
A ventral outgrowth of the Cranial part of the foregut is called _______________
Respiratory diverticulum
The proximal part of the respiratory diverticulum forms the __________ and _____________
Larynx
Trachea
The respiratory diverticulum is also called ________________
Laryngeotracheal diverticulum
The trachea is formed from what part of the respiratory diverticulum?
Proximal part
At week 4, the 2 bronchial buds become principal bronchii and divide into __________________ and __________________
Right principal bronchus
Left principal bronchus
Which principal bronchus is more aligned to the trachea?
Right principal bronchus
At week 5, the principal bronchii subdivide into secondary bronchii, ____________________ and intersegmental bronchii
Segmental/Tertiary
The lungs consist of how many bronchopulmonary segments?
10
The partial or complete collapse of the lungs or a portion of it is called ____________
Atelectasis
What is tracheoesophageal fistula?
This is an abnormal connection between the esophagus and the trachea
The most common type of Tracheoesophageal fistula is _________
Type A
With an 85-90% rate
Type A TEF is characterised by ________________
Esophagus upper part blind pouch
Lower part connects to trachea
The rare condition where the trachea is narrowed is called ____________
Tracheal stenosis
Outline the stages of lung maturation
Pseudoglandular stage
Canalicular stage
Saccular stage
Alveolar stage
The first stage of lung maturation occurs from week _____ to ______
5 to 16
The second stage of lung maturation occurs from when to when?
Week 16 to 26
The third stage of lung maturation occurs from when to when?
Week 26 till birth
Thd fourth stage of lung maturation occurs from when to when?
8 months to 8 years
Mention one event that occurs in the pseudoglandular stage of lung maturation
Basic lung structures are formed up to the terminal bronchioles
Respiratory structures are absent
The terminal bronchiole of the lungs are lined by __________________ epithelium
Simple cuboidal
Mention one event that occurs in the canalicular stage of lung maturation
Respiratory elements are formed
Lung tissue is well vascularised
Mention one event that occurs at the saccular stage of lung maturation
Alveolar sacs are formed in large numbers
Capillaries bulge into developing sacs
Intimate contact between epithelium of sac and endothelium of capillaries
Mention one event that occurs at the alveolar stage of lung maturation
Formation of true alveoli
Type II pneumocytes produce a sufficient amount of surfactant
Free exchange of gases across the blood-air barrier is formed
Mention 4 places by which lung fluids are cleared
Pulmonary artery
Mouth
Nose
Veins
Capillaries
Lymphatics
Adequate volume of amniotic fluid
Adequate thoracic space
Fetal breathing movements
The above are factors affecting ___________________
Lung development
Surfactant deficiency leads to a congenital defect called _______________
Respiratory distress syndrome (RDS)