Early Development

Question 1

Where do primordial cells live ?

Answer 1

Yolk sac

Question 2

What week do primordial cells emerge?

Answer 2

4th week

Question 3

What week do primordial cells migrate ?

Answer 3

6th week

Question 4

Where do primordial cells undergo meiosis?

Answer 4

Gonads

Question 5

What is the importance of meiosis one ?

Answer 5

replication of DNA with crossover

without splitting of centromere

Question 6

What is the importance of meiosis two ?

Answer 6

centromere splitting

Question 7

When do the male primordial cells go dormant ?

Answer 7

@ 6th week

Question 8

How long are the male primordial cells dormant for ?

Answer 8

6th week till puberty

Question 9

When does meiosis start for males ?

Answer 9

@ puberty

Question 10

What are the male cells that arise from primordial cells ?

Answer 10

Type A spermatogonia undergo mitoiss = stem ells

Type B spermatogonia undergo meiosis

Question 11

What type of cell is approaching meiosis one ?

Answer 11

”- gonia” cells

Question 12

When does female oogonia replicate?

Answer 12

6th week to 4th month

Question 13

When is there a maximum number of oocytes in a females ?

Answer 13

5th month

Question 14

When do oogonia enter meiosis one ?

Answer 14

5th month

Question 15

What are the arrested times of oocytes in the females ?

Answer 15

1st- prophase of meiosis 1 :5 mth

2nd- metaphase of meiosis II : hrs before ovulation

Question 16

When does meiosis I go to completion ?

Answer 16

during time of menses to form secondary oocyte

Question 17

How does secondary oocyte go to completion?

Answer 17

With fertilization from sperm

Question 18

Where do the reproductive organs arise from ?

Answer 18

intermediate mesoderm

Question 19

What is emerges from the intermediate mesoderm

Answer 19

Urogenital ridge

Question 20

What does the primary sex cords give rise to?

Answer 20

Males–> seminiferous tubules

Females–> primordial follicles

Question 21

What is the name of the male genital tract ?

Answer 21

Mesonephric duct ( wollfian)

Question 22

What influences the male genital tract ?

Answer 22

Testosterone

Question 23

What is the name of the female genital tract?

Answer 23

paramesonephric ducts ( mullerian)

Question 24

What influences the female genital tract ?

Answer 24

estrogen

Question 25

What differentiates the indifferent gonads ?

Answer 25

Y chromosome with the SRY gene & TDF

Question 26

When do males produce testosterone?

Answer 26

by the 8th week by Leydig cells

Question 27

what triggers the sec cords in a males?

Answer 27

testosterone from the leydig cells

Question 28

What gives rise to male external genitalia in a male?

Answer 28

Dihydrotestosterone by 5 alpha reductase

Question 29

How does the ovary form?

Answer 29

absence of Y chromosome

Question 30

What is a Gartner duct ?

Answer 30

Remnants of mesonephric duct

Question 31

Describe how a bicornuate uterus is formed?

Answer 31

improper fusion of the paramesonephric duct

Question 32

When are the external genital distinguishable ?

Answer 32

12 week

Question 33

What does the tubercle, folds, and swellings form in the females?

Answer 33

tubercle- clitoris folds- labia minora swellings - labia majora

Question 34

What does the tubercle, folds, and swellings form in the male?

Answer 34

tubercle- glands penis folds- ventral side of penis swellings- scrotum

Question 35

Hypospadias

Answer 35

Ventral opening | defect in folds

Question 36

Epispadias

Answer 36

Dorsal opening | body wall defect

Question 37

What needs to be removed for proper implantation?

Answer 37

Zona pellucida

Question 38

What is the first form of blood supply for the fetus ?

Answer 38

yolk sac until 6th week

Question 39

Where does the blood supply come from after the 6th week?

Answer 39

liver, spleen , thymus

Question 40

Where does blood supply arise in the last trimester of the fetus s?

Answer 40

bone marrow

Question 41

What sustains life for the first trimester?

Answer 41

Corpus lutem

Question 42

What is the hormone produced that sustains the first trimester?

Answer 42

Progesterone

Question 43

What forms the 3 germ layers and the notochord ?

Answer 43

migration of epiblast

Question 44

What are the three sections of mesoderm ?

Answer 44

paraxial mesoderm intermediate mesoderm lateral plate mesoderm

Question 45

What does the paraxial mesoderm give rise to?

Answer 45

sclerotome: axial skeleton myotome : muscles of the body & limbs dermatome: dermis of the back

Question 46

What does the lateral mesoderm give rise to ?

Answer 46

somatic : lateral fold | splanchnic: heart

Question 47

What does endoderm give rise to?

Answer 47

epithelial lining : GI tract, Lower respiratory system, genitourinary system, pharyngeal pouches parenchyma of: Liver, pancreas, submandibular, sublingual glands Endocrine: parathyroid glands, follicles of thyroid

Question 48

What does mesoderm give rise to?

Answer 48

Musculoskeletal, cardiovascular, genitourinary Spleen

Question 49

What are the layers of that the adrenal is derived from?

Answer 49

Cortex- mesoderm | medulla - neural crest

Question 50

What does neural crest cells give rise to ?

Answer 50

Peripheral nervous system, head ( pharyngeal arch), heart (cushion, aorticopulmonary septum ) Parafollicular cells (C cells)

Question 51

What does neuroectoderm give rise to?

Answer 51

Neural tube - CNS ( barin , spinal cord) | posterior pituitary

Question 52

What does surface ectoderm give rise to ?

Answer 52

Skin, hair, nails anterior pituitary anal canal parotid gland

Question 53

What is a sacrococcxygeal teratoma ?

Answer 53

failure of primitive streak to regress

Question 54

What is a chordoma?

Answer 54

remnant of the notochord

Question 55

What does the dorsal ramus affect?

Answer 55

Sensory and motor of the back

Question 56

What does the ventral ramus affect?

Answer 56

Sensory and motor of the anterior & limbs

Question 57

What is the components of the spinal nerve ?

Answer 57

Ventral and Dorsal

Question 58

Where are somatic sensory unipolar neurons found?

Answer 58

PNS

Question 59

Where are somatic motor multipolar neurons found ?

Answer 59

CNS

Question 60

Pia mater

Answer 60

attached to the cord ends at L2 forms denticulate ligament & filum terminale

Question 61

Dura mater

Answer 61

ends at S2 | dense outermost layer

Question 62

Arachnoid mater

Answer 62

ends at S2 | between dura and pia

Question 63

What are the meningeal spaces ?

Answer 63

subarachnoid space : CSF filled | epidural space: outside the dura, contains fat and venous plexus

Question 64

What does the autonomic system control ?

Answer 64

smooth muscle cardiac muscle glands

Question 65

What is the sympathetic cord segments for body wall and limbs?

Answer 65

T1- L2 lateral horn

Question 66

What are the segments of sympathetic COLLATERAL ?

Answer 66

Lumber splanchnic L1-L2 | Thoracic splanchnic T5-T12 ( FG:T5-9, MG:T10-11, kidney gonadsT12)

Question 67

What are the 3 sympathetic chain segments?

Answer 67

Thoracic viscera T1-T5 Head T1-T2 Body wall and limbs T1-L2

Question 68

Where does parasympathetic innervate ?

Answer 68

visceral organs of head and body cavities | limited vascular

Question 69

What are the parasympathetic innervations ?

Answer 69

Craniosacral CN III, VII, IX, X S2, S3, S4

Question 70

Where do parasympathetic neurons terminated ?

Answer 70

on the visceral organ

Question 71

What does pelvic splanchnic innervate ?

Answer 71

rectum bladder erectile tissue

Question 72

What does Vagus nerve innervate

Answer 72

Thoracic and abdominal viscera

Question 73

What does parasympathetic CN III innervate?

Answer 73

Ciliari ganglion (sphincter pupillae, ciliary muscle)

Question 74

What does parasympathetic of CN VII innervate ?

Answer 74

``` pterygopalatine ganglion (lacrimal, nasal, sublingual) submandibular ganglion (submandibular, sublingual) ```

Question 75

What does parasympathetic of CN IX innervate?

Answer 75

Otic ganglion ( parotid gland)