Histopathology Exam 1

Question 1

3 Stages of Human Development

Answer 1

Proliferation Period (0-3 wks)
Embryonic Period (3-8 wks)
Fetal Development Period (9wks-term)

Question 2

What period of human development do the germ layers mature & differentiate into specific tissues

Answer 2

Embryonic period (between 3-8 weeks)

Question 3

What is a group of more than 32 blastomeres called?

Answer 3

morula

Question 4

What is a blastocyst?

Answer 4

cluster of dividing cells made by a fertilized egg – the early stage of an embryo

64 morula once it develops into an internal blastocystic cavity

Question 5

what is the name for a blastocyst once it develops an inner cell mass @ ________ days?

Answer 5

embryoblast; 6-7 days

Question 6

________ of the embryoblast into the uterine wall between days _________.

Answer 6

implantation; 4-10 days

Question 7

What are the 2 parts of the outer cell mass?

Answer 7

cytotrophoblast & syntrophoblast

Question 8

which outer cell mass is the precursor to the placenta?

Answer 8

syntrophoblast

Question 9

what does the inner cell mass become?

Answer 9

bilaminar embryonic disc

Question 10

Epiblast = __________ + ___________
Hypoblast = ______________

Answer 10

epiblast= ectoderm–>mesoderm
hypoblast=endoderm

Question 11

After implantation, there are 3 cell layers and 3 embyronic cavities… What are they?

Answer 11

layers: epiblast, embryonic mesoderm, hypoblast
cavities: amniotic cavity, yolk sav, chorionic cavity

Question 12

The primitive streak, notochord and neural tube develop during the _____ week of development.

Answer 12

3rd

Question 13

What does the primitive streak begin to form?

Answer 13

Mesodermal layer

Question 14

What does the notochord formed from?

Answer 14

Ectodermal cells from the primitive node

Question 15

What part of the bilaminar disc INDUCES the formation of somites? (does not MAKE somites itself)

Answer 15

notochord

Question 16

What is the precursor to the nerves of the spinal column?

Answer 16

Neural tube

Question 17

What functions as the primitive axial skeleton for the embryo?

Answer 17

Notochord

Question 18

During what week of development does the bilaminar disc form the 3 embryonic germ layers?

Answer 18

3rd week of development

Question 19

Tell me some shit about the ECTODERM

Answer 19

-formerly the epiblast layer
-epidermis, hair, & nails
-epithelium of the oral and nasal cavities & paranasal sinuses
-salivary & endocrine glands + sweat glands
-nervous system
-TOOTH ENAMEL

Question 20

Tell me some shit about MESODERM

Answer 20

-paraxial mesoderm –> somites
-intermediate mesoderm –> urogenital system
-lateral plate mesoderm–> parietal & visceral mesoderm (refer to study guide if you wanna know more than that)

Question 21

Tell me some shit about ENDODERM

Answer 21

-formerly the hypoblast layer
-GI tract epithelium and associated glands

Question 22

Developmental defect where the bottom of neural tube does not fuse + folic acid deficiency:

Answer 22

Spina Bifida

Question 23

Development defect where the extrusion of dura and arachnoid mater (meninges only):

Answer 23

Meningocele

Question 24

Developmental defect where extrusion of neural tissues plus ALL THREE meninges (meninges AND neural tissue):

Answer 24

Meningomyelocele

Question 25

Developmental defect that is fatal and characterized by lack of development of the cranium and brain:

Answer 25

Anencephaly

Question 26

What do neural crest cells differentiate into?

Answer 26

dorsal root ganglion

Question 27

What cranial nerves use neural crest cells for sensory ganglion?

Answer 27

V, VII, IX, X [5, 7, 9, 10]

Question 28

What do neural crest cells make? Name 3.

Answer 28

melanocytes, adrenal medulla, meninges, facial bones, cartilage, all teeth and periodontal structures

Question 29

What layer of the bilaminar disc is responsible for making enamel and gingiva?

Answer 29

ectoderm

Question 30

What are the Branchial/pharyngeal arches?

Answer 30

-make up structures from the ear to thyroid
-stack on top of eachother
-each arch contains 1 artery, 1 nerve, 1 piece of cartilage

Question 31

Name the branchial grooves/clefts/pouches & what they correspond with.

Answer 31

1st Branchial groove: external auditory canal
1st branchial pouch: eustachian tube
2nd branchial pouch: palatine tonsils
3rd branchial pouch: inferior parathyroid/thymus
4th branchial pouch: superior parathyroids/ultimobranchial body

Question 32

Cervical flexure of the brain, maxillary & mandibular prominence, limb development –> When? _______ days.

Answer 32

32

Question 33

Pigmentation of the eye, formation of auricular hillocks & external ear development –> when? ________ days.

Answer 33

41

Question 34

What diagnosis is defective fusion of the median nasal process with the maxillary process & when does this usually occur?

Answer 34

Cleft Lip; occurs around the 35th day (5-6 weeks) – - if one child is born with a cleft lip there is 40% chance the second child will have one too.

Question 35

What diagnosis is defective fusion of the palatine shelves & when does this usually occur?

Answer 35

Cleft palate; occurs between the 8th & 12th week

Question 36

What percent of cases are combined cleft lip and cleft palate cases?

Answer 36

45%

Question 37

Are facial clefts more common in Caucasian or Chinese populations?

Answer 37

chinese - 1/500 versus caucasian1/700

Question 38

What type of cyst develops at the line of fusion between palatine shelves and primary plate?

Answer 38

Nasopalatine duct cyst

Question 39

What type of cyst develops when the cervical sinus remains past the 7th week and follows along the sternocleidomastoid muscle?

Answer 39

lateral cervical cyst