Chapter 5

Question 1

1st phase of human development

Answer 1

growth - cell division and elaboration of cell products

Question 2

2nd phase human development

Answer 2

morphogenesis - development of size, shape, or other features of a particular organ/part of body

Question 3

3rd phase human development

Answer 3

differentiation - maturation of physiological processes

Question 4

forgut derivatives

Answer 4

pharynx, esophagus, etc

Question 5

forgut location

Answer 5

between brain and heart

Question 6

what separtates forgut from stomodeum

Answer 6

oropharyngeal membrane

Question 7

what develops into the central tendon of the diaphragm

Answer 7

septum transversum

Question 8

after folding, where does the pericardial coelum lye

Answer 8

ventral to heart and cranial to septum transversum

Question 9

cloaca

Answer 9

primordium of urinary bladder and rectum

Question 10

connecting stalk

Answer 10

primordium of umbilical cord

Question 11

primitive streak location before and after folding

Answer 11

cranial to cloacal membrane before and caudal to it after

Question 12

what is lateral folding produced by

Answer 12

rapidly growing spinal cord and somites

Question 13

omphaloenteric duct

Answer 13

remnant of connection between midgut and umbilical vesicle after lateral folding

Question 14

what are inductive processes limited by

Answer 14

space and time

Question 15

3 ways transmission of signal can occur in iductive interactions

Answer 15

1) diffusion of signal substance like Shh 2) matrix-mediated 3)cell-contact mediated

Question 16

4th week overview

Answer 16

neural tube formed (open at ends), pharyngeal arches appear, heart produces large ventral prominence, forebrain produces prominent elevation, upper buds form, otic pits form, lens placodes, caudal neuropore closed by end of week

Question 17

what is formed by 24 days

Answer 17

first 2 pharyngeal arches

Question 18

first pharyngeal arch

Answer 18

aka mandibular arch; forms mandible, rostral extension contributes to maxilla

Question 19

number of arches visible by day 26

Answer 19

3 pairs

Question 20

when are upper limb buds recognizable

Answer 20

day 26-27 as small swellings on ventrolateral body walls

Question 21

how many arches are seen at the end of the 4th week

Answer 21

4 pairs

Question 22

what is a characteristic feature seen towards the end of the 4th week

Answer 22

long-tail-like caudal eminence

Question 23

5th week overview

Answer 23

head growth, face contacts heart prominence, 2nd arch overgrows 3rd and 4th arches, mesonephric ridges seen

Question 24

cervical sinus

Answer 24

formed by rapidly growing 2nd arch overgrowing arches 3 and 4; lateral ectodermal depression on each side

Question 25

overview week 6

Answer 25

refex response to touch, elbow/handplate/digital ray development (leg 4-5 days later), spontaneous movements, auricular hillocks, retinal pigment formed (eyes obvious), trunk and neck begin straigtening, intestines enter extraembryonic coelom

Question 26

auricular hillocks

Answer 26

develop around groove/cleft btwn first two arches; becomes external acoustic meatus and contributes to auricle

Question 27

overview 7th week

Answer 27

limb changes (notches btwn rays in hands), communication btwn primordial gut and umbilical vesicle reduced to slender duct, ossification of bones of upper limbs

Question 28

8th week overview

Answer 28

digits in hands separated but webbed; notches in feet rays; caudal eminece present but stubby; scalp vascular plexus appears; digit completely separated and lengthened; PURPOSEFUL limb movements; ossification in femur; caudal eminence dissapears; distinct human features; neck region established; eyelids more obvious (unite by end of week); auricles assume final shape; genitalia differences (not enough for accurate determination)

Question 29

gestational age

Answer 29

based off of last known menstral cycle (LNMP)

Question 30

oligomenorrhea

Answer 30

scanty menstration

Question 31

calculating embryonic age of 3rd to early 4th week

Answer 31

greatest length (embryos are straight)

Question 32

when is crown-rump length used

Answer 32

older embryos (use longest measurement)

Question 33

when is standing height/crown-heal length used

Answer 33

8 week embryos

Question 34

Carnegie Embryonic Staging System

Answer 34

used size, shape, developmentsal progress to stage embryos

Question 35

greatest variation in embryo size

Answer 35

4 weeks and less, less variation at end of embryonic period