Lecture 17: Body Cavities/Diaphragm Flashcards Preview

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Flashcards in Lecture 17: Body Cavities/Diaphragm Deck (49):
1

when intraembryonic coelom begins to develop

early 4th week

2

what intraembryonic coelom becomes

embryonic body cavities

3

where in embryonic tissue intraembryonic coelom develops

lateral mesoderm- spaces within this coalesce to form coelom

4

what happens in intra-extraembryonic coelom communication space

organs will develop there

5

location of extraembryonic coelom

chorionic cavity

6

where intraembryonic and extraembryonic coeloms communicate

lateral mesoderm

7

2 major body folds, week 3

cranio-caudal
lateral

8

why cranio-caudal fold occurs

because of large size of brain developing relative to rest of embryo

9

why lateral fold occurs

1. rapid growth of amniotic cavity

2. somites around notochord growing at rapid rate

10

what disconnects during lateral folding of embryo

intraembryonic and extraembryonic endoderms disconnect

11

allantois

extends from embryonic coelomic cavity into body stalk

12

when does orophorengeal membrane develop

intraembryonic coelom folding

13

layer of embryonic tissue lining amniotic cavity

surface ectoderm, a thin layer of mesodermal tissue

14

how embryonic body cavity forms

lateral/cranial-caudal folding

15

partitioned cavities of embryonic body cavity will be

pericardial cavity

2 pleuro-pericardial canals

peritoneal cavity

16

2 layers of lining of embryonic body cavity

somatic mesoderm (parietal layer) and splanchnic mesoderm (visceral layer)

17

mesentery

double layer of peritoneium that connects an organ to the body wall

18

what is within mesentery

blood vessels, nerves

19

dorsal mesentery

mesentery closer to embryo's back

suspends acudal foregut, mindgut, an hindgut in peritoneal cavity

20

ventral mesentery

mesentery that largely disappears in embryo

disappears except in proximal foregut (stomach and proximal duodenum)

21

layer of embryonic tissue that forms gut/intestines

embryonic endoderm

22

3 major arteries to primitive gut and their location

celiac - foregut
superior mesenteric - midgut
inferior mesenteric - hindgut

all in dorsal mesentery

23

physiologic herniation of midgut - how/why occurs

midgut must form outside of embryo (extraembryonic coelom) and then travel back in (intraembryonic coelom), at 10th week of embryonic development

24

tissue that separates pleuropericardial cavities

mesoderm

25

what drags with mesodermal tissue to create delineation between pleuropericardial cavities

veins

26

cardinal veins

early blood vessels in pleuropericardial membranes

27

what pleuropericardial membranes contain

common cardinal veins, phrenic nerves

28

what separates pericardial and pleural cavities

mesenchyme ventral to esophagus, in midline

29

diaphragm function in embryo

divide chest from abdomen

30

2 halves of diaphragm

left crus, right crus

31

why diaphragm needs holes

so aorta blood supply can go from chest to abdomen

so esophageal space exists for food to get from top to bottom

32

important embryonic components of diaphragm

1. septum transversum

2. pleuperitoneal membranes

3. dorsal mesentery of esophagus

4. muscular in-growth from lateral body walls

33

septum transversum

mesodermal structure, primordium to central tendon of the diaphragm, that begins cranial to heart but migrates below heart during cranial-caudal folding, and separates heart from liver

34

pleuroperitoneal membrane

membrane separating embryonic pleural and peritoneal cavitiesz

grows in from lateral body walls

fuses with dorsal mesentery of esophagus and septum transversum

35

myoblasts

muscle forming cells in pleuroperitoneal membrane that will become diaphragm's muscles - make it able to contract

close the pleuroperitoneal openings

36

effect of pleuroperitoneal membranes- fetus vs adult

large effect-fetus; small effect-adult

37

dorsal mesentery of esophagus

muscle fibers that surround vena cava and aorta

forms median part of diaphragm

38

what crura of diaphragm form from

myoblasts that migrate from dorsal mesentery

39

septum transversum, in adult

central tendon

40

as pleural cavities grow, divide body wall into 2 parts

external layer- definitive body wall

internal layer- peripheral diaphragm

41

division of pleural cavities creates

costodiaphragmatic recesses aka costo phrenic angles

42

how many phrenic nerves

2- motor and sensory- 1 on each side of the embryo

43

what septum transversum pulls down with it

from cranial end where it develops, pulls spinal nerves

44

phrenic nerve root value

C3, 4, 5

45

congential diaphragmatic hernia (CDH) - description

when L side of diaphragm doesn't close, can have herniation of abdominal contents into chest cavity - dangerous because if abdominal contents are in chest cavity, lungs don't have space to form, and child gets pulmonary hypoplasia- cannot breathe

46

CDH incidence

1/2200

47

diaphragm close order re: right/left

right then left

48

clinical sequelae of CDH

pulmonary hypoplasia, polyhydramnios

49

CDH treatment options

pre-natal: in utero surgery; tracheal occlusion

post-natal: deliver in 3o care center; ECMO; immediate surgical repair