Body Cavities, Diaphragm, & Respiratory Development Highlights

Question 1

cells of splanchnic mesoderm give rise to

Answer 1

visceral layer of serous membranes directly applied to the viscera

Question 2

3 divisions of the entraembryonic mesoderm

Answer 2

paraxial
intermediate
lateral

Question 3

lateral mesoderm segments

Answer 3

splanchnic mesoderm

somatic mesoderm

Question 4

cells of somatic mesoderm become

Answer 4

parietal layer of the serous membranes

Question 5

3 body cavities of the intra-embryonic coelom

Answer 5

pericardial cavity
pericardioperitoneal canals
peritoneal cavity

Question 6

septum transversum f(x)

Answer 6

separates the thoracic cavity from the abdominal cavity

Question 7

fibrous pericardium forms the

Answer 7

pleuropericardial folds

Question 8

Pleuropericardial folds f(x) and attachment

Answer 8

attachment: primitive mediastinum

separate the heart from the lungs; thoracic cavity is divided into pericardial and 2 pleural cavities

Question 9

adult diaphragm develops from what structures?

Answer 9

septum transversum
lateral body wall mesoderm
dorsal mesentary of esophagus
pleuroperitoneal folds

Question 10

Innervation of the diaphragm

Answer 10

C3-C5 phrenic nerve

Question 11

Descent of the diaphragm

Answer 11

as the embryo elongates, the diaphragm descends

starts at C4, ends at L1

Question 12

posterolateral defect of diaphragm

Answer 12

failure of pleuroperitoneal membranes to fuse w/ other diaphragmatic components

abdominal contents can pass into the thoracic cavity

Question 13

Eventration of the diaphragm

Answer 13

diaphragm lacks or has defective musculature and balloons into the thoracic cavity

Question 14

congenital diaphragmatic hernias are a result of

Answer 14

defect in the formation of the diaphragm

Question 15

epigastric hernia

Answer 15

hernia that occurs b/w xiphoid process and umbilicus

Question 16

hiatal hernia

Answer 16

stomach or part of the intestines herniate through a defect int he diaphragm that surrounds the esophagus

Question 17

Morgangi’s hernia

Answer 17

aka retrosternal hernia

abdominal contents herniate through sternocostal hiatus

Question 18

1st indication of respiratory development

Answer 18

laryngotracheal groove

Question 19

list the stages of development of the larynx

Answer 19

• laryngotracheal groove
• laryngotracheal diverticulum
• esophageal ridges fuse to form a tracehoesopahgeal septum

Question 20

Bronchial buds f(x)

Answer 20

differentiate into bronchi and lungs

Question 21

difference b/w left and right bronchial bud

Answer 21

left: smaller, grows more laterally, gives rise to 2 secondary buds
right: grows more vertically, gives rise to 2 secondary buds (one of which will subdivide into 2 additional buds)

Question 22

Laryngotracheal tube is the primordium of

Answer 22

the larynx, trachea, bronchi, and the lungs

Question 23

internal lining of laryngotracheal tube

origin
gives rise to

Answer 23

origin: endodermal origin

gives rise to: epithelium glands of the larynx and trachea

Question 24

all laryngeal muscles are innervated by

Answer 24

branches of cranial nerve X (vagus)

Question 25

splanchnic mesoderm covering outside lung surface becomes

Answer 25

visceral pleura

Question 26

somatic mesoderm lining internal body wall becomes

Answer 26

parietal pleura

Question 27

Highlights of the Pseudoglandular Period

Answer 27

- lung development does not have essential components for gas exchange - lung development resembles exocrine gland structure - fetuses born will not survive weeks 5-18

Question 28

Canalicular period

Answer 28

-weeks 17-25 canalization occurs: enlargement of the respiratory bronchioles and terminal sacs increased vascularity

Question 29

Terminal Sac Period

Answer 29

development of many terminal sacs & thinning of their epithelium epithelium of terminal sacs differentiate into type I and type II (surfactant type) alveolar cells

Question 30

By which period (in terms of lung development) will babies born most likely survive? Why?

Answer 30

terminal sac period increased pulmonary vascularity and surfactant production

Question 31

What are the periods of lung maturation?

Answer 31

pseudoglandular period canalicular period terminal sac period alveolar period

Question 32

When does surfactant production begin?

Answer 32

20th week

Question 33

Week 25 critical points

Answer 33

blood supply and alveolar surface are adequate for respiration

Question 34

Week 26 to 30 critical point

Answer 34

enough surfactant for respiration to occur

Question 35

What is the most common anomaly of the larynx

Answer 35

vocal cord paralysis

Question 36

tracheoesophageal fistula

Answer 36

most common malformation in the lower respiratory tract associated w/ esophageal atresia

Question 37

tracheal stenosis

Answer 37

constriction of trachea

Question 38

tracheal agenesis

Answer 38

primary bronchi develop from the esophagus

Question 39

Unilateral pulmonary agenesis

Answer 39

lung buds fail to develop on one side

Question 40

unilateral hypoplasia

Answer 40

compresses developing lungs w/ herniated abdominal viscera

Question 41

accessory lung

Answer 41

located at the base of the left lung receives blood from systemic circulation rather than pulmonary circulation

Question 42

type II alveolar cells form f(x)

Answer 42

cuboid in shape | secrete surfactant

Question 43

type I alveolar cells form f(x)

Answer 43

form: simple squamous, most abundant f(x): gas exchange b/w blood

Question 44

tracheoesophageal septum (ridge)

Answer 44

divides the cephalic portion of the foregut into ventral (trachea & lung buds) and dorsal (esophagus)

Question 45

What is the signaling pathway that is activated during branching differentiation?

Answer 45

epithelium to mesenchymal transition (EMT)

Question 46

Tracheoesophageal fistula may be associated w/ other congenital anomalies called the

Answer 46

VACTREL

Question 47

VACTREL

Answer 47

1. vertebral defect 2. anal atresia 3. cardiac anomalies 4. tracheoesophageal fistula 5. renal anomalies 6. esophageal atresia limb deformities

Question 48

alveolar period time frame

Answer 48

time: late fetal to early childhood maximum alveolar production 2 weeks before birth

Question 49

Hyaline Membrane Disease aka

Answer 49

Respiratory Distress Syndrome (RDS)

Question 50

Hyaline Membrane Disease (RDS)

Answer 50

insufficient surfactant resulting in high membrane tension & collapse of alveoli

Question 51

hyaline membrane disease (RDS) onset is usually

Answer 51

less than 2-5 hours after birth

Question 52

Clinical findings of hyaline membrane disease (RDS)

Answer 52

- abnormal retraction of chest wall - cyanosis - expiratory grunting - increased respiratory rate

Question 53

How to combat hyaline membrane disease (RDS)

Answer 53

corticosteriods and thyroixn (stimulators of surfactant) maternal glucocorticoid treatment during pregnancy (accelerates fetal lung development and surfactant production )