Term
| Embryologic origin of heart |
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Definition
- forms from angiogenic cell clusters situated between splanchnic mesoderm and the endoderm
- as right and left sides of the flat embryonic plate come together, the primitive heart tubes lie adjacent to each other and fuse |
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Term
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Definition
- Heart tube bulges to right
- becomes the right ventricle |
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Term
| ventricle (embryologically) |
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Definition
- bulge opposite of bulbus cordis
- becomes left ventricle |
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Term
| Blood flow in the fetus (4 wks) |
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Definition
1. sinus venosus
2. atrium
3. left ventricle
4. right ventricle
5. truncus arteriosus |
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Term
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Definition
- crescent of tissue tuat grows from dorsal wall of the common atrium and extends ventro-superiorly in fetal heart
- upward growth covers up septum secundum |
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Term
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Definition
- space above (caudal to) the septum primum
- "second opening" |
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Term
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Definition
- "first opening"
- lies ventral to spetum primum |
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Term
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Definition
| - muscular band that develops on the right of the septum primum |
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Term
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Definition
| - an ovel opening that passes under septum secundum and over septum primum from right to left |
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Term
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Definition
| - form the conal septum that separates the aorta and the pulmonary artery |
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Term
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Definition
- grow to form 2 atrioventricular canals
1. emptying into RV forming tricuspid valve
2. emptying into LV forming mitral valve
- also closes the ostium primum |
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Term
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Definition
- endocardial cushions that close the ostium primum
- muscuslar ventricular septum extedns downward as the ventricles evaginate
- make RA blood empty into RV and LA into LV |
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Term
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Definition
- formed from original R and L atria
- has trabeculated surface |
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Term
| Right proximal vitelline vein |
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Definition
| - froms proximal inferior vena cava |
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Term
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Definition
1. blood leaves placenta
2. passes through umbilical vein
3. passes through ductus venosus to RA
4; 60% of floww passes through foramen ovale into LA
5. of 40% through RV, 3/4 pass through patent ductus arteriosus into aorta
6. 1/4 passes through pulmonary vascular bed
- vascular resistance greater in pulmonary artery to blood flows from here to aorta |
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Term
| Blood circulation changes at birth |
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Definition
1. aeration of lungs decreases pulmonary resistance
2. cutting off placental supply decreases venouss flow and thus right atrial pressure
3. When RA pressure falls below LA pressure the septum primum pushes against septum secundum separating the two atria
4. closure of ductus arteriosus a few days later completes the partition of the circulations
5. pressures continue to fall and resistance in pulmonary beds until reach that of adult at around 6 months
6. myocardium of RV atrophies in response to lowered pressure (35/10 mmHG in pulmonary artery, 80/50 mmHG in aorta)
7. at 6 months, left ventricle is 3x as thick aws RV |
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Term
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Definition
- Diverticulum along ventral aspect of pharyngeal gut between 4th and 6th pharyngeal arches
- Enveloped by splanchnic mesoderm
- Bifurcates to form right and left mainstem bronchi |
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Term
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Definition
- By week 28 lining cells of airspaces begin to produce it
- Phospholipid material acts as a wetting agent and is critically important in decreasing surface tension of aqueous surface of airspaces facilitating lung inflation |
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Term
| Bronchi branching (embryologically) |
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Definition
1. 4.5 weeks left and right main
2. Then 2 left and 3 right secondary bronchi
3. Then in the following weeks secondary divide 17 times
4. At 18 weeks the terminal branches form outpouchings that will become alveoli
5. After term delivery airways undergo additional 6 branchings (95% of alveoli develop after birth)
6. By age 10 each lobe has 8.4 million bronchioles and 300-600 million alveoli |
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Term
| Congenital diaphragmatic hernia |
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Definition
- Pleuroperitoneal fold fails to develop
- Happens much more frequently on left side, defect is lateral
- Causes abdominal organs to herniate up into left chest pushing heart and lungs right and compressing lungs
Results in pulmonary hypoplasia |
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Term
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Definition
- Result of restricted lung growth
- When baby is delivered it causes pulmonary insufficiency and death frequently
- Caused by congenital diaphragmatic hernias and severe fetal edema causing pleural effusions |
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Term
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Definition
- Severe fetal edema
- Causes pleural effusions
May be due to chromosomal abnormality (trisomy 21, monosomy x) or viral infection |
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Term
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Definition
- Little amniotic fluid
- Causees external compression of lungs and thus produces pulmonary hypoplasia |
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Term
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Definition
- Formed from growth of shelves of septum transversum
- This septum is splanchnic mesoderm and is first plate of tissue that begins separation of thoracic and abdominal cavities, contributes tissue mostly to ant. And midline regions of diaphragm
- Both somatic and splanchnic mesoderm |
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Term
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Definition
| - Part of diaphragm anterior and midline |
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Term
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Definition
- 2 shelves of somatic mesoderm coming from chest wall
- Form lateral muscular portions of diaphragm |
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Term
| Dorsal region of diaphragm (embryo) |
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Definition
- In region of aorta, inf. Vena cava and espphagus
- Formed by dorsal mesentary (splanchnic mesoderm origin) |
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Term
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Definition
part of bones of head
- bones ossify through membranous ossification
1. membranous part: includes flat bones of skull which are formed by membranous ossification. Under control of neural crest cells
2. Cartilaginous part: consists of the bones of the base of the skull |
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Term
| Embryological origin of bones anterior to sella turcica |
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Definition
| - bones anterior to sella turcica form neural crest cells |
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Term
| Embryologic origin of bones posterior to sella turcica |
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Definition
| - bones posterior to sella turcica develop from 1st somite (paraxial mesoderm) |
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Term
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Definition
- part of skull bones that encompass bones of face
- arise from neural crest-derived mesenchyme and the 1st pharyngeal arch
- from my endochondral ossification |
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Term
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Definition
- most common form of dwarfism
- autosomal dominant (but most mutations are sporadic)
- basic abnormality is diminution of endocondral ossification
- chondrocytes at epiphysis do not proliferate and thus there is shortening of the bones
- typically normal braincases but facial bones are small because neurocranium ossifies by membranous ossification and is unaffected |
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Term
| Facial prominences develop into... |
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Definition
1. 2 maxillary prominences (on either side of stomodeum
2. mandibular prominence (caudal to stomodeum)
3. frontonasal prominence (along midline)
4. nasal placodes (on either side of frontonasal prominence): two circular depressions |
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Term
| Lower face embryologic formation |
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Definition
1. frontonasal prominence grows down towards stomodeum and the 2 nasal placodes move closer so the medial ridges fuse
2. the 2 maxillary prominences gro toward stomodeum from lateral locations and each fuses with the side of the frontonasal prominence
3. the mandibular prominence enlarges to form the mandible |
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Term
| Embryologic origin of palate |
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Definition
1. frontonasal forms region of roof of mouth just behind and including four front teeth (intermaxillary segment)
2. maxillary prominences form 2 palatal shelves which move towards the midline fusing together and forming roof of mouth (palate) around 7 weeks |
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Term
| Cleft palate and cleft lips |
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Definition
- lips more common
- failure of fusion of maxillary and frontonasal prominences (why they are usually just off midline, not central)
- difficulty with phonation and swallowing |
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Term
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Definition
| - paraxial mesoderm (1st somite) |
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Term
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Definition
| - syndr5omes characterized by premature closure of certain sutures of neurocranium |
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