The aortic sac or aortic bulb is a dilated structure in
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
ian
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
s, lined by
endothelial
The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...
cell
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
s and is the most distal part of the
truncus arteriosus
The truncus arteriosus is a structure that is present during embryonic development. It is an arterial trunk that originates from both ventricles of the heart that later divides into the aorta and the pulmonary trunk.
Structure
The truncus arterio ...
.
It is the primordial vascular channel from which the
aortic arches
The aortic arches or pharyngeal arch arteries (previously referred to as branchial arches in human embryos) are a series of six paired embryological vascular structures which give rise to the great arteries of the neck and head. They are ventral ...
arise (and eventually the
dorsal aorta
The dorsal aortae are paired (left and right) embryological vessels which progress to form the descending aorta. The paired dorsal aortae arise from aortic arches that in turn arise from the aortic sac.
The primary dorsal aorta is located deep t ...
e) and is homologous to the ventral aorta of gill-bearing vertebrates. The aortic sac eventually forms right and left horns, which subsequently give rise to the
brachiocephalic trunk
The brachiocephalic artery (or brachiocephalic trunk or innominate artery) is an artery of the mediastinum that supplies blood to the right arm and the head and neck.
It is the first branch of the aortic arch. Soon after it emerges, the brachi ...
and the proximal segment of the
arch of aorta
The aortic arch, arch of the aorta, or transverse aortic arch () is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea.
Structure
The aorta begins a ...
, respectively.
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
s ''
HAND2
Heart- and neural crest derivatives-expressed protein 2 is a protein that in humans is encoded by the ''HAND2'' gene.
Function
The protein encoded by this gene belongs to the basic helix-loop-helix family of transcription factors. This gene p ...
'' (''dHAND'') and ''
HAND1
Heart- and neural crest derivatives-expressed protein 1 is a protein that in humans is encoded by the ''HAND1'' gene.
A member of the HAND subclass of basic Helix-loop-helix (bHLH) transcription factors, the Heart and neural crest-derived transc ...
'' (''eHAND'') are expressed during the development of the aortic bulb and the arteries which arise from it.
[Richard P. Harvey, Nadia Rosenthal (ed)]
Heart Development
Gulf Professional Publishing, 1999; page 150-151. The protein encoded by these genes belong to the
basic helix-loop-helix
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
family of
transcription factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The fu ...
s.
References
Cardiac anatomy
Embryology of cardiovascular system
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