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Septum secundum | |
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Details | |
Carnegie stage | 14 |
Days | 33 |
Gives rise to | Atrial septum |
Identifiers | |
Latin | septum secundum |
Anatomical terminology |
The septum secundum is a muscular flap that is important in heart development. It is semilunar in shape, and grows downward from the upper wall of the atrium immediately to the right of the septum primum and ostium secundum. It is important in the closure of the foramen ovale after birth.
At the end of the fifth week of development, the septum secundum grows from the upper wall of the primitive atrium. [1] It grows to the right of the septum primum, which has already started growing. [1] It grows down towards the septum intermedium formed from the endocardial cushions. [1] Before birth, it does not fuse with the septum intermedium, leaving a gap to form the foramen ovale. [1] Shortly after birth, it fuses with the septum primum to form the interatrial septum, and the foramen ovale is closed. [1] The fossa ovalis denotes the free margin of the septum secundum after birth.
Sometimes, the fusion of the septum secundum to the septum intermedium is incomplete, and the upper part of the foramen remains patent. [2] This creates an atrial septal defect (ASD). [2]
The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.
dextro-Transposition of the great arteries is a potentially life-threatening birth defect in the large arteries of the heart. The primary arteries are transposed.
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO). It is common in patients with a congenital atrial septal aneurysm (ASA).
A congenital heart defect (CHD), also known as a congenital heart anomaly, congenital cardiovascular malformation, and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascular disease. Signs and symptoms depend on the specific type of defect. Symptoms can vary from none to life-threatening. When present, symptoms are variable and may include rapid breathing, bluish skin (cyanosis), poor weight gain, and feeling tired. CHD does not cause chest pain. Most congenital heart defects are not associated with other diseases. A complication of CHD is heart failure.
The atrium is one of the two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular mitral and tricuspid heart valves.
The fossa ovalis is a depression in the right atrium of the heart, at the level of the interatrial septum, the wall between right and left atrium. The fossa ovalis is the remnant of a thin fibrous sheet that covered the foramen ovale during fetal development.
In the fetal heart, the foramen ovale, also foramen Botalli or the ostium secundum of Born, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus. Another similar adaptation in the fetus is the ductus venosus. In most individuals, the foramen ovale closes at birth. It later forms the fossa ovalis.
The interatrial septum is the wall of tissue that separates the right and left atria of the heart.
The bulbus cordis is a part of the developing heart that lies ventral to the primitive ventricle after the heart assumes its S-shaped form. The superior end of the bulbus cordis is also called the conotruncus.
The primitive ventricle or embryonic ventricle of the developing heart, together with the bulbus cordis that lies in front of it, gives rise to the left and right ventricles. The primitive ventricle provides the trabeculated parts of the walls, and the bulbus cordis the smooth parts.
The primitive atrium is a stage in the embryonic development of the human heart. It grows rapidly and partially encircles the bulbus cordis; the groove against which the bulbus cordis lies is the first indication of a division into right and left atria.
During heart development of a human embryo, the single primitive atrium becomes divided into right and left by a septum, the septum primum. The septum primum grows downward into the single atrium.
The foramen secundum or ostium secundum is a foramen in the septum primum, a precursor to the interatrial septum of the human heart.
In the developing heart, the atria are initially open to each other, with the opening known as the primary interatrial foramen or ostium primum. The foramen lies beneath the edge of septum primum and the endocardial cushions. It progressively decreases in size as the septum grows downwards, and disappears with the formation of the atrial septum.
The valve of the inferior vena cava is a venous valve that lies at the junction of the inferior vena cava and right atrium.
The heart is the first functional organ in a vertebrate embryo. There are 5 stages to heart development.
Human embryonic development or human embryogenesis is the development and formation of the human embryo. It is characterised by the processes of cell division and cellular differentiation of the embryo that occurs during the early stages of development. In biological terms, the development of the human body entails growth from a one-celled zygote to an adult human being. Fertilization occurs when the sperm cell successfully enters and fuses with an egg cell (ovum). The genetic material of the sperm and egg then combine to form the single cell zygote and the germinal stage of development commences. Embryonic development in the human, covers the first eight weeks of development; at the beginning of the ninth week the embryo is termed a fetus. The eight weeks have 23 stages.
Lutembacher's syndrome is a very rare form of congenital heart disease that affects one of the chambers of the heart as well as a valve. It is commonly known as both congenital atrial septal defect (ASD) and acquired mitral stenosis (MS). Congenital atrial septal defect refers to a hole being in the septum or wall that separates the two atria; this condition is usually seen in fetuses and infants. Mitral stenosis refers to mitral valve leaflets sticking to each other making the opening for blood to pass from the atrium to the ventricles very small. With the valve being so small, blood has difficulty passing from the left atrium into the left ventricle. Septal defects that may occur with Lutembacher's syndrome include: Ostium primum atrial septal defect or ostium secundum which is more prevalent.
A fetus or foetus is the unborn offspring that develops from a mammal embryo. Following embryonic development, the fetal stage of development takes place. In human prenatal development, fetal development begins from the ninth week after fertilization and continues until the birth of a newborn. Prenatal development is a continuum, with no clear defining feature distinguishing an embryo from a fetus. However, a fetus is characterized by the presence of all the major body organs, though they will not yet be fully developed and functional and some not yet situated in their final anatomical location.
Heart development, also known as cardiogenesis, refers to the prenatal development of the heart. This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos.
This article incorporates text in the public domain from page 512 of the 20th edition of Gray's Anatomy (1918)