In biology, a septum (Latin for something that encloses; pl.septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate.
Histological septa are seen throughout most tissues of the body, particularly where they are needed to stiffen soft cellular tissue, and they also provide planes of ingress for small blood vessels.[ citation needed ] Because the dense collagen fibres of a septum usually extend out into the softer adjacent tissues, microscopic fibrous septa are less clearly defined than the macroscopic types of septa listed above. [13] In rare instances, a septum is a cross-wall. Thus it divides a structure into smaller parts. [14]
The septum (cell biology) is the boundary formed between dividing cells in the course of cell division. [15]
A coral septum is one of the radial calcareous plates in the corallites of a coral. [18]
Annelids have septa that divide their coelom into segmented chambers. [19]
Many shelled organisms have septa subdividing their shell chamber, including rhizopods, cephalopods and gastropods, the latter seemingly serving as a defence against shell-boring predators. [20] [21]
In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, is the bulbous structure at the distal end of the human penis that is the human male's most sensitive erogenous zone and primary anatomical source of sexual pleasure. The glans penis is present in the male reproductive organs of humans and most other mammals where it may appear smooth, spiny, elongated or divided. It is externally lined with mucosal tissue, which creates a smooth texture and glossy appearance. In humans, the glans is located over the distal ends of the corpora cavernosa and is a continuation of the corpus spongiosum of the penis. At the summit appears the urinary meatus and at the base forms the corona glandis. An elastic band of tissue, known as the frenulum, runs on its ventral surface. In men who are not circumcised, it is completely or partially covered by a fold of skin called the foreskin. In adults, the foreskin can generally be retracted over and past the glans manually or sometimes automatically during an erection.
The atrioventricular node or AV node electrically connects the heart's atria and ventricles to coordinate beating in the top of the heart; it is part of the electrical conduction system of the heart. The AV node lies at the lower back section of the interatrial septum near the opening of the coronary sinus, and conducts the normal electrical impulse from the atria to the ventricles. The AV node is quite compact.
The subcutaneous tissue, also called the hypodermis, hypoderm, subcutis, or superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and macrophages. The subcutaneous tissue is derived from the mesoderm, but unlike the dermis, it is not derived from the mesoderm's dermatome region. It consists primarily of loose connective tissue and contains larger blood vessels and nerves than those found in the dermis. It is a major site of fat storage in the body.
Nasal septum deviation is a physical disorder of the nose, involving a displacement of the nasal septum. Some displacement is common, affecting 80% of people, mostly without their knowledge.
The interventricular septum is the stout wall separating the ventricles, the lower chambers of the heart, from one another.
The interatrial septum is the wall of tissue that separates the right and left atria of the heart.
The proper development of the atrioventricular canal into its prospective components to create a clear division between the four compartments of the heart and ensure proper blood movement through the heart, are essential for proper heart function. When this process does not happen correctly, a child will develop atrioventricular canal defect which occurs in 2 out of every 10,000 births. It also has a correlation with Down syndrome because 20% of children with Down syndrome have atrioventricular canal disease as well. This is a very serious condition and surgery is necessary within the first six months of life for a child. Half of the children who are untreated with this condition die during their first year due to heart failure or pneumonia.
The corpus cavernosum of the clitoris is one of a pair of sponge-like regions of erectile tissue that engorge with blood during an erection. This is homologous to the corpus cavernosum of the penis. The term corpora cavernosa literally means "cave-like bodies".
The frenulum of the penis, often known simply as the frenulum or frenum, is a thin elastic strip of tissue on the underside of the glans and the neck of the human penis. In men who are not circumcised, it also connects the foreskin to the glans and the ventral mucosa. In adults, the frenulum is typically supple enough to allow manual movement of the foreskin over the glans and help retract the foreskin during erection. In flaccid state, it tightens to narrow the foreskin opening.
In human male anatomy, the radix or root of the penis is the internal and most proximal portion of the human penis that lies in the perineum. Unlike the pendulous body of the penis, which is suspended from the pubic symphysis, the root is attached to the pubic arch of the pelvis and is not visible externally. It is triradiate in form, consisting of three masses of erectile tissue; the two diverging crura, one on either side, and the median bulb of the penis or urethral bulb. Approximately one third to one half of the penis is embedded in the pelvis and can be felt through the scrotum and in the perineum.
In human male anatomy, the septum of the penis or penile septum refers to the fibrous junction (septum) between the two corpora cavernosa of the human penis. The tunica albuginea of the penis forms a thick fibrous coat to the spongy tissue of the corpora cavernosa and corpus spongiosum. The two corpora cavernosa are surrounded by a strong fibrous envelope consisting of superficial and deep fibers. The superficial or outer fibers are longitudinal in direction, and form a single tube which encloses both corpora; the deep or inner fibers are arranged circularly around each corpus and meet in the center. By their junction in the median plane, the inner fibers form the intercavernous septum of the penis.
The corona of glans penis or penis crown refers to the rounded projecting border or flare that forms at the base of the glans in human males. The corona overhangs a mucosal surface, known as the neck of the penis, which separates the shaft and the glans. The deep retro-glandular coronal sulcus forms between the corona and the neck of the penis. The two sides of the corona merge on the ventral midline forming the septum glandis. The circumference of the corona is richly innervated and is described as a highly erogenous area of the glans.
Angiofibroma (AGF) is a descriptive term for a wide range of benign skin or mucous membrane lesions in which individuals have:
In most terrestrial mammals, the scrotum or scrotal sac is a part of the external male genitalia located at the base of the penis. It consists of a sac of skin containing the external spermatic fascia, testicles, epididymides, and vasa deferentia. The scrotum will usually tighten when exposed to cold temperatures.
In biology, a tunica is a layer, coat, sheath, or similar covering. The word came to English from the Neo-Latin of science and medicine. Its literal sense is about the same as that of the word tunic, with which it is cognate. In biology, one of its senses used to be the taxonomic name of a genus of plants, but the nomenclature has been revised and those plants are now included in the genus Petrorhagia.
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.
The septum glandis, also septum of the glans, refers to the fibrous partition of the ventral aspect of the glans penis that separates the two glans wings in the ventral midline. The septum extends from the urethral meatus through the glanular urethra and ends in the tunica albuginea of the human penis. Externally it is attached to the frenulum which extends lower on the neck of the penis.
The septum of scrotum or scrotal septum is an incomplete vertical wall (septum) that divides the scrotum into two compartments –each containing a single testis. It consists of flexible connective tissue and nonstriated muscle. The site of the median septum is apparent on the surface of the scrotum along a median longitudinal ridge called the scrotal raphe. The perineal raphe further extends forward to the undersurface of the penis and backward to the anal opening. The purpose of the median septum is to compartmentalize each testis in order to prevent friction or trauma.
The heart is a muscular organ situated in the mediastinum. It consists of four chambers, four valves, two main arteries, and the conduction system. The left and right sides of the heart have different functions: the right side receives de-oxygenated blood through the superior and inferior venae cavae and pumps blood to the lungs through the pulmonary artery, and the left side receives saturated blood from the lungs.
The penile raphe is a visible line or ridge of tissue that runs on the ventral (urethral) side of the human penis beginning from the base of the shaft and ending in the prepuce between the penile frenulum. The line is typically darker than the rest of the shaft skin, even though its shape and pigmentation may vary greatly among males. The penile raphe is part of a broader line in the male reproductive organs, that runs from the anus through the perineum and continues to the scrotum and penis, collectively referred to as median raphe. The penile raphe along with the skin between it are homologous to the female labia minora.
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