Pronephros

Information about Pronephros

subject #252 1205
Carnegie stage10
Precursornephrotome
Gives rise tomesonephros
Dorlands/Elsevier p_36/12670025
Pronephros the most primitive of the three excretory organs that develop in vertebrate, corresponding to the first stage of kidney development.

The pronephros develops in the anterior nephrotomes of all vertebrates. It is a paired organ, consisting of a series of nephrons filtering urine from both the pericardium fluids via openings called nephrostomes and blood from the glomerulus.

The organ is active in adult forms of some primitive fish, like lampreys or hagfish. It is present at the embryo of more advanced fish and at the larval stage of amphibians. In human beings, it is rudimentary, appears at the end of the third week (day 20) and replaced by mesonephros after 3.5 weeks.

See also

External links

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Prenatal development/mammalian embryogenesis - Development of the urinary and reproductive organs
General Urinary/Reproductive systemCloacal membrane - Urogenital folds - Urethral groove - Urogenital sinus
Kidney developmentPronephros - Mesonephros - Ureteric bud - Metanephric blastema
Fetal genital developmentPronephric duct - Wolffian duct - Mllerian duct - Gubernaculum - Labioscrotal folds - Genital tubercle - Gonadal ridge - Sex cord - Cortical cords
In embryology, Carnegie stages are a standardized system of 23 stages used to provide a unified developmental chronology of the vertebrate embryo.

The stages are delineated through the development of structures, not by size or the number of days of development, and so the
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Embryology is the study of the development of an embryo. An embryo is defined as any vertebrate in a stage before birth or hatching. Embryology refers to the development of the egg cell (zygote) after fertilization and the differentiation of cells into tissues and organs.
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The nephrotome is a section of the mesoderm. It gives rise to the pronephros and eventually to the rest of the kidney.

External links

  • Embryology at UNC mslimb-010

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The mesonephros (Latin for "middle kidney") is one of three excretory organs that develop in vertebrates. It serves as the main excretory organ of aquatic vertebrates and as a temporary kidney in higher vertebrates.
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The excretory system is the system of an organism's body that performs the function of excretion, the bodily process of discharging wastes.
  • Urinary system
  • Kidneys

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Vertebrata
Cuvier, 1812

Classes and Clades

See below
Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns.
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The kidneys are organs that filter wastes (such as urea) from the blood and excrete them, along with water, as urine. The medical field that studies the kidneys and diseases of the kidney is called nephrology[1].
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The nephrotome is a section of the mesoderm. It gives rise to the pronephros and eventually to the rest of the kidney.

External links

  • Embryology at UNC mslimb-010

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A nephron (from Greek νεφρός (nephros) meaning "kidney") is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood,
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Urine is a liquid produced by animals through the kidney, and is collected in the bladder and excreted through the urethra.

Urine formation helps to maintain the balance of minerals and other substances in the body.
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The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.

Layers

There are two layers to this sac: the fibrous pericardium and the serous pericardium.
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Nephrostome is the funnel-like component of a metanephridium. It is always oriented towards the coelom. The nephrostome is covered from the inside with cilia, which push the water, metabolic wastes, unnecessary hormones and other substances into the metanephridium.
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glomerulus is a capillary tuft surrounded by Bowman's capsule in nephrons of the vertebrate kidney. It receives its blood supply from an afferent arteriole of the renal circulation.
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Petromyzontiformes

Family: Petromyzontidae

Subfamilies

Geotriinae
Mordaciinae
Petromyzontinae

A lamprey (sometimes also called lamprey eel
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Myxini

Order: Myxiniformes

Family: Myxinidae

Genera

Eptatretus
Myxine
Nemamyxine
Neomyxine
Notomyxine

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larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians).

The larva can look completely different from the adult form, for example, a caterpillar differs from a butterfly.
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Amphibia
Linnaeus, 1758

Subclasses and Orders

   Order Temnospondyli - extinct
Subclass Lepospondyli - extinct
Subclass Lissamphibia
   Order Anura
   Order Caudata
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The mesonephros (Latin for "middle kidney") is one of three excretory organs that develop in vertebrates. It serves as the main excretory organ of aquatic vertebrates and as a temporary kidney in higher vertebrates.
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The mesonephros (Latin for "middle kidney") is one of three excretory organs that develop in vertebrates. It serves as the main excretory organ of aquatic vertebrates and as a temporary kidney in higher vertebrates.
..... Click the link for more information.
The kidneys are organs that filter wastes (such as urea) from the blood and excrete them, along with water, as urine. The medical field that studies the kidneys and diseases of the kidney is called nephrology[1].
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Memorial University of Newfoundland, (popularly known as Memorial University or "MUN") is a comprehensive university located primarily in St. John's, Newfoundland and Labrador, Canada.
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Prenatal development is the process in which an embryo or fetus (or foetus) gestates during pregnancy, from fertilization until birth. Often, the terms fetal development, foetal development, or embryology are used in a similar sense.
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Mammalian embryogenesis is the process of cell division and cellular differentiation during early prenatal development which leads to the development of a mammalian embryo.
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The development of the urinary and reproductive organs is a part of the prenatal development, and concerns the urinary system and sex organs. The latter is a part of the stages of sexual differentiation.
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The urinary system is the organ system that produces, stores, and eliminates urine. In humans it includes two kidneys, two ureters, the bladder, and the urethra. The analogous organ in invertebrates is the nephridium.
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The reproductive system is the ensembles and interactions of organs and/or substances within an organism that strictly pertain to reproduction. As an example, this would include in the case of female mammals, the hormone estrogen, ova, and the uterus and the vagina, and the breasts.
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The cloacal membrane is the membrane that covers the embryonic cloaca when still in the development of the urinary and reproductive organs.

It is formed by ectoderm and endoderm coming into contact with each other.
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