| Papillary Duct |
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Position of the papillary duct in the kidney
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| Details |
| Latin |
ductus papillaris |
| Precursor |
Ureteric bud |
| System |
Urinary System |
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Artery
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vasa recta |
| Identifiers |
| Gray's |
p.1223 |
Dorlands
/Elsevier |
d_29/12314994 |
| TH |
H3.06.00.1.00086 |
| Anatomical terminology |
Papillary (collecting) ducts are anatomical structures of the kidneys, previously known as the ducts of Bellini. Papillary ducts represent the most distal portion of the collecting duct system. They receive renal filtrate (precursor to urine) from several medullary collecting ducts and empty into a minor calyx. Papillary ducts continue the work of water reabsorbtion and electrolyte balance initiated in the collecting tubules.[1]
Contents
- 1 Structure
- 2 Histology and Physiology
- 2.1 Cells of upper duct
- 2.2 Cells of lower duct
- 2.3 Renal filtration physiology
- 3 Clinical relevance
- 3.1 Collecting duct carcinoma
- 4 References
Structure
Medullary collecting ducts converge to form a central (papillary) duct near the apex of each renal pyramid. This "papillary duct" exits the renal pyramid at the renal papillae. The renal filtrate it carries drains into a minor calyx as urine.[2]
Histology and Physiology
Cells of upper duct
The cells that comprise the duct itself are similar to rest of the collecting system. The duct is lined by a layer of simple columnar epithelium resting on a thin basement membrane. The epithelium is comprised primarily of principle cells and α-intercilated cells.383[3]
Cells of lower duct
The simple columnar epithelium of the collecting duct system transitions into urothelium near the junction of a papillary duct and a minor calyx.[2]
Renal filtration physiology
These cells work in tandem to reabsorb water, sodium, and urea and secrete acid and potassium. The amount of reabsorbtion or secretion that occurs is related to needs of the body at any given time. These processes are mediated by hormones (aldosterone, vasopressin) and the osmolarity (concentration of electrically charged chemicals) of the surrounding medulla.
Diagram outlining movement of ions in nephron, with the collecting ducts on the right.
Hormones regulate how permeable the papillary duct is to water and electrolytes. In the medullary collecting duct specifically, vasopressin upregulates urea transporter A1. This increases the concentration of urea in the surrounding interstitium and increases the osmolarity.
Osmolarity influences the strength of the force that pulls (reabsorbs) water from the papillary duct into the medullary interstitium. This is especially important in the papillary ducts. Osmolarity increases from the base of the renal pyramid to the apex. It is highest at the renal apex (up to 1200 mOsm). Thus the force driving the reabsorbtion of water from the collecting system is the greatest in the papillary duct.[4]
Clinical relevance
Collecting duct carcinoma
Main article: Collecting duct carcinoma
Carcinoma of the collecting duct is a relatively rare subtype of renal cell carcinoma (RCC), accounting for less than 1% of all RCCs.[5][6] Many reported cases have occurred in younger patients, often in the third, fourth, or fifth decade of life.[7] Collecting duct carcinomas are derived from the medulla, but many are infiltrative, and extension into the cortex is common.[8] Most reported cases have been high grade and advanced stage and have not responded to conventional therapies.[7][9] Most patients are symptomatic at presentation.[10] Immunohistochemical and molecular analyses suggest that collecting duct RCC may resemble transitional cell carcinoma, and some patients with advanced collecting duct RCC have responded to cisplatin- or gemcitabine-based chemotherapy.[11][12]
References
This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)
- ^ Mescher, Anthony (2013). Junqueira's Basic Histology. McGraw-Hill. pp. 385–403. ISBN 9780071807203.
- ^ a b Mescher, Anthony (2013). Junqueira's Basic Histology. McGraw-Hill. p. 400. ISBN 9780071807203.
- ^ Gartner, Leslie; Hiatt (2014). Color Atlas and Text of Histology. Baltimore, MD 21201: Lippincott & Wilkins. pp. 383–399. ISBN 9781451113433.
- ^ Costanzo, Linda (2011). Physiology. Baltimore, MD 21201: Wolters Kluwer Health. pp. 167–172. ISBN 9781451187953.
- ^ Kennedy et al., 1990[full citation needed]
- ^ Rumpelt et al., 1991[full citation needed]
- ^ a b Carter et al., 1992[full citation needed]
- ^ Pickhardt et al., 2001[full citation needed]
- ^ Chao et al., 2002b[full citation needed]
- ^ Tokuda et al., 2004[full citation needed]
- ^ Milowsky et al., 2002[full citation needed]
- ^ Peyromaure et al., 2003[full citation needed]
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Anatomy of the urinary system
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| Abdomen |
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Kidneys
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Layers
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- Fascia
- Capsule
- Cortex
- Medulla
- sinus
- pyramids
- medullary interstitium
- Lobe
- Cortical lobule
- Medullary ray
- Nephron
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Intrarenal arteries
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- Renal artery
- Segmental arteries
- Interlobar arteries
- Arcuate arteries
- Interlobular arteries
- Afferent arterioles
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Renal tubule
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- Renal corpuscle
- Glomerulus
- Bowman's capsule
- Proximal convoluted tubule
- Loop of Henle
- Descending
- Thin ascending
- Thick ascending
- Distal convoluted tubule
- Connecting tubule
- Collecting ducts
- Renal papilla
- Minor calyx
- Major calyx
- Renal pelvis
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|
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Intrarenal veins
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- Efferent arterioles
- Peritubular capillaries/Vasa recta
- Arcuate vein
- Interlobar veins
- Renal vein
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Juxtaglomerular
apparatus
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- Macula densa
- Juxtaglomerular cells
- Mesangium
- Extraglomerular mesangial cell
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Filtration
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- Glomerular basement membrane
- Podocyte
- Filtration slits
- Mesangium
- Intraglomerular mesangial cell
- Tubular fluid
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Ureters
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- Orifice of ureter
- Adventitia
- Muscular layer
- Mucosa
- Ureteropelvic junction
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| Pelvis |
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Bladder
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- Apex
- Uvula
- Neck
- Median umbilical ligament
- Muscular layer
- Mucosa
- Submucosa
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Urethra
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- Urethral sphincters
- External sphincter muscle of male urethra
- External sphincter muscle of female urethra
- Internal sphincter muscle of urethra
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Index of the urinary system
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| Description |
- Anatomy
- Physiology
- Development
- Cells
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| Disease |
- Electrolyte and acid-base
- Congenital
- Neoplasms and cancer
- Other
- Symptoms and signs
- Urine tests
- Blood tests
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| Treatment |
- Procedures
- Drugs
- Intravenous fluids
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