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Flashcards in Male Deck (16):
1

Tunica Albuginea

  • Is the thick fibrous connective tissue capsule of the testis. 
  • Is thickened posteriorly to form the mediastinum testis from which connective tissue septa arise to divide the organ into approximately 250 compartments (lobuli testis).

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2

Lobule Testis

  • Are pyramidal-shaped incomplete compartments that intercommunicate.
  • Contain from 1 to 4 seminiferous tubules each, embedded in a meshwork of loose connective tissue where nerves, vessels, and scattered interstitial cells of Leydig are present.

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3

Interstitial Cells of Leydig

  • Are round to polygonal in shape, possessed a large central nucleus, many mitochondria, a well-developed Golgi apparatus, smooth endoplasmic reticulum, and many lipid droplets.
  • Are endocrine cells that produce the male sex hormone testosterone, when stimulated by luteinizing hormone (interstitial cell stimulating hormone) from the pituitary gland.

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4

Seminiferous Tubules

  • Are the sites where spermatozoa are produced.
  • Are lined by a complex, stratified epithelium.
  • Are enveloped by a fibrous connective tissue tunic, composed of several layers of fibroblasts. Myoid cells, resembling smooth muscle, are present in the inner layer of some species

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5

Tubuli Recti

  • Have a narrow lumen lined by a simple cuboidal epithelium.
  • Lead into the rete testis, a network of epithelial-lined channels located in the mediastinum.

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6

Ductuli Efferentes

Lead from the rete testis into the epididymis.

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7

Seminiferous Epithelium

  • Is composed of two different types of cells, the spermatogenic cells from which the germ cells eventually develop and the Sertoli cells, which support and provide nutrition to the spermatogenic cells.
  • Is 4 to 8 cell layers thick.

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8

Spermatocytogenesis

  • The division of the spermatogonia to provide a continuous supply of cells that will give rise to primary spermatocytes.

9

Spermiogenesis

  • Is cytodifferentiation and transformation of spermatids to form spermatozoa.

10

What cells form the blood - testis barrier?

 Sertoli cells 

11

What are the functions of Sertoli cells?

  1. Support, protect, and nourish developing spermatozoa.
  2. Phagocytose excess cytoplasm discarded by spermatids in the process of spermiogenesis.
  3. Secrete a fluid into the seminiferous tubules that transports spermatozoa to the genital ducts.
  4. Contain FSH receptors and under FSH influence synthesize androgen-binding protein (ABP) that binds testosterone, concentrating it to permit sperm maturation.
  5. Secrete inhibin, a hormone that inhibits synthesis and release of FSH from the anterior pituitary.

12

Spermatogenic Cells

  • Include several characteristic cell types in the seminiferous epithelium: spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, and spermatozoa.
  • Each of these cells represents a distinct stage in the differentiation of male germ cells. The entire process is known as spermatogenesis.

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13

Spermatogenesis - List the 3 phases

  1. Spermatocytogenesis
  2. Meiosis
  3. Spermiogenesis

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Extra:

  • In man takes approximately 74 days
  • Its cell divisions are unusual, in that the daughter cells remain connected to each other via intercellular bridges (forming a syncytium).

14

Spermatogonia

  1. Are the diploid germ cells that sit upon the basal lamina.

 

Are of three types:

  • Pale type A - Euchromatic
  • Dark type A - Heerochromatic
  • Type B.

15

Pale Type A

At puberty these cells undergo mitosis and give rise to either more pale type A spermatogonia (to maintain the supply of spermatogonia) or type B spermatogonia (which undergo mitosis and give rise to primary spermatocytes).

16

Dark Type A

  • (with dark nuclei) represent noncycling, reserve cells that have the potential to produce more pale type A cells.