Testes: Stroma & Parenchyma

What are the 2 structures that form testes?

• Stroma (supporting tissue) #00a5ff

• Parenchyma (functional tissue) #ff8300

What are the structures of the stroma? #00a5ff

• Tunica vaginalis

• Tunica albungiea

• Septila testis

• Mediastinum testis

• Interstitial tissue

Stroma: What is

• Tunica vaginalis

• Tunica albungiea

• Septila testis

• Mediastinum testis

#00a5ff

Tunica vaginalis: Serosal peritoneal layer of scrotum

Tunica albungiea: Dense, irregular collagenous CT (1)

Septila testis: Internally radiated tunica albunginea to form lobuli testis (3)

Mediastinum testis: Central emerging of tunica albuginea to form tiny cavity (2)

Interstitial tissue of stroma #00a5ff

• Interstitial fibers

  • What

  • From 

  • Surrounds 

• Interstitial cell 

  • Name 

  • Arrangement 

  • Adjacent to 

    • How they connect 

  • Cytoplasm 

  • Shape

  • Nucleus 

  • Abundant of which organelles 

  • Function 

Interstitial fibers

• What: Infiltration of loose connective tissue

• From: Septula testis

• Surrounds: Seminiferous tubules

Interstitial cell

• Name: Leydig cells

• Arrangement: Clusters or cords

• Adjacent to: Capillaries

  • How they connect: Gap junctions

• Cytoplasm:

  • Pale due to acidophilical cytoplasm

• Shape: Polyhedral 

• Nucleus: 

  • Spherical 

  • Euchromatic

• Abundant of which organelles:

  • Lopid vacuoles

  • sER

  • Mitochondria

• Function: Synthesise testosterone under influenced of LH

What are the structures of parenchyma? #ff8300

• Convoluted seimiferous tubules (forms sperm) 

• Straight seminiferous tubules (forms sperm) 

• Rete testis (sperm transport)

• Efferent ductules (sperm transport) 

Parenchyma: Seminiferous tubules #ff8300

• Shape

• Location

• Straight seminiferous tubule is formed

• What is ductuli efferentes

• What is lamina propria

• Myofibroblaat

  • What

  • Why needed

• Function

• Lined by

Shape: Tightly convoluted

Location: Within pyramidal lobuli testis

Straight seminiferous tubule is formed: Prior merging with rete testis within mediastinum testis 

What is ductuli efferentes: Duct that empties the spermatozoa into epididymis

What is lamina propria: Fine collagen and elastic fibers

Myofibroblast:

• What: Peritubular contractile cell with actin bundles

• Why needed: For contraction

Function: Important for spermatogenesis

Lined by:

• Stratified spermatogenic epithelium

• With Sertoli cells

Parenchyma: How is secondary spermatocytes produced? #ff8300

Primary spermatocytes undergo meiosis I 

Parenchyma: How is spermatid produced?

Secondary spermatocytes undergo meiosis II

Parenchyma: Spermatogonia #ff8300

• Closely associated with

• Shape

• Nucleus

Closely associated with: Basement membrane

Shape: Round, pear-shaped

Nucleus: Heterochormatic 

Parenchyma: Primary spermatocytes #ff8300

• Nucleus

• Abundant of what organelles

Nucleus: Varying chromatin density of nucleus

Abundant of what organelles:

• Mitochondria

• rER

• Large GA

Parenchyma: Secondary spermatocytes #ff8300

• Location 

• Shape 

• Nucleus 

Location: Near luminal surface of seminiferous tubule

Shape: Spherical

Nucleus: Weakly stained

Parenchyma: Sertoli Cell #ff8300

• Shape

• Location 

• Nucleus 

• Abundant organelles 

• How do they communicate with adjacent cells

• Function 

Shape: Pyramidal cell 

Location: Extend the entire height of spermatogenic epithelium

Nucleus: Ovoid and euchromatic 

Abundant organelles:

• Cytoplasmic projections to all spermatogenic epithelium

• GA

• Mitochondria

• sER (surrounds periacrosomal region of spermatid)

• Fat vacuoles (at cellular base) 

How do they communicate with adjacent cells: Tight junction and desmosomes

Function: 

• Structural and nutiritonal support 

• Intra-tubular fluid secretion 

• Formation of blood testis barrier