The testes

Why are the testes outside the body

• they need to be cooler than body temperature

What are the testes in

• tunica vaginalis

• Thick outer capsule

Tunica albuginea

• outermost layer of testes

• Fibrous

• Runs deep into testes to divide into segments

Semiferous tubules

• densely packed tubes

• Highly convoluted

• Present in each lobule

Epididymis

• tube which sperm from all segments runs into

Separation of Semiferous tubules

• connective tissue

• Contains blood vessels

Groups of cells between tubules

• interstital cells of leydig

• Secretory

Lining of Semiferous tubules

• Spermatogenic cells

• Sertoli cells

Spermatogenic cells

• produce sperm

• Darkly stained nuclei

• Towards periphery of tubule

Sertoli cells

• Supporting function

• Outermost row of tubule cells

• Weaved between cell layers

• Undergo mitosis

Rete testes

• Point where tubules join

• Enters epididymis

Spermatogonia cells

• light appearance = undergoing mitosis (type A)

• Darker appearance = reserve cells, not undergoing mitosis (type A)

• Type B = very light, differentiating cells forming spermatocytes

Primary spermatocyte

• diploid

Secondary spermatocyte

• haploid

• Transitional state

Spermatogenesis

• spermatogonium

• Mitosis - primary spermatocyte

• Meiosis 1 - secondary spermatocyte

• Meiosis 2 - spermatogenesis

• Spermiogenesis - spermatozoa

Septa

• tissue between lobules