1AA3 - WEEK 9

Lymphatic Tissue

reticular CT with lymphocytes, B cells, T cells

Lymphatic Capillaries

• larger and more permeable than blood capillaries

• endothelial cells organized for one way flow

Lymph

• portion of blood plasma

• into spaces around cells

• from interstitial fluid

Lymph Trunks

• lumbar

• pelvic

• bronchomediastinal

• subclavian

• jugular

Structure of Lymph Nodes

stroma

• capsule

• trabeculae extensions

parenchyma (outer)

• primary

• secondary

  • b cells

  • follicular dendritic cells

  • macrophages

parenchyma (inner)

• T cells (cytotoxic and helper)

Movement of Lymph

interstitial fluid → lymph capillaries → lymph vessels → lymph trunks → lymph ducts

Primary Lymphatic Organs

RBM and thymus

Secondary Lymphatic Organs

spleen and lymphatic nodules

Reproductive Functions

• gametogenesis

• fertilization

• development/nourishment

• reproductive hormone production

Components of Male Reproductive System

• testicles

  • tunica albuginea

  • septa

  • tunica vaginalis

• scrotum

  • scrotal septum

  • cremaster muscle

  • dartos muscle

• epididymis

• vas deferens

• ejaculatory ducts

Sperm Formation

~300 million/day

• sertoli cells

• leydig cells

Blood-Testis Barrier

to avoid immune response on sperm

Inhibin

slows down sperm production by reducing testosterone

Pathway of Sperm

seminiferous tubule → straight tubule → rete testis→ efferent duct → ductus epididymis → vas deferens

Epididymis

• ductus epididymus (w/ stereocilia)

• vas deferens

Functions of Ductus Epididymis

• sperm maturation

• storage

• peristaltic contractions

Accessory Sex Glands

• spermatic cord

• seminal vesicles

• prostate gland

• cowper’s gland

Erectile Tissue of Penis

• corpora cavernosa

• corpus spongiosum

• penile/spongy urethra

Components of Semen

alkaline (60%)

• neutralizes vagina for sperm

• fructose for ATP

• prostaglandins for motility and viability

• clotting proteins for coagulation

milky/slightly acidic fluid (30%)

• citric acid for ATP

• enzymes for seminal liquefaction

• seminalplasmin to destroy bacteria

alkaline mucous (5%)

• neutralizes acids

• lubricates

Erection

• from sexual stimulation

• PNS

• blood enters penis → compressed veins → trapped blood

Ejaculation

• SNS

• sphincter contraction

• peristalsis

• ischocavernosus

• bulbospongiosus