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

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* 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

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* ischocavernosus
* bulbospongiosus