PSIO 202 LAB Block 4

PART 1 — URINARY SYSTEM Core Functions

Main function of kidneys?

Filter blood, remove wastes, regulate water/electrolytes/pH, make urine.

Main function of ureters?

Transport urine from kidneys to bladder.

Main function of bladder?

Store urine.

Main function of urethra?

Carry urine out of body.

Kidney Concepts

Where does filtration begin?

Renal corpuscle (glomerulus + Bowman’s capsule).

What forces filtration at glomerulus?

Blood pressure.

What is reabsorption?

Moving useful substances from tubule back to blood.

What is secretion?

Moving substances from blood into tubule.

What is excretion?

Removal in urine.

Why is medulla important?

Creates concentration gradient to concentrate urine.

Nephron Flow

Filtrate pathway?

Bowman’s capsule → PCT → Loop of Henle → DCT → Collecting duct.

Urine pathway after nephron?

Collecting duct → papilla → calyx → renal pelvis → ureter → bladder → urethra.

Hormones

ADH function?

Increases water reabsorption.

Aldosterone function?

Reabsorbs Na+, water follows; increases K+ secretion.

ANP function?

Promotes Na+/water loss; lowers blood volume.

Erythropoietin source/function?

Kidney; stimulates RBC production.

Histology

Transitional epithelium found where?

Ureters, bladder, proximal urethra.

Why transitional epithelium?

Stretches with changing volume.

PART 2 — FEMALE REPRODUCTIVE SYSTEM Core Functions

Main functions of female reproductive system?

Produce oocytes, hormones, support fertilization/pregnancy, lactation.

Female gonads?

Ovaries.

Endocrine products of ovaries?

Estrogen, progesterone.

Exocrine product of ovaries?

Oocytes.

Oogenesis

Oogenesis starts when?

Before birth.

Primary oocyte arrested where?

Prophase I.

Secondary oocyte arrested where?

Metaphase II.

Meiosis II completes when?

Fertilization.

Final products of oogenesis?

One ovum + polar bodies.

Follicle Stages

Primordial follicle feature?

Smallest; flattened cells.

Primary follicle feature?

One layer cuboidal granulosa cells.

Secondary follicle feature?

Multiple granulosa layers.

Tertiary follicle feature?

Small antrum present.

Mature/Graafian follicle feature?

Large antrum; ready to ovulate.

Tube / Fertilization

Function of fimbriae?

Sweep oocyte into uterine tube.

Common site of fertilization?

Ampulla.

Function of cilia in uterine tube?

Move oocyte toward uterus.

Uterus

Thickest uterine layer?

Myometrium.

Implantation occurs where?

Endometrium.

What sheds during menstruation?

Stratum functionalis.

What regenerates endometrium?

Stratum basalis.

Function of cervix?

Passage between uterus and vagina.

Hormones

Estrogen main effects?

Builds endometrium, female traits, helps ovulation.

Progesterone main effects?

Maintains uterine lining, supports pregnancy.

What secretes progesterone after ovulation?

Corpus luteum.

If no fertilization, what happens to corpus luteum?

Degenerates to corpus albicans.

Menstrual Cycle

Proliferative phase driven by?

Estrogen.

Secretory phase driven by?

Progesterone.

Menstrual phase caused by drop in what hormones?

Estrogen and progesterone.

Accessory Structures

Greater vestibular glands function?

Lubrication.

Mammary glands function?

Produce milk.

Milk pathway?

Lobules → lactiferous ducts → nipple.

Histology

Vagina epithelium?

Stratified squamous.

Ovary histology clue?

Follicles in cortex.

Uterus histology clue?

Endometrial glands + thick muscle.

PART 3 — MALE REPRODUCTIVE SYSTEM Core Functions

Main functions of male reproductive system?

Produce sperm, transport sperm, secrete hormones.

Male gonads?

Testes.

Endocrine product of testes?

Testosterone.

Exocrine product of testes?

Sperm in seminal fluid.

Testes / Thermoregulation

Why are testes outside body cavity?

Cooler temperature for sperm production.

Cremaster muscle function?

Raises/lowers testes.

Dartos muscle function?

Wrinkles scrotum to conserve heat.

Pampiniform plexus function?

Cools arterial blood to testes.

Spermatogenesis

Where does sperm production occur?

Seminiferous tubules.

Sertoli (nurse) cell function?

Support spermatogenesis.

Leydig cell function?

Produce testosterone.

How many sperm from one primary spermatocyte?

Four.

Sperm Pathway

Sperm pathway?

Seminiferous tubules → rete testis → efferent ductules → epididymis → ductus deferens → ampulla → ejaculatory duct → prostatic urethra → membranous urethra → spongy urethra.

Where do sperm mature and gain motility?

Epididymis.

Where are sperm stored?

Epididymis.

Accessory Glands

Largest semen contribution?

Seminal vesicles.

Seminal vesicle secretion?

Fructose-rich fluid; prostaglandins.

Prostate secretion?

Alkaline/proteolytic fluid activates sperm.

Bulbourethral gland secretion?

Mucus/lubrication.

Why is semen slightly alkaline?

Neutralizes acidity.

Penis

Erectile tissues?

Two corpora cavernosa, one corpus spongiosum.

What fills during erection?

Erectile tissue with blood.

Function of corpus spongiosum?

Surrounds urethra; keeps it open.

Glans penis?

Sensitive enlarged distal tip.

Prepuce?

Foreskin.

Histology

Seminiferous tubule clue?

Layers of developing sperm cells around lumen.

Epididymis clue?

Pseudostratified epithelium with stereocilia; smooth muscle.

CROSSOVER / HIGH-YIELD COMPARE

Spermatogenesis vs oogenesis output?

4 sperm vs 1 ovum.

Male process timing?

Continuous after puberty.

Female process timing?

Cyclic until menopause.

Homologous: ovaries ↔ ?

Testes.

Homologous: clitoris ↔ ?

Glans penis.

Homologous: greater vestibular glands ↔ ?

Bulbourethral glands.

Homologous: paraurethral glands ↔ ?

Prostate.

Normal urine component: glucose?

No, normally absent or negligible.

Normal urine component: erythrocytes?

No.

Normal urine component: leukocytes?

No.

Normal urine component: albumin?

No.

Normal urine component: microbes?

No.

Main nitrogenous wastes in urine?

Urea, uric acid, creatinine.

Why is albumin abnormal in urine?

Filtration barrier damage or increased permeability.

Why are RBCs abnormal in urine?

Bleeding, stone, trauma, inflammation, pathology.

Why are leukocytes/microbes abnormal in urine?

Infection/inflammation.

Why is glucose abnormal in urine?

Reabsorption threshold exceeded or transporter issue.

FEMALE REPRODUCTIVE — TINY DETAILS Ovary Anatomy

Outer covering of ovary?

Ovarian surface epithelium.

Dense connective tissue under surface epithelium?

Tunica albuginea.