Urinary and Reproductive System: Structure, Function, and Assessment

Objectives of the Lecture

Overview

This study guide covers the anatomy, physiology, and clinical assessment of the urinary and reproductive systems, with a focus on age-related changes, common pathologies, and health promotion strategies.

• Functions of the urinary system

• Age-related changes in urinary function

• Types of urinary incontinence

• Risks associated with nocturia

• Prostate gland structure and pathology

• Assessment of genitourinary system

Function of the Urinary System

Main Functions

The urinary system is essential for maintaining homeostasis by regulating fluid balance, waste excretion, and hormone production.

• Regulation of blood pressure: The kidneys secrete renin, activating the Renin-Angiotensin-Aldosterone System (RAAS) to control blood pressure.

• Production of hormones: Kidneys produce calcitriol (active vitamin D) and erythropoietin (stimulates red blood cell production).

• Regulation of blood glucose levels: Kidneys contribute to gluconeogenesis and glucose reabsorption.

• Excretion of wastes: Removal of metabolic waste products (e.g., urea, creatinine) via urine.

• Urine transport and storage: Urine passes from kidneys to bladder via ureters; bladder stores urine until excretion.

• Urine elimination: Urine is expelled from the bladder through the urethra.

Urinary Function and the Ageing Process

Age-Related Changes

Urinary function is affected by physiological changes associated with ageing, increasing the risk of certain disorders.

• Bladder issues: Incontinence and urinary retention are common but not inevitable; often linked to other diseases.

• Antidiuretic hormone (ADH): Night-time ADH production declines, leading to increased nocturnal urine output.

• Kidney function: May increase at night due to reduced demands from other organs.

• Urine concentration: Older adults have reduced ability to concentrate urine, increasing dehydration risk.

• Drug accumulation: Impaired clearance can lead to toxic effects.

• Detrusor muscle changes: Overactivity causes urgency; impaired contractility leads to incomplete bladder emptying and residual urine.

Types of Urinary Incontinence

Classification and Mechanisms

Urinary incontinence is the involuntary loss of urine, classified by underlying mechanism.

• Stress incontinence: Leakage occurs when increased abdominal pressure (coughing, sneezing, laughing) overcomes weak pelvic floor muscles.

• Urge incontinence (Overactive Bladder, OAB): Detrusor muscle contracts prematurely during bladder filling, causing sudden urge to void.

• Functional incontinence: Incontinence due to non-urinary tract factors (e.g., mobility impairment, cognitive dysfunction).

Nocturia

Definition and Risks

Nocturia is the need to wake and void urine during the night, prevalent in older adults and associated with increased fall risk.

• Prevalence: Affects up to 59% of men and 62% of women aged 70+.

• Risks:

  • Rushing to the toilet increases risk of tripping.

  • Postural hypotension may cause dizziness.

  • Mobility deficits further increase fall risk.

Prostate Gland

Anatomy and Function

The prostate gland is a male accessory reproductive organ with important roles in semen production and urinary function.

• Location: In front of the rectum, behind the symphysis pubis, surrounds bladder neck and urethra.

• Ducts: 15–30 ducts open into the urethra.

• Seminal vesicles: Project above the prostate, contribute to seminal fluid.

• Secretions: Prostate fluid is rich in fructose (nourishes sperm) and prostaglandins.

• Cowper's (bulbourethral) glands: Inferior to prostate, secrete clear mucus for lubrication.

• Bladder outlet obstruction: Enlarged prostate in older males may block urine flow.

Prostate Cancer

Pathology and Risk Factors

Prostate cancer is the most common cancer in men, with several established risk factors and variable outcomes.

• Risk factors:

  • Increasing age

  • Family history

  • Inherited mutations in BRCA1 and BRCA2 genes

  • Ethnic/geographic variation (higher mortality in men of African descent)

  • Diets high in red meat or high-fat dairy

  • Obesity (possible association)

• Screening: Recommendations depend on individual risk profile.

Assessment of the Genitourinary System

Subjective Data Collection

Subjective assessment involves gathering information about urinary and reproductive symptoms from the patient.

• Urinary frequency or urgency

• Burning or pain during urination (dysuria)

• Nocturia

• Hematuria (blood in urine)

• Changes in urine color or odor

• Incontinence or loss of control

• Leakage associated with activities (e.g., sneezing, coughing)

Objective Data Collection

Objective assessment includes physical examination and diagnostic tests.

• Inspection:

  • Height-to-weight ratio, body shape, mobility

  • Hygiene and appearance

  • Demeanour

  • Lower abdomen/genitalia for discharge or excoriation

• Vital signs: Focus on temperature and blood pressure

• Bladder scan: Assess post-void residual urine

• Urine examination: Collect sample, perform urinalysis

• Fluid balance: Assess adequacy of fluid intake

Reproductive Assessment

Structures of the Female and Male Reproductive Systems

Assessment includes identification and examination of key anatomical structures.

Female Structures	Male Structures
Vagina	Testis
Cervix	Scrotum
Squamocolumnar junction	Glans penis
Anterior fornix	Urethra
Posterior fornix	Corona
Rectouterine pouch (cul-de-sac of Douglas)	Foreskin
Uterus	Corpus spongiosum
Fallopian tubes	Corpus cavernosum
Labia majora/minora	Symphysis pubis
Perineum	Ductus deferens
Vestibule	Seminal vesicle
Clitoris	Rectum
Mons pubis	Prostate
Rectum	Bulbourethral gland

Additional Info: Age-Related Changes in Reproductive System

Infants, Adolescents, and Older Adults

• Infants: External genitalia may be engorged due to maternal estrogen.

• Adolescents: Puberty triggers growth of reproductive organs and secondary sex characteristics (breast, pubic hair).

• Older adults:

  • Females: Menopause, uterine and ovarian atrophy, vaginal changes, decreased pubic hair.

  • Males: Decreased testicular mass, lower testosterone, erectile dysfunction, benign prostatic hyperplasia (BPH), reduced sperm count.

Health Promotion and Screening

Preventive Strategies

• Cervical screening: Women and people with a cervix aged 25–74 years, every 5 years.

• Self-examination: Regular breast and testicular self-exams.

• Prostate screening: PSA blood test for prostate cancer risk.

• HPV vaccination: Recommended for men and women under 26 years.

Summary Table: Types of Urinary Incontinence

Type	Mechanism	Key Features
Stress	Increased abdominal pressure	Leakage during coughing, sneezing, laughing
Urge (OAB)	Detrusor overactivity	Sudden urge, inability to delay voiding
Functional	Non-urinary tract factors	Impaired mobility, cognition

Key Equations and Concepts

• Renin-Angiotensin-Aldosterone System (RAAS): $\text{Renin} \rightarrow \text{Angiotensin I} \rightarrow \text{Angiotensin II} \rightarrow \text{Aldosterone}$ Regulates blood pressure and fluid balance.

• Glomerular Filtration Rate (GFR): $\text{GFR} = \frac{\text{Urine Concentration} \times \text{Urine Flow Rate}}{\text{Plasma Concentration}}$ Indicates kidney function. Additional info: GFR decreases with age, increasing risk of drug toxicity.