Men's Health

Where does spermatogenesis occur?

Seminiferous tubules

Leydig cells

Located between tubules

Produce testosterone

Sertoli cells

Located within tubules

Support and nourish developing sperm cells

Releases ABP

Gonadotropin-releasing hormone

Released by hypothalamus in pulses

Acts on anterior pituitary gonadotrophs to release LH and FSH

What happens when a male hits puberty?

LH and FSH cells released at an extended rate

Luteinizing hormone (LH)

Stimulates Leydig cells

Follicle-stimulating hormone (FSH)

Stimulates Sertoli cells

Androgen

Male hormone that binds to testosterone

What happens when androgen and testosterone bind together?

Promotes spermatogenesis

Spermatogenesis

Spermatozoa produced in seminiferous tubules

4 phases: Spermatogonial, Primary Spermatocyte, Secondary Spermatocyte, Spermatid

Takes 64-72 days

Spermatogonial phase

Spermatogonia (stem cells) undergo mitosis forming primary spermatocytes

Primary Spermatocyte

Meiosis I forms two secondary spermatocytes

Secondary spermatocytes

Meiosis II forms four spermatids

Spermatid phase

Spermatids undergo spermiogenesis to mature into spermatozoa, develops tail

Sperm cell structure

Head: Nucleus (DNA) and Acrosome (enzymes to penetrate egg)

Midpiece: mitochondria produces ATP for movement

Tail (flagellum)

Epididymis

Stores and matures sperm from testes and transports to vas deferens

Vas deferens (ductus deferens)

Transports sperm to seminal vesicles, where 2/3 of semen volume is produced

Seminal vesicles

Produce seminal fluid (semen)

What does the ejaculatory duct merge with?

Prostatic urethra

Prostate gland

Houses the ejaculatory duct and surrounds prostatic urethra

Contributes seminal fluid

Urethra

Carries urine from bladder out of body

Transports semen during ejaculation

Penis

Made of spongiform tissue

Made of 3 long cylindrical bodies: corpus spongiosum and 2 cavernosum

Corpus cavernosa

Two spongy tubular vessels that run down length of penis

When filled with blood, penis is hard

Erection

mediated by parasympathetic nervous system (PNS)

Blood vessels dilate and veins compress

Ejaculation

mediated by sympathetic nervous system (SNS)

Smooth muscle contraction in vas deferens

Erectile Dysfunction causes

Cardiovascular disease

Diabetes

Organic causes of ED

Gradual deterioration

Functional causes of ED

Sudden onset

Hypogonadism

Insufficient production of testosterone

Cause is multifactorial

Treatment involves hormone replacement therapy

Primary Hypogonadism

Direct dysfunction of testes

Causes include Klinefelter, trauma, infections, and cancer

Klinefelter syndrome

Extra X chromosome leads to underdeveloped testes

Secondary Hypogonadism

Problems with hypothalamus or pituitary gland

Caused by tumors or genetic disordersC

Causes of Hypogonadism

Genetic disorders

Diabetes

Obesity

Liver/kidney disease

Lifestyle factors

Age-related

Symptoms of Hypogonadism

Decreased libido

ED

Fatigue

Loss of muscle mass

Depression

Prostate

Walnut-sized gland surrounding urethra

Secretes fluid that becomes part of seminal fluid

Metabolism of testosterone

Aided by 5-alpha-reductase

Metabolized to dihydrotestosterone (DHT)

DHT necessary for normal and hyperplastic growth

Prostate growth

Increased DHT and sensitivity to it

Hyperplasia of stromal and epithelial cells lead to gland enlargement

Benign Prostatic Hyperplasia

Non-cancerous enlargement of prostate

Due to overgrowth of stromal and epithelial cells

Symptoms of BPH

Lower urinary tract symptoms (LUTS) especially in older men

Obstructed urine outflow and impaired bladder function

Digital Rectal Exam (DRE)

Prostate exam to assess shape, size, and texture for BPH abnormalities or other stuff

Recommended for men over 50

How does a normal prostate usually feel like?

Smooth and firm

What does a BPH prostate feel like?

Enlarged, rubbery, has distinct midline groove

Urinalysis

Identifies UTI and may show signs of BPH

Serum Prostate-Specific Antigen

Measures levels of PSA in blood, which could be elevated in conditions

(>4.0 indicative of BPH)

What is the most common treatment for BPH?

Pharmacological treatment

Transurethral resection of the prostate (TURP)

Minimally invasive surgical intervention that removes excess prostate tissue

Detrusor muscle

Outer muscular layer of bladder that helps store and expel urine

Contracts to increase pressure inside to expel

Urethral sphincters

Maintains adequate closure to resist urine leakage

Internal urethral sphincter

Involuntary muscle to allow urine to flow from bladder to urethra

External urethral sphincter

Voluntary muscle that relaxes to release urine from the body

Urinary incontinence

Loss of bladder control

Characterized by leakage

Can occur during physical activity (stress) or strong urge (urge)

Overactive bladder

Overwhelming urge to urinate, increased frequency and nocturia

Can lead to incontinence, but not always leakage

Causes of overactive bladder

Inappropriate stimulation of muscarinic receptors on detrusor muscles

M2 and M3 receptors found on bladder, with M3 being prominent

Nocturia

2 or more awakenings at night to urinate