L2 - Urine Production and Micturition

Nephron

Functional unit of the kidney for urine formation.

Bowman's Capsule

Encloses glomerulus; site of blood filtration.

Glomerulus

Network of capillaries for blood filtration.

Proximal Convoluted Tubule

Reabsorbs 70% of glomerular filtrate.

Loop of Henle

Establishes concentration gradient for urine.

Distal Convoluted Tubule

Site for secretion and reabsorption of ions.

Collecting Duct

Controls final urine concentration and volume.

Filtration Membrane

Allows passage based on size and charge.

Net Filtration Pressure (NFP)

Pressure driving fluid through filtration membrane.

Glomerular Filtration Rate (GFR)

Rate of filtrate formation in kidneys.

Intrinsic Regulation

Autoregulation mechanisms maintaining GFR stability.

Extrinsic Regulation

Neural and hormonal control of GFR.

Myogenic Mechanism

Afferent arteriole contraction in response to stretch.

Tubuloglomerular Feedback

MD cells regulate GFR based on fluid flow.

Renin Angiotensin Aldosterone System (RAAS)

Hormonal system regulating blood pressure and GFR.

Aquaporins

Water channels facilitating water reabsorption.

Detrusor Muscle

Smooth muscle facilitating bladder contraction.

Internal Urethral Sphincter

Smooth muscle forming physiological sphincter.

Urethralis Muscle

Skeletal muscle acting as external sphincter.

Prostate Gland

Surrounds urethra; may enlarge with age.

Pudendal Nerve

Innervates external urethral sphincter for control.

Sympathetic Innervation

Regulates detrusor muscle and internal sphincter.

Parasympathetic Innervation

Stimulates detrusor muscle contraction.

Urinary Bladder

Stores urine until micturition occurs.

Ureter

Transports urine from kidneys to bladder.

Urethra

Conducts urine from bladder to outside body.

Micturition

Process of expelling urine from bladder.