A&P Urinary System

Urinary system is a body system that …? (2)

removes waste and maintains water and salt balance

What are the main functions of the urinary system? (3)

filter blood, remove waste, maintain homeostasis

Excretion is the process of…?

removing metabolic wastes from the body

Kidneys are organs that…? (2)

filter blood and produce urine

What are the main parts/organs of the urinary system? (4)

Kidneys, ureters, bladder, and urethra

Renal cortex ^{(where is it relative to kidney & what does it contain)}

Outer layer of kidney containing blood vessels

Renal medulla ^{(where is it relative to kidney & what is it’s function)}

Inner layer of kidney that regulates urine concentration

What are Ureters

Tubes that carry urine from kidneys to bladder

Define the Urinary bladder

Organ that stores urine

What is the Urethra

Tube that carries urine out of the body

What is unique about the male urethra?

carries urine and sperm

Why are females more prone to UTIs?

They have a shorter urethra

What is the Nephron; what is the function?

Functional unit of the kidney; filters blood

What is the Glomerulus; What occurs here?

Cluster of capillaries; filtration

Filtrate is the fluid that’s been…? What is in filtrate (2)?

filtered from blood; waste and small molecules

Proximal tubule (what is it part of & what occurs here)

Part of nephron where reabsorption occurs

What is reabsorption?

Process of returning useful substances to the blood

What substances are reabsorbed? (4)

Water, glucose, salts, and nutrients

Urine is the _____ fluid; It’s composed of (mostly) … (3)?

Waste; water, urea, and salts

What is urine made of? (3)

(about) 95% water, urea, and waste products

What happens to filtrate after reabsorption? ^{(what is the fluid now called)}

It becomes urine

What is the role of the kidneys in homeostasis? (3)

They regulate water, salts, and waste levels

What waste do kidneys remove from protein metabolism?

Nitrogenous wastes (urea/ammonia)

Why is ammonia dangerous? (2)

It is toxic and must be excreted

What hormone do kidneys produce to regulate red blood cells?

Erythropoietin

What is Erythropoietin & what is it’s function

Hormone; stimulates RBC production

What vitamin do kidneys help activate?

Vitamin D

How do kidneys help regulate blood pressure? (2)

By controlling blood volume and releasing hormones

Renin is a ________ that does what?

Hormone; helps regulate blood pressure

How does renin affect blood pressure? ^{(what’s it’s effect on BP & how does it do this)}

It increases blood pressure by retaining water and salt

What is the relationship between urinary and cardiovascular systems?

Blood is filtered by kidneys and returned clean

Renal artery

Vessel that carries blood into the kidney

Renal vein

Vessel that carries filtered blood away from the kidney

What drives filtration in the kidneys?

Blood pressure

What happens in the glomerulus?

Blood is filtered into filtrate

What happens if blood pressure is too low?

Filtration decreases

What happens if kidneys fail? (2)

Waste builds up and homeostasis is disrupted

How is urine transported out of the body? ^{4 step w arrows}

Kidney → ureter → bladder → urethra

What triggers urination?

Signals from bladder to nervous system

Sphincters (bladder)

Muscles that control urine release

What must happen for urination to occur?

Internal and external sphincters must relax

Why is water balance important? (2)

It maintains blood volume and cell function

How does the urinary system interact with endocrine system? ^{(what is used to regulate 3 things?)}

Hormones regulate water, salt, and pressure

What would happen without kidney function?

Toxic waste would accumulate in blood

Which structure filters blood?

Nephron

Which structure stores urine?

Urinary bladder

Which structure carries urine to bladder?

Ureters

Which structure removes urine from body?

Urethra

Why is the urinary system essential? (2)

It maintains internal balance and removes harmful waste

What is another name for the urinary system, and why?

The urogenital system (because some structures, like the urethra, are shared with the reproductive system)

Where are the kidneys located in the body? (3 key locations)

Against the dorsal body wall, above the waist, superior to the lumbar region

How much fluid can the urinary bladder hold?

400-800 mL

How does the bladder communicate the need to urinate?

It has sensors that send signals to the CNS

What is the difference between blood in the renal artery versus the renal vein?

The renal artery carries oxygenated blood into the kidney; the renal vein carries filtered, deoxygenated blood out

Where specifically is erythropoietin produced, and what does it do?

renal cortex; it stimulates the production of new RBCs