Chapter 15 The Urinary System Functions of the Urinary System 1. Elimination of waste Nitrogenous wastes Toxins Drugs 2. Regulates homeostasis
Water balance Electrolytes Acid-base balance in the blood Blood pressure RBC blood cell production Activation of vit. D Importance of Water in Human Body Water helps to remove the dangerous toxins that our body takes in from the air, the food
and the chemicals we use on our skin and hair. Water also provides cushion for our body joints. Water carries oxygen and nutrients into all our cells. Water also helps to regulate our body temperature. Our body has integrative body systems. When we say integrative, this means that our body systems are interconnected to each
other to maintain homeostasis. What is human homeostasis? Word origin: from the Greek: homeo, meaning unchanging + stasis, meaning standing. Human homeostasis refers to the body's ability to physiologically regulate its inner environment to ensure its stability, in response to fluctuations in the outside environment.
it is the state of balance in our body. What will happen if you do not have the ability to maintain homeostasis in our body? Homeostatic imbalance will lead to diseases or even death. Maintaining Chemical Homeostasis
The Urinary System Organs of the Urinary system
Kidneys Ureters Urinary bladder Urethra Location of the Kidneys Right lower than left Attached to ureters, renal blood vessels, & nerves at renal hilus
Atop kidney is adrenal gland Regions of the Kidney Renal cortex outer region Renal medulla inside the cortex
Renal pelvis inner collecting tube Blood Flow in the Kidneys Nephrons Structural and functional units of the kidneys
Forms urine Main structures a. Glomerulus b. Renal tubule nephron renal artery renal vein
Kidney Anatomy Nephrons Excess salts, water, wastes remain in the tubule and become urine Urine enters collecting ducts (tubes) in the medulla
Collecting tubes empty into the renal pelvis (first section of the ureter) All the blood in the body passes through the kidneys about 20 times every hour. Glomerulus Actual Filtration occurs here Excess salts, water,
nitrogenous wastes Water and solutes smaller than proteins are forced through capillary walls Blood cells too big to filter Becomes urine Renal Tubule Collecting tube Reabsorption
Things that are useful to the body are brought back into circulation. water, glucose, amino acids, and sodium. NOT: Nitrogenous waste products - Urea - Uric acid -Creatinine -Excess water
Characteristics of Urine Yellow due to pigment urochrome (from break-down of hemoglobin) & solutes
Sterile Slightly aromatic Normal pH of ~ 6 Specific gravity of 1.001 to 1.035 Ureters The urine leaves the kidneys through the
ureters, a muscular tubes 25 to 30 cm long that moves urine from the kidney to the urinary bladder. Urinary Bladder Smooth, collapsible, muscular sac
Temporarily stores urine Trigone 3 openings - Two from ureters - One to urethrea Urethra Thin-walled tube Carries urine from bladder by peristalsis Release controlled by 2 sphincters
- Internal urethral sphincter (involuntary) - External urethral sphincter (voluntary) Urethra Gender Differences Length - Females 34 cm (1 inch) - Males 20 cm inches)
(8 Location - Females along wall of the vagina - Males through the prostate and penis Function - Females only urine
- Males urine and sperm Micturition (Voiding) Both sphincters must open - internal relaxes after bladder stretches
- Activation - impulse to spinal cord and back via pelvic splanchnic nerves - external voluntarily relaxes
