Presentation on theme: "Figure 3. Urine formation takes place in the nephron."— Presentation transcript:
1Figure 3. Urine formation takes place in the nephron. The Urinary System
2Functions of the Urinary system: Removes salts and nitrogenous wastesMaintains normal amounts of water and electrolytesRegulates the pH level and volume of fluids.Helps control red bloodcell production and bloodpressure.
3The organs of the Urinary System: The Kidney (2 of them)And all of the accessory organs with the kidneyA pair of ureters (tube structures)Urinary bladderUrethra (tube structure)
4They Kidney Reddish brown bean shaped organ that is smooth. They lie on both sides of the vertebral column on the upper posterior wall of the abdominal.The kidney attaches to blood vessels and lymphatic vessels from the cardiovascular system at the renal pelvis.
8The role of the kidney:Helps maintain homeostasis by removing wastes from the blood and combining them with excess water and electrolytes to form urine which eventually gets excreted.Help control the rate of red blood cell production through a hormone they secrete.Help maintain blood pressurePlay a role in the activation of Vitamin D
9The role of the kidney: Lined with blood vessels. Recieves oxygenated blood through the Abdominal Aorta. This branches to interlobar arterioles, and finally small capillaries called glomerulus located on the nephron (where urine is formed and processed).Deoxygenated blood leaves the kidneys through the Inferior Vena Cave to be returned to the heart.
10The Ureters A tube about 25cm long Begins at the renal pelvis of the kidney and runs parallel to the vertebral column on each side until it reaches the urinary bladder.Made up of mucous lining, smooth muscle and connective tissue.What do you think the smooth muscle does?
11The Ureters Correct- they propel the urine to your bladder! Your ureters have a valve just like the heart to prevent the flow of urine back through the ureters.This valve called: ureteral mucous opening, opens when urine is pushed against it and closes when urine reaches the bladder.
12The BladderA hallow, muscular organ, spherical shape, very flexible, located in the pelvic cavity.Do you remember what type of tissues it is made up of?Transitional Epithelium Tissue!!It is also made up of smooth muscle, mucous membranes, and connective tissues (elastic).
13The BladderAt the triangular portion it attaches to the urethra tube. Label the structure of the bladder:
14The BladderWhat is the difference between the Internal urethral sphincter and the external urethral sphincter?The internal urethral sphincter is a smooth muscle. Which means what?Does it automatically. You can not control when urine wants to leave the bladder.The external is a skeletal muscle. You can control though if you release urine from the urethra.You are able to “hold it” like when I don’t give you a pass to the bathroom- your external urethral sphincter muscles are working.
15The UrethraThe tube that transports urine from the urinary bladder to outside the body.Contains glands that secrete mucous into the tube to help urine pass.
17FiltrationFiltrationFiltrationFiltrationFigure 3. Urine formation takes place in the nephron.Figure 3. Urine formation takes place in the nephron.Figure 3. Urine formation takes place in the nephron.Figure 3. Urine formation takes place in the nephron.Figure 3. Urine formation takes place in the nephron (Functional unit of the kidney).
19Urine productionUrine formation begins with the process of filtration of blood, which goes on continually in the renal corpusclesAs blood flows through the glomeruli (capillaries), much of its fluid, containing both useful chemicals and waste materials, soaks out of the blood through the membranes (by osmosis and diffusion) where it is filtered and then flows into the Bowman's capsule (The next spot on the nephron).
20This process is called glomerular filtration. water, excess salts (primarily Na+ and K+), glucose, and waste products of the body are called ureaUrea is formed in the body to eliminate toxic ammonia products that are formed in the liver from amino acids
21WHAT IS EXCRETED???About 125 ml of water and dissolved substances are filtered out of the blood per minute.After waste or water is excreted, it can also be REABSORBED.Reabsorption, by definition, is the movement of substances out of the blood into the renal tubules then back into the blood capillaries located around the tubulesSubstances reabsorbed are water, glucose and other nutrients, and sodium (Na+) and other ions
22The pathway of urine: Excretion and reabsorption next goes in the proximal convoluted tubules and continues in the loop of Henle, distal convoluted tubules, and collecting tubules
26Substances secreted and removed are hydrogen ions (H+), potassium ions (K+), ammonia (NH3), and certain drugsKidney tubule secretion plays a crucial role in maintaining the body's acid-base balance, another important body function that the kidney participates in.
27Control of Urine Production Urine is produced not only in order to eliminate many of the cellular waste products, but also to control both the amount and the composition of the extracellular fluid in the bodyThe kidney tubule regulation of the salt and water in our bodies is the most important factor in determining urine volume.
28The level of water and salts excreted in urine - the urine volume - is adjusted to the needs of the body. As a general rule, however, and under optimum conditions, the body produces urine at a rate of about 1 ml/min.Controlled by hormones, chemical messengers that travel through the blood system and act as regulators of many of the body's internal activities
29Control of Urine Volume through ADH (anti-diuretic hormone ) Diuretic is a substance that acts to increase urine productionfeeling "bloated" = retaining waterAn anti- diuretic, on the other hand, is a chemical that inhibits urine formationADH produces its anti-diuretic effect by acting on the kidneys and causing them to reduce the amount of water they excrete
30ADH is important in regulating the water concentration of body fluids, which ultimately helps to maintain an appropriate sodium concentration in the bodyThe sodium concentration in the fluid is the factor that either stimulates the pituitary to release ADH or to inhibit the release of ADH
31Figure 5. The regulation of body water and sodium ion (Na+) concentration in the blood is controlled through the release of anti-diuretic hormone (ADH). This system operates using a negative feedback loop.
32For this reason, ADH is described as the "water-retaining hormone For this reason, ADH is described as the "water-retaining hormone." You might also think of it as the "urine-decreasing hormone."When a person drinks an excess of water, the sodium in the body fluids, including the blood becomes more dilute and the release of ADH is inhibited.The kidneys excrete more watery urine until the water concentration of the body fluids returns to normal