Urinary system

sphincters

(2).close proximity are found where the urethra exits the bladder

efferent arteriole

Blood leaving the glomerulus is carried away by the... divides and forms the peritubular capillary network

gout

Crystals of uric acid sometimes collect in the joints, producing a painful ailment

Nervous system controls urination

Figure 10.2 Sensory impulses trigger a desire to urinate. As the bladder fills with urine, sensory impulses go to the spinal cord and then to the brain. The brain can override the urge to urinate. When urination occurs, motor nerve impulses cause the bladder to contract and the sphincters to relax.

Nephron structure

Figure 10.5 . A nephron is made up of a glomerular capsule, the proximal convoluted tubule, the loop of the nephron, the distal convoluted tubule, and the collecting duct. The photomicrographs show the microscopic anatomy of these structures. You can trace the path of blood about the nephron by following the arrows.

Urinary tract infections

In females much smaller urethra about 4cm

Pathway of Urinary System

Kidneys--Utreters----Urinary bladder---Urethra

Kidney Structure

Microscopically, the kidneys are composed of kidney tubules (nephrons). These tubules have a blood supply that interacts with parts of the tubule as they produce urine.

Tubular Reabsorption

Nutrient and salt molecules are actively reabsorbed from the convoluted tubules into the peritubular capillary network, and water flows passively.

loop of the nephron (loop of Henle).

Simple squamous epithelium appears as the tube narrows and makes a U-turn..). Each loop consists of a descending limb and an ascending limb. The descending limb of the loop allows water to diffuse into tissue surrounding the nephron. The ascending limb actively transports salt from its lumen to interstitial tissue

proximal convoluted tubule

The cuboidal epithelial cells lining this part of the nephron have numerous microvilli, about 1 μm in length, that are tightly packed and form a brush border

Kidneys and Homeostasis

The kidneys are involved in the salt-water balance and the acid-base balance of the blood, in addition to excreting nitrogenous wastes.

reabsorbtion along the length of nephron.

The loop on the nephron(deep in the renal medulla)(made up of a descending limb and an ascending limb) Fig.10.10 Salt (NaCl) diffuses and is actively transported out of the ascending limb of the loop of the nephron into the renal medulla; also, urea is believed to leak from the collecting duct and to enter the tissues of the renal medulla. This creates a hypertonic environment, which draws water out of the descending limb and the collecting duct. This water is returned to the cardiovascular system. (The thick black outline of the ascending limb means that it is impermeable to water.)

creatinine

The metabolic breakdown of creatine phosphate results

Alkolosis

This is a condition characterized by an excessive loss of hydrogen ions. When this occurs, symptoms are a heightened state of nervous system activity, resulting in spasmodic muscle contractions, convulsions & even death.

Urine Formation

Urine is composed primarily of nitrogenous waste products and salts in water. Urine formation is a stepwise process.

Kidney Function Disorders

Various types of illnesses, including diabetes, kidney stones, and infections, can lead to renal failure. Hemodialysis is needed for the survival of patients with renal failure.

acidosis

abnormally high acidity (excess hydrogen-ion concentration) of the blood and other body tissues

folds of bladder mucosa

act like a valve to prevent backward flow

stretch receptors

activated by the enlargement of the bladder. send sensory nerve signals to the spinal cord.

adipose tissue

adhere to each kidney

Collecting ducts

also located in the renal medulla, and together they give the renal pyramids their appearance

glomerulus

an afferent arteriole transports blood to. a knot of capillaries inside the glomerular capsule

renin

an enzyme that leads to aldosterone secretion

Diuretic

any substance that tends to increase the flow of urine ex. alchol and Caffeine

bladder's rugae

are similar to those of the stomach. A layer of transitional epithelium enables the bladder to stretch and contain an increased volume of urine.

epithelium of the mucosa

becomes thinner, and folds in the mucosa called rugae disappear as the bladder enlarges

Peristaltic contractions

cause urine to enter the bladder even if a person is lying down

glomerular capsule (Bowman's capsule)

closed end of the nephron is pushed in on itself to form a cuplike structure

ureters

conduct urine from the kidneys to the bladder..They are small, muscular tubes about 25 cm long and 5 mm in diameter.

renal medulla

consists of cone-shaped tissue masses called renal pyramids

uric acid(too much blood)

crystals form and precipitate out

peritubular capillary network

efferent arteriole divides and forms..

bladder wall

expandable because it contains a middle layer of circular fibers of smooth muscle and two layers of longitudinal smooth muscle.

motor nerve impulses

from the spinal cord cause the urinary bladder to contract and the sphincters to relax so that urination, also called micturition, is possible (Fig. 10.2).

brush border

greatly increases the surface area for the tubular reabsorption of filtrate components

ureter(wall)

has three layers: an inner mucosa (mucous membrane), a smooth muscle layer, and an outer fibrous coat of connective tissue.

podocytes

have long cytoplasmic extensions... cling to the capillary walls of the glomerulus and leave pores that allow easy passage of small molecules from the glomerulus to the inside of the glomerular capsule.

distal convoluted tubule

have numerous mitochondria, but they lack micro-villi. This means that the distal convoluted tubule is not specialized for reabsorption. Instead, its primary function is ion exchange

angiogram

injects a contrast medium that is opaque to X-rays into the blood vessels, which highlights them when an X-ray of the area is taken

uric acid

insoluable

renal pelvis

is a central space, or cavity, continuous with the ureter (Fig. 10.3b, c).

Creatine phosphate

is a high-energy phosphate reserve molecule in muscles

Aldosterone

is a hormone produced by the adrenal glands (see Fig. 10.1), which lie atop the kidneys. involved in regulating the water-salt balance of the blood.

Aldostone(effect)

is a hormone secreted by the adrenal glands, which sit atop the kidneys. This hormone promotes ion exchange at the distal convoluted tubule. Potassium ions (K+) are excreted, and sodium ions (Na+) are reabsorbed into the blood. The release of aldosterone is set into motion by the kidneys.

Atrial natriuretic hormone(ANH)

is a hormone secreted by the atria of the heart when cardiac cells are stretched due to increased blood volume. ANH inhibits the secretion of renin by the juxtaglomerular apparatus and the secretion of aldosterone by the adrenal glands. Its effect, therefore, is to promote the excretion of sodium ions (Na+ ), called natriuresis. Normally, salt reabsorption creates an osmotic gradient that causes water to be reabsorbed. Thus, by causing salt excretion, ANH causes water excretion, too. If ANH is present, less water will be reabsorbed, even if ADH is also present.

Erythropoietin (EPO)

is a hormone secreted by the kidneys. When blood oxygen decreases, EPO increases red blood cell synthesis by stem cells in the bone marrow

renal cortex

is an outer, granulated layer that dips down in between a radially striated inner layer called the renal medulla

external sphincter

is composed of skeletal muscle that can be voluntarily controlled.

Urea

is the primary nitrogenous end product of metabolism in human beings. is a by-product of amino acid metabolism. The breakdown of amino acids in the liver releases ammonia, a compound that is very toxic to cells.

Urinary System

kidneys produce urine, which is stored in the bladder before being discharged from the body. The kidneys are major organs of homeostasis. consists of the kidneys, ureters, urinary bladder, and urethra

Renal Medulla(what is found there)

loop of the nephron,peritubular capillaries, collecting ducts

micturition

motor nerve impulses from the spinal cord cause the urinary bladder to contract and the sphincters to relax so that urination

antidiuretic hormone(ADH)

must be present. ADH is produced by the hypothalamus and secreted by the posterior pituitary according to the osmolarity of the blood. If our intake of water has been low, ADH is secreted by the posterior pituitary. Water moves from the distal convoluted tubule and the collecting duct into the blood.

Urine enters the bladder in spurts

occur at the rate of one to five per minute.

internal sphincter

occurs around the opening to the urethra. It is composed of smooth muscle and is involuntarily controlled

nephroptosis(floating kidney)

occurs when the kidney becomes detached from its position and moves freely beneath the peritoneum

Nephrons

one of a million tiny filtered structures found in the kidneys that removes wastes from blood and produces urine....positioned so that the urine flows into collecting ducts. collecting ducts eventually enter the renal pelvis.

Adrenal glands

produce aldostone

glomerular filtration

produces a filtrate of the blood

kidneys

reabsorb filtered nutrients and synthesize vitamin D. maintain the appropriate level of other ions, such as potassium ions (K+), bicarbonate ions (HCO3-), and calcium ions (Ca2+), in the blood. Principal purpse:maintain the appropriate water-salt balance of the blood. Regulate blood pressure

Homestasis of kidneys

regulate blood pressure, appropriate level of ions in the blood, regulate the acid-base balance of the blood, excrete waste molecules, water-salt balance, reabsorption of salt and water form corical and Medullary portions of the nephron, Mostly Adjust the PH or most important.

excretion

removal of metabolic waste from the body

kidneys(3 regions inside)

renal cortex, renal medulla, and renal pelvis

renal vein

renal vein carries filtered blood away from the kidneys.

Urinary Bladder

stores urine until it is expelled from the body, has three openings: two for the ureters and one for the urethra, which drains

nucleotides(breakdown)

such as those containing adenine and thymine, produces uric acid

renal artery

transports blood to be filtered to the kidneys

Urine

usually has a pH of 6 or lower because our diet often contains acidic foods.

nephrons(aka renal or kidney tubles)

filter the blood and produce urine, is positioned so that the urine flows into a collecting duct

renal capsule

fist-sized organs are covered by a tough capsule of fibrous connective tissue