Week 13: Chp 61: Renal System Flashcards
What is the Renal System Composed of?
two kidneys
What is the Urinary system composed of?
two ureters, the urinary bladder, and the urethra
The Renal system and the Urinary System work together to do what?
help maintain homeostasis in the human body
ex: urine is formed as blood is filtered through the kidneys; the bladder then provides storage, and the ureters and urethra act as passages for urine to exit the body
Functions of the kidney regarding maintenance of homeostasis in the human body
- Excretion of wastes
- Regulation of fluid and electrolyte balance
- Regulation of acid-base balance
- Regulation of blood pressure
- Secretion of erythropoietin for red blood cell (RBC) production
- Activation of vitamin D
Function of the Urinary System
provides for the storage (bladder) and passage of urine, promoting continence and facilitating voiding
Kidneys
bean-shaped organs located retroperitoneally (behind the abdominal contents), one on each side of the spinal column
- held in place by connective tissue known as renal fascia
- left kidney is located slightly higher than the right because of the position of the liver
- an adrenal gland sits atop of each organ
The Outermost layer of the kidney
renal capsule
- thin, fibrous tissue serves to protect the organ and absorb shock
- capsule covers the distal surface of the kidney and extends to the medial portion of the kidney termed hilum
Hilum
indented part of the kidney
- medial portion of the kidney
- the location at which the renal artery and nerves enter the organ and the renal vein and ureters exit
Parenchyma
the inner tissue of the kidney
-lies beneath the renal capsule and contains the functional layers of the organ
When the parenchyma is viewed as a cross-section, the tissue layer laying directly beneath the renal capsule is called?
the cortex
The medulla
innermost layer of tissue and is composed of multiple pyramids
Papillae
the narrow tips of the renal pyramids
-empty urine into the calyces, cuplike collection structures
Minor Calyx
small cluster cuplike collection structures that papillae empty out into
-minor calyces, when moving toward the hilum, merge to form major calyces, which empty into the larger collection sac known as the renal pelvis
Major Calyces
what minor calyces merge into when moving toward the hilum
-major calyces then empty into the larger collection sac known as the renal pelvis
Renal pelvis
where the major calyces empty into
- can hold only 3 to 5 mL of urine
- narrows to become the ureters
The Flow of Urine
papillae of the pyramids into the minor calyces, the major calyces, the renal pelvis, and the ureters en route to the bladder
Nephron
functional unit of the kidney
-here is the work of filtering the blood to remove wastes and produce urine occurs
>80% are cortical nephrons; short in length and fully contained within the cortex region
>20% are juxtamedullary nephrons and contain structures that lie deep within the medulla
Each Nephron is Composed of What?
glomerulus, a Bowman’s capsule, and a tubular system
Nephron: Glomerulus
collection of semipermeable capillaries responsible for filtering blood
Nephron: Bowman’s capsule
structure surrounding each glomerulus
Nephron: Tubular system
composed of the proximal convoluted tubule (PCT), the loop of Henle, the distal convoluted tubules (DCTs), and a collecting tubule
>the PCT emerges from the bowman’s capsule and winds until straightening into the loop of Henle; The loop of Henle is composed of a descending and an ascending limb, each of which is responsible for reabsorbing different substances in the process of urine formation; the DCT is a continuation of the ascending limb of the loop of Henle that thickens and continues twisting until it widens further into a collecting tubule
Blood Supply of the Kidneys
receive 20 to 25% of cardiac output/ 1200 mL of blood per minute
-the renal artery, a branch of the abdominal aorta, enters the kidney at the hilum and delivers blood to the kidney; as the renal artery enters the kidney, it branches into several segmented arteries which then branch into interlobar arteries
Interlobar arteries
travel through the renal columns between the pyramids, moving outward toward the renal cortex tissue
-as they approach the renal cortex, they divide, forming arcuate arteries and then cortical radiate arteries; the branches formed off these cortical radiate arteries are the afferent arterioles
Afferent Arterioles
the branches formed off the cortical radiate arteries
- afferent arterioles for a collection of capillaries that direct blood flow to the glomeruli of the nephrons, where the process of urine formation begins
- capillaries within the glomeruli then merge into efferent arterioles to transport blood away from the glomeruli and into the peritubular capillaries
Efferent arterioles
transport blood away from the glomeruli and into the peritubular capillaries
Peritubular Capillaries
this collection of capillaries drains blood into the venous system
-the renal vein then carries blood away from the kidneys and drains into the inferior vena cava