Chapter 23- Urinary System Flashcards
The primary function of the urinary system is to maintain homeostasis of the body by:
1.Controlling the volume, pH, and concentration of the blood
2.Regulating red blood cell production.
3.Eliminating waste
4.Regulating blood pressure
5.Vitamin D synthesis- helps regulate Calcium levels
The organs of the urinary system are:
2 kidneys, 2 ureters, 1 urinary bladder and 1 urethra
The kidneys are located on either side of the spinal column in a ______ position between level ___ and ___
The kidneys are located on either side of the spinal column in a retroperitoneal position between level T12 and L3
3 layers surrounding the kidney
Renal fascia (1st)
Perirenal fat capsule (2nd)
Renal/fibrous capsule (3rd)
2 layers within the kidney
cortex and medulla
Basic pathway of the kidney
Pyramids -> Papillae -> Minor Calyx -> Major Calyx -> Renal Pelvis -> Hilum -> Ureter
Nephron
The functional unit of the kidney
2 types of nephrons
Cortical and Juxtamedullary
Cortical vs Juxtamedullary
Juxtamedullary can pull more water out compared to Cortical
What components make up the renal corpuscle?
The glomerulus and the Bowman’s capsule
What components make up the renal tubule?
A proximal convoluted tubule (PCT), a loop of Henle (LOH), a distal convoluted tubule (DCT), and a collecting duct (CD)
Are nephrons mitotic?
No
How much of the kidney do you need to maintain homeostasis?
1/3 of just 1 kidney
Urine is the fluid that is produced by the kidneys that contain wastes or excess materials.
The nephron forms urine by three different processes:
- Glomerular filtration
- Tubular reabsorption
3.Tubular secretion
Glomerular Filtration: This occurs in the ___ ____, which is composed of the glomerulus plus the Bowman’s capsule. The glomerulus is a tuft of capillaries, which is closely associated with the Bowman’s Capsule. The capsule wall is indented to form a double layered chamber. The outer wall is called the _____ LAYER and the inner portion is the _____ LAYER. It is the visceral layer that is closely associated with the walls of the glomerulus and is composed of _____ _____that actually wrap around the glomerular capillaries.
Glomerular Filtration: This occurs in the renal corpuscle, which is composed of the glomerulus plus the Bowman’s capsule. The glomerulus is a tuft of capillaries, which is closely associated with the Bowman’s Capsule. The capsule wall is indented to form a double layered chamber. The outer wall is called the PARIETAL LAYER and the inner portion is the VISCERAL LAYER. It is the visceral layer that is closely associated with the walls of the glomerulus and is composed of PODOCYTE CELLS that actually wrap around the glomerular capillaries.
Glomerular Filtration involves a _____ _____ (____). Also keep in mind that ___ is important.
Glomerular Filtration involves a pressure gradient (Hydrostatic). Also keep in mind that size is important.
The fluid produced in the capsular space during Glomerular Filtration is called
Filtrate
What’s in filtrate?
Glucose, sodium, potassium, urea, and water
Glomerular filtation:
Blood enters the glomerulus by way of an ______ ARTERIOLE. The blood pressure forces some water and dissolved solutes from the blood through the fenestrae of the capillaries and through the filtration slits of the Bowman’s capsule. This fluid holds wastes that need to be gotten rid of, plus solutes that are valuable and need to return to the body. This fluid is called _____ and is what urine will be derived from. Not everything is filtered by the glomerulus. Some material like _____ and ____ will remain in the blood vessels. This blood will then be taken away from the glomerulus by the ______ ARTERIOLE. The formation of filtrate depends upon the ______ ______, created inside of the glomerulus, being high enough to form filtrate. To help in this pressure formation, ….
Blood enters the glomerulus by way of an AFFERENT ARTERIOLE. (afferent = towards, arteriole = small blood vessel). The blood pressure forces some water and dissolved solutes from the blood through the fenestrae of the capillaries and through the filtration slits of the Bowman’s capsule. This fluid holds wastes that need to be gotten rid of, plus solutes that are valuable and need to return to the body. This fluid is called FILTRATE and is what urine will be derived from. Not everything is filtered by the glomerulus. Some material like red blood cells and proteins will remain in the blood vessels. This blood will then be taken away from the glomerulus by the EFFERENT ARTERIOLE (efferent = away from). The formation of filtrate depends upon the HYDROSTATIC PRESSURE, created inside of the glomerulus, being high enough to form filtrate. To help in this pressure formation, the efferent arteriole has a smaller lumen than the afferent arteriole.
Why don’t RBCs or WBCs become part of the filtrate?
They’re too big
The only membrane transport being used in Glomerular Filtration is
filtration
The amount of filtrate produced each minute is called the __________ _______ _____. This can be measured to see how well the kidneys are functioning.
The amount of filtrate produced each minute is called the GLOMERULAR FILTRATION RATE (or the GFR). This can be measured to see how well the kidneys are functioning.
Tubular reabsorption
Movement of solutes from the filtration back into the blood
Tubular reabsorption occurs throughout the tubular system, but the major site is the _______ _____ _____
Proximal convoluted tubule
4 transport methods used for tubular reabsorption
- Active transport
- Secondary active transport
- Facilitated diffusion
- Osmosis
Secondary active transport and Osmosis occurs on the
Apical surface
Facilitated diffusion and Osmosis occur on the
Basal surface
____ moves by facilitated diffusion on the basal surface
Glucose
The goal of tubular reabsorption
To get solutes that are nutrients back into the blood
Obligatory water reabsorption
The water that gets returned back into the blood
In tubular reabsorption, all glucose molecules will enter the PCT by _____ and leave the PCT by _____ _____ using a transporter.
Normally, all glucose molecules will enter the PCT by cotransport and leave the PCT by facilitated diffusion using a transporter.
There will be more reabsorption in the Loop Of Henle (additional 15%), with the final result being a
movement of more water from the nephron into the blood