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
How does the glucose in tubular reabsorption contribute to the symptoms observed in a diabetic patient?
Symptoms: PU (peeing a lot) PD (drinking a lot)
- Where solute (glucose) goes, water goes with it
Who receives the water during the Loop of Henle reabsorption?
Vasa Recta
Substances reabsorbed in the Loop of Henle are
still considered obligatory water reabsorption
Descending Loop of Henle (where do solutes and water go)
water comes out, which goes into the blood and gets reabsorbed
solutes go in, into the filtrate
Ascending Loop of Henle (where do solutes and water go)
water does not move- it’s impermeable
solutes from filtrate come out and go to medullary pyramid/tissue
Ascending Loop of Henle (where do solutes and water go)
water does not move- it’s impermeable
solutes from filtrate come out and go to the medullary pyramid/tissue
Amino acids and glucose molecules will be reabsorbed back into the blood by
facilitated diffusion
Ions like potassium (K) and Chloride (Cl) are reabsorbed by _____ ____ while sodium ions are _____ _____ _____
Ions like potassium (K) and Chloride (Cl) are reabsorbed by facilitated diffusion while sodium ions are obligatory water reabsorption
After glucose tubular reabsorption, absorption occurs in the _____ _____ _____ and _____ ____. This reabsorption is the only one to be under the control of _____, and is called _____ ___ ________
After glucose tubular reabsorption, absorption occurs in the Distal Convoluted Tubule and Collecting Duct. This reabsorption is the only one to be under the control of hormones, and is called Falculative water reabsorption.
Hormones involved with reabsorption from the Distal Convoluted Tubule and Collecting Duct:
antidiuretic hormone and aldosterone
A diuretic is something that will increase the amount of ____. Natural diuretics = _____ and ______; and are also known as _____
A diuretic is something that will increase the amount of urine. Natural diuretics = caffeine, alcohol; and are also known as anti-ADH
ADH is produced by the ______ and released by the..
ADH is produced by the hypothalamus and released by the posterior pituitary gland
The stimulus for release in both ADH and Aldosterone is
Hypotension
Result of ADH
increases the permeability of water
Diabetes insipidus
Hyposecretion of ADH
Massive amount of urination leading to dehydration/thirst
Some people with diabetes insipidus must use _____ ______ to help
exogenous ADH (comes in a nasal spray)
Pathway involved for Aldosterone
Renin -> Angiotensinogen -> Angiotensin 1 -> Angiotensin 2 -> Aldosterone
Aldosterone result
increases the permeability for sodium
Renin converts
angiotensinogen (inactive) into active form (Anginotensin 1)
ACE stands for
Angiotensin converting enzyme
ACE converts..
angiotensin 1 into angiotensin 2
4 primary effects of Angiotensin 2
Increased thirst
Vasoconstriction
Release of ADH
Release of Aldosterone
Other hormones are also important in regulating blood volume/urination. One in particular called ______ _____ _____ is secreted by cardiac muscle cells in the right atrium of the heart. These prevent sodium reabsorption in the kidney tubules and inhibit ADH secretion. The result is more sodium is excreted and along with it water resulting in a decrease in blood volume and an increase in urine volume.
Atrial Natriuretic Hormone/Polypeptide
Atrial Natriuretic Hormone/Polypeptide-
Atrial:
Na:
triutetic:
Atrial: made by heart
Na: sodium
triutetic: diuretic
______ _____: This is the third process that is involved with the formation of urine.
Secretion: The ______ of materials that are___ ______ by the body. The primary location for secretion is the ____ and _____.
Tubular Secretion: This is the third process that is involved with the formation of urine.
Secretion: The removal of materials that are not needed by the body. The primary location for secretion is the PCT and DCT. (proximal/convoluted tubule)
Tubular Secretion:
One of the most important substances that can be secreted into the filtrate is ___ because it affects the _____(___) of the blood. The higher the concentration of H+, the lower the pH.
One of the most important substances that can be secreted into the filtrate is H+ because it affects the acidity (pH) of the blood. The higher the concentration of H+, the lower the pH.
Tubular Secretion
1. Active Transport on basal surface
2. ________ instead of _____. This gets rid of the ___, putting it into the filtrate
- Countertransport instead of cotransport. This gets rid of the H+, putting it into the filtrate
Urine ____,____, and _____ all fluctuate to maintain ____ ____
Urine volume, pH, and concentration all fluctuate to maintain blood homeostasis
Contents of urine
95% (majority) water
2% urea
The urine has now been formed and it is ready to move from the collecting ducts through the papillae and into the pelvis of the kidney. From the pelvis, it continues down the ureters aided by _______ and _______
The urine has now been formed and it is ready to move from the collecting ducts through the papillae and into the pelvis of the kidney. From the pelvis, it continues down the ureters aided by PERISTALSIS and GRAVITY.
Urinary Bladder
Only stores urine
After the ureters, urine moves to the urinary bladder which functions to store urine until _______ (urination)
Micturition
Micturition
Occurs when walls are stretched and is defined as emptying of the bladder
Components of the urinary bladder
Trigone
Rugae
Sphincter at base
Loss of voluntary control of Micturition:
Incontinence
The awareness to urinate is stimulated by the fullness or distention of the bladder (sensation occurs when reach approximately 150ml), which will lead to the stimulation of ______ receptors in the bladder walls. These receptors send an impulse to the brain, and a person becomes aware of the need.
The awareness to urinate is stimulated by the fullness or distention of the bladder (sensation occurs when reach approximately 150ml), which will lead to the stimulation of STRETCH receptors in the bladder walls. These receptors send an impulse to the brain, and a person becomes aware of the need.
In the urethra, there are 2 sets of sphincters:
An internal urethral sphincter and external urethral sphincterr
Micturition can also be seen as a modified ____, meaning..
reflex, meaning it doesn’t need the brain to work
Can a person with a spinal cord injury still urinate?
Yes, but they wouldn’t have voluntary control over it. They still have the reflex though.
____s are more common in females due to a
UTIs are more common in females due to a shorter and wider urethra
_____ _____ are more problematic in men because their..
Kidney stones are more problematic in men because their urethra is narrower and longer
When the person has insufficient numbers of nephrons to maintain homeostasis they experience ____ ______
When a person is suffering from renal failure, it may be necessary to go on ____
When the person has insufficient numbers of nephrons to maintain homeostasis they experience RENAL FAILURE.
When a person is suffering from renal failure, it may be necessary to go on dialysis.
Urethra:
Parasympathetic (______)- A signal is sent to the spinal cord which comes back to the_____ _____ and ____ _____
Somatic (______)- Signal sent to spinal cord which comes back to the _____ _____
Parasympathetic (involuntary)- A signal is sent to the spinal cord which comes back to the bladder wall and internal sphincter.
Somatic (voluntary)- Signal sent to spinal cord which comes back to external sphincter
2 methods of dialysis
Hemodialysis and Continous Ambulatory Peritoneal Dialysis (CAPD)
- HEMODIALYSIS: This method directly filters the blood, using an _______ _____ ______. As blood flows through the selectively permeable tubing, waste products diffuse from the blood into the dialysis solution that surrounds the tube. This solution must ______replaced to maintain a solute gradient that allows for ______ (it must be hypotonic to the blood). After passing through the dialysis tubing, the cleansed blood flows back into the body.
- HEMODIALYSIS: This method directly filters the blood, using an ARTIFICIAL KIDNEY MACHINE. As blood flows through the selectively permeable tubing, waste products diffuse from the blood into the dialysis solution that surrounds the tube. This solution must continually replaced to maintain a solute gradient that allows for diffusion (it must be hypotonic to the blood). After passing through the dialysis tubing, the cleansed blood flows back into the body.
CONTINUOUS AMBULATORY PERITONEAL DIALYSIS (CAPD): _____ dialysis solution is inserted into the cavity through a tube (catheter) that has been surgically placed. This solution remains in the cavity until metabolic wastes from the blood vessels ____into the solution. The solution is then ___ from the cavity and _____
CONTINUOUS AMBULATORY PERITONEAL DIALYSIS (CAPD): Sterile dialysis solution is inserted into the cavity through a tube (catheter) that has been surgically placed. This solution remains in the cavity until metabolic wastes from the blood vessels diffuse into the solution. The solution is then drained from the cavity and discarded
RBC production is due to the production of a hormone called ______
Erythropoietin
Cystitis
Urinary Tract Infection
Calculus
Kidney stone
The renal calculi forms in the renal pelvis; is only problematic when it leaves. It can easily get stuck in the ureter.
Renal Failure
Transplant required
Nephrons are no longer able to maintain homeostasis
