Excretory System

Question 1

What is the excretory system?

Answer 1

the excretory system is used to regulate the volume and the composition of body fluids by removing waste and returning useable substances to the body

Question 2

Why is it important for waste to be removed?
- examples of waste
- how is waste removed

Answer 2

Waste should be removed as it can be a threat to our health. though some can be reuseable others can pose a greater threat to our body as they can raise our body pH.
Examples of waste would be carbon dioxide, ions like sodium (Na+), chloride (Cl-), and hydrogen (H+).
to get rid of these, our body excretes them.
Excretion is the process by which waste is separated from the body fluids and eliminated.

Question 3

Organs in the Excretory system

Answer 3

1. kidneys
2. renal artery - aorta
3. renal vein - inferior vena cava
4. ureters
5. urinary bladder
6. urethra

Question 4

Function of the organs
1. kidneys
2. renal artery - aorta
3. renal vein - inferior vena cava
4. ureters
5. urinary bladder
6. urethra

Answer 4

kidneys: produce urine
renal artery: provide kidneys with blood
renal vein: filtered blood from kidney
ureters: transports urine
urinary bladder: stores urine until it needs to be excreted
urethra: excretes urine

Question 5

Parts of the kidney

Answer 5

1. renal medulla
2. renal cortex
3. filtering areas (nephrons)
4. renal pelvis where everything is connected1

Question 6

How does the kidney filter?
- what does it consist of

Answer 6

the kidney’s filtering site is called the nephron which consists of the glomerulus, the Bowmans capsule, the proximal as well as distal tubule, the loop of Henle, capillaries the cortex, and medulla side of the collecting duct and the collecting duct itself

Question 7

What are the functions of the filtration system in the kidney?
- glomerulus
- bowmans capsule
- proximal and distal tubule
- loop of Henle
- collecting duct

Answer 7

Glomerulus:
the walls of the glomerulus act as the filtration. they are impermeable ( don’t allow) to proteins or other large molecules and red blood cells so these stay with the blood. *However water, small molecules like amino acids and ions such as sodium and chloride as well as waste can pass through and further into the nephron.

Bowman’s Capsule:
the capsule wraps around the glomerulus and will then branch into the tubules

the tubule is divided into three sections:
Proximal Tubule
absorbs useful solutes back into the blood vessels (capillaries)
Loop of Henle:
The loop reabsorbs water by osmosis
Distal Tubule
The distal tubule actively transports waste and hydrogen (H+) out to be excreted.
Reabsorption of Chloride and bicarbonate
Collecting Duct
the tubule empties into a larger pipe-like channel this is called the collect duct.
the collecting duct. the collecting duct is used as a water-conserving device reclaiming water so that very little water is lost from the body.

Question 8

Process and Location
- FRSR

Answer 8

Filtration happens from the glomerulus to the Bowman’s capsule. The filtration happens because of a pressure gradient or blood pressure as the blood pressure in the glomerulus is about 4 times greater, this is what causes the filtration. Small molecules such as sodium, amino acids, glucose, chloride, and waste can pass through the glomerulus but bigger solutes such as red blood cells will be left in the blood.

Question 9

Process and Location
- FRSR
» loop of Henle:
descending
ascending

Answer 9

Reabsorption happens in the proximal tubule. In this process, we are trying to reabsorb nutrients and then they are returned to the body. These substances/solutes are moved by active transport as they are moving from an area of even concentration to an area of uneven. Negatively charged ions such as Chloride will move passively and water is moved in by osmosis and into the capillaries.

In the loop of Henle, we reabsorb water. The loop of Henle passes through the medulla region and then loops to go back to the cortex area. The medulla region is a salty environment therefore its HYPERTONIC.
The descending part of the tubule is permeable to water so it lets water into the capillaries as water moves by osmosis due to high to low concentration.. It’s also semi-permeable to certain ions which it’ll let into the tubule. When water moves the concentration of sodium rises.

The ascending part of the loop, the thin part of the tubule is now impermeable to water and slightly permeable to solutes. sodium will now pass into the blood vessels nearby by diffusion. In the thick segment, sodium ions are moved out of the filtrated fluid by active transport. The transport of sodium helps with two things
1. it helps the hypertonic environment of the medulla by restoring it and letting water be absorbed from the filtered liquid in the descending limb.
2. the absorbed sodium also makes the filtrate less concentrated than the tissues and blood surrounding the cortex tissue.
The reabsorption of solutes help decrease the concentration of the filtrate

However, the active reabsorption of sodium ions depends on the needs of the body.
Passive reabsorption of negative ions such as chloride happens to due electrical attraction.

Question 10

Process and Location
- FRSR
- secreted meaning

Answer 10

secreted means to remove
Secretion of waste happens in the distal tubule. Potassium ions (K+), Hydrogen ions (H+) which make our blood pH acidic and other substances like waste penicillin and other drugs are actively secreted/ just secreted into the distal tubule.

Question 11

Process and Location
- FRSR
- dehydrated and hydrated

Answer 11

Reabsorption of water happens in the collecting duct.
The collecting duct extends deep into the medulla which increases the concentration of ions along its length. because of this, the passive reabsorption of water from the filtrate into the collecting duct is done by osmosis. However, reabsorption can be affected by how hydrated or dehydrated a person is.
HDRATED** If a person is hydrated the permeability to water will be decreased so that not much water will be reabsorbed.
**DEHYDRATED* if a person is hydrated then permeability to water will be increased so that water is reabsorbed.

The reabsorbed water causes the filtrate to become four times concentrated by the time its out of the duct and is now urine.

Question 12

What affects the amount of water reabsorbed from filtrate?

Answer 12

1. its volume
2. concentration of blood plasma

Question 13

Osmotic Pressure
- what does osmotic pressure affect

Answer 13

the force generated as water is moved by the process of osmosis.
the greater the concentration gradient, the greater the osmotic pressure will be. the weaker the concentration gradient the weaker the osmotic pressure will be.

Osmotic pressure affects many cellular activities especially the exchange of materials between cells and blood.

Question 14

Antidiuretic Hormone
what is involved?

Answer 14

Diuretic means to increase urine excretion, anti means against so together antidiuretic is to stop the increased amount of urine being excreted.

Examples of diuretics would be alcohol and coffee.
1. Osmoreceptors
2. Hypothatemus
3. pituitary gland

Question 15

What does each do?
1. Osmoreceptors
2. Hypothalamus
3. pituitary gland

Answer 15

Osmoreceptors
sensitive to osmotic pressure

Hypothatemus
part of the brain that regulates hunger, thirst, blood pressure, body temperature, fluid balance, and salt balance. in other words, regulates mechanisms to enable the body to maintain homeostasis.

Pituitary Gland
is to produce and release several hormones that help carry out important bodily functions such as the release of ADH.

Question 16

How do all of these work together?
ADH

Answer 16

Osmoreceptors located in the hypothalamus are cells sensitive to osmotic pressure. When you’re dehydrated, your blood plasma becomes concentrated meaning it becomes stronger(?) so the osmotic pressure increases. the osmoreceptors will sense this and in response, the hypothalamus sends signals to the pituitary gland located in the brain as well and releases ADH.

– ADH will then travel through the blood to the kidneys where it will increase the permeability of the distal tubule and collecting duct that’ll stimulate the reabsorption of water in the blood. This dilutes blood, lowering osmotic pressure. When it becomes too dilute, osmoreceptors will stop the release of ADH so that the distal tubule and collecting duct will become less permeable to water.
- ADH travels everywhere but only some tissues will respond to it

Question 17

Diabetes Insipidus
Diabetes Mellitus

Answer 17

Insipidus is when our urine is really dilute. this means that ADH activity is either insufficient or the collecting duct and tubule aren’t responding. The person who has diabetes insipidus would pee a lot and would be very thirsty

Mellitus is when glucose is present in pee. this would be due to the fact reabsorption in the proximal tubule isn’t functioning well or there’s too much glucose to keep up with.

Question 18

Reabsorption of Salt
- aldosterone

Answer 18

• kidneys regulate salt balance in the body by controlling what it absorbs or lets out. Sodium is the most plentiful but it could also rise and fall dramatically.

Aldosterone stimulates the reabsorption of Na+ and the secretion of potassium by actively moving potassium if blood concentration is too high

when Na+ decreases, the body will release aldosterone from the adrenal gland in an attempt to increase body salts. In the collecting duct and distal tubule aldosterone will increase the reabsorption of Na+ and this will be done through active transport.
- Because of ion charges, chloride will follow Na+ because of charge attraction
- increased salt absorption making kidney tissues hypertonic
- to balance its water will be reabsorbed by osmosis so that we won’t become too salty

Question 19

Blood pH

Answer 19

the normal pH of our body would 7.4
By adding or removing hydrogen (H+) which will prevent changes in pH.

if the blood pH is too acidic it will then reabsorb the bicarbonate ions so it will go back to the blood and maintain the blood

If its too basic, it’ll stop supply of bicarbonate

Question 20

Renal Insufficiency
- what could these be

Answer 20

When kidneys don’t work as they should
- kidney infection
- high blood pressure
- diabetes mellitus
- trauma from a blow to the lower back or constant vibration from machinery
- poisoning
- atherosclerosis reduces blood flow to kidneys
- blockage

Question 21

Urinary Tract Infection
- cystitis
- urethritis

Answer 21

Cystitis is when the bladder has bacterial or viral infection

Urethritis only happens in the urethra

Question 22

Symptoms of Urinary Tract Infection and Treatments

Answer 22

Symptoms could be that u need to urinate much more even if there is no urine coming out, brown or bloody pee, lower , and upper body may feel tender, fever, nausea, and vomiting.
could possibly lead to urine infection

Treatments could be antibiotics or surgery if it becomes really serious

Question 23

Kidney stones

Answer 23

kidney stones are when there are a lot of excessive amounts of calcium in our nephron located in the loop of Henle. Calcium will crystalize as in the loop of Henle, there are parts where it is very hypertonic so there isn’t much water. (water is removed)

1-2 mm can be passed in our system
up to 2 cm can be broken down using ultrasound soundwaves
but if it over 2 cm we will need to be surgically removed the kidney stones or if it gets bad enough the whole kidney.
however, kidney surgery isnt preferred because our own body can attack the transplant if we get or cut off circulation to that transplanted organ.

Question 24

Dialysis
- types of dialysis

Answer 24

• stimulates FRSR by using diffusion principles.
• dialysis is the diffusion of dissolved substances through a semipermeable membrane, moving from an area of high to low concentration.
• substances that are more concentrated in blood will be diffused into the dialysis solution called the dialysate.
• substances that are more concentrated than the dialysis fluid will be diffused back into the blood.
• other substances can be added into the dialysate to balance other stuff like our pH levels.

types of dialysis
1. hemodialysis
2. peritoneal dialysis

Question 25

Hemodialysis

Answer 25

• blood is filtered by a machine
• utilization of an artificial membrane

Question 26

Peritoneal

Answer 26

• uses body tissues called peritoneum, a lining in the intestines.
  –used as the membrane

Question 27

How it works
- Hemodialysis is more of a needed treatment and is done by the hospital

Answer 27

blood is pumped from an artery to the dialysis machine and returned through the vein and back into our bodies.
— the artery and vein are surgically joined and is now called a fistula

In the dialyzer, waste is filtered from the blood through the artificial membrane and into the dialysate into the dirty dialysis fluid. purified blood will then move back

Question 28

How it works
- peritoneal made for mild situations

Answer 28

it’s the same process as hemodialysis except, a catheter which is a flexible tube is surgically inserted into the abdominal cavity so that the dialysis fluid can be moved. fluid will be drained into the peritoneal cavity and then afterward when the purification of the blood is done fluid and waste are drained from the cavity

Question 29

How to prevent the good stuff from moving out

Answer 29

to prevent that, in the membrane, the other side will have almost the same amount of solutes as the other side so that equilibrium is reached.
to lose the unnecessary stuff, such as waste the other side of the artificial membrane will have little to none so that waste goes from an area of high to low concentration

Question 30

Kidney-Coronary Connection

Answer 30

• * High blood pressure is another reason why our kidneys fail* if blood pressure is high, our heart needs to pump greater volumes for a prolonged amount of time which can damage blood vessels.
• the blood vessels in our kidneys is sensitive to changes in blood pressure which can damage them
• the amount of waste and fluid filtered from blood will be reduced then the extra fluid will increase and so will the blood volume much more. this will cause the blood pressure to rise even more and this will continue reducing the function of the kidneys and it wont be as noticeable until the damage is one