Hormones Flashcards
ADH
Anti-Diuretic Hormone.
Produced in the Brain - controls water content of the body (osmoregulation) reabsorbed by the Kidneys.
Auxins
Plant hormones that control cell elongation.
Capillaries
Small, permeable blood vessels
- present in bodily organs that allow the diffusion of substances like O2 and glucose.
Cortex
The outer layer of the Kidney
- between the Renal Medulla and Renal Capsule.
Glycogen
Storage of carbs in the liver.
Can be broken down to glucose when sugar reserves are low.
Homeostasis
This is the body maintaining a constant internal environment in response to changes inside and outside
Needed for the proper functioning of Cells and Enzymes.
Insulin
Hormone produced in the Pancreas that decreases Blood Glucose levels.
Medulla
Inner part of the Kidney.
Nervous System
Body system
Includes; Brain, Spinal Cord and Nerves.
Oestrogen
Female Sex Hormone
- produced in the ovaries; responsible for Puberty in girls and the regulation of the Menstrual Cycle.
Osmoregulation
A homeostatic process that controls the amount of water in body fluids (e.g. blood).
Osmosis
6 marks
Diffusion of water molecules from a dilute (high) to a more concentrated (low) solution across a semi-permeable membrane - in & out of Cells
Area of high to low concentration- down a gradient.
Pancreas
Organ that monitors Blood Glucose concentrations and produces Insulin.
Phototropism
The response of a plant to light.
Renal Artery
Carries Blood to the Kidneys.
Respiration
Series of chemical reactions that happen in every living cell
- to release energy from Food Molecules.
Single Circulatory System
Found in Fish
Heart consists of 1 Atria + 1 Ventricle.
- Blood is pumped to the gills to become oxygenated.
Testosterone
Male Sex Hormone
- produced in the Testes; responsible for puberty in boys.
Hormones
Chemical messengers released by Glands into the Blood and carried to specific organ(s).
What acts slower than the Nervous System?
Hormones
Example; Sex hormones (testosterone and oestrogen) act over years.
What plays a role in Homeostasis?
Hormones
2 examples of Hormones in the Homeostatic role:
Explained
Insulin – controlling blood glucose concentrations.
ADH – controlling the water content of the body, referred to as osmoregulation.
2 examples of Hormones in the Homeostatic role:
Simplified
Insulin
ADH
Glucose is needed in blood to?
Supply cells with glucose for respiration.
Blood glucose concentrations too high =
Cells damaged due to a loss of water by osmosis.
The pancreas continually monitors what?
Level of glucose in blood.
How insulin works
Normal blood glucose concen. + meal high in carb is eaten.
Blood glucose (BG) concen. increases as glucose is absorbed from the ileum.
Pancreas makes insulin after detecting BG increase.
Insulin acts in the liver to reduce BG concen.
Normal BG concen. restored.
Insulin acts in the liver to reduce blood glucose concentration by:
Increasing glucose absorption from the blood by the liver and muscles;
* converting excess glucose to glycogen which is stored mainly in liver but also muscle; * increasing respiration in the liver.
When blood glucose concentrations are low
Less insulin is produced + processes do not take place or slow down.
Low blood glucose levels helps raise
Concentration of glucose in the blood.
Normal BG concent. -> Eat high carb meal =
BG increases as Glucose is absorbed from Ileum
- > Pancreas makes Insulin after detecting increase
- > Insulin (in Liver) reduces BG concent.
- > Normal BG concent. restored
Negative Feedback
Mechanism to ensure the concentration of a substance does not deviate too far from normal.
Usually involves a hormone and continual monitoring of the substance being controlled.
Why is - the mechanism to ensure the concentration of a substance does not deviate too far from normal - known as Negative Feedback
Because an increase in hormone decreases the substance being controlled.
Example of Negative Feedback in Human Organs
Pancreas adjusting amount of insulin it makes depending on the BG concentration.
Example of Negative Feedback in Hormones
Increase in insulin decreases blood glucose concentration.
Increase in insulin =
Decrease in BG concentration.
Pancreas adjusting the amount of insulin it makes depending on the BG concentration.
Example of Negative Feedback
Diabetes
Underproduction of insulin needed to control BG concentration.
Symptoms of Diabetes
- Glucose in the urine
- High blood glucose levels
- Being thirsty
- Overactive bladder/need to pee a lot
- Lethargy
Why Diabetics find Glucose in the urine
BG concentration is so high that some is filtered out by the kidneys and passed into the urine.
Lethargy
Feeling tired/having low energy
When does Type 1 Diabetes typically develop?
Childhood
When does Type 2 diabetes typically develop?
Geriatric/senior years
Progressive Form of Diabetes
Type 2
What is Type 2 Diabetes linked to?
- Poor Diet
- Lack of Exercise
- Obesity
Effects of Type 1 Diabetes on the Body
Pancreas stops producing insulin.
Effects of Type 2 Diabetes on the Body
Pancreas gradually produces less insulin
- Insulin is less effective.
Type 1 Diabetes Treatment
- Control Carb intake
- Injection of insulin
Type 2 Diabetes Treatment
- Control Carb intake
- Increase exercise in order to lose weight
- Tablets
- Injection of insulin
Future of Type 2 Diabetes
- Increase in No. Of sufferers due to an increase in obesity
- Becoming more common in young people
Why are more people being diagnosed with Type 2 Diabetes?
Increase in Obesity
More people in this age group are being diagnosed with Diabetes
Young people
Hypoglycaemia Causes
- Too much insulin is injected
- Not enough food is eaten regularly
What can happen when too much insulin is injected or not enough food is eaten regularly?
BG concentration can drop too low
Hypoglycaemic attack may occur
Dangerous Effects of Hypoglycaemic attack
- Unconsciousness/coma
- Death
Serious long-term effects can arise if
BG concentrations remain too high over a long period
- if diabetic for a long time or diabetes has been undiagnosed or uncontrolled.
Long term effects of Hyperglycaemia
- Eye damage/blindness
- Heart disease
- Stroke
- Kidney damage
Causes of Complications due to High BG Concentrations
Damage to the capillaries that supply to that part of the body.
Poor control of water in the body (osmoregulation) can lead to…?
Osmotic damage of body cells.
How is water gained through drinking lost?
Evaporation in Lungs.
How is water gained from eating lost?
Evaporation of sweat.
How is water gained from respiration lost?
Production of urine/faeces.
In normal conditions; the amount of water gained balances with…?
…the amount lost.
Osmoregulation balances…?
Amount of water found in the body; bodily fluids and cells.
During exercise water is lost via?
Sweat.
Drinking more water increases the amount of…?
Water in the body.
During hot weather or exercise/too little water in body
- Osmoregulation Functions:
Kidney releases a small volume of concentrated water
- makes us thirsty so we increase water intake.
Too much water in the body;
Osmoregulation Function:
Kidney produces a large volume of dilute urine.
More water retained =
Water levels increase.
More water is lost =
Water levels decrease.
ADH
Anti-diuretic Hormone
Reabsorption of water back into the blood (at medulla) is controlled by…?
ADH
ADH is produced by
Part of the brain that monitors water levels in the Blood
- from where it is carried to the Kidneys (target organ)
Urine
Waste product secreted by Kidneys.
Kidney Functions:
- Remove waste from the body
- Osmoregulation
How the Kidney works:
- Blood enters Kidney via the Renal Artery.
- Liquid and many dissolved substances are filtered out in the Cortex.
- In Medulla; Water and some of the substances are reabsorbed back into the Blood in a controlled way until normal concentrations are reached.
- Any water and dissolved substances left over pass into the urine, which collects in the renal pelvis.
When brain detects lower than normal water levels in the blood;
ADH is produced.
Urine passes out from the Bladder to…?
The Urethra
ADH Function
Produced after Brain detects lower than normal water levels in blood
- then carried to the Kidneys
- controls reabsorption of water back into the Blood at Medulla
Urine passes urine from the Kidney into
The Ureter
Urine is stored
In the Bladder.
Urine passes from the Ureter into
The Bladder
Kidneys
2 bean-shaped organs that filter waste from the blood and produce urine.
Ureters
2 thin tubes that take pee from the kidney to the bladder.
Bladder
Organ (a sac) that collects urine as it is produced by the kidneys
- released when a mammal urinates.
Urethra
Tube that carries urine from the bladder out of the body when you pee.
Urinary Tract Order
- Kidneys
- Ureters
- Bladder
- Urethra
Urinary Tract (Order); Explained
Kidneys: 2 bean-shaped organs that filter waste from the blood and produce urine
Ureters: 2 thin tubes that take pee from the kidney to the Bladder
Bladder: sac that holds pee until it’s time to go to the bathroom
Urethra: tube that carries urine from the Bladder out of the body when you pee
In the medulla -
Simplified:
- ADH causes more water to be reabsorbed from Urine back into Blood.
- When Brain detects higher than normal water levels in blood = less or no ADH is produced.
- Less water is reabsorbed back into Blood.
- Produces larger volume of Dilute Urine and returns Blood Water levels to normal.
ADH causes more water to be reabsorbed from the Urine back into the Blood.
This Produces:
Lower volume of more Concentrated Urine and returns blood water levels to normal.
When brain detects higher than normal water levels in blood (e.g. from drinking more than normal):
Less or no ADH is produced.
Once less or no ADH is produced.
Less water is reabsorbed back into the Blood.
Less ADH produced, less water is absorbed into the Blood.
As a result:
The body produces a larger volume of Dilute Urine and returns blood water levels to normal.
More ADH, more water reabsorbed into the Blood.
As a result:
Lower volume of more Concentrated Urine and returns blood water levels to normal.
Balancing low Blood Water levels, high levels of concentrated urine -
More ADH produced and Osmoregulation occurs;
Less concentrated urine released from body.
More water absorbed into Blood.
Balancing high Blood Water levels, low levels of concentrated urine:
Less/no ADH produced and Osmoregulation occurs;
More concentrated urine released from body.
Less water absorbed into Blood.
Plants respond to stimuli slowly:
- Roots grow towards water.
- Shoots grow away from gravity.
- Shoots grow towards light (phototropism).
How Phototropism works:
- Plant responds to unidirectional light
- Plant shoot bends towards light.
Example of Unidirectional Light
Plant on windowsill.
Advantages of Phototropism
More light
More photosynthesis
More growth
How does a shoot bend towards unidirectional light?
Shoot tip is sensitive to light and produces auxin – if the tip is covered phototropism doesn’t occur.
Light causes the uneven distribution of auxin – it moves downwards and accumulates on the shaded side.
Auxin causes cells on shaded side to elongate faster than on the illuminated side – this is known as differential growth.
Stem bends towards light.
If the Shoot tip is covered
Phototropism doesn’t occur.
Where is Auxin produced?
Shoot tip
What causes the uneven distribution of auxin?
Light
Where does more auxin accumulate?
Shaded side of plant.
Cells on the shaded side of the plant grow to…?
Be more elongated.
Cells on the non-shaded side of the plant grow to…?
A normal length.
How does auxin move
Downwards and accumulates on the shaded side.
Differential growth
Auxin causes cells on shaded side to elongate faster than on the illuminated side.
Stem bends towards…?
The light.
