Topic 7 - Animal Coordination, Control and Homeostasis Flashcards
What are hormones?
Chemicals released directly into the blood which send messages
What carry hormones?
The blood
What is a target organ/s?
The specific organ/s that a hormone has an affect on
Where are hormones produced and secreted from?
Glands
Name endocrine glands
The Pituitary Gland Ovaries (female only) Thyroid Gland The Pancreas Testes (male only) Adrenal Glands
Give the name of the female only endocrine gland
The ovaries
Give the name of the male only endocrine gland
The testes
What is the hypothalamus in charge of?
Regulating body conditions
What is the pituitary gland often called?
The ‘master gland’
Why is the pituitary gland considered the master gland?
Because it releases hormones which direct glands to release other hormones
Where is the pituitary gland located?
In the head (brain)
What is the thyroid gland in charge of?
The rate of metabolism
Heart rate
Temperature
What main hormone does the thryoid gland produce?
Thyroxine
Where is the thyroid gland located?
The neck
What cycle are the ovaries involved in?
The menstrual cycle
What main hormne do the ovaries produce?
Oestrogen
Where are the ovaries located?
The pelvis area (between the hips and stomach)
What main hormone do the adrenal glands produce?
Adrenaline
What is adrenaline associated with?
Fight or flight
Where are the adrenal glands located?
Above the kidneys
What main hormone is produced in the testes?
Testosterone
What does testerone do?
Control puberty and sperm production
Where are the testes located?
The scrotum (below the penis)
What is the pancreas’ job?
To regulate the blood glucose level
What hormones ass produced in the pancreas?
Insulin/Glucagon
What is insulin used for?
Blood glucose level regulation
Where is the pancreas located?
Near the adrenal glands (kidneys)
True or False? Hormones and Neurones have differences?
True
True or False? Hormones and Neurones have differences?
True
Give some differences between neurones and hormones?
Neurones are very fast where as hormones are much slower
Neurones act for a short time where as hormones act for a longer time
Neurones act on a precise area where as hormones act on a much broader area
If a response to a stimulus was really quick, what is the response most likely to be?
Nervous
If a response to a stimulus lasted for a long time, what is the response most likely to be?
Hormonal
Name the endocrine glands that only males have?
Testes
What does adrenaline prepare you for?
Fight or flight
What releases adrenaline?
The adrenal glands
How does adrenaline work?
By activatingprocesses that increase the supply of oxygen and glucose to cells
Give ways in how adrenaline works?
By binding to specific receptors in the heart to increae heart contraction with more frequency and force which increases blood flow to the muscles
By binding to receptors in the liver which causes the glycogen to be broken down into glucose which increases the blood glucose level
How does your body control hormone release?
Negative Feedback
How does negative feedback work with hormone release?
When too much of a hormone is released it triggers a response to release less
What does thyroxine regulate?
Metabolism
Where is thyroxine released from?
The thyroid gland
What is the metabolic rate?
The speed at which chemical reactions in the body occur
Describe the negative feedback system used for regulation of thyroxine
When thyroxine level is lower than normal the hypothalamus releases TRH (thyrotropin releasing hormone) which stimulates the pituitary gland to release TRH (thyroid stimulating hormone) which stimulates the thyroid gland to release thyroxine.
However, when thyroxine level is higher than normal, the release of TRH is inhibited which reduces TSH and so the thryoxine level falls
Name the gland which releases thyroxine?
The thyroid gland
Describe how the release of TRH from the hypohalamus affects the blood thyroxine level
TRH stimulates the pituitary gland to release TSH which stimulates the thyroid gland to release thyroxine, so the blood thyroxine level rises
How many stages does the menstrual cycle have?
Four
What is the menstrual cycle?
The monthly sequence of events in which the female body releases and egg and prepares the uterus in case the egg is fertilised
What happens in stage 1 of the menstrual cycle?
The lining of the uterus breaks down and is released
What happens in stage 2 of the menstrual cycle?
The uterus lining is repaired from day 4 to 14 until it becomes thick and spongey ready for a fertilised egg to implant there
What happens in stage 3 of the menstrual cycle?
An egg develops and is released from the ovary (ovulation)
What happens in stage 4 of the menstrual cycle?
The linin is then maintained for about 14 days until day 28 in which if no egg has landed, the lining starts to break down and the whole cycle starts over
The menstrual cycle is controlled by ____ hormones
The menstrual cycle is controlled by four hormones
What releases the FSH?
The pituitary gland
What does FSH do?
Causes a follicle to mature in one of the ovaries and stimulates oestrogen production
What is a follicle?
An egg and it’s surrounding cells
What releases the oestrogen?
The ovaries
What does oestrogen do?
Causes the lining of the uterus to thicken and grow with a high enough level causing an LH surge
What releases LH?
The pituitary gland
What does LH do?
Stimulates ovulation and ruptures the follicle to release the egg with the remains of the follicle to form into a corpus luteum
What releases progesterone>
Corpus luteum
What does progesterone do?
Maintains the lining of the uterus, inhibits the release of FSH and LH
When the level of progesterone falls, and there’s a low oesterogen level, the uterus lining __________
When the level of progesterone falls, and there’s a low oesterogen level, the uterus lining breaks down
If a woman becomes pregnant what will happen to the level of progesterone?
It will stay high to maintain the lining of the uterus
Explain the role of LH in the menstrual cycle
LH stimulates the release of an egg. It also stimulates the remains of the follicle to develop into a corpus luteum which secretes progesterone
What does someone being infertile mean?
That they can’t reproduce naturally
Name two methods of treating infertility?
Clomifene therapy
IVF
How does clomifene work?
By causing more FSH and LH to be released which stimulates egg maturation and ovulation
How does IVF work?
Many eggs are taken from a woman and are fertilised in a lab with a man’s sperm
These are grown which are then put back into the mothers uterus
What do some contraceptives often involve?
Hormones
What do some contraceptives often involve?
Hormones
Why does daily intake of oestrogen inhibit egg release?
Constant high levels of oestrogen inhibits the production of FSH which stops egg release
How does progesterone reduce fertility?
By stimulating the production of thick cervical mucus which prevents any sperm getting through the entrance to the uterus and reaching an egg
What are the pros of hormonal contraceptive methods?
More effective than barrier methods
No need to stop and think about each time they have intercourse
What are the cons of hormonal contraceptive methods?
Unpleasant side-effects (headaches, acne and mood changes)
Don’t protect against sexually transmitted infections
How are hormones used in IVF?
FSH and LH are given before egg collection to stimulate egg production
What is homeostasis?
Maintaining a constant internal environment
Why do conditions in your body need to be kepy steady?
Because your cells need the right conditions in order to function properly for things like ezymes
It can also be dangerous for your health if conditions vary too much
To maintain a constant internal environment, your body needs to respond to both _____ and ______
To maintain a constant internal environment, your body needs to respond to both internal and external
Examples of homeostasis in action include
Osmosregulation
Thermoregulation
Blood glucose regulation
What is osmoregulation?
Regulating water content
What is thermoregulation?
Regulating body temperature
How are negative feedback systems used to keep conditions steady?
If a condition changes away from a normal level, a response is triggered that counteracts the change
_______ and _______ control blood glucose concentration
Insulin and Glucagon control blood glucose concentration
What type of food puts glucose into the blood?
Carbohydrates
What removes the glucose from the blood?
The metabolism of cells
What happens to excess glucose?
Is stored as glycogen in the liver and in the muscles
What happens to excess glucose when the stores are full?
The glucose is stored as lipid (fat)
What monitores and controls blood glucose levels?
Pancreas
When is insulin added?
When blood glucose concentration is too high
What is added when blood glucose concentration is too high?
Insulin
When is glucagon added?
When blood glucose concentration is too low
Describe the story of insulin being added to the bloodstream
Blood has too much glucose
Insulin added to blood by pancreas
Insulin caused glucose to turn into glycogen which reduces blood glucose
Describe the story of glucagon being added to the bloodstream
Blood has too little glucose
Glucagon added to blood by pancreas
Glucagon causes glycogen to turn into glucose which increase blood glucose
What organ releases/takes in glucose?
The liver
What does insullin do?
Removes glucose from the blood
Explain how blood glucose concentration is returned to normal when it has become too high?
Insulin is secreted by the pancreas into the bloodstream. The insulin causes glucose to move into the liver and muscle cells, so the concentration in the blood returns to normal
What causes type 1 diabetes?
A lack of insulin
Type 1 diabetes is a condition where the _______ produces _________
Type 1 diabetes is a condition where the pancreas produces little or no insulin
What does a lack of insulin cause?
A rise in blood glucose
What does insulin therapy often involve?
Injecting insulin into the subcutaneous tissue
What do people with type 1 diabetes need to think about?
Limiting the intake of foods rich in simple carbohydrates
Taking regular excercise
What causes type 2 diabetes?y
A person being resistant to insulin
Type 2 diabetes is a condition where the _______ doesn’t produce enough _______
Type 2 diabetes is a condition where the pancreas doesn’t produce enough insulin
How can a person be resistant to insulin?
Because the body cells dont respond properly to the hormone
What is the bmi formula?
BMI = Mass / Height²
What does waist-to-hip ratio give an indication of?
How fat is stored
Why is where the body stores fat important?
Because storing a lot of fat around the abdomen is associated with an increased risk of developing type 2 diabetes
What is the waist-to-hip ratio formula?
W:H ratio = Waist circumference / Hip circumference
How can type 2 diabetes be controlled?
By eating a healthy diet
By regularly excercising
By losing weight
By taking medication
Describe the cause of type 1 diabetes
Pancreas producing little or no insulin
Give two measures of obesity that can help assess a person’s risk of developing type 2 diabetes
BMI
Waist-to-hip ratio
What controls body temperature?
The hypothalamus
What infomation does the hypothalamus recieve?
Temperature of skin from receptors
Temperature of the brain
What happens to the skin when you’re too hot?
Erector muscles relax so hairs lie flat
Sweat is produced and released
Blood vessels close to the surface of the skin dilate (widen) to lose energy to the surroundings
What happens when you’re too cold?
Erector muscles contract so hairs stand up which insulates the skin
No sweat is produced
Blood vessels close to the surface of the skin constrict which means less blood flow near the surface so less energy is lost to the surroundings
The muscles automatically contract which increases your rate of respiration which transfers more energy
What does vasodilation do?
Allows more blood to flow near the surface so it can transer more energy into the surroundings which cools you down
What does vasoconstriction do?
Allows less blod to flow near the surface so less energy is transferred to the surroundings
What happens to the body when heat changes in the body?
Hair on the skin movement
Sweat production changes
Blood vessels move and change width
What is the main optimum temperature for enzymes in the human body?
37*C
Explain how blood flow through the skin is affected when a person is too cold
Less blood flow near the surface of the skin because vasoconstriction occurs in the blood vessels near the surface
Why is regulating water concent important?
To keep cells functioning normally
What will happen if the blood has too much water?d
Water will move via osmosis into the cell eventually causing into to burst
What will happen if the blood has too little water?
Water will move via osmosis from cells into the blood causing the cells to shrink
How do kidneys help?
By controlling how much water is reabsorbed and how much is lost in urine
What are the main roles of kidneys?
Removal of urea from the blood
Adjustment of ion levels
Adjustment of water content
Where is urea produced?
The liver
What is urea?
The breakdown of excess amino acids
How does the kidney actually work?
By filtering stuff out of the blood under high pressure and then reabsorbing the useful things
Nephrons are the _______ of the kidney
Nephrons are the filters of the kidney
Where is the liquid part of the blood forced out?
The glomerulus
Where is the liquid part of the blood forced into?
The bowman’s capsule
What is ultrafiltration?
Liquid part of the blood being forced out of the glomerulus and into the bowman’s capsule at high pressure
What doesn’t the kidney take in?
Bigger molecules and blood cells as they can’t pass through the membranes
What happens as the liquid flows along the nephron?
Useful substances are reabsorbed
What are the useful substances that would be reabsorbed by the blood?
The glucose
Sufficient ions
Sufficient water (according to the level of ADH)
What happens to the substances that aren’t reabsorbed?
It continues out of the nephron via the collecting duct which then passes into the ureter and down to the bladder as urine
For animals living in drought conditions, what will be the size of loops of henle compared to animals in sufficient water conditions?
The loops will be longer in order to reabsorb more water
State the function of the glomerulus and the Bowman’s capsule in a nephron
They filter the blood
Water Content is controlled by a ________ Feedback System
Water Content is controlled by a Negative Feedback System
What hormone controls the amount of water reabsorbed in the kidney nephrons?
Anti-diuretic hormone (ADH)
What does anti-diuretic hormone control?
The amount of water reabsorbed in the kidney nephrons by making the collecting ducts of the nephrons more permeable
What does the brain do when the water content gets too high/low?
The brain will monitor the content and instruct the pituitary gland to release ADH into the blood according to how much is needed. ADH makes the collecting ducts of the nephrons more permeable so that more water is reabsorbed back into the blood
What does ADH stop?
The body from becoming dehydrated
What gland releases ADH?
The pituitary gland
What filters the blood mechanically?
Dialysis
Who is the dialysis filter used for?
People with kidney failure
Why is dialysis filters used?
To keep dissolved substances at the right concentrations and to remove waste
Why aren’t minerals in the blood moved from the blood through the filter of the dialysis machine?
Because the concentration of salts and glucose in the dialysis fluid is the same as blood plasma
What things go through the filter in the dialysis machine?
Ions and waste substances (eg. urea)
What things don’t go through the dialysis filter?
Big molecules (eg. proteins) Cells
What is the only cure for kidney disease?
A kidney transplant
What is a kidney transplant?
Healthy kidneys are swapped with unhealthy kidneys which are inside the patient
What is the problem with kidney transplants?
Requires a willing donor
Potential of rejection
What does rejection from a kidney transplant mean?
When a donor kidney is rejected by the patients immune system
Why does rejection occur?
Because the immune system treats it like a foreign body and attacks it with antibodies
What is required for a kidney transplant?
For the donor kidney to have the same tissue type
For the patient to be treated with drugs that suppress the immune system
What is the purpose of the selectively permeable membrane in a dialysis machine?
It allows ions and waste substances to diffuse out of the blood into the dialysis fluid but not large molecules like proteins
How do hormones travel to target organs?
In the blood
What is an endocrine gland?
Glands in which hormones are produced and secreted
Name the gland where oestrogen is produced?
Ovaries
Name the gland where testosterone is produced?
Testes
Name the gland where insulin is produced?
The pancreas`
Name the gland where adrenaline is produced?
The Adrenal glands
Explain how adrenaline prepares the body for flight or fight?
By binding to receptors in the heart which causes the heart to contract more and harder which increases blood flow to the muscles
Also by binding to receptors in the liver which causes the liver to break down its glycogen stores to release glucose
Describe how a negative feedback loop works within the body?
By decreasing the number of hormones as soon as it exceeds a certain level
Which hormones, released by the thyroid gland, controls metabolism?
Thyroxine
Describe two effects of FSH on the female body
Stimulates oestrogen production and causes a follicle to mature
Describe two effects of oestrogen on the female body
Causes the lining of the uterus to thicken and grow
A high level will cause a surge of LH
Which hormone is secreted by a corpus luteum?
Progesterone
What is clomifene therapy?
Who might use it?
The giving of FSH and LH to a woman to stimulate egg maturation and ovulation
Women who are infertile
Briefly describe how IVF is carried out?
Eggs are taken out of a woman and are then fertilised with sperm cells which is then put inside the mother
Explain how progesterone can be used in contraception to prevent pregnancy?
By stimulating the production of thick cervical mucus which prevents any sperm getting through the entrance to the uterus
Write down two pros and two cons of hormonal contraceptives
PROS:
- More effective at preventing pregnancy
- No need to stop and think during intercourse
CONS:
- Don’t protect against STI’s
- Some have unpleasant side-effects
What is homeostasis?
Why is it important?
The maintaining of a constant internal environment
Because conditions in your body need to be kept steady
Describe the roles of insulin and glucagon in controlling a person’s blood glucose concentration?
Insulin converts glucose into glycogen
Glucagon converts glycogen into glucose
What is thermoregulation?
Why is it important for enzymes in the body?
The regulation of a constant temperature within the body
Enzymes require a optimum temperature
Explain how changes in the skin help to control body temperature?
Hair on skin moving
Movement of blood vessels
Sweat
What is osmoregulation?
The regulation of water in the body
Describe what might happen t obody cells if the concentration of water in the blood is too low?
The water will move via osmosis from the cell into the blood causing the cells to shrink
Excess amino acids are broken down in the liver
Name the waste product of this process, which must be removed in urine?
Urea
List the main structures in the urinary system
Kidneys, ureters, bladder and urethra
Describe how urine is formed?
The kidney removing all the waste via filtration and then reabsorbment into the blood from the collecting duct
Describe how the brain responds when it detects a fall in the water content of the blood?
By increasing the amount of ADH
