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