Biology Flashcards
(24 cards)
Define endocrine system:
The collection of glands that release hormones into the bloodstream which then travel through the blood.
Define hormones
A chemical messenger that travels through blood vessels to target cells.
What is the purpose of hormones?
Hormones serve as messengers, controlling and coordinating activities throughout the body.
How do the hormones travel around the body?
Through the blood
What is a target cell?
A cell that has a receptor that matches a specific hormone
Name three effects of the “fight or flight” response:
- Increase in heart rate
- Cold sweat
- Widening of pupils
What is the usual role of the hormone adrenaline?
The function is to stimulate the heart rate and enlarge blood vessels.
Define homeostasis:
Your body’s ability to regulate and maintain a stable condition inside your body.
An example of how your body keeps homeostasis:
Muscles to make you shiver, (to warm up). The body carries heat via the blood to your skin so that you sweat cools you down.
How does blood glucose regulation work?
When your blood glucose level is to high, the receptors in your pancreas detects this and releases more insulin which causes muscles and liver cells to increase their intake of glucose from the blood
Why blood glucose regulation is negative feedback?
Removes original stimuli
What are pathogens?
Anything that causes disease.
Eg: Fungi, bacteria
Why is negative feedback often associated with maintaining homeostasis?
The effectors respond by removing the stimulus.
The body becomes to hot: negative feedback?
The effectors include your sweat glands and blood vessels, your body than carry’s the heat to your skin so that sweat evaporates and cools you.
What is the germ theory?
- The microorganism or other pathogen must be present in all cases of disease.
- The pathogen can be isolated from the diseased host and grown in the lab.
- The pathogen from a pure culture must cause the disease when inoculated into a healthy lab animal
- The pathogen must be re-isolated from the new host and shown to be the same as the originally inoculated pathogen.
What are antibiotics?
An antibiotic is a drug used to treat a bacterial infections, but not viruses or other pathogens.
What is the role of your immune system?
To protect you against foreign invaders by physically stopping them from entering your body, identifying and attacking them if they manage to enter.
What is the first line of defence?
To stop the pathogens from getting inside your body. Stopped by skin and mucous membranes.
Define white blood cells:
An immune system cell that destroys pathogens
What are the two ways apart of the second line of defense:
- “Seek & destroy” blood clotting stop infection through skin damage, inflammation increase amount of blood cells reaching affected areas and fever pathogens can’t survive in high temps.
- White blood cells are produced by the body to destroy pathogens.
What’s the third line of defense?
Specific immune response, two forms of attack. B cells produce special molecules called antibodies. T cells then recognise the same specific pathogen, attack & kill it.
What can a vaccine be?
- Dead pathogen
- A living but weakened form of a pathogen
- Parts of the broken pathogen
Define ectotherm and give an example?
Animals that cannot produce their own thermal energy and rely on their surrounding temperature. Eg: Reptiles such as snakes
Define endotherm and give an example?
Animals that can produce their own thermal energy and regulate their own temperature. Eg: Humans
