Homeostasis Flashcards
What is the metabolism?
All the chemical reactions inside the cells of an organism
What are hormones?
A chemical messenger carried by blood around the body. This is a lot slower
Where are hormones produced?
In the endocrine glands
Which hormone regulates sugar?
Insulin
What does glucose do for cells?
It allows them to respire
Where is insulin produced?
By the pancreas
Admire this please
What happens when there are overly high levels of glucose
Glucose is stored as glycogen and normal levels are restored because insulin is released by the pancreas
How is homeostasis control achieved?
Using negative feedback mechanisms
Define negative feedback mechanism
A mechanism to lower raised levels of something, and to increase reduced levels
What does glucagon do?
It dissolves glycogen into glucose
What temperature is the body maintained at?
37 degrees, the temperature where the body’s enzymes work best
What happens to hairs when the body is too cold
They stand up
What muscle makes hair stand up?
The hair erector muscle (lol)
What is a response to being too cold?
Vasoconstriction
What is vasoconstriction?
Blood vessels at the skin surface are narrowed to reduce heat loss through the skin
What is vasodilation?
The opposite to vasoconstriction (too hot)
What are arterioles?
A small branch of an artery leading into capillaries
What is shivering caused by?
Involuntary muscular contractions
What happens with sweat?
It is produced by sweat glands and travels up the sweat duct and out of the sweat pore
What is the purpose of sweat?
When it evaporates from skin it takes the heat with it
I can’t understand this rn but please appreciate it
What is a tropism?
A plant’s way of growing towards light and water
How does the stem respond to light?
In a positive phototropism
What is the response of plant roots to gravity?
A positive geotropism (it grows in the direction of the force of gravity)
What is auxin?
A family of plant hormones
Where are auxins made?
In the tips of growing stems and roots
What are meristems?
A region of plant tissue comprised of actively dividing cells
How do auxins move to other part of stems and roots?
They diffuse
What do auxin do?
Change the rate of elongation in plant cells which controls their length
How do cells in the stem respond to higher concentrations of auxin?
They grow more
How do cells in the root respond to higher concentrations of auxin?
They grow less
Which side of a stem contains more auxins?
The shaded one, so it grows more - meaning it bends towards the light
What happens if a root is placed horizontally?
The bottom side contains more auxin and grows less, causing the root to bend in the direction of the source of gravity
How is diabetes treated?
By injecting insulin
What is type 1 diabetes caused by?
Damage to the beta cells in the pancreas, which produce insulin
How do people get type 1 diabetes?
It is either inherited or caused by some viruses
How is type 1 diabetes treated?
A low sugar diet, injecting insulin, and sometimes transplanting tissue
What is type 2 diabetes caused by?
The body becoming resistant to insulin
