animal physiology - challenge 2 (Intracellular Communication) Flashcards
(41 cards)
because animals are multicellular this proposes what challenge?
since cells all have special structure and function it is a challenge to coordinate all the functions in cells
how do cells communicate?
Cells can signal to each
other and interpret the
signals they receive from
other cells and the
environment
Signals are most often
chemicals
Animals will utilize two distinct types of signaling to organize the cells of the body, what are the two types?
- Electrical Signaling
2. Chemical Signaling
what is one type/example of electrical signaling ?
Action potentials
- Along an axon - Along the sarcolemma (plasma membrane of a muscle cell)
what are 3 types of chemical signaling?
- Neurotransmitters
- Such as acetylcholine
- Paracrine (localized)
- Endocrine(long distance)
- Hormones
In local signaling, animal cells may communicate by direct contact- what is direct contact?
Animal cells have cell junctions that directly connect the cytoplasm of adjacent cells and Signaling substances in the cytosol can pass freely between adjacent cells
what enables cells for direct contact?
cellular junctions and the structure of gap junctions
These structures enable cells in direct contact to communicate
This is one form of local signaling
In many other cases, animal cells communicate using secreted messenger molecules that travel only short distances, what are the two types of secreted messengers?
Synaptic signaling
Paracrine signaling
In both of these forms chemical signals will be secreted from the cell
where and when does Synaptic signaling occur?
Synaptic signaling occurs in the animal nervous system when a neurotransmitter is released in response to an electric signal
In long-distance signaling, animals use chemical messengers referred to as?
hormones
Hormonal signaling in animals is called ?
endocrine signaling;
specialized cells release hormones, which travel to target cells via the circulatory system
The ability of a cell to respond to a signal depends on what?
whether or not it has a receptor specific to that signal
what are Glands?
Specialized organ (or a group of cells) which manufacture and secrete chemical signals (hormones)
what does Production of these chemical messages (from glands) allows for
the coordination of activities in multiple areas of the body
Many of these glands (or cells) are associated with the integrating center (comparer) of negative feedback loops
Why?
because the physiological response is tied to negative feedback loops which send messages to other cells to maintain homeostasis.
it coordinates amount other cells for growth and development for bilateral symmetry
what are three types of glands?
- Exocrine glands
- Endocrine glands
- Mixed function glands
what do Exocrine glands do? give 2 examples.
secrete their products into ducts that carry these products to other organs or outside the body
- Salivary glands
- Sweat glands
what do Endocrine glands do? give 2 examples
secrete their products directly into the bloodstream
- Pituitary gland
- Thyroid gland
what do Mixed function glands do? give one example
capable of both exocrine and endocrine secretion
1. Pancreas
What are hormones?
Chemical signals that promote communication between cells, body parts, and even individuals
what does it mean that hormones are targeted?
they will only interact with a target cell
target cell will be carried in the extracellular fluid or blood of an animal
why must hormones exhibit complexity but yet be simple?
they have to be complex enough to avoid mixing up signals and they have to be simple enough to travel around the body
what are Hormone Receptors?
Proteins of target cells in which a hormone will bind -
Once binding occurs a response will occur
and Internal conditions of cell could change triggering a response
why is specificity of protein receptor to specific hormones
vital?
so that the hormone goes to the right place and coordinates the correct response.
