Weekly Wrap-Up 13: Homeostasis and Osmosis

In the homeostatic control system, which part of the body structures performs a response?

effector

In the homeostatic control system, which part of the body structure senses a change in the environment?

receptor

In the homeostatic control system, what is a message sent to the controller about a stimulus called?

incoming signal

In the homeostatic control system, what is a message sent to the effector about a response?

outgoing signal

In the homeostatic control system, which part of the body structure processes information about a stimulus and decides on a response?

controller

The term anatomy describes the study of:

the structure of a body part

If a homeostatic control system causes a body response that reduces, counteracts, or shuts off the original stimulus it is a ____

negative feedback system

What are the two ways in which a homeostatic system with chemical signals can be different than other types of homeostasis?

1.  the incoming signal is always a signal created inside of the cells of that body structure (an intracellular signal)

2. the receptor and the controller can be the same body structure

What is an example of studying the anatomy of a human?

comparing the size, shape and weight of bones between athletes and non-athletes

When the levels of calcium in the blood are low, the body releases parathyroid hormone or PTH. PTH tells the cells of bone to start releasing calcium into the blood, until the levels of blood calcium come back to normal.  What type of feedback is this?

negative feedback

What three things are true about a positive feedback system?

1. They are relatively rare in homeostasis

2. The system pushes the body away from the set point

3. The system's response amplifies the stimulus

If the environment an organism lives in has a higher concentraton of solutes/electrolytes than the body of the organism, then that environment is _____________

hypertonic

If the environment an organism lives in has a lower concentration of solutes/electrolytes than the body of the organism, then that environment is _____________

hypotonic

If an organism lives in a hypertonic environment, how are two ways that its body and cell chemistry change? 

1. gain excess electrolytes by diffusion

2. lose water by osmosis

An animal that is an osmoconformer alters their body chemistry so that it is always ___________________ to their surrounding environment

isotonic

How do marine fish (fish that live in seawater) replace the water they lose in the hypertonic environment of the sea?

They drink large amounts of seawater

How do freshwater fish replace the electrolytes that they lose?

they pump electrolytes into their body using active transport in their gills

How can fish that live in both freshwater and seawater environments regulate their salts differently than other fish types?

they can move their electrolyte pumps to different sides of the gill cells in different environments

What are three ways that animals that live on land lose water from their bodies?

1. water evaporates from respiratory surfaces like the lungs

2. water evaporates from outer body surfaces exposed to air

3. water is lost in urine and feces

How do land-based insects minimize loss of water from their outer body surface?

the outer surface is coated in fat-based wax that blocks evaporation of water

In an insect, the pre-urine is formed by ____________________________

filtration of hemolymph in the Malpighian tubule