Quiz 1 Flashcards
The act of breathing raises the blood oxygen level, lowers the blood carbon dioxide level, and raises the blood pH. According to principles of negative feedback, sensors that regulate breathing should respond to
A rise in blood carbon dioxide.
Which of the following is an example of feedforward regulation?
The smell of rotten food on a plate triggers the vomit reflex.
Which of the following consists of dense parallel arrangements of collagen fibers?
Tendons
Mass balance involves determining the total amount of a substance in the body. We can determine mass flow of this substance by which formula?
(concentration of a substance) x (volume/min)
Feedforward regulatory processes
Work in anticipation of changes in regulated variables
When a blood vessel is injured, it releases chemicals, that activate platelets and cause them to stick to the injury site. The activated platelets in turn release more chemicals and attract more platelets to the injury site until the wound is fully sealed. This process of blood clotting is an example of
Positive feedback
The esophagus is a tube that carries food from the mouth to the stomach. It does not secrete any enzymes or absorb any nutrients, but it does need to stand up to significant friction and stress. The type of epithelium most likely lining the esophagus would be
Stratified squamous epithelium
Dynamic constancy is a term used to describe homeostasis. Which of the following is NOT an example of dynamic constancy?
Administering IV fluids to a person presenting to the emergency room with dehydration.
Which type of cell junction would allow glucose molecules to diffuse from the cytosol of one cell to the cytosol of a neighboring cell?
Gap
Which of the following is FALSE regarding the extracellular fluid compartment?
It makes up 65% of the total body fluid volume.
Glands are derived from
Epithelial tissue
Which best describes how the total body balance of chemical substance is determined?
The difference between the amount of substance lost from the body and the amount of the substance gained by the body.
Choose the best definition of homeostasis.
The ability of an organism to maintain relatively constant internal environment even though external conditions may change.
Identify the effectors in this homeostatic reflex. Eating a salt-rich meal increases blood volume and pressure, stretching blood vessel walls. Nerve signals sent to the brainstem stimulate changes in hormonal and neural signaling. The heart rate is reduced, blood vessel walls are relaxed, and the kidneys increase excretion of salt in the urine. The blood pressure returns to baseline.
Heart, blood vessels, and kidneys
In a negative feedback loop, the effector produces changes that
Opposite in direction to the change produced by the initial stimulus.
Which body fluid compartment contains high levels K+ ions, large anions, and proteins?
Intracellular fluid
When cancer develops in one tissue and spreads to another through the blood or the lymph, the cancer is said to have undergone what process?
metastasis
Homeostatic regulation usually involves a(n) ______ that detects a particular stimulus, and a(n) ______ that responds to the stimulus by communicating with a(n) ________ whose activity has an effect on the same stimulus.
Sensor; integrating center; effector
The wall of the intestines needs to form an impenetrable barrier that prevents the passage of molecules through the extracellular space (the only route of passage must be for molecules to move through the cells). What type of cellular junction would be most appropriate for this task?
Tight junctions
Circadian rhythms are biological rhythms with what main characteristic?
They repeat approximately every 24 hours, like daily spikes in hormone secretion.
