Section 1 Flashcards
Who was the first to define homeostasis?
Walter Cannon (1929)
What is Homeostasis?
Refers to the maintenance of nearly constant conditions in an INTERNAL environment.
internal body conditions remain nearly constant
What are adaptive responses?
The homeostatic mechanisms that allow for a return to homeostasis
What are the conditions of homeostasis?
Contains optimum concentration of nutrient, gases, ions, and water optimal temperature
optimal pressure
What is stress?
anything that creates an imbalance in the internal environment
What is the most abundant extracellular cation?
Na+
What is the most abundant extracellular anion?
Chloride
What is the most abundant intracellular cation?
K+
List the extracellular ions in decreasing order?
Na+>Chloride>HCO3->Proteins (anion)>K+, Calcium
List the intracellular ions in decreasing order?
K+, PO4^-3, protein, magnesium, Na+
What is a feedback system?
Circular situation in which the information about the status of something is continually reported to the central control region.
Negative feedback loops
A change in a parameter that causes a response that results in a reverse of the initial back to its normal parameter
Example of a negative feedback loops?
Regulation of Arterial blood pressure.
Explain what type of feedback Arterial blood pressure is and how it works
Baroreceptors in the arterial walls sense the blood pressure either by stretching. This leads to a inhibitory signal in the medulla which stimulates the vagus nerve to decrease HR and dilation of blood vessels.
Explain positive feedback system
A change in a parameter sends signals to continue to move parameter in that direction Thus making it further from the nl
Example of positive feedback system
Childbirth. The stretching of the cervix sends signals to posterior pituitary that triggers a release of oxytocin and increase in uterine contractions. Since the child is born the signal has a natural decrease and thus does not have the detrimental effect that most of the positive feedbacks do.
What is Gain?
Gain is the degree of effectiveness with which a control system maintains constant conditions.
Gain= correction/error
What does uncontrolled system mean?
Adaptive process is not working
what is error? (in terms of gain equation)
The amount of uncorrected increase
what is the gain of a system if:
Adding to liter of blood to a controlled system and to an uncontrolled system: uncontrolled rises from 100 to 175
Controlled BP rises from 100 to 125
gain= correction/error correction= -50 error= 25 gain= -2
Which of the following has to be a transmembrane protein? A.) receptor protein B.) protein binding to cytoskeleton C.) Channel protein D.) phosphorylase
C.) Channel protein
what is the function of a cell membrane?
separate intracellular and extracellular environments and controls what enters and leaves the cell.
What is the structure of a cell membrane?
all cell membranes and plasma membranes have the same basic function, known as the “unit membrane”
Unit membrane- is a phospholipid bilayer with cholesterol inserted among the phospholipids.
Proteins are associated with the membrane.
Integral proteins are inserted into the membrane on one side or the other and are exposed on either side of the membrane
Peripheral proteins- are loosely attached to either side of the membrane and are easily removed.
Cholesterol- mediates fluidity of membrane
Integral proteins
are inserted either on one side or extend through the membrane. They are exposed on one or both sides of the membrane. Removal would destroy the bilayer.
Peripheral proteins
Are loosely attached to either side of the protein. They can be easily removed. Many are attached to membrane using glycophosphatidylinositol= GPI- anchored proteins.
GPI anchored proteins
Are peripheral proteins that are anchored to the membrane by use of glycophosphatidylinositol.
What is the purpose of cholesterol in the membrane
It is relatively inflexible and therefore is used to regulate the flexibility of the membrane.
functions of the plasma membrane
Serves as a filter and regulates what can move from one side of the membrane to the other.
regulates the intracellular and extracellular cell conditions.
plays a role in informational exchange between cell and its environment
Involved in exocytosis and endocytosis.
What substances can easily pass through the cell and plasma membranes
Lipids
Which membrane bound organelle (s) are associated with cell trafficking?
Smooth and Rough ER
Golgi Apparatus
Which membrane bound organelle (s) makes the most ATP?
The Mitochondria
which organelle(s) is directly associated with the production and section of proteins
Rough ER
What is Human physiology?
The study of the functional organization of the body
What are lysosome
Digestive enzymes
low pH
What is the role of the Golgi apparatus?
Plays a role in packaging proteins for secretion
- forms lysosomes
- modifies proteins from the RER
What is glycolysis
- anaerobic respiration
- begins with glucose
- occurs I cytoplasm of the cells
- does not require oxygen
- produces pyruvic acid (lactic acid) and a small amount of ATP
what does glycolysis begin with?
Glucose
Where does glycolysis occur
In the cytoplasm of all cells
Is glycolysis anaerobic or aerobic
Anaerobic
What are the products of glycolysis
Pyruvic acid (lactic acid) and a small amount of ATP
what does the kreb’s cycle and ETC use for a starting material?
Pyruvic acid form glycolysis
Where does the Kreb’s cycle and ETC occur
Only in the mitochondria
What is the final electron receptor of Krebs and ETC
Oxygen
What are the products of ETC and Krebs cycle
More ATP than Glycolysis, CO2, and water
is Kreb’s cycle and ETC aerobic or anerobic?
Aerobic
Who uses amoeboid movement
used by macrophages and some other leukocytes
what are the only flagellated cells in mammals?
sperm cells
what is the purpose of cilia
Move other material , usually mucous that coats a layer of ciliated cells.
cell itself does not move
What is the purpose of microtubules
Provide tracks on which motor molecules can move cargo
