Biology 101 Study Guide Part C

1. Why is the velocity of blood flow lower in capillaries than in arteries?

a. Capillary walls are thin, so as to allow exchange of O₂ and CO₂ with tissues.

b. Capillaries are far from the heart, and blood flow slows as distance from the heart increases.

c. The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate.

d. The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle.

e. The total surface area of the capillaries is larger than the total surface area of the arteries.

2 In which of the following structures is average blood pressure the lowest?

a. aorta d. venae cavae

b. venules e. arteries

      c. arterioles    f. capillaries 

3. Which of the following statement is correct?

1. Heart contraction is called diastole  d. Heart contraction is called stroke
2. Heart relaxation is called systole   e. Heart relaxation is called stroke
3. Heart contraction is called systole

 

4. A cardiac cycle occurs every ____________, and the diastole lasts _________

1. 0.8 sec, 0.1 sec
2. 0.8 sec, 0.4 sec
3. 0.4 sec, 0.1 sec
4. 1.5 sec, 1.0 sec
5. 3.0 sec, 2.0 sec

 

5. Which one of the following best describes hemoglobin properties?

1. Hemoglobin is a protein found in the blood and binds oxygen
2. Hemoglobin has four polypeptidic chains and gives the red color to blood
3. Hemoglobin binds oxygen and carbon dioxide
4. Hemoglobin has four polypeptide chains, each with a heme group that contains one iron atom, which can bind one oxygen molecule
5. Hemoglobin is released by B cells when oxygen levels are low

 

6. White blood cells are _______________ and defend the body against _____________

1. Platelets, bacteria
2. Basophils, viruses
3. Erythrocytes, prions
4. Leukocytes, disease and injury
5. Stem cells, infection

 
 

7. Damage to blood vessels results in

1. The release of thrombin and the formation of fibrinogen
2. The release of prothrombin and the degradation of fibrin
3. The release of prothrombin and the formation of fibrin
4. The release of fibrin and the formation of thrombin
5. The release of fibrinogen and the degradation of thrombin

 

8. Which one of the following best describes the difference between immune responses to a tissue graft and immune responses to a bacterium?

a. MHC molecules may stimulate rejection of the tissue graft.

b. The tissue graft, unlike the bacterium, is isolated from the circulation and will not stimulate immune responses.

c. Immune responses to the graft will involve T cells and immune responses to the bacterium will not.

d. The bacteria cannot escape the immune system by replicating inside normal body cells.

      e. The graft will stimulate an autoimmune response in the recipient. 

9. An autoimmune disease is characterized by:

1. The presence of increased red blood cells
2. A lack of B cells
3. The defective recognition of self molecules by the immune system
4. A proliferation of T cells
5. A decrease in platelets

 

10. Which of the following statement is not true?

1. The Human immunodeficiency virus (HIV) is a single-stranded RNA virus
2. AIDS stands for Acquired Immune Deficiency Syndrome
3. HIV enters B cells by attaching to the CD21 receptor
4. HIV is transmitted in body fluids
5. AIDS takes years to develop

 

11. When you hold your breath, which of the following changes in blood gas concentration causes the strongest urge to breathe?

a. rising O₂

b. falling O₂

c. rising CO₂

d. falling CO₂

e. rising CO₂ and falling O₂ 

12. Which of the following statements regarding asthma is true?

1. Asthma is characterized by bronchial swelling
2. Asthma is a chronic lung disorder
3. Asthma attacks are triggered by allergies
4. Asthma is treated by bronchodilators
5. All of the above

 
 

13. What acid is responsible for stomach acidity, how does it create stomach ulcers?

a. hydrochloric acid, reduces mucosal lining of stomach

b. carbonic acid, reduced mucosal lining of stomach

c. carbonic acid, stronger acid content

d. hydrochloric acid, stronger acid content

e. sodium hydroxide, stronger basic content 

14. Protein digestion begins in the _____, and is finalized in the ____________.

a. mouth, stomach

b. esophagus, stomach

c. stomach, small intestine

d. small intestine, large intestine

e. stomach, large intestine 

15. When you are dehydrated, the pituitary releases ____________, and urine is more ____________

1. Aldosterone, diluted
2. ADH, diluted
3. ADH, concentrated
4. Renin, salty
5. Renin, acidic

 

Section II. Filling the Blanks (Total 30 points, each correct answer is worth 3 points). 

1. A blood clot in the pulmonary artery is called a ____pulmonary embolism________ _________, while a _____stroke_______ is due to interruption of blood supply to parts of the brain. 

2. Normal systolic pressure is less than __120_____ (mm Hg), and diastolic pressure less than ___80___ (mm Hg). High blood pressure is called _hypertension_________. 

3. When blood pressure rises, __baroreceptors_________ in the carotid arteries send signals to brain to produce a reduced __cardiac output_____________. 

4. _________PLATELETS ________________________ are small protein packets that are important in blood clotting. Red blood cells are the most numerous cells in the body and are responsible for the transport of _____OXYGEN __________________ and ____CARBON DIOXIDE______________. 
 

5. T cells mature in the __THYMUS____, while B cells mature in the ______bone marrow_____.

T cells don't produce antibodies. Each T cell, however, is different from its fellow T cells in having the capacity to recognize only one very specific antigen by specific T -cell  ___RECEPTOR______ . 

6. Antibodies produced by a clone of cells derived from a single B cells are called ___monoclonal___________ antibodies, while circulating antibodies generally recognize different __epitope________ from the same _____antigen_______.  
 

7. The maximal volume you can exhale is called the _____vital_________ _capacity_________, while the amount of air that remains in the lungs is called the __residual___ __volume______. 

8. The enzyme __amylase_______ degrades carbohydrates into simple ____sugars_______, while the enzyme __pepsin/trypsin/chymotrypsin_______ degrades proteins into ___amino_______  __acids________. 

9. The liver produces _____bile_______, and inactivates many chemicals, including _____alcohol__________ and _____poisons_________. The pancreas secretes ____digestive__  ____enzymes_________ and sodium ____bicarbonate ___________. 

10. Aldosterone increases the reabsorption of _____sodium__________ ions across the ____distal_______  ____tubules______. A decline in blood volume causes the kidneys to secrete __renin____ to cause kidneys to save __salts_____ and __water_______. 

Section III. Short Answer (Total 25 points, each correct answer is worth 5 points).

1. Briefly describe the three steps of the cardiac cycle. 

1. Atrial and ventricular diastole (0.4 sec):

• atria and ventricles are relaxed
• atria and ventricles filled passively
• AV valves are open, semilunar valves are closed

 

2. Atrial systole (0.1 sec):

• The semilunar valves are closed, the AV valves are open
• Both atria contract, forcing blood into the ventricles

 
 

3. Ventricular systole (0.3 sec):

• Both ventricles contract simultaneously
• The AV valves are closed
• The semilunar valves are open and the blood enter pulmonary trunk and aorta

 
 
 

2. Briefly describe how cytotoxic T cells kill target cells (you can also use a schematic drawing). 

1. An infected cell dysplays an antigen-fragment using class I MHC molecule. A Tc cell is activated, and CD8 protein enhances the activation as does interleukin-2. 

2. Activated Tc cell releases perforins which make pores in infected cell. 

3. Water and ions flow into cells and the cell lyses and dies. 
 

3. Explain the three functions of the larynx. 

The larynx consists of four basic anatomic components: a cartilaginous skeleton, intrinsic and extrinsic muscles, and a mucosal lining. The cartilaginous skeleton houses the vocal cords. These cartilages are connected to other structures of the head and neck through the extrinsic muscles. The intrinsic muscles of the larynx alter the position, shape and tension of the vocal folds. 

The larynx functions in deglutition (swallowing), respiration (breathing), and phonation (voice production). The production of voice can be thought of in terms of three components: the production of airflow, the generation and resonance of sound and the articulation of voice. 
 

4. What are the major hormonal regulatory processes for food digestion? 

• Gastrin: is released in the stomach and stimulates release of gastric juice in response to peptides, amino acids, and calcium.

• Secretin: is released by mucosa from stomach and small intestine. It causes the pancreas to send out a digestive juice that is rich in bicarbonate. It stimulates the stomach to produce pepsin, an enzyme that digests protein, and it also stimulates the liver to produce bile.

• Cholecystokinin (CCK): is released by mucosa from stomach and small intestine. It signals pancreas to secrete digestive enzymes. 

• Insulin: is secreted by pancreas and regulates glucose transport by cells.

• Glucagon: is secreted by pancreas and opposes insulin action, stimulates glucose secretion by cells.  

5. What is the Renin Angiotension Aldosterone System and what is its function? 

The renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system is a hormone system that helps regulate long-term blood pressure and blood volume in the body.

The system can be activated when there is a loss of blood volume or a drop in blood pressure (such as in a hemorrhage).

If the perfusion of the juxtaglomerular apparatus in the kidneys decreases, then the juxtaglomerular cells release the enzymatic hormone renin. Renin cleaves an inactive peptide called angiotensinogen, converting it into angiotensin II.  

Angiotensin II has a variety of effects on the body: 

    * It is a potent vasoconstrictor throughout the body.

    * In the kidneys, it increases arterial blood pressure and decreases the blood flow.

    * It also acts on the adrenal cortex causing the release of aldosterone. Aldosterone acts on the tubules (i.e. the distal convoluted tubules and the cortical collecting ducts) in the kidneys, causing them to reabsorb more sodium and water from the urine. Aldosterone also acts on the central nervous system to increase a person's appetite for salt, and to make them feel thirsty. 

These effects directly act to increase the amount of fluid in the blood, making up for a loss in volume, and to increase blood pressure. 

IV (Total 15 points).

(a) Describe how a vaccine produces immunity from a specific viral disease (6 points). Why has it been so difficult to develop a vaccine for AIDS? (4 points). 

Vaccines help reduce the risk of diseases resulting from viruses by introducing a greatly weakened or dead virus to the immune system. Antibodies against the virus are made without the person getting sick. If the real disease-causing virus is ever encountered, the immune system knows how to defeat it, and illness is avoided. 

Vaccines are designed against a particular virus. For example, the reaction to measles is to the whole organism. However, in tetanus, the body reacts to the poison produced by the tetanus germ, rather than the germ itself. 

Some vaccines offer lifelong immunity. In other cases, booster shots are needed. 
 

Development of any new vaccine normally is a long and complicated scientific research process. It usually takes 10 to 15 years and US$100 to $200 million to develop and test a vaccine, and for every success there are many leads that provide valuable scientific insights but prove not to work. Developing a vaccine to prevent HIV/AIDS is particularly challenging in that HIV is one of the most complicated viruses ever identified. HIV targets and destroys the very immune system that a vaccine traditionally triggers. And the genetic instability of HIV is daunting: millions of viruses are constantly produced and their mutation rates are spectacular. The immune system is presented with an endless stream of with new forms of the virus that it is unable to recognize and control. 

(b) You get the results of a lab test on your blood, indicating that you have a high blood sugar level. What could be the reasons? (5 points)  

• Eating too much food. You may be eating portions that are too large or eating too often.

• Eating the wrong foods. You may be eating too many carbohydrates.

• Diabetes

• Infections

• Illness (such as cold, flu) or surgery

• Stress

• Less exercise than usual.

• Certain medications such as steroids.

• Pregnancy