BIO 224: chapter 20 HOMEWORK

Identify the type of shock: *Occurs when cardiac output is low because too little blood is returning to the heart.*

Low venous return shock

Identify the type of shock: *Any state in which the cardiac output is insufficient to match the bodies needs.*

circulatory shock

Identify the type of shock: *Occurs when any object compresses a vein and reduces its blood flow.*

obstructed venous return

Identify the type of shock: *Occurs when bacterial toxins trigger vasodilation and increased capillary permeability.*

septic shock

Identify the type of shock: *Produced by a loss of blood volume as a result of hemorrhage, trauma, etc.*

Hypovolemic shock

Describe the differences between continuous, fenestrated, and discontinuous capillaries. Your answer should include representative locations of each.

*Continuous Capillaries:* Occur in most tissue (i.e. skeletal muscle) and are the most common. The endothelial cells are held together by tight junctions. Contain intercellular clefts so small solutes such as glucose can pass through but plasma proteins, large molecules, and platelets and blood cells are held back. Contain pericytes that have long tendrils that wrap around the capillary and contract and help regulate blood flow through the capillaries. *Fenestrated Capillaries: * Have endothelial cells riddled with patches of filtration pores (fenestrations). They allow for rapid passage of smaller molecules and do not allow larger particles or proteins pass. They are important and found in organs that must undergo rapid absorption and filtration such as the kidneys, endocrine glands, small intestine, and choroid plexuses of the brain. *Discontinuous Capillaries (Sinusoids):* Conform to the shape of the surrounding tissue. Endothelial cells are separated by wide gaps with no basal lamina that also contain especially large fenestrations. Larger molecules such as proteins and blood cells can pass through them. They are commonly found in the liver, spleen, and bone marrow.

Indicate if the following characteristics are associated with arteries or veins. 1. Divergence arteries 2. Thicker layers of smooth muscle arteries 3. Relatively larger lumen veins 4. Sites used for blood donation veins 5. Contain valves veins 6. Convergence veins 7. Relatively larger diameter veins 8. Relatively thicker walls arteries 9. Profuse elastic fibers in the tunica media arteries 10. Superficial locations veins

1. arteries 2.arteries 3. veins 4. veins 5. veins 6. veins 7. veins 8. arteries 9. arteries 10. veins

Indicate whether the given condition would increase or decrease blood flow with all other factors being equal. 1. Increasing blood viscosity 2. Increasing blood pressure 3. Increasing blood velocity 4. Dehydration 5. Vasoconstriction 6. Increasing vessel radius 7. Increasing vessel length 8. Increasing red blood cell count 9. Increased resistance 10. Aldosterone hyper secretion

1. decreased flow 2. increased flow 3. increased flow 4. decreased flow 5. decreased flow 6. increased flow 7. decreased flow 8. decreased flow 9. decreased flow 10. increased flow

Action potentials are conducted from the baroreceptors to the brain via which nerve? A) hypoglossal nerve B) glossopharyngeal nerve C) accessory nerve D) facial nerve E )vagus nerve

B) glossopharyngeal nerve

What is the main chemical stimulus for cerebral autoregulation? A) pH B) sodium levels C) CO2 levels D) O2 levels E) chloride levels

A) pH

In the baroreflex the action potential are carried from the brain to the heart by which nerve/s? A) vagus nerve B) vagus and glossopharyngeal nerves C) vagus and phrenic nerves D) glossopharyngeal nerves E) phrenic nerve

A) vagus nerve

Choose the correct statements regarding the effects of edema. Select all that apply. A) Cerebral edema can cause headaches, nausea, and sometimes delirium, seizures, coma, and death. B) As the tissues become congested with fluid oxygen delivery and waste removal are impaired. C) Pulmonary edema presents a threat of suffocation. D) As the tissues become congested with fluid oxygen delivery and waste removal are improved. E) Edema cannot cause blood pressure to drop and shock to occur.

A, B, C

Where are baroreceptors found? A) subclavian arteries B) carotid sinuses C) carotid veins D) aorta and subclavian veins E) common iliac arteries

B) carotid sinuses

What forces favor capillary filtration and what forces flavor capillary reabsorption?

Capillary filtration is favored by blood hydrostatic pressure (BHP) and tissue osmotic pressure (TOP) Capillary reabsorption is favored by tissue hydrostatic pressure (THP) and blood osmotic pressure (BOP)

Identify the type of shock: *Caused by inadequate pumping by the heart.*

Cardiogenic shock

What is/are the physiological purposes of vasoreflexes? A) To cause a generalized raising or lowering of blood pressure throughout the body. B) To selectively modify the perfusion of an organ by rerouting blood flow. C) To cause widespread vasodilation to increase blood pressure throughout the body. D) Both A and B are correct. E) Both B and C are correct.

D) Both A and B are correct.

What does decompensated shock result in? A) Ischemia and acidosis of the brainstem B) Several life-threatening positive feedback loops C) Myocardial ischemia D) Disseminated intravascular coagulation E) All of the above are potential consequences of decompensated shock.

E) All of the above are potential consequences of decompensated shock.

When a person is still, blood accumulates in the limbs because venous pressure is not high enough to overcome the weight of the blood and push it upward. True OR False

TRUE

In what conspicuous way does perfusion of the brain contrast with perfusion of skeletal muscle tissue?

Total blood flow to the brain fluctuates less than any other organ in the body and receives about 700mL/in at rest. Reduced oxygen for a few seconds can cause loss of consciousness and 4-5 minutes can cause irreversible damage. Skeletal muscle perfusion varies drastically and is determined by how active the muscle is. After a large meal for example, blood flow is reduced to the muscles by around 90% which redirects blood flow to the digestive tract to absorbs nutrients from digestion. However, during vigorous exercise blood flow is drastically reduced to the urinary and digestive system and redirected to the skeletal muscle to sustain exercise.

Identify the type of shock: *Results from exposure to an antigen to which a person is allergic.*

anaphylactic shock

Identify the type of shock: *Form of venous pooling shock that results form a sudden loss of vasomotor tone.*

neurogenic shock