21.6 Shock and Homeostasis

Question 1

shock

Answer 1

• a failure of the cardiovascular system to deliver enough O2 and nutrients to meet cellular metabolic needs
• causes cells to switch from aerobic to anaerobic production of ATP, making lactic acid accumulate in body fluids

Question 2

hypovolemic shock

Answer 2

• one of the four types of shock

- shock caused by a decreased blood volume, such as by an acute hemorrhage

Question 3

cardiogenic shock

Answer 3

• one of the four types of shock

- shock caused by poor heart function, most often due to a myocardial infarction (heart attack)

Question 4

vascular shock

Answer 4

• one of the four types of shock
• shock caused by inappropriate vasodilation
• can occur for many reasons, including anaphylactic shock, neurogenic shock, and septic shock

Question 5

anaphylactic shock

Answer 5

-a type of vascular shock caused by an allergic reaction and an overproduction of histamine

Question 6

neurogenic shock

Answer 6

-a type of vascular shock caused by trauma to the head leading to malfunction in the CV center of the medulla

Question 7

septic shock

Answer 7

• a type of vascular shock caused by certain bacterial toxins that produce vasodilation
• the most common cause of death in hospital critical care units

Question 8

obstructive shock

Answer 8

• one of the four types of shock
• shock caused by obstruction of blood flow, most often due to a pulmonary embolism (blood clot in the vessels of the lungs)

Question 9

homeostatic responses to shock

Answer 9

-negative feedback systems which compensate for shock, working to return cardiac output and arterial blood pressure to normal

Question 10

activation of the renin-angiotensis-aldosterone system

Answer 10

• one of the homeostatic responses to shock
• decreased bloodflow to the kidneys to secrete renin which turns into angiotensin|| and promotes the production of aldosterone
• angiotensis II causes vasoconstriction and aldosterone increases reabsorption of Na+ and water in kidneys, leading to increased vascular resistance and blood volume, increasing blood pressure

Question 11

secretion of antidiuretic hormone

Answer 11

• one of the homeostatic responses to shock
• decreased blood pressure causes release of ADH, enhancing water reabsorption by kidneys, conserving blood volume and thus increasing blood pressure

Question 12

activation of the sympathetic division of the ANS

Answer 12

• one of the homeostatic responses to shock
• baroreceptors detect low blood pressure and send signals to the CV center to increase hearte rate and contractility, and to increase vasoconstriction in the skin, kidneys, and abdominal viscera, increasing blood pressure

Question 13

release of local vasodilators

Answer 13

• one of the homeostatic responses to shock
• response to hypoxia, caused by K+, H+, lactic acid, adenosine, and nitric oxide, which lead to vasodilation
• helps increase local blood flow which restores O2 locally, but decreases systemic vascular resistance, lowering blood pressure

Question 14

signs and symptoms of shock

Answer 14

• systolic blood pressure lower than 90mmHg
• rapid resting heart rate
• weak and rapid pulse
• cool, pale, clammy skin
• mental state altered due to reduced oxygen supply to the brain
• reduced urine formation
• thist (due to loss of extracellular fluid)
• low blood pH due to buildup of lactic acid
• nausea due to impared blood flow to digestive organs