5 Homeostasis Flashcards
1
Q
It is a response to the stretching of the cervix that sends signals to the brain and stimulate the posterior pituitary gland to release oxytocin that promotes further uterine contractions during labor.
A
Ferguson reflex
2
Q
It is a feedback loop that amplifies the change in the variable, has destabilizing effect, and can be valuable in some major cases.
A
Positive feedback
3
Q
It is an anticipatory mechanism that takes corrective action even before a disturbance is sensed by sending central command signals to either the lower order feedback controllers or the effectors.<br></br>
A
Feedforward control
4
Q
It involves physiological adjustments to change in temperature, humidity, photoperiod, or pH allowing the organism to maintain performance across a range of environmental conditions.<br></br>
A
Acclimatization
5
Q
It is a control system that involves the integration of feedforward and negative feedback systems.<br></br>
A
Adaptive control
6
Q
What is another term for adaptive control (essentially the same)?
A
Delayed negative feedback control
7
Q
How much mg/dL does blood sugar increase to each morning after the first meal?
A
120 to 140 mg/dL
8
Q
Total body fluid (ECF+ICF) makes up _____ % of total body weight.
A
60%
9
Q
The levels of body constituents must remain at a fixed value.
A
False. There is a range of values for each body constituent
10
Q
Which hormone controls sodium and potassium ions as well as protein metabolism?
A
Adrenocortical hormone
11
Q
Both the cardio acceleratory- and cardio inhibitory areas are found in the hypothalamus. T or F
A
False. Found in the medulla oblongata<br></br>
12
Q
What is the term for the kind of growth that commonly occurs in the heart muscles of endurance athletes?
A
Eccentric hypertrophy - cardiac muscles enlarge by 25% in volume
13
Q
What is the term for the kind of growth that commonly occurs in the heart muscles of resistance (sprint/powerlifter) athletes?
A
Concentric hypertrophy - the ventricle walls thicken
14
Q
What is a common intracellular control system alongside genetic control systems?
A
Homeostasis by negative feedback
15
Q
Is childbirth (parturition) a case of negative or positive feedback?
A
Childbirth is a case of positive feedback.
16
Q
What hormone is released by the posterior pituitary during childbirth?
A
Oxytocin
17
Q
<div> <div> <div> <div>This amplifies the change in the variable and has a destabilizing effect</div> </div> </div> </div>
A
Positive Feedback
18
Q
What are the examples of a positive feedback mechanism?
A
blood Clotting (Hemostasis), Parturition (Childbirth)Activation of Neurons (Action potential), Ovulation
19
Q
What is initiated when a break or tear occurs in a blood vessel?
A
Blood clotting (Hemostasis)
20
Q
What happens after platelets adhere to a site of injury during blood clotting?
A
<div> <div> <div> <div> <div>Released chemicals attract more platelets.</div> </div> </div> </div></div>
21
Q
What ends the positive feedback cycle in blood clotting?
A
Feedback cycle ends when plug is formed
22
Q
What type of feedback loop is involved in the baroreceptor reflex?
A
Negative feedback loop
23
Q
What is an example of an anticipatory negative feedback mechanism?
A
<div>Exercise, controlled by a feedforward loop.</div>
<div></div>
24
Q
What is the purpose of adaptive control in homeostasis?
A
Adaptive control involves the interaction of feedforward and negative feedback loops, allowing for delayed negative feedback control.
25
What kind of hypertrophy occurs in endurance athletes' hearts?
Eccentric hypertrophy.
26
What physiological adjustments are part of acclimatization in homeostasis?
Adjustments to temperature, humidity, photoperiod, or pH to maintain performance across environmental conditions.
27
Homeostasis (Intro)
What is the study of the normal functions of the human body at various levels of organization called?A) Anatomy B) Physiology C) Pathology D) Biochemistry
B) Physiology
Physiology is the scientific study that focuses on understanding how the human body functions, from the smallest components like biomolecules and cells to larger systems like organs and the whole organism. This foundational knowledge is crucial for understanding diseases and medical practice.
Physiology is the scientific study that focuses on understanding how the human body functions, from the smallest components like biomolecules and cells to larger systems like organs and the whole organism. This foundational knowledge is crucial for understanding diseases and medical practice.
28
Homeostasis (Intro)
What is the study of the normal functions of the human body at various levels of organization called?A) Anatomy B) Physiology C) Pathology D) Biochemistry
B) Physiology
Physiology is the scientific study that focuses on understanding how the human body functions, from the smallest components like biomolecules and cells to larger systems like organs and the whole organism. This foundational knowledge is crucial for understanding diseases and medical practice.
Physiology is the scientific study that focuses on understanding how the human body functions, from the smallest components like biomolecules and cells to larger systems like organs and the whole organism. This foundational knowledge is crucial for understanding diseases and medical practice.
29
Homeostasis (Intro)
What are the different levels of organization in the human body, starting from the smallest unit?A) Cellular, Tissue, Organ, Systemic, Organismic, Molecular
B) Molecular, Cellular, Tissue, Organ, Systemic, Organismic
C) Organismic, Systemic, Organ, Tissue, Cellular, Molecular
D) Tissue, Molecular, Organ, Cellular, Systemic, Organismic
B) Molecular, Cellular, Tissue, Organ, Systemic, Organismic
The human body is structured in a hierarchical manner. It begins at the molecular level, where biomolecules interact, progresses through cellular and tissue levels, and continues through the organization of tissues into organs, which function together in organ systems. The highest level is the organismic level, representing the whole body as a functioning unit.
The human body is structured in a hierarchical manner. It begins at the molecular level, where biomolecules interact, progresses through cellular and tissue levels, and continues through the organization of tissues into organs, which function together in organ systems. The highest level is the organismic level, representing the whole body as a functioning unit.
30
Homeostasis (Intro)
What are the different levels of organization in the human body, starting from the smallest unit?A) Cellular, Tissue, Organ, Systemic, Organismic, Molecular
B) Molecular, Cellular, Tissue, Organ, Systemic, Organismic
C) Organismic, Systemic, Organ, Tissue, Cellular, Molecular
D) Tissue, Molecular, Organ, Cellular, Systemic, Organismic
B) Molecular, Cellular, Tissue, Organ, Systemic, Organismic
The human body is structured in a hierarchical manner. It begins at the molecular level, where biomolecules interact, progresses through cellular and tissue levels, and continues through the organization of tissues into organs, which function together in organ systems. The highest level is the organismic level, representing the whole body as a functioning unit.
The human body is structured in a hierarchical manner. It begins at the molecular level, where biomolecules interact, progresses through cellular and tissue levels, and continues through the organization of tissues into organs, which function together in organ systems. The highest level is the organismic level, representing the whole body as a functioning unit.
31
Homeostasis (Intro)
Which level of organization in the human body involves the study of tissues forming organs?A) Cellular Level B) Tissue Level C) Organ Level D) Systemic Level
C) Organ Level
The organ level of organization is where tissues—groups of similar cells that work together—are organized into organs. Each organ has a specific function and contributes to the overall operation of the body.
The organ level of organization is where tissues—groups of similar cells that work together—are organized into organs. Each organ has a specific function and contributes to the overall operation of the body.
32
Homeostasis (Intro)
Which level of organization in the human body involves the study of tissues forming organs?A) Cellular Level B) Tissue Level C) Organ Level D) Systemic Level
C) Organ Level
The organ level of organization is where tissues—groups of similar cells that work together—are organized into organs. Each organ has a specific function and contributes to the overall operation of the body.
The organ level of organization is where tissues—groups of similar cells that work together—are organized into organs. Each organ has a specific function and contributes to the overall operation of the body.
33
Homeostasis (Intro)
Why is physiology important for understanding diseases and medical practice?A) It provides insights into the structure of the body.
B) It helps in identifying how normal body functions can be disrupted by disease.
C) It focuses on the chemical processes within the body.
D) It is primarily concerned with the body's external appearance.
B) It helps in identifying how normal body functions can be disrupted by disease.
By studying physiology, we learn how the body is supposed to function normally. This knowledge is crucial for identifying when and how these functions are impaired, leading to diseases. It also helps in developing medical treatments and interventions.
By studying physiology, we learn how the body is supposed to function normally. This knowledge is crucial for identifying when and how these functions are impaired, leading to diseases. It also helps in developing medical treatments and interventions.
34
Homeostasis (Intro)
Why is physiology important for understanding diseases and medical practice?A) It provides insights into the structure of the body.
B) It helps in identifying how normal body functions can be disrupted by disease.
C) It focuses on the chemical processes within the body.
D) It is primarily concerned with the body's external appearance.
B) It helps in identifying how normal body functions can be disrupted by disease.
By studying physiology, we learn how the body is supposed to function normally. This knowledge is crucial for identifying when and how these functions are impaired, leading to diseases. It also helps in developing medical treatments and interventions.
By studying physiology, we learn how the body is supposed to function normally. This knowledge is crucial for identifying when and how these functions are impaired, leading to diseases. It also helps in developing medical treatments and interventions.
35
Homeostasis (Intro)
What is the highest level of organization in the human body?
A) Organ Level B) Cellular Level C) Organismic Level D) Systemic Level
C) Organismic Level
The organismic level refers to the entire human body functioning as a whole. It encompasses all the other levels of organization (molecular, cellular, tissue, organ, and systemic), integrating them into a single, living entity.
The organismic level refers to the entire human body functioning as a whole. It encompasses all the other levels of organization (molecular, cellular, tissue, organ, and systemic), integrating them into a single, living entity.
36
Homeostasis (Intro)
What is the highest level of organization in the human body?
A) Organ Level B) Cellular Level C) Organismic Level D) Systemic Level
C) Organismic Level
The organismic level refers to the entire human body functioning as a whole. It encompasses all the other levels of organization (molecular, cellular, tissue, organ, and systemic), integrating them into a single, living entity.
The organismic level refers to the entire human body functioning as a whole. It encompasses all the other levels of organization (molecular, cellular, tissue, organ, and systemic), integrating them into a single, living entity.
37
Homeostasis (Intro)
How are cells organized in the human body?
A) Cells form organs directly, which are part of tissues and then organ systems.B) Cells are grouped into tissues, which combine to form organs, and these organs are part of interconnected organ systems.
C) Cells operate independently and do not organize into higher structures.
D) Cells form tissues, which function as individual systems without forming organs.
B) Cells are grouped into tissues, which combine to form organs, and these organs are part of interconnected organ systems.
Cells are the basic building blocks of life. In the human body, they group together to form tissues. Tissues then combine to create organs, each with specific functions. These organs are part of larger organ systems that work together to maintain homeostasis in the body.
Cells are the basic building blocks of life. In the human body, they group together to form tissues. Tissues then combine to create organs, each with specific functions. These organs are part of larger organ systems that work together to maintain homeostasis in the body.
38
Homeostasis (Intro)
How are cells organized in the human body?
A) Cells form organs directly, which are part of tissues and then organ systems.B) Cells are grouped into tissues, which combine to form organs, and these organs are part of interconnected organ systems.
C) Cells operate independently and do not organize into higher structures.
D) Cells form tissues, which function as individual systems without forming organs.
B) Cells are grouped into tissues, which combine to form organs, and these organs are part of interconnected organ systems.
Cells are the basic building blocks of life. In the human body, they group together to form tissues. Tissues then combine to create organs, each with specific functions. These organs are part of larger organ systems that work together to maintain homeostasis in the body.
Cells are the basic building blocks of life. In the human body, they group together to form tissues. Tissues then combine to create organs, each with specific functions. These organs are part of larger organ systems that work together to maintain homeostasis in the body.
39
Which systems coordinates the homeostasis of the internal environment?
The nervous and endocrine systems
40
What system transports nutrients and gases around the body?
Cardiovascular system
41
What transports waste products to the respective systems for excretion?
Cardiovascular system
42
What is the function of the gastrointestinal system in maintaining homeostasis?
The digestion and absorption of nutrients, water and electrolytes. It also helps in detoxification
43
What protects the internal environment from infections?
The immune system
44
This system protects the internal environment from the external environment
The integumentary system (Skin)
45
This system coordinates the regulation and coordination of homeostatic feedback mechanisms
The nervous system
46
What is the role of the endocrine system?
It has glands that secrete hormones that regulate physiological functions. Examples include growth, metabolism, reproduction
47
This system helps to maintain blood gas levels
Respiratory system
48
What system(s) help with the excretion of waste products?
Renal/urinary system for organic waste, respiratory for carbon dioxide
49
How does the body deal with increased levels of electrolytes and water in the body?
Excess electrolytes and water are excreted via the urinary system
50
How does the musculoskeletal system help with the internal environment?
Its primary function is support and movement. Hence, they can help other systems accomplish their homeostatic mechanisms. Foe example, it can assist in consuming foods for the digestive system to replenish electrolytes in the body.
51
What systems maintain electrolyte levels?
Digestive system replenishes electrolytes via consumption, urinary system excretes excess electrolytes.
52
What organ detoxifies waste products?
Liver
53
What organ system helps maintain blood pH?
Renal/urinary system
54
What percentage of the adult human body is fluid, and what is this fluid primarily composed of?
- 50-70%
- water solution containing ions and other substances
55
What are the two main compartments of body fluid, and where are they located?
- Intracellular Fluid (inside the cells)
- Extracellular Fluid (outside the cells)
56
What proportion of the body's fluid is Intracellular Fluid?
- about 2/3 of the body’s fluid is Intracellular Fluid
57
What fraction of the body’s fluid is Extracellular Fluid, and where is it found?
- about 1/3 of the body’s fluid is Extracellular Fluid
- found in spaces outside the cells
58
What term did Claude Bernard introduce to describe the environment of the body's cells, and what does it mean?
Claude Bernard introduced the term "milieu intérieur," referring to the stable internal environment in which cells exist, also known as the internal environment of the body.
59
What are the primary components of Extracellular Fluid?
- large amounts of sodium (Na⁺)
- chloride (Cl⁻)
- bicarbonate ions (HCO₃⁻)
- cell nutrients (such as oxygen, glucose, fatty acids, & amino acids)
60
What ions and molecules are predominantly found in Intracellular Fluid?
- large amounts of potassium (K⁺)
- magnesium (Mg²⁺)
- phosphate ions (PO₄³⁻)
61
How does the composition of Intracellular Fluid differ from that of Extracellular Fluid?
Intracellular Fluid is rich in potassium, magnesium, and phosphate ions.
Extracellular Fluid is rich in sodium, chloride, and bicarbonate ions, cell nutrients ( oxygen, glucose, fatty acids, and amino acids) and waste products.
Extracellular Fluid is rich in sodium, chloride, and bicarbonate ions, cell nutrients ( oxygen, glucose, fatty acids, and amino acids) and waste products.
62
In a routine medical examination, [ ] is examined when blood is extracted to check for abnormalities
ECF
63
Most commonly used feedback control system
Negative feedback
64
What are the negative feedback common response?
1. Reverse change in variable
2. Stabilizing effect
3. Return physiological variablke within normal range
4. Used for condition with frequent adjustment.
2. Stabilizing effect
3. Return physiological variablke within normal range
4. Used for condition with frequent adjustment.
65
If some factor become excessive or deficient, a control system will initiate____? Which include series of changes in order to go towards mean value, thus mantaining____?
negative feedback, homeostasis
66
How does a negative feedback control system operate?
1st. Disturbance produces a change in the controlled variable
2nd. The change is detected by receptor or a sensor
3rd. The information is sent along the afferent pathway to the feedback controller/ integrator comparator.
4th. A efferor signal is sent along the efferent pathway
2nd. The change is detected by receptor or a sensor
3rd. The information is sent along the afferent pathway to the feedback controller/ integrator comparator.
4th. A efferor signal is sent along the efferent pathway
67
Change detected by receptor is also calles?
stimulus
68
Effector response is to?
change the magnitude of the stimulus and return the variable to homeostasis.
69
detectable change in regulated variable; picked up by sensor
stimulus
70
received feedback signal. relays information about the nature of the change via affarent pathway
sensor
71
mantains conditions around set point values and relayed signal via efferent pathway. compares feedback signal with set point value; generates error signal which is sent to effectors
Integrating center (feedback controller/comparator)
72
cause the response, which is a reversal of the change in the biologic system which is within the normal range of the controlled variable
effector(S)
73
the desired value of the control system
set point value
74
difference between actual value of input signal picked up bysensor and the set point value
error signal
75
error signal is directed to the _____ to produce the neccessary change to bring the physiological variable to the normal range of the physiological set point
effector
76
blood glucose concentration is controlled by the?
pancreas
77
Pancreas has this type of mechanisms that monitor the concentration of glucose in the blood
Glucose sensing mechanisms
78
In pancreas, ______ secretes hormones to regulate blood sugar
islet of langerhans
79
This type of cell secretes insulin
beta cells
80
Helps lower the blood glucose when there is an abundance in the blood, secreted after meal.
Insulin
81
Storage of glucose in the liver
Glycogen
82
This type of cell secretes glucagon
alpha cells
83
Facilitates the breakdown of liver glycogen into glucose, which results in raising of blood sugar levels
glucagon
84
What is the primary function of the set point in a negative feedback control system?
A) To maintain a constant value for physiological variables
A) To maintain a constant value for physiological variables
B) To serve as a target value around which physiological variables fluctuate
C) To create a fixed value for extracellular fluid composition
D) To eliminate the need for homeostatic regulation
Correct answer: B To serve as a target value around which physiological variables fluctuate
85
How does a negative feedback control system respond to an imbalance in the system?
A) It amplifies the disturbance to correct the imbalance
B) It reverses the change in the variable to return it to the set point
C) It ignores the disturbance and maintains the original state
D) It introduces a new variable to counteract the disturbance
Correct answer: B It reverses the change in the variable to return it to the set point
86
Which of the following is NOT a variable controlled by negative feedback systems?
A) Blood pressure
B) Body temperature
C) Rate of enzyme reaction in cells
D) Fixed concentration of extracellular fluid
Correct answer: D Fixed concentration of extracellular fluid
87
In the negative feedback control system, what role does the receptor or sensor play?
A) It compares the value of the control variable with the set point
B) It detects changes or stimuli in the controlled variable
C) It sends error signals to the effector
D) It initiates the disturbance in the system
Correct answer: B It detects changes or stimuli in the controlled variable
88
What happens after the receptor detects a change in the controlled variable?
A) The change is ignored until it stabilizes on its own
B) Information about the change is sent along the efferent pathway to the effectors
C) The information is sent along the afferent pathway to the feedback controller
D) The feedback controller immediately reverses the disturbance without further processing
Correct answer: C The information is sent along the afferent pathway to the feedback controller
89
What is the consequence of uncontrolled chronic blood pressure
A) Improved nutrient delivery to the brain
B) Damage to blood vessel walls and potential for blood clots
C) Enhanced oxygenation of vital organs
D) Stabilization of blood pressure within normal range
B. Damage to blood vessel walls and potential for blood clots
90
Which physiological variable is closely regulated to maintain body temperature within a narrow range?
A) Hydrogen ions concentration
B) Mean arterial blood pressure
C) Electrolyte concentration
D) Blood pH
Correct answer: B Mean arterial blood pressure
91
There are two thermoreceptors involved in thermoregulation. What are they?
A. Peripheral thermoreceptors & Warm receptors
B. Hypothalamic Controller & Peripheral thermoreceptor
C. Central thermoreceptor & Peripheral thermoreceptor
D. Hypothalamic Controller & Warm receptors
Correct answer: C Central thermoreceptor & Peripheral thermoreceptor
92
What do the error signals sent by the anterior hypothalamus stimulate on a hot sunny day? What does it allow for?
A. Sweating & vasodilation; to allow for the decrease of heat loss across the skin surface
B. Sweating & vasoconstriction; to allow the blood vessels to dilate to allow better blood flow
C. Sweating & vasodilation; to allow for the increase of heat loss across the skin surface
D. Sweating & vasoconstriction; to prevent heat loss and increase temperature
Correct answer: C Sweating & vasodilation; to allow for the increase of heat loss across the skin surface
93
When the body is too cold, the thermoregulatory centre sends signals to prevent heat loss. What does the body do to prevent heat loss?
A. Sweat glands stop producing sweat to minimise energy transfer to environment
B. Blood vessels will constrict to reduce blood flow and prevent further loss of heat energy and allow conservation of core temperature
C. Skeletal muscles start to contract involuntarily and the adrenal gland releases epinephrine into the bloodstream
D. All of the above
Correct answer: D All of the above
94
Which part of the brain are the afferent signals sent to when the body is too hot?
A. Hypothalamus
B. Posterior hypothalamus
C. Anterior hypothalamus
D. Thermoregulatory centre
Correct answer: C Anterior hypothalamus
95
Which of the following best describes the role of insulin in glucose metabolism?
A) Insulin raises blood glucose levels by breaking down glycogen in the liver.
B) Insulin lowers blood glucose levels by facilitating glucose uptake by cells and storing it as glycogen in the liver.
C) Insulin raises blood glucose levels by promoting the release of glucose from adipose tissue.
D) Insulin lowers blood glucose levels by converting glucose into fatty acids stored in adipose tissue.
Correct Answer: B Insulin lowers blood glucose levels by facilitating glucose uptake by cells and storing it as glycogen in the liver.
96
Which statement accurately describes the role of the liver in glucose regulation?
A) The liver stores glucose as insulin.
B) The liver secretes glucagon to regulate blood glucose.
C) The liver stores glycogen and releases glucose during fasting in response to glucagon.
D) The liver directly lowers blood glucose by increasing insulin production.
Correct Answer: C The liver stores glycogen and releases glucose during fasting in response to glucagon.
97
Which of the following best describes the negative feedback mechanism in blood glucose regulation?
A) High blood glucose levels trigger the release of insulin, which further increases glucose levels.
B) Low blood glucose levels inhibit glucagon release to maintain homeostasis.
C) High blood glucose levels trigger insulin release, which lowers glucose levels, thereby reducing the stimulus for insulin secretion.
D) Glucagon is released in response to high glucose levels, stimulating glucose storage.
Correct Answer: C High blood glucose levels trigger insulin release, which lowers glucose levels, thereby reducing the stimulus for insulin secretion.
98
Which of the following scenarios would most likely result in hypoglycemia, and why?
A) Increased insulin sensitivity in peripheral tissues leading to enhanced glucose uptake
B) Excessive glucagon secretion causing rapid glycogen breakdown in the liver
C) Reduced insulin secretion by beta cells despite normal glucose levels
D) Impaired glucagon receptor function in the liver, leading to decreased glycogen breakdown
Correct Answer: A Increased insulin sensitivity in peripheral tissues leading to enhanced glucose uptake
99
A patient with diabetes mellitus has been prescribed insulin therapy. After administering their insulin injection, the patient decides to skip lunch. Which of the following is the most likely consequence of this decision?
A) The patient's blood glucose levels will rise, leading to hyperglycemia.
B) The patient's blood glucose levels will remain stable due to the effects of glucagon.
C) The patient's blood glucose levels will drop, potentially leading to hypoglycemia.
D) The patient's insulin levels will decrease, preventing any significant changes in blood glucose.
Correct Answer: C The patient's blood glucose levels will drop, potentially leading to hypoglycemia.
100
A 30-year-old patient is admitted to the hospital after collapsing during a marathon. Blood tests reveal low blood glucose levels. Which physiological response is most likely occurring in the patient’s body to restore normal glucose levels?
A) Increased secretion of insulin from the beta cells
B) Increased breakdown of glycogen in the liver due to glucagon release
C) Increased storage of glucose as glycogen in the liver
D) Decreased glucagon secretion from the alpha cells
Correct Answer: B Increased breakdown of glycogen in the liver due to glucagon release
101
What is the role of baroreceptors in the regulation of blood pressure?
A) They increase the pumping activity of the heart.
B) They sense changes in blood pressure and send signals to the brain.
C) They control the degree of constriction in blood vessels.
D) They act as the effector organs in the blood pressure control system.
Correct Answer: B They sense changes in blood pressure and send signals to the brain.
102
Which of the following is NOT a function of the medulla oblongata in the homeostatic blood pressure control system?
A) Serving as the feedback controller.
B) Sending signals to the sympathetic and parasympathetic nervous systems.
C) Sensing changes in blood pressure directly.
D) Controlling the heart's pumping activity through CAA and CIA.
Correct Answer: C Sensing changes in blood pressure directly.
103
What happens when the parasympathetic nervous system (PNS) is activated in response to elevated blood pressure?
A) Increased heart rate and blood vessel constriction.
B) Decreased heart rate and vasodilation of blood vessels.
C) Increased heart rate and vasodilation of blood vessels.
D) Decreased heart rate and blood vessel constriction.
Correct Answer: B Decreased heart rate and vasodilation of blood vessels.
104
What is the effect of vasomotor center activity in the blood pressure control system?
A) It directly increases blood pressure by pumping more blood.
B) It regulates the degree of constriction in blood vessels.
C) It acts as a sensor detecting changes in blood pressure.
D) It triggers the release of hormones to regulate blood pressure.
Correct Answer: B It regulates the degree of constriction in blood vessels.
105
If there is a decrease in blood pressure, what is the expected response from the medulla's vasomotor center?
A) Vasodilation and decreased heart pumping activity.
B) Vasoconstriction and increased heart pumping activity.
C) Decrease in sympathetic nervous system activity.
D) Increase in parasympathetic nervous system activity.
Correct Answer: B Vasoconstriction and increased heart pumping activity.
106
Which of the following correctly describes the effect of a negative feedback mechanism in response to an increase in blood pressure?
A) The heart's pumping activity increases, leading to further elevation of blood pressure.
B) Blood vessels constrict to maintain the elevated blood pressure.
C) The sympathetic nervous system increases its activity to lower blood pressure.
D) The parasympathetic nervous system increases its activity, leading to a decrease in blood pressure.
Correct Answer: D The parasympathetic nervous system increases its activity, leading to a decrease in blood pressure.
107
What is the primary effect of low arterial oxygen (O2) levels on respiration?
A) Increased CO2 production.
B) Stimulation of chemoreceptors to increase breathing rate.
C) Decreased breathing rate.
D) Reduced sensitivity to CO2.
Correct Answer: B Stimulation of chemoreceptors to increase breathing rate.
108
What triggers the activation of chemoreceptors in the regulation of blood gases?
A) Decrease in arterial oxygen concentration.
B) Increase in blood pH levels.
C) Decrease in carbon dioxide concentration.
D) Increase in oxygen concentration.
Correct Answer: A Decrease in arterial oxygen concentration.
109
How does the medulla ensure proper control of blood gases?
A) By directly measuring the oxygen content in the lungs.
B) By comparing incoming signals from sensors to a physiological set point.
C) By increasing the production of CO2 in the body.
D) By adjusting the sensitivity of chemoreceptors to CO2 levels.
B) By comparing incoming signals from sensors to a physiological set point.
C) By increasing the production of CO2 in the body.
D) By adjusting the sensitivity of chemoreceptors to CO2 levels.
Correct Answer: B By comparing incoming signals from sensors to a physiological set point.
110
True or False. The control system for blood gases primarily regulates blood CO2 and oxygen levels.
Correct Answer: True
