Chapter 25 Vital Signs
Learning Objectives
1. Explain the physiologic processes involved in homeostatic regulation of temperature, pulse,
respirations, and blood pressure.
҉ Vital signs= temp, pulse, respiration, blood pressure, pain
҉ Heat production
o Primary source is metabolism
o Hormones, muscle movements, and exercise increase metabolism
o Epinephrine and norepinephrine are released when additional heat is
required, and alter metabolism
o Thyroid hormone and shivering also increase heat production
o Energy production decreases and heat productions increases
҉ Sources of heat loss
o Skin (primary source)
The sympathetic nervous system controls the opening and
closing of the arteriovenous shunts in response to changes in
core body temp and in environmental temp
o Evaporation of sweat
o Warming and humidifying inspired air
o Eliminating urine and feces
҉ Physical effects of fever
o Loss of appetite, headache, hot dry skin, flushed face, thirst, muscle
aches, and fatigue
o Respiration and pulse increase
o Young children can have seizures and older adults can have confusion or
delirium
o Fever blisters may develop as fever activates type 1 herpes simplex virus
o Fluid, electrolyte, and acid-base imbalances can occur
҉ Transfer of body heat to external environment
o Radiation: the diffusion or dissemination of heat by electromagnetic
waves (ex=heat escaping from head)
o Convection: dissemination of heat by motion between areas of unequal
density (fan blowing a warm body)
o Evaporation: conversion of a liquid to a vapor (sweat)
o Conduction: transfer of heat to another object during direct contact (ice
pack)
҉ Pulse Physiology
, o Regulated by the autonomic nervous system through cardiac sinoatrial
node
o Parasympathetic stimulation- decreases heart rate
o Sympathetic stimulation- increases heart rate
o Pulse rate- number of contractions over a peripheral artery in 1 min
҉ Characteristics of the peripheral pulse
o Rate: normal, tachycardia, bradycardia
o Amplitude and quality (strong or weak)
o Rhythm (regular or irregular)
o Volume of blood ejected with each heartbeat (stroke volume)
o An apical pulse may also be auscultated (listened to) over the apex of
the heart as the heart beats. Heart sounds, which are produced by
closure of the valves of the heart, are characterized as “lub-dub.” The
apical pulse is the result of closure of the mitral and tricuspid valves
(“lub”) and aortic and pulmonic valves (“dub”)
Pulse Amplitude Grade Description
0 Absent, unable to palpate
+1 Diminished, weaker than expected
+2 Brisk, expected (normal)
+3 Bounding
҉ Rate and depth of breathing
o Changes in response to tissue demands
o Controlled by respiratory centers in the medulla and pons
o Activated by impulses from chemoreceptors
o Increase in carbon dioxide is the most powerful respiratory stimulant
҉ Blood pressure
o Measured in mm Hg (millimeters of mercury)
o Arterial walls contain elastic tissue that allows them to stretch and
extend as blood enters with each ventricular contraction
o The elasticity of the arterial walls and resistance of the arterioles help
maintain a normal blood pressure
2. Compare and contrast factors that increase or decrease body temperature, pulse, respirations,
and blood pressure
҉ Factors affecting body temperature
o Circadian rhythms (every 24 hours)
Body temp is lower in the early morning than in the late
afternoon/evening
Peak elevation of temp is between 4-8pm
o Age and gender
, Older adults have lower temp
Older and very young are more sensitive to changes in
environmental temp
Women experience more fluctuations in body temp than men
due to hormones
o Physical activity
o State of health
o Environmental temp
Hypothermia (low body temp)
Hyperthermia (high body temp)
o Hypothalamus triggers fever
҉ Factors affecting blood pressure
o Age, gender, race
Older adult has decreased elasticity of arteries, increasing
peripheral resistance, therefore increasing BP
o Circadian rhythm
Lowest in morning, rising late afternoon, falls during sleep
o Food intake
o Exercise
o Weight
Higher in obese people
o Emotional state
o Body position
o Drugs/medication
Oral contraceptives cause a mild increase in BP
o Race
Hypertension is more common and severe in African American
men and women
Overactivation of both angiotensin and aldosterone result in an
increase in blood pressure. Over time, this sustained increase
results in a permanent remodeling and thickening of the blood
vessels. As a result, there is increased peripheral resistance and
a back-up of pressure to organs affected by the vascular system,
such as the brain, heart, and kidneys
҉ Factors affecting respiration
o anemia
o exercise
o respiratory and cardiovascular disease
o alterations in fluid, electrolyte, and acid-base balances
o medications
o trauma
Learning Objectives
1. Explain the physiologic processes involved in homeostatic regulation of temperature, pulse,
respirations, and blood pressure.
҉ Vital signs= temp, pulse, respiration, blood pressure, pain
҉ Heat production
o Primary source is metabolism
o Hormones, muscle movements, and exercise increase metabolism
o Epinephrine and norepinephrine are released when additional heat is
required, and alter metabolism
o Thyroid hormone and shivering also increase heat production
o Energy production decreases and heat productions increases
҉ Sources of heat loss
o Skin (primary source)
The sympathetic nervous system controls the opening and
closing of the arteriovenous shunts in response to changes in
core body temp and in environmental temp
o Evaporation of sweat
o Warming and humidifying inspired air
o Eliminating urine and feces
҉ Physical effects of fever
o Loss of appetite, headache, hot dry skin, flushed face, thirst, muscle
aches, and fatigue
o Respiration and pulse increase
o Young children can have seizures and older adults can have confusion or
delirium
o Fever blisters may develop as fever activates type 1 herpes simplex virus
o Fluid, electrolyte, and acid-base imbalances can occur
҉ Transfer of body heat to external environment
o Radiation: the diffusion or dissemination of heat by electromagnetic
waves (ex=heat escaping from head)
o Convection: dissemination of heat by motion between areas of unequal
density (fan blowing a warm body)
o Evaporation: conversion of a liquid to a vapor (sweat)
o Conduction: transfer of heat to another object during direct contact (ice
pack)
҉ Pulse Physiology
, o Regulated by the autonomic nervous system through cardiac sinoatrial
node
o Parasympathetic stimulation- decreases heart rate
o Sympathetic stimulation- increases heart rate
o Pulse rate- number of contractions over a peripheral artery in 1 min
҉ Characteristics of the peripheral pulse
o Rate: normal, tachycardia, bradycardia
o Amplitude and quality (strong or weak)
o Rhythm (regular or irregular)
o Volume of blood ejected with each heartbeat (stroke volume)
o An apical pulse may also be auscultated (listened to) over the apex of
the heart as the heart beats. Heart sounds, which are produced by
closure of the valves of the heart, are characterized as “lub-dub.” The
apical pulse is the result of closure of the mitral and tricuspid valves
(“lub”) and aortic and pulmonic valves (“dub”)
Pulse Amplitude Grade Description
0 Absent, unable to palpate
+1 Diminished, weaker than expected
+2 Brisk, expected (normal)
+3 Bounding
҉ Rate and depth of breathing
o Changes in response to tissue demands
o Controlled by respiratory centers in the medulla and pons
o Activated by impulses from chemoreceptors
o Increase in carbon dioxide is the most powerful respiratory stimulant
҉ Blood pressure
o Measured in mm Hg (millimeters of mercury)
o Arterial walls contain elastic tissue that allows them to stretch and
extend as blood enters with each ventricular contraction
o The elasticity of the arterial walls and resistance of the arterioles help
maintain a normal blood pressure
2. Compare and contrast factors that increase or decrease body temperature, pulse, respirations,
and blood pressure
҉ Factors affecting body temperature
o Circadian rhythms (every 24 hours)
Body temp is lower in the early morning than in the late
afternoon/evening
Peak elevation of temp is between 4-8pm
o Age and gender
, Older adults have lower temp
Older and very young are more sensitive to changes in
environmental temp
Women experience more fluctuations in body temp than men
due to hormones
o Physical activity
o State of health
o Environmental temp
Hypothermia (low body temp)
Hyperthermia (high body temp)
o Hypothalamus triggers fever
҉ Factors affecting blood pressure
o Age, gender, race
Older adult has decreased elasticity of arteries, increasing
peripheral resistance, therefore increasing BP
o Circadian rhythm
Lowest in morning, rising late afternoon, falls during sleep
o Food intake
o Exercise
o Weight
Higher in obese people
o Emotional state
o Body position
o Drugs/medication
Oral contraceptives cause a mild increase in BP
o Race
Hypertension is more common and severe in African American
men and women
Overactivation of both angiotensin and aldosterone result in an
increase in blood pressure. Over time, this sustained increase
results in a permanent remodeling and thickening of the blood
vessels. As a result, there is increased peripheral resistance and
a back-up of pressure to organs affected by the vascular system,
such as the brain, heart, and kidneys
҉ Factors affecting respiration
o anemia
o exercise
o respiratory and cardiovascular disease
o alterations in fluid, electrolyte, and acid-base balances
o medications
o trauma
