SNC4M Exam Review-Questions, Answers| Newest
Update 2026/2027
What is the definition of homeostasis
The "internal balance" or narrow range of conditions a living thing must maintain to be healthy
and function efficiently.
How is body temperature defined?
The balance between heat loss (sweating, breathing, & excretion) and heat produced through
digestion and muscle contraction
What is the standard baseline for human body temperature
Approx. 98.6 F or 37 C
Define hyperthermia (fever) and hypothermia based on their temperature thresholds
Hyperthermia/Fever: A temperature above 101 DF, often in response to infection
Hypothermia: A temperature below 96 DF due to prolonged cold exposure
What is heart rate and what is its healthy adult range?
It's the number of times the heart beats in one minute. The healthy adult range is 60-100 beats
per minute
What are the four common sites used to measure a pulse?
The wrist (radical), neck (carotid), inner elbow (brachial), and heart (apical)
What is the respiratory rate and what is its healthy adult range at rest?
,The number of breaths taken per minute. The healthy adult range is 12-20 breaths per minute at
rest.
List the five breathing sounds observed with a stethoscope and what they indicate.
Clear: Unobstructed breathing.
Wheeze: Obstructed breathing.
Stridor: A blockage in the trachea.
Stertor: Snoring or fluid presence.
Crackle: Inflammation.
Define systolic and diastolic blood pressure, including their standard millimeter of mercury
(mmHg) ranges.
Systolic: Peak pressure during heart contraction, standardly 90-120 mmHg.
Diastolic: Lowest pressure during heart relaxation, standardly 60-80 mmHg.
Compare hypertension and hypotension by their numeric thresholds and common causes.
Hypertension (>140/90): Linked to obesity and high-sodium diets.
Hypotension (<100/60): Can be caused by blood loss or infection.
What does Oxygen Saturation (SpO2) measure and what is its standard range?
It measures the percentage of red blood cells saturated with oxygen. The standard range is 95-
100%.
How does a pulse oximeter estimate oxygen saturation through the skin?
It utilizes red light at 660nm and infrared light at 940nm.
, What is the general biological classification of blood?
Blood is a connective tissue where cells are suspended in a liquid extracellular matrix known as
plasma.
Describe the anatomical structure of erythrocytes (red blood cells) and why they are
formed this way.
They are structured as biconcave discs that completely lack a nucleus, endoplasmic reticulum
(ER), or mitochondria in order to maximize internal space for carrying hemoglobin.
Where does erythrocyte production occur and what mechanism controls it?
Production occurs in the red bone marrow. It is controlled by the hormone erythropoietin via a
negative feedback loop triggered by low oxygen levels.
What is the life cycle duration of a red blood cell, and how are they cleared from the body?
They live for about 120 days and are recycled in the liver and spleen by specialized cells called
macrophages.
What is the normal count range for leukocytes (white blood cells)?
3,500 to 10,500 cells per microliter.
Name the two major structural categories of leukocytes and their respective cell types.
Granulocytes: Neutrophils, eosinophils, and basophils.
Agranulocytes: Monocytes and lymphocytes.
Differentiate between leukocytosis and leukopenia, noting potential causes.
Update 2026/2027
What is the definition of homeostasis
The "internal balance" or narrow range of conditions a living thing must maintain to be healthy
and function efficiently.
How is body temperature defined?
The balance between heat loss (sweating, breathing, & excretion) and heat produced through
digestion and muscle contraction
What is the standard baseline for human body temperature
Approx. 98.6 F or 37 C
Define hyperthermia (fever) and hypothermia based on their temperature thresholds
Hyperthermia/Fever: A temperature above 101 DF, often in response to infection
Hypothermia: A temperature below 96 DF due to prolonged cold exposure
What is heart rate and what is its healthy adult range?
It's the number of times the heart beats in one minute. The healthy adult range is 60-100 beats
per minute
What are the four common sites used to measure a pulse?
The wrist (radical), neck (carotid), inner elbow (brachial), and heart (apical)
What is the respiratory rate and what is its healthy adult range at rest?
,The number of breaths taken per minute. The healthy adult range is 12-20 breaths per minute at
rest.
List the five breathing sounds observed with a stethoscope and what they indicate.
Clear: Unobstructed breathing.
Wheeze: Obstructed breathing.
Stridor: A blockage in the trachea.
Stertor: Snoring or fluid presence.
Crackle: Inflammation.
Define systolic and diastolic blood pressure, including their standard millimeter of mercury
(mmHg) ranges.
Systolic: Peak pressure during heart contraction, standardly 90-120 mmHg.
Diastolic: Lowest pressure during heart relaxation, standardly 60-80 mmHg.
Compare hypertension and hypotension by their numeric thresholds and common causes.
Hypertension (>140/90): Linked to obesity and high-sodium diets.
Hypotension (<100/60): Can be caused by blood loss or infection.
What does Oxygen Saturation (SpO2) measure and what is its standard range?
It measures the percentage of red blood cells saturated with oxygen. The standard range is 95-
100%.
How does a pulse oximeter estimate oxygen saturation through the skin?
It utilizes red light at 660nm and infrared light at 940nm.
, What is the general biological classification of blood?
Blood is a connective tissue where cells are suspended in a liquid extracellular matrix known as
plasma.
Describe the anatomical structure of erythrocytes (red blood cells) and why they are
formed this way.
They are structured as biconcave discs that completely lack a nucleus, endoplasmic reticulum
(ER), or mitochondria in order to maximize internal space for carrying hemoglobin.
Where does erythrocyte production occur and what mechanism controls it?
Production occurs in the red bone marrow. It is controlled by the hormone erythropoietin via a
negative feedback loop triggered by low oxygen levels.
What is the life cycle duration of a red blood cell, and how are they cleared from the body?
They live for about 120 days and are recycled in the liver and spleen by specialized cells called
macrophages.
What is the normal count range for leukocytes (white blood cells)?
3,500 to 10,500 cells per microliter.
Name the two major structural categories of leukocytes and their respective cell types.
Granulocytes: Neutrophils, eosinophils, and basophils.
Agranulocytes: Monocytes and lymphocytes.
Differentiate between leukocytosis and leukopenia, noting potential causes.
