WGU D236 Pathophysiology 2026 by
Megan/Shay’s Study Guides
Tay-Sachs Disease
An autosomal recessive inherited genetic disorder caused by a recessive allele
(chromosome 15) that leads to the accumulation of certain lipids in the brain. Seizures,
blindness, and degeneration of motor and mental performance usually become manifest
a few months after birth, followed by death within a few years.
Marfan Syndrome
Inherited autosomal dominant trait (only one abnormal copy of the Marfan gene
inherited from one parent) FBN1 gene. Genetic connective tissue disorder that can
affect aorta and heart valve structures.
**If one parent has Marfan syndrome, each child has a 50% chance of inheriting the
abnormal gene and developing the condition. If both parents have the condition, the risk
of their child inheriting the abnormal gene and developing Marfan syndrome increases
to 75%.
Turner Syndrome
A chromosomal disorder in females in which either an X chromosome is missing,
making the person XO instead of XX, or part of one X chromosome is deleted.
Underdeveloped ovaries (sterile)
Short stature (under 4' 7")
Amenorrhea
Webbing of the neck
Edema
Underdeveloped breasts/wide nipples
Respiratory rate increases during exercise. How does this increased respiratory rate
allow the body to maintain a homeostatic pH level?
The increased exhalation of CO2 helps to increase pH.
(The increased respiratory rate allows more CO2 to be exhaled. Since CO2 reacts with
water to form carbonic acid, getting rid of more CO2 through increased respiration will
raise pH)
,An ICU patient's arterial blood gas results show low pH and low CO2 levels. The
patient's respiratory rate is increased. What is the name of this condition?
Metabolic acidosis
(Since the pH is low, and the pH and CO2 are trending in the same direction, the
condition is metabolic acidosis. The low CO2 indicates that CO2 is not causing the
acidosis. The increased respiratory rate lowers blood CO2 in an attempt to compensate
for the metabolic acidosis.)
Your patient has pulmonary edema, which raises levels of CO2 in the blood. What helps
the patient's body to compensate for this increase?
The kidneys conserve H+ and conserve HCO3-
The kidneys excrete more H+ and conserve HCO3-
The kidneys conserve H+ and excrete more HCO3-
The kidneys excrete more H+ and excrete more HCO3-
The kidneys excrete more H+ and conserve HCO3-
(The increased CO2 level will generate more carbonic acid. The body must compensate
for the decreased pH. Excreting more H+ and conserving HCO3- will both help to
increase pH.)
Heberden and Bouchard's nodes are indicative of what disease process?
Osteoarthritis
You receive a patient who has experienced a burn on the right leg. The burn has small
blisters, is markedly pinkish red, and has a shiny and moist appearance. When the
patient is asked about pain level, the patient describes it as severe.
What level of burn does this patient present?
Superficial thickness / Partial or intermediate thickness / Full Thickness / Fourth Degree
Second Degree (partial thickness)
Second degree: Partial thickness burns can be either superficial partial thickness or
deep partial thickness, depending on the degree of tissue necrosis of the dermal layer.
These burns can char the epidermis and papillary dermal layer, with resultant edema
and formation of epidermal blisters. Burned skin is wet, raw, and pink or cherry red in
color that blanches with pressure.
Identify degrees of burn, and other s/s to that degree burn
,First-degree (Superficial) burns affect only the outer layer of the skin. They cause pain,
redness, and swelling (no blistering/scarring).
Second-degree (Partial or intermediate thickness) burns affect both the outer and
underlying layer of skin. They cause pain, redness, swelling, and blistering. Pink/Cherry
in color that blanches.
Third-degree (Full thickness) burns affect the deep layers of skin. High risk of infection.
Fourth-degree burns involve muscle or bone.
A 56-year-old female presents with superficial partial-thickness burns to the anterior
head and neck, front and back of the left arm, front of the right arm, posterior trunk, front
and back of the right leg, and back of the left leg.
Calculate the total body surface area percentage that is burned using the Rule of Nines.
63%
The Rule of Nines is a rapid method used during the prehospital and emergent phase of
care. The body is divided into regions that present 9%, or multiples of 9, with the
exception of the perineum, which is 1% of BSA (body surface area). The face and back
of the head are 4.5% each, so the entire head is 9%, the anterior and posterior portion
of the arm is 9%, and the total for each leg is 18%. Anterior head and neck (4.5%), front
and back of the left arm (9%), front of the right arm (4.5%), posterior trunk (18%), front
and back of the right leg (18%), back of the left leg (9%) which equals 63%.
An adolescent male patient is brought to the emergency department after spending a
long day at the beach. The patient's head, neck, and trunk from the waist upwards and
legs from the knees downward are bright red and edematous. The patient is crying and
reports 8 out of 10 on the pain scale and an inability to find a comfortable position.
What is the most likely classification of this burn?
Superficial Thickness / Partial or Intermediate Thickness / Full Thickness / Fourth
Degree
Superficial / First Degree Burn
Superficial burns are reddened and painful.
Burn that requires surgery, forms more scars and are less painful?
Superficial thickness / Partial or Intermediate Thickness / Full Thickness / 4th Degree
Deep partial thickness / Second Degree Burn
-Blisters/weeps
-Risk of infection/scarring increase with depth of burn
, Describe an intracranial bleed in the epidural space
Typically caused by a head injury and usually with a skull fracture.
Occurs between the skull bone and the outmost membrane layer, the dura mater.
High pressure bleeding is a prominent feature.
You may briefly lose consciousness.
Describe an intracranial bleed in the subdural space
Collection of blood on the surface of your brain.
Typically caused by your head moving rapidly forward and stopping, such as a car
accident or shaken baby syndrome.
More common in older people and people with a history of heavy alcohol use.
Describe an intracranial bleed in the subarachnoid space
Occurs between the brain and the thin tissues that cover the brain.
The most common cause is trauma but it can also be d/t the rupture of a major blood
vessel in the brain (intracerebral aneurysm).
A sudden, sharp headache usually comes before a subarachnoid hemorrhage. Typical
symptoms also include loss of consciousness and vomiting.
Describe an intracranial bleed in the intracerebral space
Occurs inside the brain.
Not usually the result of an injury.
Prominent warning sign is the sudden onset of neurological deficits. Symptoms
progress over minutes to hours and include headache, difficulty speaking, n/v,
decreased consciousness, weakness in one part of the body, and elevated blood
pressure.
Cerebral Concussion (Mild Traumatic Brain Injury)
Individuals with mild TBI can develop postconcussive syndrome (PCS), which includes
headaches, lethargy, mental dullness, and other symptoms that can persist for several
months after a TBI.
Signs and symptoms of cerebral contusion
Megan/Shay’s Study Guides
Tay-Sachs Disease
An autosomal recessive inherited genetic disorder caused by a recessive allele
(chromosome 15) that leads to the accumulation of certain lipids in the brain. Seizures,
blindness, and degeneration of motor and mental performance usually become manifest
a few months after birth, followed by death within a few years.
Marfan Syndrome
Inherited autosomal dominant trait (only one abnormal copy of the Marfan gene
inherited from one parent) FBN1 gene. Genetic connective tissue disorder that can
affect aorta and heart valve structures.
**If one parent has Marfan syndrome, each child has a 50% chance of inheriting the
abnormal gene and developing the condition. If both parents have the condition, the risk
of their child inheriting the abnormal gene and developing Marfan syndrome increases
to 75%.
Turner Syndrome
A chromosomal disorder in females in which either an X chromosome is missing,
making the person XO instead of XX, or part of one X chromosome is deleted.
Underdeveloped ovaries (sterile)
Short stature (under 4' 7")
Amenorrhea
Webbing of the neck
Edema
Underdeveloped breasts/wide nipples
Respiratory rate increases during exercise. How does this increased respiratory rate
allow the body to maintain a homeostatic pH level?
The increased exhalation of CO2 helps to increase pH.
(The increased respiratory rate allows more CO2 to be exhaled. Since CO2 reacts with
water to form carbonic acid, getting rid of more CO2 through increased respiration will
raise pH)
,An ICU patient's arterial blood gas results show low pH and low CO2 levels. The
patient's respiratory rate is increased. What is the name of this condition?
Metabolic acidosis
(Since the pH is low, and the pH and CO2 are trending in the same direction, the
condition is metabolic acidosis. The low CO2 indicates that CO2 is not causing the
acidosis. The increased respiratory rate lowers blood CO2 in an attempt to compensate
for the metabolic acidosis.)
Your patient has pulmonary edema, which raises levels of CO2 in the blood. What helps
the patient's body to compensate for this increase?
The kidneys conserve H+ and conserve HCO3-
The kidneys excrete more H+ and conserve HCO3-
The kidneys conserve H+ and excrete more HCO3-
The kidneys excrete more H+ and excrete more HCO3-
The kidneys excrete more H+ and conserve HCO3-
(The increased CO2 level will generate more carbonic acid. The body must compensate
for the decreased pH. Excreting more H+ and conserving HCO3- will both help to
increase pH.)
Heberden and Bouchard's nodes are indicative of what disease process?
Osteoarthritis
You receive a patient who has experienced a burn on the right leg. The burn has small
blisters, is markedly pinkish red, and has a shiny and moist appearance. When the
patient is asked about pain level, the patient describes it as severe.
What level of burn does this patient present?
Superficial thickness / Partial or intermediate thickness / Full Thickness / Fourth Degree
Second Degree (partial thickness)
Second degree: Partial thickness burns can be either superficial partial thickness or
deep partial thickness, depending on the degree of tissue necrosis of the dermal layer.
These burns can char the epidermis and papillary dermal layer, with resultant edema
and formation of epidermal blisters. Burned skin is wet, raw, and pink or cherry red in
color that blanches with pressure.
Identify degrees of burn, and other s/s to that degree burn
,First-degree (Superficial) burns affect only the outer layer of the skin. They cause pain,
redness, and swelling (no blistering/scarring).
Second-degree (Partial or intermediate thickness) burns affect both the outer and
underlying layer of skin. They cause pain, redness, swelling, and blistering. Pink/Cherry
in color that blanches.
Third-degree (Full thickness) burns affect the deep layers of skin. High risk of infection.
Fourth-degree burns involve muscle or bone.
A 56-year-old female presents with superficial partial-thickness burns to the anterior
head and neck, front and back of the left arm, front of the right arm, posterior trunk, front
and back of the right leg, and back of the left leg.
Calculate the total body surface area percentage that is burned using the Rule of Nines.
63%
The Rule of Nines is a rapid method used during the prehospital and emergent phase of
care. The body is divided into regions that present 9%, or multiples of 9, with the
exception of the perineum, which is 1% of BSA (body surface area). The face and back
of the head are 4.5% each, so the entire head is 9%, the anterior and posterior portion
of the arm is 9%, and the total for each leg is 18%. Anterior head and neck (4.5%), front
and back of the left arm (9%), front of the right arm (4.5%), posterior trunk (18%), front
and back of the right leg (18%), back of the left leg (9%) which equals 63%.
An adolescent male patient is brought to the emergency department after spending a
long day at the beach. The patient's head, neck, and trunk from the waist upwards and
legs from the knees downward are bright red and edematous. The patient is crying and
reports 8 out of 10 on the pain scale and an inability to find a comfortable position.
What is the most likely classification of this burn?
Superficial Thickness / Partial or Intermediate Thickness / Full Thickness / Fourth
Degree
Superficial / First Degree Burn
Superficial burns are reddened and painful.
Burn that requires surgery, forms more scars and are less painful?
Superficial thickness / Partial or Intermediate Thickness / Full Thickness / 4th Degree
Deep partial thickness / Second Degree Burn
-Blisters/weeps
-Risk of infection/scarring increase with depth of burn
, Describe an intracranial bleed in the epidural space
Typically caused by a head injury and usually with a skull fracture.
Occurs between the skull bone and the outmost membrane layer, the dura mater.
High pressure bleeding is a prominent feature.
You may briefly lose consciousness.
Describe an intracranial bleed in the subdural space
Collection of blood on the surface of your brain.
Typically caused by your head moving rapidly forward and stopping, such as a car
accident or shaken baby syndrome.
More common in older people and people with a history of heavy alcohol use.
Describe an intracranial bleed in the subarachnoid space
Occurs between the brain and the thin tissues that cover the brain.
The most common cause is trauma but it can also be d/t the rupture of a major blood
vessel in the brain (intracerebral aneurysm).
A sudden, sharp headache usually comes before a subarachnoid hemorrhage. Typical
symptoms also include loss of consciousness and vomiting.
Describe an intracranial bleed in the intracerebral space
Occurs inside the brain.
Not usually the result of an injury.
Prominent warning sign is the sudden onset of neurological deficits. Symptoms
progress over minutes to hours and include headache, difficulty speaking, n/v,
decreased consciousness, weakness in one part of the body, and elevated blood
pressure.
Cerebral Concussion (Mild Traumatic Brain Injury)
Individuals with mild TBI can develop postconcussive syndrome (PCS), which includes
headaches, lethargy, mental dullness, and other symptoms that can persist for several
months after a TBI.
Signs and symptoms of cerebral contusion
