California CPT-1 Practice Exam|
phlebotomy exam with verified answers
and a rationale for student PASS
2026|2027
Question 1
Which layer of a blood vessel is primarily responsible for constriction and
dilation?
A) Tunica adventitia
B) Tunica intima
C) Tunica media
D) Tunica externa
Correct Answer: C
Rationale: The tunica media contains smooth muscle and elastic fibers, allowing
vasoconstriction and vasodilation. The tunica intima is the inner lining, and tunica
adventitia/externa is connective tissue.
Question 2
The brachial artery is most commonly used for which procedure?
A) Capillary puncture on an infant
B) Venipuncture in the antecubital area
C) Arterial blood gas collection
D) Blood culture collection from a hand vein
,Correct Answer: C
Rationale: The brachial artery is a common site for arterial blood gas (ABG) draws
in adults. Venipuncture uses median cubital, cephalic, or basilic veins.
Question 3
Which vein is the first choice for routine venipuncture in the antecubital fossa?
A) Basilic vein
B) Cephalic vein
C) Median cubital vein
D) Median antebrachial vein
Correct Answer: C
Rationale: The median cubital vein is large, well-anchored, and less likely to roll,
minimizing patient discomfort and risk of nerve injury (unlike the basilic).
Question 4
What is the normal pH range of arterial blood?
A) 7.00–7.25
B) 7.35–7.45
C) 7.50–7.65
D) 6.95–7.10
Correct Answer: B
Rationale: Normal arterial pH is 7.35–7.45. Venous blood is slightly lower (7.31–
7.41).
Question 5
Which formed element in blood is primarily responsible for clotting?
,A) Erythrocytes
B) Leukocytes
C) Thrombocytes
D) Plasma
Correct Answer: C
Rationale: Thrombocytes (platelets) aggregate to form a platelet plug and
activate coagulation factors. Erythrocytes carry oxygen; leukocytes fight infection.
Question 6
The liquid portion of blood after clotting is called:
A) Plasma
B) Serum
C) Whole blood
D) Lymph
Correct Answer: B
Rationale: Serum is plasma without clotting factors (fibrinogen). Plasma is the
liquid before clotting.
Question 7
Which vein should be avoided due to its proximity to the brachial artery and
median nerve?
A) Cephalic
B) Basilic
C) Median cubital
D) Dorsal metacarpal
, Correct Answer: B
Rationale: The basilic vein lies near the brachial artery and median nerve;
accidental puncture can cause severe injury. Use only if no other site exists.
Question 8
What is the primary function of albumin in blood?
A) Oxygen transport
B) Immune defense
C) Maintain oncotic pressure
D) Blood coagulation
Correct Answer: C
Rationale: Albumin maintains colloidal osmotic pressure, preventing fluid from
leaking out of vessels.
Question 9
Capillary blood is a mixture of:
A) Arterial blood only
B) Venous blood only
C) Arterial, venous, and interstitial fluid
D) Lymph and plasma
Correct Answer: C
Rationale: Capillary puncture collects arteriolar, venular, and interstitial fluid. Not
identical to venous or arterial blood.
Question 10
Which vein runs along the thumb side of the forearm?
phlebotomy exam with verified answers
and a rationale for student PASS
2026|2027
Question 1
Which layer of a blood vessel is primarily responsible for constriction and
dilation?
A) Tunica adventitia
B) Tunica intima
C) Tunica media
D) Tunica externa
Correct Answer: C
Rationale: The tunica media contains smooth muscle and elastic fibers, allowing
vasoconstriction and vasodilation. The tunica intima is the inner lining, and tunica
adventitia/externa is connective tissue.
Question 2
The brachial artery is most commonly used for which procedure?
A) Capillary puncture on an infant
B) Venipuncture in the antecubital area
C) Arterial blood gas collection
D) Blood culture collection from a hand vein
,Correct Answer: C
Rationale: The brachial artery is a common site for arterial blood gas (ABG) draws
in adults. Venipuncture uses median cubital, cephalic, or basilic veins.
Question 3
Which vein is the first choice for routine venipuncture in the antecubital fossa?
A) Basilic vein
B) Cephalic vein
C) Median cubital vein
D) Median antebrachial vein
Correct Answer: C
Rationale: The median cubital vein is large, well-anchored, and less likely to roll,
minimizing patient discomfort and risk of nerve injury (unlike the basilic).
Question 4
What is the normal pH range of arterial blood?
A) 7.00–7.25
B) 7.35–7.45
C) 7.50–7.65
D) 6.95–7.10
Correct Answer: B
Rationale: Normal arterial pH is 7.35–7.45. Venous blood is slightly lower (7.31–
7.41).
Question 5
Which formed element in blood is primarily responsible for clotting?
,A) Erythrocytes
B) Leukocytes
C) Thrombocytes
D) Plasma
Correct Answer: C
Rationale: Thrombocytes (platelets) aggregate to form a platelet plug and
activate coagulation factors. Erythrocytes carry oxygen; leukocytes fight infection.
Question 6
The liquid portion of blood after clotting is called:
A) Plasma
B) Serum
C) Whole blood
D) Lymph
Correct Answer: B
Rationale: Serum is plasma without clotting factors (fibrinogen). Plasma is the
liquid before clotting.
Question 7
Which vein should be avoided due to its proximity to the brachial artery and
median nerve?
A) Cephalic
B) Basilic
C) Median cubital
D) Dorsal metacarpal
, Correct Answer: B
Rationale: The basilic vein lies near the brachial artery and median nerve;
accidental puncture can cause severe injury. Use only if no other site exists.
Question 8
What is the primary function of albumin in blood?
A) Oxygen transport
B) Immune defense
C) Maintain oncotic pressure
D) Blood coagulation
Correct Answer: C
Rationale: Albumin maintains colloidal osmotic pressure, preventing fluid from
leaking out of vessels.
Question 9
Capillary blood is a mixture of:
A) Arterial blood only
B) Venous blood only
C) Arterial, venous, and interstitial fluid
D) Lymph and plasma
Correct Answer: C
Rationale: Capillary puncture collects arteriolar, venular, and interstitial fluid. Not
identical to venous or arterial blood.
Question 10
Which vein runs along the thumb side of the forearm?
