BIOS252 Exam 1 (Anatomy & Physiology) – 2025-2026 Complete
Exam and Key Answers||Latest Version!!!Already Graded A+
What 3 features of RBCs support efficient gas exchange?
1. Biconcave shape offers huge surface area relative to volume for gas
exchange
2. Hemoglobin makes up 97% of cell volume (not counting water)
3. RBCs have no mitochondria, ATP production is anaerobic, so they
do not consume O2 they transport
What is the function of red blood cells?
RBCs are dedicated to respiratory gas transport, Hemoglobin binds
reversibly with O2 and CO2
How many molecules of oxygen can each hemoglobin molecule
carry?
Up to 4
What is the term for blood cell production? Where does it occur in
adults?
Hematopoiesis: formation of all blood cells, occurs in red bone
marrow (in adults, found in axial skeleton, girdles, and proximal
epiphyses of humerus and femur)
What does erythropoietin do? What triggers its release? Where does it
come from?
Erythropoietin (EPO): hormone that stimulates formation of RBCs
released by the kidneys (some from liver) in response to hypoxia
What is the process of red blood cell breakdown?
RBC breakdown: Heme, Iron, and Globin are separated
1. Iron is stored for reuse
2. Heme is degraded to yellow pigment bilirubin, which is secreted
into the intestines by the liver, where it is degraded into the pigment
pg. 1
,urobilinogen (transformed into brown pigment stercobilin that leaves
the body in feces)
3. Globin is metabolized into amino acids and released into
circulation
What is anaemia?
blood has abnormally low O2 carrying capacity that is too low to
support normal metabolism (not enough erythrocytes)
What are the symptoms of anaemia?
fatigue, pallor, dyspnoea, and chills
What is haemorrhagic anaemia?
Anaemia caused by blood loss
What is iron-deficiency anaemia?
caused by haemorrhagic anaemia, low iron intake, or impaired
absorption (cannot make haemoglobin without iron)
What is pernicious anaemia?
autoimmune disease that destroys stomach mucosa that produces
intrinsic factor (which is needed to absorb B12), B12 is needed to
help RBCs divide
What is renal anaemia?
caused by lack of EPO, often accompanies renal disease
What is aplastic anaemia?
destruction or inhibition of red bone marrow by drugs, chemicals,
radiation, or viruses; all formed element cell lines are affected; results
in anaemia as well as clotting and immunity defects
What is haemolytic anaemia?
premature lysis of RBCs; thalassemia’s; sickle-cell anaemia
What is polycythaemia?
pg. 2
,abnormal excess of RBCs; increases blood viscosity, causing sluggish
blood flow
What causes polycythemia?
bone marrow cancer; low O2 levels (high altitude) or increased EPO
production
What factors affect blood viscosity?
1. increased RBC count
2. dehydration
3. increased albumin levels
What is the main function of leukocytes?
the only formed element that is a complete cell with nuclei and
organelles
What are the characteristics of leukocytes?
1. make up <1% of total blood volume (4800-10800 WBC)
2. function in defense against disease
What is diapedesis? Which cells primarily perform this process?
diapedesis is the ability of white blood cells to squeeze through blood
vessel walls to leave the capillaries and enter the interstitial space
What is the relative abundance of the 5 types of WBCs?
Neutrophils > Lymphocytes > Monocytes > Eosinophils > Basophils
Which WBC responds to allergies and asthma?
Eosinophils
Which WBC secretes histamine and heparin?
Basophils
pg. 3
, Which WBC become macrophages?
Monocytes
Which WBC typically increases in response to bacterial infections?
Neutrophils
What is leukopoiesis?
the production of WBCs
What stimulates leukopoiesis?
interleukins and colony-stimulating factors (CSFs)
What is leukopenia?
abnormally low WBC count
What is leukocytosis?
WBC count over 11000, increase is a normal response to infection
What is leukemia?
a cancerous condition involving overproduction of abnormal WBCs
What are the cells that produce platelets called?
Megakaryocytes
What role do platelets play in hemostasis?
platelets act in the clotting process
What are the average amounts of RBCs, WBCs, and platelets in the
blood?
RBCs - 4-6 million
WBCs - 4800-10800
platelets - 150000-400000
What is hemostasis?
the stoppage of bleeding
pg. 4
Exam and Key Answers||Latest Version!!!Already Graded A+
What 3 features of RBCs support efficient gas exchange?
1. Biconcave shape offers huge surface area relative to volume for gas
exchange
2. Hemoglobin makes up 97% of cell volume (not counting water)
3. RBCs have no mitochondria, ATP production is anaerobic, so they
do not consume O2 they transport
What is the function of red blood cells?
RBCs are dedicated to respiratory gas transport, Hemoglobin binds
reversibly with O2 and CO2
How many molecules of oxygen can each hemoglobin molecule
carry?
Up to 4
What is the term for blood cell production? Where does it occur in
adults?
Hematopoiesis: formation of all blood cells, occurs in red bone
marrow (in adults, found in axial skeleton, girdles, and proximal
epiphyses of humerus and femur)
What does erythropoietin do? What triggers its release? Where does it
come from?
Erythropoietin (EPO): hormone that stimulates formation of RBCs
released by the kidneys (some from liver) in response to hypoxia
What is the process of red blood cell breakdown?
RBC breakdown: Heme, Iron, and Globin are separated
1. Iron is stored for reuse
2. Heme is degraded to yellow pigment bilirubin, which is secreted
into the intestines by the liver, where it is degraded into the pigment
pg. 1
,urobilinogen (transformed into brown pigment stercobilin that leaves
the body in feces)
3. Globin is metabolized into amino acids and released into
circulation
What is anaemia?
blood has abnormally low O2 carrying capacity that is too low to
support normal metabolism (not enough erythrocytes)
What are the symptoms of anaemia?
fatigue, pallor, dyspnoea, and chills
What is haemorrhagic anaemia?
Anaemia caused by blood loss
What is iron-deficiency anaemia?
caused by haemorrhagic anaemia, low iron intake, or impaired
absorption (cannot make haemoglobin without iron)
What is pernicious anaemia?
autoimmune disease that destroys stomach mucosa that produces
intrinsic factor (which is needed to absorb B12), B12 is needed to
help RBCs divide
What is renal anaemia?
caused by lack of EPO, often accompanies renal disease
What is aplastic anaemia?
destruction or inhibition of red bone marrow by drugs, chemicals,
radiation, or viruses; all formed element cell lines are affected; results
in anaemia as well as clotting and immunity defects
What is haemolytic anaemia?
premature lysis of RBCs; thalassemia’s; sickle-cell anaemia
What is polycythaemia?
pg. 2
,abnormal excess of RBCs; increases blood viscosity, causing sluggish
blood flow
What causes polycythemia?
bone marrow cancer; low O2 levels (high altitude) or increased EPO
production
What factors affect blood viscosity?
1. increased RBC count
2. dehydration
3. increased albumin levels
What is the main function of leukocytes?
the only formed element that is a complete cell with nuclei and
organelles
What are the characteristics of leukocytes?
1. make up <1% of total blood volume (4800-10800 WBC)
2. function in defense against disease
What is diapedesis? Which cells primarily perform this process?
diapedesis is the ability of white blood cells to squeeze through blood
vessel walls to leave the capillaries and enter the interstitial space
What is the relative abundance of the 5 types of WBCs?
Neutrophils > Lymphocytes > Monocytes > Eosinophils > Basophils
Which WBC responds to allergies and asthma?
Eosinophils
Which WBC secretes histamine and heparin?
Basophils
pg. 3
, Which WBC become macrophages?
Monocytes
Which WBC typically increases in response to bacterial infections?
Neutrophils
What is leukopoiesis?
the production of WBCs
What stimulates leukopoiesis?
interleukins and colony-stimulating factors (CSFs)
What is leukopenia?
abnormally low WBC count
What is leukocytosis?
WBC count over 11000, increase is a normal response to infection
What is leukemia?
a cancerous condition involving overproduction of abnormal WBCs
What are the cells that produce platelets called?
Megakaryocytes
What role do platelets play in hemostasis?
platelets act in the clotting process
What are the average amounts of RBCs, WBCs, and platelets in the
blood?
RBCs - 4-6 million
WBCs - 4800-10800
platelets - 150000-400000
What is hemostasis?
the stoppage of bleeding
pg. 4
