BIO 230 Lab Exam 2: Blood, Respiratory, Renal, and Endocrine Physiology Study Notes

Blood Physiology

Red Blood Cells (RBCs)

Red blood cells are crucial for oxygen transport in the body. Their concentration and characteristics are important indicators of health.

• Hematocrit (Hct): The percentage of blood volume occupied by RBCs. Equation: $\text{Hct} = \frac{\text{RBC volume}}{\text{Total blood volume}} \times 100$

• Hemoglobin (Hb): The oxygen-carrying protein in RBCs. Measured in g/dL.

• Mean Corpuscular Volume (MCV): Average volume of a single RBC. Equation: $\text{MCV} = \frac{\text{Hct} \times 10}{\text{RBC count}}$

• Mean Corpuscular Hemoglobin (MCH): Average amount of hemoglobin per RBC. Equation: $\text{MCH} = \frac{\text{Hb} \times 10}{\text{RBC count}}$

• Mean Corpuscular Hemoglobin Concentration (MCHC): Average concentration of hemoglobin in RBCs. Equation: $\text{MCHC} = \frac{\text{Hb} \times 100}{\text{Hct}}$

• RBC Count: Number of RBCs per unit volume of blood.

Example: A low hematocrit may indicate anemia, while a high value may suggest polycythemia.

White Blood Cells (WBCs)

White blood cells are essential for immune defense. Their types and counts help diagnose infections and immune disorders.

• WBC Count: Number of WBCs per unit volume of blood.

• Differential Count: Percentage of each type of WBC (neutrophils, lymphocytes, monocytes, eosinophils, basophils).

• Blood Smear: Used to identify and count different WBC types under a microscope.

Example: Elevated neutrophils may indicate bacterial infection; increased lymphocytes may suggest viral infection.

Blood Typing

Blood typing determines the presence of specific antigens (A, B, Rh) on RBCs, which is critical for safe transfusions.

• ABO System: Classifies blood as A, B, AB, or O based on antigens.

• Rh Factor: Presence (+) or absence (−) of Rh antigen.

• Antibodies: Individuals produce antibodies against antigens they lack.

Example: Type O− is the universal donor; AB+ is the universal recipient.

Respiratory Physiology

Lung Volumes and Capacities

Lung volumes and capacities are measured to assess respiratory health and function.

• Tidal Volume (TV): Volume of air inhaled or exhaled in a normal breath.

• Inspiratory Reserve Volume (IRV): Additional air inhaled after a normal inspiration.

• Expiratory Reserve Volume (ERV): Additional air exhaled after a normal expiration.

• Vital Capacity (VC): Total volume of air that can be exhaled after maximal inhalation. Equation: $\text{VC} = \text{TV} + \text{IRV} + \text{ERV}$

• Forced Expiratory Volume (FEV): Volume of air exhaled in the first second of a forced expiration.

Example: Reduced FEV1/VC ratio may indicate obstructive lung disease (e.g., asthma).

pH Regulation

The body maintains blood pH within a narrow range (7.35–7.45) through respiratory and renal mechanisms.

• Acidosis: Blood pH below 7.35; can be respiratory (CO₂ retention) or metabolic (acid accumulation).

• Alkalosis: Blood pH above 7.45; can be respiratory (CO₂ loss) or metabolic (base accumulation).

• Buffer Systems: Bicarbonate, phosphate, and protein buffers help stabilize pH.

Example: Hyperventilation causes respiratory alkalosis; kidney failure may cause metabolic acidosis.

Renal Physiology

Urinalysis

Urinalysis assesses kidney function and detects metabolic or infectious diseases.

• Physical Properties: Color, clarity, specific gravity.

• Chemical Properties: pH, protein, glucose, ketones, blood.

• Microscopic Properties: Cells, crystals, casts.

Example: Proteinuria may indicate glomerular damage; glucose in urine suggests diabetes mellitus.

Renal Regulation and Endocrine Histology

The kidneys regulate fluid, electrolyte balance, and blood pressure. Endocrine glands control metabolic processes.

• Nephron: Functional unit of the kidney; filters blood and forms urine.

• Hormones: ADH (antidiuretic hormone) regulates water reabsorption; aldosterone controls sodium reabsorption.

• Histology: Microscopic examination of kidney and endocrine tissues reveals structural and functional details.

Example: ADH deficiency leads to diabetes insipidus; aldosterone excess causes hypertension.

Summary Table: Blood Cell Types and Functions

Cell Type	Main Function	Clinical Significance
RBC (Erythrocyte)	Oxygen transport	Anemia, polycythemia
Neutrophil	Bacterial defense	Infection, inflammation
Lymphocyte	Viral defense, immunity	Viral infection, leukemia
Monocyte	Phagocytosis	Chronic infection
Eosinophil	Parasitic defense, allergy	Allergic reactions, parasitic infection
Basophil	Inflammation, allergy	Allergic reactions

Additional info:

• Students should be able to design experiments, interpret lab data, and relate physiological concepts to clinical scenarios.

• Understanding the relationships between blood cell counts, lung volumes, pH regulation, and renal function is essential for integrative physiology.