Bio 243

🔬 Lecture 1: Course Intro & Review of BIO 143 Concepts

Q: What is the focus of BIO 243?
A: The integrated study of human body structure (anatomy) and organ function (physiology).

Q: What organs are emphasized in BIO 243?
A: Brain, heart, kidney, and others in relation to system function.

Q: What are the four basic tissue types?
A: Epithelial, connective, muscle, and nervous tissue.

Q: What are the three germ layers formed during gastrulation?
A: Ectoderm, mesoderm, endoderm.

Q: What are the three layers of the integumentary system?
A: Epidermis, dermis, hypodermis.

Q: What systems were covered in BIO 143?
A: Histology, immunology, embryology, genetics, integumentary, reproductive.

Q: Which part of the brain regulates reproduction?
A: The hypothalamus.

Q: What is an organ?
A: A structure composed of at least two tissue types that performs a specific function.

Q: What should you begin reviewing for BIO 243?
A: Content from BIO 143 and associated textbook readings.

🧬 Lecture 2: Structural Organization & Intro to Homeostasis

Q: What is the chemical level of organization?
A: Atoms combine to form molecules.

Q: What is the cellular level?
A: Cells are made up of molecules.

Q: What is the tissue level?
A: Groups of similar cells performing a specific function.

Q: What is the organ level?
A: Organs are made up of different types of tissues.

Q: What is the organ system level?
A: Different organs working together closely.

Q: What is the organismal level?
A: All systems working together to maintain life.

Q: Name some interdependent systems involved in nutrient/waste exchange.
A: Digestive, respiratory, cardiovascular, urinary, and integumentary systems.

Q: What does the digestive system do?
A: Takes in nutrients, breaks them down, eliminates unabsorbed matter.

Q: What does the respiratory system do?
A: Takes in O₂ and eliminates CO₂.

Q: What does the cardiovascular system do?
A: Transports gases, nutrients, and wastes.

Q: What does the urinary system do?
A: Eliminates nitrogenous wastes and maintains ion balance.

Q: What does the integumentary system do?
A: Protects the body from the external environment.

Q: What is interstitial fluid?
A: The fluid that surrounds cells, mediating exchange between blood and cells.

Q: What is homeostasis?
A: The maintenance of a stable internal environment.

Q: What are the key variables maintained by homeostasis?
A: Temperature, water, glucose, oxygen, nutrients, pH, ions, blood pressure, excretion.

Q: What systems are involved in homeostatic regulation?
A: Nervous and endocrine systems.

Q: What is a negative feedback mechanism?
A: A response that reduces or shuts off the original stimulus.

Q: Give an example of negative feedback.
A: Thermoregulation via sweating or shivering.

Q: What is the role of effectors in feedback loops?
A: To carry out the response dictated by the control center.

Q: What is homeostatic imbalance?
A: A disturbance in homeostasis that can lead to disease or aging.

⚖ Lecture 3: Homeostasis, Acid-Base Balance & Buffering

Q: What is the normal blood pH range?
A: 7.35–7.45

Q: What is acidosis?
A: Arterial blood pH < 7.35

Q: What is alkalosis?
A: Arterial blood pH > 7.45

Q: What is the pH of intracellular fluid?
A: Around 7.0

Q: What is the pH formula?
A: pH = –log[H⁺]

Q: What are strong acids?
A: Acids that fully dissociate in water.

Q: What are weak acids?
A: Acids that only partially dissociate.

Q: What are strong bases?
A: Bases that fully dissociate and bind H⁺ quickly.

Q: What are weak bases?
A: Bases that slowly accept H⁺ (e.g., bicarbonate, ammonia).

Q: What are buffers?
A: Molecules that resist changes in pH.

Q: What are the three major chemical buffer systems?
A: Bicarbonate, phosphate, protein.

Q: Where is the bicarbonate buffer system most important?
A: In the extracellular fluid (ECF).

Q: What happens when a strong acid is added to the bicarbonate buffer system?
A: H⁺ combines with HCO₃⁻ to form H₂CO₃ (weak acid), limiting pH change.

Q: What happens when a strong base is added to the bicarbonate buffer system?
A: Reacts with H₂CO₃ to form a weak base, limiting pH increase.

Q: Where is the phosphate buffer system most active?
A: In urine and intracellular fluid.

Q: What makes proteins effective buffers?
A: They can act as both acids and bases due to their amino acid groups.

Q: What are the physiological buffering systems?
A: Respiratory and renal systems.

Q: What does the respiratory system regulate in acid-base balance?
A: CO₂ levels (affecting H⁺ concentration).

Q: What does the renal system regulate?
A: Excretion or retention of H⁺ and HCO₃⁻.

Q: What is respiratory acidosis?
A: Condition from hypoventilation or lung disease → CO₂ builds up → pH drops.

Q: What compensates for respiratory acidosis?
A: Kidneys excrete H⁺ and reabsorb HCO₃⁻.

Q: What is respiratory alkalosis?
A: Condition from hyperventilation → CO₂ drops → pH rises.

Q: What compensates for respiratory alkalosis?
A: Kidneys retain H⁺ and excrete HCO₃⁻.

Q: What causes metabolic acidosis?
A: Excess acid production or loss of bicarbonate (e.g., DKA, diarrhea).

Q: How does the body compensate for metabolic acidosis?
A: Hyperventilation (Kussmaul respiration) to blow off CO₂.

Q: What causes metabolic alkalosis?
A: Vomiting, excess antacids, constipation.

Q: How does the body compensate for metabolic alkalosis?
A: Hypoventilation to retain CO₂ and increase H⁺ production.

• Q: What is homeostasis?
  A: The body’s ability to maintain a stable internal environment.

• Q: What is the normal blood calcium range?
  A: 8.6-10.3 mg/dL

• Q: What cells produce insulin and where?
  A: Beta (β) cells in the pancreas.

• Q: What does insulin do?
  A: Lowers blood glucose by increasing glucose uptake into cells.

• Q: What cells produce glucagon and where?
  A: Alpha (α) cells in the pancreas.

• Q: What does glucagon do?
  A: Increases blood glucose by breaking down glycogen (glycogenolysis).

• Q: What is diabetes mellitus?
  A: A disease where blood glucose levels are too high due to issues with insulin.

• Q: What are the types of diabetes and their causes?
  A: Type 1: No insulin production; Type 2: Insulin resistance.

Lecture 5: Endocrine System Overview

Endocrine System Basics

• Q: What is the function of the endocrine system?
  A: To regulate body processes using hormones.

• Q: How does the endocrine system differ from the nervous system?
  A: The endocrine system uses hormones (slower, longer-lasting effects), while the nervous system uses nerve impulses (fast, short-lived).

• Q: What are the major endocrine glands?
  A: Pituitary, thyroid, parathyroid, adrenal, pineal.

• Q: What are amino acid-based hormones?
  A: Water-soluble hormones that bind to membrane receptors.

• Q: What are steroid hormones?
  A: Lipid-soluble hormones that enter cells and affect gene expression.

• Q: What is negative feedback?
  A: A system where a hormone’s effects reduce its further release.

Lecture 6: Hypothalamus-Pituitary (H-P) System

Pituitary Gland & Hypothalamus

• Q: What are the two lobes of the pituitary gland?
  A: Anterior (adenohypophysis) and posterior (neurohypophysis).

• Q: What hormones are stored in the posterior pituitary?
  A: Oxytocin & ADH (antidiuretic hormone).

• Q: Where are oxytocin and ADH produced?
  A: In the hypothalamus.

• Q: What is the function of ADH?
  A: Reduces urine production by increasing water reabsorption in kidneys.

• Q: What does GH (growth hormone) do?
  A: Stimulates body growth, protein synthesis, and metabolism.

• Q: What is the function of TSH (thyroid-stimulating hormone)?
  A: Stimulates the thyroid gland to produce thyroid hormones.

• Q: What is ACTH (adrenocorticotropic hormone)?
  A: A hormone that stimulates the adrenal cortex to release cortisol.

Lecture 7: Thyroid, Adrenal Glands & Growth Hormone

Thyroid Hormone (HPT Axis)

• Q: What is the major metabolic hormone?
  A: Thyroid hormone (T3 & T4).

• Q: What does thyroid hormone regulate?
  A: Metabolism, growth, and blood pressure.

• Q: What happens in hypothyroidism?
  A: Slow metabolism, weight gain, cold intolerance.

• Q: What happens in hyperthyroidism?
  A: Fast metabolism, weight loss, heat intolerance.

Adrenal Glands (HPA Axis)

• Q: What hormones does the adrenal cortex produce?
  A: Aldosterone, cortisol, and androgens.

• Q: What does aldosterone do?
  A: Regulates sodium and potassium levels, affecting blood pressure.

• Q: What is cortisol’s main function?
  A: Increases blood glucose and suppresses the immune system.

• Q: What hormones are released by the adrenal medulla?
  A: Epinephrine and norepinephrine.

Lecture 8: Bone Remodeling & Growth

Bone Structure & Growth

• Q: What are the two types of bone?
  A: Compact bone and spongy bone.

• Q: Where is red bone marrow found?
  A: In spongy bone.

• Q: What is the function of osteoblasts?
  A: To build new bone tissue.

• Q: What is the function of osteoclasts?
  A: To break down bone tissue.

• Q: What is the epiphyseal plate?
  A: The growth plate where bones lengthen.

Bone Homeostasis

• Q: What hormone increases blood calcium levels?
  A: Parathyroid hormone (PTH).

• Q: What hormone lowers blood calcium levels?
  A: Calcitonin.

• Q: What is osteoporosis?
  A: A condition where bones become weak and brittle.

• Q: What are two types of bone growth?
  A: Interstitial (length) and appositional (width).

Lecture 9: Membrane Transport

Types of Membrane Transport

• Q: What is passive transport?
  A: Movement of molecules without energy input.

• Q: What is diffusion?
  A: Movement from high to low concentration.

• Q: What is osmosis?
  A: Diffusion of water.

• Q: What is facilitated diffusion?
  A: Passive transport using a protein channel.

• Q: What is active transport?
  A: Movement of molecules using ATP.

• Q: What is an example of primary active transport?
  A: Na+/K+ pump.

• Q: What is an example of secondary active transport?
  A: Glucose transport using sodium gradients.

• Q: What is endocytosis?
  A: The process of engulfing substances into the cell.

• Q: What is exocytosis?
  A: The process of expelling substances from the cell.