BIOL 2202 Exam 2 Study Guide: Lymphatic, Endocrine, Respiratory, and Urinary Systems

Chapter 20 – Lymphatic System

Overview of the Lymphatic System

The lymphatic system is a vital part of the circulatory and immune systems, responsible for fluid balance, fat absorption, and defense against pathogens.

• Basic Functions: Cardiovascular assistance, immune system support, and transport of fats from the digestive system.

• Pathway of Lymph: Lymph originates from capillary beds, returns to the blood via lymphatic capillaries → vessels → trunks → collecting ducts → subclavian vein.

• Structure of Lymphatic Capillaries: Thin-walled, highly permeable vessels that absorb excess tissue fluid and large molecules.

• Movement of Lymph: Lymph is moved through vessels by skeletal muscle contraction, pressure changes, and valves that prevent backflow.

• Primary Lymph Organs: Red bone marrow and thymus; sites of lymphocyte production and maturation.

• Secondary Lymph Organs: Lymph nodes, spleen, and lymphatic nodules; sites of immune response activation.

• Lymph Node Structure: Lymph nodes filter lymph and contain immune cells that respond to pathogens.

• Immune Function: Lymph nodes initiate immune responses to foreign antigens.

• Fat Absorption: Lymphatic vessels called lacteals absorb fats from the small intestine.

• Difference Between Infected and Cancerous Lymph Nodes: Infected nodes are swollen and tender; cancerous nodes are typically hard and painless.

Key Terms and Concepts

• Lymph: Fluid containing white blood cells, proteins, and fats.

• Lymphatic Capillaries: Smallest vessels, begin in tissues and merge to form larger vessels.

• Lymph Nodes: Small, bean-shaped structures that filter lymph.

• Lacteals: Specialized lymphatic capillaries in the small intestine for fat absorption.

Chapter 16 – Endocrine System

Overview of the Endocrine System

The endocrine system consists of glands that secrete hormones to regulate body functions such as growth, metabolism, and reproduction.

• Major Endocrine Organs: Pituitary, thyroid, parathyroid, adrenal, pineal, and reproductive glands.

• Hormone Release Regulation: Controlled by feedback mechanisms (negative and positive feedback).

• Hormone Classes: Amino acid-based (peptides, proteins) and steroid hormones.

• Hormone Transport: Hormones travel in blood, may be bound to carrier proteins.

• Signal Transduction: Hormones bind to receptors (G protein, enzyme-linked, intracellular) to initiate cellular responses.

• Neural vs. Hormonal Control: Neural control is rapid and short-lived; hormonal control is slower but longer-lasting.

• Hypothalamus and Pituitary: Hypothalamus controls pituitary hormone release; anterior pituitary secretes GH, TSH, FSH, LH, PRL; posterior pituitary releases ADH and oxytocin.

• Adrenal Gland: Cortex produces steroid hormones (aldosterone, cortisol); medulla produces catecholamines (epinephrine, norepinephrine).

• Hormone Effects: Hormones affect target organs, regulate metabolism, growth, and homeostasis.

Key Terms and Concepts

• Hormone: Chemical messenger secreted by endocrine glands.

• Feedback Mechanism: Process that regulates hormone levels.

• Anterior Pituitary Hormones: GH, TSH, FSH, LH, PRL.

• Posterior Pituitary Hormones: ADH, oxytocin.

• Adrenal Hormones: Aldosterone, cortisol, epinephrine, norepinephrine.

Chapter 22 – Respiratory System

Overview of the Respiratory System

The respiratory system is responsible for gas exchange, supplying oxygen to the body and removing carbon dioxide.

• Conducting Division: Includes nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles; transports air to the lungs.

• Respiratory Division: Includes respiratory bronchioles, alveolar ducts, and alveoli; site of gas exchange.

• Pharynx: Divided into nasopharynx, oropharynx, and laryngopharynx; passageway for air and food.

• Swallowing Mechanism: Prevents food and liquids from entering the trachea.

• Larynx Structure: Contains cartilages (thyroid, cricoid, arytenoid, epiglottis) and vocal folds.

• Lung Anatomy: Lobes, fissures, bronchopulmonary segments.

• Alveoli: Site of gas exchange; surrounded by capillaries.

• Pleura: Serous membrane covering lungs and lining thoracic cavity.

• Ventilation: Movement of air in and out of lungs; regulated by pressure changes.

• Respiratory Cycle: Inspiration and expiration phases.

• Gas Exchange: Occurs across respiratory membrane; influenced by surface area, partial pressure gradients.

• Control of Breathing: Regulated by respiratory centers in the brainstem (medulla, pons).

• Respiratory Pathologies: Pneumothorax, hypoxia, asthma, COPD.

Key Terms and Concepts

• Alveolus: Air sac in the lung where gas exchange occurs.

• Pleura: Double-layered membrane surrounding the lungs.

• Ventilation: Movement of air into and out of the lungs.

• Respiratory Membrane: Barrier for gas exchange between alveolar air and blood.

Chapter 25 – Urinary System

Urinary Anatomy

The urinary system removes waste products from the blood, regulates fluid and electrolyte balance, and maintains homeostasis.

• Main Organs: Kidneys, ureters, urinary bladder, urethra.

• Kidney Structure: Cortex, medulla, renal pyramids, renal columns, minor and major calyces, renal pelvis.

• Nephron: Functional unit of the kidney; consists of renal corpuscle (glomerulus and Bowman's capsule) and renal tubule (proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct).

• Urethra: Tube that carries urine from bladder to outside; differs in length and function between males and females.

Urinary Physiology

• Functions: Excretion of wastes, regulation of blood volume and pressure, electrolyte balance, acid-base balance.

• Homeostasis: Kidneys maintain homeostasis by filtering blood and adjusting urine composition.

• Filtration: Occurs in glomerulus; driven by hydrostatic pressure.

• Reabsorption: Movement of substances from filtrate back into blood; occurs in renal tubules.

• Secretion: Active transport of substances from blood into filtrate.

• Glomerular Filtration Rate (GFR): Volume of filtrate produced per minute; regulated by blood pressure and renal autoregulation.

• Hormonal Regulation: Aldosterone increases sodium reabsorption; ADH increases water reabsorption; ANP decreases sodium reabsorption.

• Renin-Angiotensin-Aldosterone System (RAAS): Regulates blood pressure and fluid balance.

• Acid-Base Balance: Kidneys excrete hydrogen ions and reabsorb bicarbonate to maintain pH.

• Renal Clearance: Measure of kidney's ability to remove a substance from blood.

Key Terms and Concepts

• Nephron: Functional unit of the kidney.

• Glomerulus: Capillary network for filtration.

• Bowman's Capsule: Surrounds glomerulus; collects filtrate.

• Renal Tubule: Site of reabsorption and secretion.

• ADH (Antidiuretic Hormone): Increases water reabsorption.

• Aldosterone: Increases sodium reabsorption.

• Renal Clearance: Volume of plasma cleared of a substance per unit time.

Important Equations

• Glomerular Filtration Rate (GFR): $GFR = K_f \times (P_{GC} - P_{BS} - \pi_{GC})$ Where $K_f$ is the filtration coefficient, $P_{GC}$ is glomerular capillary hydrostatic pressure, $P_{BS}$ is Bowman's space hydrostatic pressure, and $\pi_{GC}$ is glomerular capillary oncotic pressure.

• Renal Clearance: $C = \frac{U \times V}{P}$ Where $C$ is clearance, $U$ is urine concentration of substance, $V$ is urine flow rate, and $P$ is plasma concentration of substance.

Comparison Table: Hormonal Regulation in the Urinary System

Hormone	Source	Main Effect
Aldosterone	Adrenal cortex	Increases Na+ reabsorption, increases K+ secretion
ADH	Posterior pituitary	Increases water reabsorption
ANP	Atria of heart	Decreases Na+ reabsorption