Lymphatic System & Immune Defenses

Lymphatic System and Immune Defenses

• The lymphatic system includes lymph, lymph nodes, and lymphatic vessels.
• Primary lymphoid organs are where T and B cells mature, including the thymus, bone marrow, and cisterna chyli.
• Secondary lymphoid organs are where mature lymphocytes encounter antigens, which includes lymph nodes, tonsils (palatine, lingual, pharyngeal, tubal), Peyer's patches, appendix, and spleen.
• Lymphatic vessels have one-way valves and are closed at one end.
• Lymphatic vessel flow: arteries, interstitial fluid, lymphatic capillaries, lymph vessels, lymph trunks, lymph ducts, then veins (subclavian).
• The innate immune system represents non-specific immunity (what you are born with).
• Innate immunity includes physical barriers (skin, organ, mucosal layers), chemical barriers (stomach acid, lysozyme), and inflammatory response cells (mast cells, neutrophils, macrophages, and NK cells).
• Phagocytosis is a function of the innate immune system.
• Adaptive immunity is built up over time and includes cell-mediated (T cell) and humoral (B cell and antibodies) responses.
• Passive immunity example: mother-infant breast-feeding.
• Lymph node structure: cortex/medulla, lymphatic nodule, fibrous capsule, trabeculae, medullary cords, lymph sinuses.
• Spleen contains white and red pulp.
• Tonsils, Peyer's patches, and the appendix have specific locations and features.
• Peyer's patches location and function important
• Immune system lines of defense: 1st, 2nd, and 3rd.
• Antigens differ from epitopes.
• Exogenous and Endogenous antigen processing occurs
• Antigen-presenting cells (APCs) include macrophages, dendritic cells, and lymph node stromal cells.
• Adaptive immunity includes T cell activation and costimulation, formation and activation of cytotoxic T cells, and memory helper T cells.
• Helper and cytotoxic T cells have different functions, activation requires antigen recognition AND costimulation.
• Antibody-mediated immunity involves activation and clonal selection of B cells, with T cells playing a role. Memory B cells, CD4+, and CD8+ cells are involved.
• Cytokines, antimicrobial proteins (IFNs), the complement system, and complement protein complexes play roles in immunity.
• The structure and function of antibody (Ig) classes determine the mechanisms of antibody action.
• Complement pathways include classical and lectin pathways, which differ in how they are activated and function, C3.
• Immunological memory underlies primary and secondary responses.

Respiratory System

• Respiratory system functions: pulmonary ventilation (inspiration and expiration), pulmonary gas exchange, transport, tissue gas exchange.
• Upper and lower respiratory systems differ; there are conducting and respiratory zones.
• Nose functions: cilia and particle trapping ability.
• Pharynx includes the nasopharynx, oropharynx, and laryngopharynx.
• Larynx includes the voicebox, cartilages, organization, vestibular folds, and mechanism of voice production.
• Trachea, esophagus, and epiglottis: all part of the respiratory system
• Trachea layers: mucosal, submucosa, adventitia; trachealis, carina, ciliated, pseudostratified columnar epithelial cells, goblet (mucous secreting cells).
• Conducting zone structures: Main bronchus, right and left bronchi (primary), lobar bronchi (secondary), segmental bronchi (tertiary), bronchioles, terminal bronchioles.
• Respiratory zone structures: respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli.
• Lung structure: right = 3 lobes, left = 2 lobes; fissures (horizontal and oblique), base, apex, hilium, cardiac notch, costal surfaces, lung root, pleura (visceral, parietal), pleural cavity (filled with pleural fluid), lobules, stroma, bronchopulmonary segments.
• Pneumocyte Type I and II cells reside in specific locations, structure, function.
• Monocytes and macrophages location and function, respiratory membrane.
• Phases of pulmonary ventilation: inspiration and expiration; role of pressure and volume in inflating and deflating the lungs); understand pressure changes in pulmonary ventilation
• Pressure relationships: atmospheric pressure, intrapleural pressure, transpulmonary pressure; Boyle's Law, Dalton's Law and Henry's Law.
• Pleura layers and functions
• Diaphragm and intercostal muscles: location and function; surface tension, elastic recoil, compliance.
• Breathing patterns and respiratory moments: eupnea, apnea, dyspnea, tachypnea, costal/diaphragmatic breathing.
• Modified breath movements (coughing, crying, sneezing).
• Volumes: Tidal volume, Inspiratory reserve volume, expiratory reserve volume, residual volume, inspiratory capacity, Functional residual capacity, vital capacity, Total lung capacity.
• Ventilation and perfusion coupling affects the respiratory system.
• Gases are transported in the blood (plasma vs RBC, carbaminohemoglobin, vs Hb). Factors affect Hb affinity for molecular oxygen.
• Chemical reactions during gas exchange involve three forms of CO2 in the blood. Haldane effect
• Respiratory centers location: medulla oblongata, pons, cortical influences, chemoreceptors, hypothalamus, cortex, Regulation of pH

Digestive System

• Alimentary canal versus accessory organs; GI tract: Location and function
• Major organs (mouth, pharynx, tongue, esophagus, glottis, stomach, small intestine (and its regions), large intestines (and its regions).
• Phases of digestion: cephalic, gastric, intestinal.
• 6 basic processes of digestion: ingestion, propulsion, mechanical breakdown, digestion, absorption, defecation.
• Mechanical digestion, chemical digestion, absorption (where they happen and what is involved in each process)
• Layers of the GI tract
• Gut brain (aka enteric nervous system) and the parasympathetic control (Vagus nerve and enteric nerve plexus)
• Peritoneum and its anatomical features/functions, organs found intra-and retro-peritoneally
• Mesentery: location and function
• Oral cavity (mouth) and tongue anatomy and function
• Salivary glands and general features of teeth are important.
• Segments/sections of the pharynx, function and physiology of the esophagus
• Stomach anatomical structure and functions (all features), chyme, GERD
• Cells of the digestive system and their function: absorptive, goblet, Paneth, G, I, K, M, S cells
• Anatomy and function of the gastric pits (know parietal cells, chief cell, enteroendocrine cells, neck cells, stem cells, etc)
• Liver and gallbladder functions, structure, and features (i.e ducts, secretions), CCK, secreten, etc
• Pancreas: segments of the pancreas, functions, pancreatic enzymes, secretions, and ducts
• Small intestine: regions, functions of each region, location, villi, microvilli, circular folds; brush border and brush border enzymes
• MALT, mesentery, Peyer's Patches
• The processes of intestinal digestion break down carbs, proteins, lipids, nucleic acids
• Intestinal juice and brush border enzymes
• Migrating Motor Complex (MMC), segmentation, peristalsis, motility
• Accessory organs (structure and function): liver, gallbladder, pancreas, and the ducts (see below)
• Large intestine: regions, structures, functions, unique features of the large intestine, haustral contractions, cecum, appendix
• Haustral contractions
• Absorption of vitamins, minerals and nutrients
• Haustral contractions in the large intestine
• Defecation reflex, internal and external sphincters