Lymphopoiesis and Immunity

• Here are study notes based on the images you provided.

Lymphopoiesis

• Starts with a hemocytoblast.
• Transports to the thymus, creating lymphoid T cells.
• Myeloid cells differentiate into NK cells and B cells.
• Mature T cells are produced and undergo apoptosis.
• Peripheral tissue and the bloodstream are involved.

Innate Immunity

• Involves complement proteins, leading to inflammation and fever.

Adaptive Immunity

• Cell-mediated immunity involves phagocytes, activating T cells to directly attack pathogens physically and/or chemically.
• Antibody-mediated immunity involves B cells transforming into plasma cells that produce circulating antibodies.

Antigen Presentation

• MHC I is present in all body cells
• Presents antigen or self markers on the cell surface
• MHC I is read by any immune cell, if there is no match, apoptosis occurs.
• MHC II is present in APCs (antigen-presenting cells) such as macrophages.
• APCs engulf and present antigens on the surface for T cells.
• The T cell matches the TCR (T-cell receptor).
• If it matches, then cell-mediated cytotoxity, or antibody-mediated killing occurs
• Child cells produce TCRs for remaining T cells.
• Helper CD4 cells are also produced.

Antibody-Mediated Immunity

• Sensitization: Antibody takes in an antigen and presents it on MHC II.
• Activation: TCR and CD4 match, activating the B cell.
• Division & Differentiation: B cells differentiate into plasma cells, producing more antibodies, which use seven mechanisms: activation of complement proteins, agglutination, stimulation of inflammation, neutralization (big hug), opsonization, and attraction of phagocytes.

Cytotoxic T Cells

• Secrete perforins, creating pores in the plasma membrane, causing the cell to lyse.
• Release cytokines to initiate apoptosis.
• Release lymphotoxins, disrupting metabolism.

Types of Antibodies

• IgG: Largest and most effective.
• IgE: Attaches to basophils and mast cells, stimulating inflammation.
• IgD: Located on the surface of B cells.
• IgM: First antibody secreted after exposure to an antigen; distinctive.
• IgA: Found in glandular secretions.

Lymphatic Drainage

• Top-right: Drains into the right lymphatic duct and right subclavian vein.
• Rest of body: Drains into the thoracic duct and left subclavian vein.
• Both systems drain into the superior vena cava.

Pulmonary Ventilation

• Atmospheric pressure compared to body pressure uses Boyle's Law.
• Volume is inversely proportional to pressure.
• The lungs can be filled using the concepts of volume and atmospheric pressure
• Inhalation: Contracting the diaphragm and intercostal muscles increases volume and decreases pressure.
• Exhalation: Contracting the diaphragm and intercostal muscles decreases volume and increases pressure.

Air Flow

• Air flows from the atmosphere through the nose, nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles.
• Smallest bronchioles connect to alveoli, where capillary exchange occurs.
• Oxygen deposits into the bloodstream, and carbon dioxide removes it for exhalation.
• Air flows externally from outside to lungs, and internally from the capillary to cells and tissues.

Gas Transport

• Oxygen binds to heme in hemoglobin, changing its shape.
• Carbon dioxide binds to globin in hemoglobin, which also changes its shape.
• Carbon dioxide transforms into carbonic acid in the plasma and dissolves within the plasma.

Hypercapnia and Hypocapnia

• Stimulus: High carbon dioxide levels (hypercapnia) or low carbon dioxide levels (hypocapnia).
• Receptor: Chemoreceptors in arteries and the medulla oblongata detect carbon dioxide levels.
• Brain: The control center.
• Effector: Respiratory muscles are stimulated or inhibited.
• Stimulating respiratory muscles increases the respiratory rate. Inhibiting respiratory muscles decreases the respiratory rate.
• This negates the stimulus (negative feedback).
• Result: Exhaling carbon dioxide or maintaining carbon dioxide, achieving homeostasis.

Digestive Tract

• Bolus enters through the mouth.
• Teeth aid in mastication (chewing).
• The tongue moves the bolus down
• Amylase, from salivary glands, breaks down carbohydrates.
• The bolus passes through the pharynx and esophagus to the stomach, which secretes digestive juices.
• Peristalsis is muscle contraction where things get pushed down
• Chyme enters the small intestine.
• Large intestines pulls digestive enymes from the liver and pancreas, there is a majority of water absorbtion
• Bulk goes to the intestines(large) which perform more absorption; waste;

Peristalsis

• Circular muscles behind the bolus contract.
• Longitudinal muscles ahead of the bolus contract.
• Waves of circular and longitudinal muscles force the bolus forward.

Deglutition (Swallowing)

• Includes the buccal, pharyngeal, and esophageal phases.
• Buccal: Mouth retracts tongue, and the soft palate + uvula seal off the nasopharynx.
• Pharyngeal: Epiglottis collapses, laryngopharynx elevates, and the larynx elevates.
• Esophageal: Peristalsis occurs, and the bolus enters the stomach as the lower esophageal sphincter opens.

Gastric Regulation

• Local response: Distention
• Neural response: Stretch receptors
• Hormonal response: Stimulates G cells
• Gastrin travels through the bloodstream to parietal and chief, reducing pH

Salivary Glands

• Include the parotid, sublingual, and submandibular glands; which all drain into the pharynx.
• The pharynx includes the nasopharynx, oropharynx, and laryngopharynx.
• Pylorus directs to: Duodenum, Jejunum, lleum

Large Intestine

• Includes the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, recum, and anus

Gastric Regulation

• Cephalic Phase: Triggered by seeing, thinking, or smelling food.
• Vagus nerve triggers mucous, parietal, chief, and G cells.
• Parietal cells secrete intrinsic factor & hydrochloric acid.
• Chief cells secrete pepsinogen.
• G cells secrete gastrin.
• Mucous cells secrete mucus.
• Gastric Phase: Local response to distention.
• Intestinal Phase: Lipids & carbs in intestines trigger secretion of CCK & GIP.
• Low pH (<4.5) stimulates secretion of secretin.