PowerPoint Presentation

Respiratory

Olfactory EpitheliumSerous glands (secrete fluid)Bipolar neuronsImmotile cilia with olfactory receptors

Respiratory EpitheliumCiliated columnar cells: ciliated cells have a basal bodyGoblet cells: secrete mucusBrush cells: microvilliNeuroendocrine (Kulchitskys) cellsBasal reserve cells

C-shaped cartilage ringsTrachealis muscle holds together

Subdivisions of the LungsLobes: right (3) left (2) containing secondary bronchiBronchopulmonary segments containing tertiary segmental bronchiAcinus (Terminal Respiratory Unit)Secondary lobulesPrimary lobules

TracheaSubmucosa glandsFibroelastic lamina propiaNo smooth muscleHyalin cartilageBroncusCartilage arranged in islandsSubmucosa glandsSmooth muscle presentBronchioleLoose cartilage, glands, mucous producing cellsSubmucosa increasesClara cells presentGas exchange airwaysHybrid: brochiole to a respiratory bronchiole (bronchiole function and also gas exchange)Progresses into alveolar

The Respiratory Portion

Respiratory bronchiole: similar to terminal bronchiole, but wall is interrupted by alveoli; contains ciliated, goblet, and clara cellsAs R.B. divide, the number of alveoli increases, goblet cells become absent, and cilias cells decrease in numberAlveolar ductAlveolar sacAlveolus

Alveolar CellsType I: 97% of alveolar surfaceType II: Secretes surfactant which is packaged into multilamellar bodies and reduces surface tension at air-blood interface; contains lamellar bodies (lipid + protein); have mitotic capacity

Pulmonary Defense MechanismsSecretions from the goblet cells, seromucous glands, Clara cells, immune cellsMucociliary clearance mechanismAlveolar macrophagesImmune / Inflammatory Cells in the InterstitiumMacrophagesl Lymphocytes; Plasma cells etc.

BLOOD VESSELS OF THE LUNGPulmonary ArteriesArise from the pulmonary trunk; leave the heartCarry deoxygenated blood**Run with conducting airways**Low pressure, low resistance systemThin walledEnd as capillary networksPulmonary VeinsRun by themselves, not connected to conducting airwayCarry oxygenated bloodGoes back to the heart

NUTRITIVE BLOOD VESSELS IN THE LUNG Bronchial Arteries & VeinsStart from thoracic aorta or posterior intercostal arteriesArteries carry oxygenated bloodVeins carry deoxygenated bloodFound within the walls of the bronchial treeAlso supply the pleuraUrinary Systemremoval of waste products from blood

excretion of metabolic waste products in urineregulation of ion concentration (Na+, K+, etc.)regulation of acid-base balanceregulation of blood pressure (renin secretion)regulation of erythrocyte production (erythropoietin)vitamin D metabolism & storage (parathyroid hormone)regulation of calcium levels (parathyroid hormone)heme bilirubin urobilin

Mesangial cells:middle vesselSupport; phagocytosis; repair; contractile; EPO synthesis (extraglomerular mesangial cells = lacis cells)

Most of the resorption of nutrients:PCT small intestine*most tubules are proximal convolutedResorption is a two-step process:1) pump into extracellular space2) pass into capillary lumen

Most of resorption of water:DCT large intestine

Collecting DuctReceived partially concentrated urine at the distal end of the DCTADH (antidiuretic hormone) from pituitary: causes aquaporin channels to open up, letting water move from lumen into interstitumCells of the C.D. are impermeable to water in the absence of ADHBeer acts to negate ADH releaseDiabetes (Gr. A siphon)Diabetes insipidus:inability to make or respond to ADH CD remain impermeable to waterDiabetes mellitus: insulin deficiency (osmotic diuresis); results in high glucose in blood; offsets osmotic gradient resulting in high water excretionDucts of bellini: ends of the collecting ducts

Blood Pressure Regulation

juxtaglomerular (JG) cells respond to arterial pressure(baroreceptors); found in the wall of afferent arterioleLow pressure signals to JG cells to release renin to increase BPmacula densa: responds to low salt conc.(chemoreceptors); specialized cells of the DCT; signal nearby JG cells to release renin

21Urinary Abbreviations to KnowPCTDCTJG cells/apparatusADHACEEndocrine System

Ductless glandsUsually secrete hormones into bloodstreamGenerally have systemic effects

Endocrine tissue exists in many "non-endocrine" organs:mesangial & JG cells (EPO & renin) in kidneyenteroendocrine cells in gut, lung

Functions of hormones:regulation of metabolism and energy balanceregulation of smooth and cardiac muscle contractionregulation of glandular secretionsregulation of growth and developmentregulation of 'flight or fight" responses and reproduction

Types of hormones:Protein: prolactin, growth hormone, etc.Peptide: ADH, calcitonin, etc.water-soluble: bind to cell surface receptors, activate 2nd messengers etc.Lipid-derived: from cholesterol: steroid hormones (estrogen, glucocorticoids, etc.)from eicosanoids: prostaglandinslipid-soluble: diffuse through cell/nuclear membranes, bind to nuclear receptors to effect gene expression

Monoamine: derived from: phenylalanine, tyrosine, tryptophan thyroxine, melatonin, catecholamines, etc.

posterior lobeunmyelinated axons & supporting cells

Rathkes pouch separates the pars distalis from pars intermedia

Thyroid

Lots of circular structures with homogenous staining due to colloid (storage form of precursor hormone thyroglobulin)Only endocrine organ that stores its hormone on outside of the cellHomogeneous staining with dark staining around indicating follicular epithelium (single layer surrounding each follicle)Setpa of CT divide into lobes

Thyroglobuliniodinated glycoprotein comprises the major colloid component; extracellular storage form of inactive thyroid hormone

THYROID: Parafollicular (C) cells

Clear cells on the side of the follicular; lies within the epithelium but makes contact only with the basal surface and blood vesselsMakes calcitoninLowers blood calcium levels by:Decreasing osteoclast activityDecreasing calcium absorptionStimulates calcium deposition in bone

PARATHYROID: Chief Cells

Parathyroid hormone (PTH)Stimulated by falling blood Ca levelsIncreases blood calcium by:Increasing osteoclast activityStimulating Vitamin D activation in kidneyVitamin D stimulates Ca resorption in GI tract and kidneyPTH opposes action of calcitonin, but only PTH is VITAL

ADRENAL CORTEX Hormone Production

Zona glomerulosa: mineralocorticoids (aldosterone)Na2+ resorption in kidney, increases b.p.controlled by Na+ & K+ levels, ACTH, and angiotensin IIpromotes Na+ resorption & K+ excretion Zona fasciculata: glucocorticoids (cortisol)glucose metabolism (e.g. gluconeogenesis)anti-inflammatory agentcontrolled by ACTHZona reticularis: androgens (gonadicorticoids)precursors for M & F sex hormones (DHEA dehydroepiandrosterone converted to estrogen and testosterone in ovaries & testes)controlled by ACTH

ADRENAL MEDULLA Hormone Production

Chromaffin Cells80% Epinephrine (adrenaline) [lighter cell]20% Norepinephrine (noradrenaline) [darker cell]Neuroendocrine cell derived from neural crestStimulated by endocrine system to release hormones

Endocrine Abbreviations to KnowACTHADHFSHGHLHPRLPTHT3/T4