Anatomy Exam 3
Describe the structure, function, and body locations of continuous, fenestrated, and sinusoidal capillaries.
- Continuous- ~Location - skin, muscles, lung, CNS ~Characteristics: *least permeable (leaky), most common *components = tight junctions, intercellular clefts, complete basement membrane, pericytes (support cells) *continuous or unbroken since adjacent endothelial cells are held together mostly by tight junctions *involved in perfusion of capillary beds *blood-brain barrier - modified continuous capillaries found in majority of brain tissue *tight junctions between all endothelium, which means no intercellular clefts -Fenestrated- ~Location - sm. intestine, endocrine glands kidneys ~Characteristics: *more permeable than continuous capillaries *components = tight junctions, intercellular clefts, complete basement membrane, fenestrations *fenestrations - small oval pores riddle endothelial surface *involved primarily in active nutrient absorption or filtrate formation -Sinusoidal- ~Location - liver, bone marrow, lymphoid tissue, some endocrine organs ~Characteristics: *most permeable type (fewest tight junctions), limited distribution *components = tight junctions, intercellular clefts, incomplete basement membrane, sinusoids *sinusoids - large intercellular clefts appearing as window-like pores, makes an irregularly shaped lumen *involved in large molecule passage between blood & surrounding tissues *sluggish blood flow allows for great solute exchange
Define the terms intercellular cleft, fenestration, and sinusoid.
- intercellular clefts - incomplete or unjoined tight junction areas that allow outward passage of fluids/small solutes. - fenestration- small pores - sinusoid- large pores
Explain the structural relationship between a terminal arterioles, true capillaries, metarterioles, thoroughfare channels, and postcapillary venules in a capillary bed. Order the sequence of blood flow entering a capillary bed.
-ANS vasomotor nerves/local chemical conditions can rapidly change blood flow into true capillaries *sympathetic stimulation causes precapillary sphincter (smooth muscle "cuff") surrounding of each true capillary to contract *arteriovenous shunt - blood moves from metarteriole directly into thoroughfare channel & not into true capillaries *altered flow = terminal arteriole > vascular shunt > postcapillary venule *postcapillary venules - smallest venules only composed of endothelium + a few associated pericytes extremely porous vessels, allow fluids/inflammatory WBCs to pass from bloodstream into tissues
Explain the relationship between atmospheric, intrapulmonary, and intrapleural pressures.
-Any event that equalizes Pip w/ atmospheric pressure (Patm) or intrapulmonary pressure (Ppul) will cause immediate lung collapse *pneumothorax - presence of air or gas in plural space impairs oxygenation and/or ventilation
Explain why the aorta is called a pressure reservoir.
-Aorta is the largest elastic (conducting) artery: *expands as a large volume of blood enters it from left ventricle *recoils as blood moves to distal areas decreasing local pressure -Expansion/subsequent recoil provides pressure differential (delta P) while ventricles are receiving blood from atria *elastic arteries serve as auxiliary pumps or pressure reservoirs in between ventricular contractions *moves blood while ventricles are filling
Explain the relationship between blood flow, difference in blood pressure, and peripheral resistance. Recall which factor is more important in controlling local blood flow.
-Blood flow (F) is directly proportional to difference in blood pressure (delta P) between two points in circulation *pressure difference(delta P) between a proximal point & a distal point creates a hydrostatic pressure gradient (high-to-low) *delta P is directly related to F: if delta P increases, then F increases if delta P decreases, then F decreases -Blood flow (F) is inversely proportional to resistance (R) encountered during systemic circulation *R is a more important factor than delta P in influencing local blood pressures *vasoconstriction of a renal artery/arterioles causes decrease F into the kidneys w/o affecting blood flow to other organs *R is indirectly related to F: if R increases, then F decreases if R decreases, then F increases
Define the terms blood flow, cardiac output, blood pressure, and resistance.
-Blood flow (F)- blood volume flowing through a vessel, an organ, or entire circulation in a given time (mL/min) -cardiac output (CO)- under resting conditions. HR x SV -BP- force per unit area that is exerted on a blood vessel wall by its contained blood -Resistance- opposition to blood flow (F) through one or more vessels
List the 3 sources of peripheral resistance and know how each affects blood flow.
-Blood viscosity - internal resistance to blood flow that is related to its "thickness" or "stickiness" *usually a constant value w/ little fluctuation (solvent:solute ratio) -Blood vessel length - longer vessels demonstrate greater resistance *usually a constant value but varies with body mass changes -Blood vessel diameter - changes in blood vessel diameter significantly alter peripheral resistance (R) *not a constant value, frequently changing to accommodate changing tissue demands
Explain Boyle's law and the relationship to air inspiration and expiration.
-Boyle's law (P1V1 = P2V2) - describes relationship that exists between pressure (P) & gas volume (V) *gas pressure (mm Hg) varies inversely w/ its volume (mm3) when temperature is held constant -Effects of V/P changes on contained alveolar gases: *expansion (inspiration) - occurs as lung volume increases *increased alveoli size (V↑) causes decreased alveoli pressure (↓P) *compression (exhalation) - occurs as lung volume decreases *decreased alveoli size (V↓) causes increased alveoli pressure (↑P)
Describe the structural composition of the bronchi and bronchioles.
-Bronchioles- composed of cuboidal epithelium; no supportive cartilage; see increased smooth muscle/elastic bands -Bronchi- lumen is lined w/ ciliated pseudostratified columnar epi. changing distally to columnar epi., displays outer irregular cartilage plates
Describe structure/function of lymph nodes. Explain lymph circulation through lymph node.
-Characteristics: *well-defined outer connective tissue capsule *larger than diffuse lymphoid tissue/follicles *filters lymph being fed by lymphatic vessels *location: along lymphatic collecting vessels in large clusters near body surface in inguinal, axillary, cervical regions -Vary in size/shape, < 1" long, trabeculae extend inward from fibrous capsule dividing node into many sections -Lymph movement: *lymph enters a node's subcapsular area through several afferent lymphatic vessels *travels through a large subcapsular sinus into a number of smaller sinuses then enters medulla *moves through medullary sinuses exiting node at hilus (indented region) through fewer efferent lymphatic vessels *fewer efferent than afferent vessels slows lymph movement in node *gives lymphocytes/macrophages time to carry out protective functions
Define Dalton's Law and Henry's Law.
-Dalton's law - pressure of a gas mixture equals the sum of partial pressures of individual gases in mixture *atmospheric pressure = pN2 + pO2 + pCO2 + pOthers (water vapor, Ag) *pO2 = 760 mm Hg x 0.21= 160 mm Hg → enters conducting zone -Henry's law - solubility of a gas in a liquid is directly proportional to partial pressure of gas (pGas) above liquid *a higher p value forces more gas into liquid phase *gas solubility in water = CO2 > O2 > N2 *pN2 has greatest partial pressure at 592.8 mm Hg but it's the least soluble gas in blood *O2/CO2 solubility defines required pressure gradients for lung & tissue gas exchange
Describe the gas exchange gradients for O2 & CO2 in the lungs and other tissues.
-Differences between lung/tissue pO2 & pCO2 values defines necessary pressure gradient for gas exchange *pO2 160 mm Hg enters nose, but only 100 mm Hg reaches alveoli *conducting zone lumen cells use some passing O2
Describe structure/function of elastic (conducting) arteries, muscular (distributing) arteries, arterioles, and capillaries
-Elastic (conducting) arteries - large ID w/ thick-walls, size ranges from 1-2.5 cm *includes aorta/major aortic branches *contains most elastin of any blood vessel *expands as blood is ejected from heart ventricles... recoils as blood moves on *elastin can withstand large blood pressure fluctuations so aorta does not burst *primary role is to conduct blood from heart to medium-size arteries *large lumens allow low-resistance blood conduction ( increases blood flow) -Muscular (distributing) arteries - distal to elastic arteries, proximal to arterioles, size ranges from 0.1-10 mm *more smooth muscle than elastic arteries... so less elastin *less distention than elastic arteries *more active in vasoconstriction *primary role is to deliver blood to body organs *makes up most of named arteries (e.g.,renal artery, splenic artery, etc.) -Arterioles - smallest arteries interfacing with tissue capillary beds, size ranges from 10 um up to 0.3 mm *larger arterioles have all 3 tunics *tunica media is mostly smooth muscle that surrounds endothelium *changes in lumen dia. is effected by smooth muscle (same manner as arteries) *primary role is to deliver blood to tissues located inside body organs *minute-to-minute blood flow into tissue capillary beds is regulated by arteriolar dia. *responds to neural stimulation, blood hormone changes, local chemical changes -Capillaries - microscopic blood vessels present in most body tissues, avg. length = 1mm w/ an ID = 8-10 μm *thin-walled tunica interna, smallest only 1 endothelial cell thick *functions in timely exchange of materials (respiratory gases, nutrients, hormones) between blood plasma & interstitial fluid *small ID means that RBCs ~7.5μm in dia. must pass one at a time... *pericytes - mesenchymal-like cells located on outer endothelium surface to help stabilize capillary walls *Absent in: - cartilage - epithelium - eye cornea/lens
Describe the structure and function of trachea.
-Flexible, mobile tube 4" L x 3/4" D, extends from larynx into mediastinum, reinforced to prevent airway collapse *carina - terminal keel-shaped tracheal cartilage marks end of trachea, two distal branches are beginnings of R/L bronchi
Define the terms interstitial fluid and lymph.
-IF - fluid in spaces between tissue cells formed as blood plasma is forced out at capillary bed arteriole end *exchange medium between blood/tissues (gases, nutrients, wastes) *resembles blood plasma but contains less protein *drained away from interstitial space as lymph -Lymph - clear to yellowish watery fluid circulating through lymphatic vessels *3L of IF formed each 24-hrs, must be returned to venous circulation *flows towards heart in a 1-way system
Recall the muscles involved in air inspiration and expiration and Describe how changes in thoracic volume affect air inspiration and expiration.
-Inspiration (Inhalation) Quiet/normal inspiration is an active process *diaphragm/external intercostal muscles contract & rib cage rises- lungs expand *increase lung volume (V) causes decrease *internal alveolar pressure (Ppul) intrapulmonary pressure (Ppul) drops about 1 mm Hg causing inflow of air -Expiration (Exhalation) Quiet/normal expiration is a passive process *diaphragm/external intercostal muscles relax & rib cage descends - lungs recoil *decrease lung volume (V) causes increase internal alveolar pressure (Ppul) *intrapulmonary pressure (Ppul) rises about 1 mm Hg causing outflow of air Ppul [761] > Patm [760] *internal intercostals muscles only contract during a forced expiration
Define the terms inspiration and expiration.
-Inspiration- *Rib cages move up and out. *Diaphragm contracts and move down. *Pressure in lungs decreases, and air comes rushing in. -Expiration- *Rib cage moves down and in. *Diaphragm relaxes and moves up. *Pressure in lungs increases, and air is pushed out.
Describe location, structure, and functions of larynx.
-Location: attached to hyoid bone, opens into laryngopharynx superiorly, continuous w/ trachea inferiorly -Functions: *maintains a patent airway to trachea *a switching mechanism to route air/food into proper channels *allows voice production via vocal (folds) cords -Structure: nine single/paired hyaline or elastic cartilages connected to each other by ligaments & membranes *8 hyaline cartilages - thyroid (laryngeal prominence), cricoid arytenoid, corniculate, cuneiform *1 elastic cartilage - epiglottis, which covers laryngeal opening during swallowing, stops air passage into trachea unless unconscious
Describe the structure/function of the pharynx and list its 3 regions.
-Location: extends from skull base to about level of 6th cervical vertebra -Structure: *funnel-shaped skeletal muscle tube connecting nasal cavity/mouth & larynx/esophagus, 3 continuous regions: 1. nasopharynx - air passage only 2. oropharynx - passes both food & air 3. laryngopharynx - divergence point for air to trachea & food to esophagus -Function: common passageway for food & air
Explain why lung alveoli are so small.
-Lung contains approximately 300 million tiny alveoli *majority of lung volume, provides large surface area for gas exchange
Describe structure/function of lymphoid tissue and recall body areas containing the same
-Lymphoid tissue - widespread reticular connective tissue found in many organs holding immune calls *houses both inactive & activated lymphocytes *ideal vantage point for resident macrophages & lymphocytes *includes diffuse lymphoid tissue, lymphoid follicles (nodules), lymph nodes, lymphoid organs *MALT, tonsils, Peyer's patches, spleen, thymus, appendix *all do the same thing, so distinction between lymphoid tissue is mostly based upon level of tissue organization -Characteristics: *no outer connective tissue capsule *smaller than lymph nodes *does not filter lymph (no vessels)
Describe blood O2 & CO2 transport mechanisms and their associations with hemoglobin.
-O2 transport - 98.5% is bound to Hb w/ another 1.5% traveling free in blood plasma *partially saturated - only some heme groups bind O2 (1-3) *fully saturated - all four heme groups bind O2 -CO2 transport - 70% is converted to plasma bicarbonate ion (HCO3-) by RBCs, 20% is bound to Hb, & 10% travels free in blood plasma *20% of CO2 binds to Hb globin chain & not Fe *bicarbonate/carbonic acid conversion can provide CO2 buffering
Describe structure and location of Peyer's patches and appendix.
-Peyer's patches - large clusters of lymphoid follicles (nodules) similar to tonsils *found in distal portion of small intestine -Appendix - thin tube of lymphoid follicles, ~4" long at junction of small/large intestines (lower right quadrant) *function unknown but is thought to be involved in replenishing commensal (beneficial) bacterial flora after diarrheal illness
Define the terms pleura, parietal pleura, visceral pleura, pleural cavity, and pleural fluid.
-Pleura - thin, double-layered serosa, separated by a pleural cavity filled with lubricating pleural (synovial) fluid -parietal pleura - covers thoracic wall + superior face of diaphragm, continues around heart & lungs -visceral (pulmonary pleura) - covers external lung surface, divides thoracic cavity into three chambers -pleural fluid provides required surface tension so that lungs do not easily pull away from chest wall during breathing process
Distinguish between pulmonary and bronchial circulations based on blood vessels serving each circuit and its respiratory gas content.
-Pulmonary circulation: 1. pulmonary arteries - brings CO2-rich blood to lungs, branches along w/ bronchi, transitions into alveolar pulmonary capillaries 2. pulmonary veins - carries O2-rich blood from respiratory zone back to heart -Systemic (bronchial) circulation: 1. bronchial arteries - provides O2-rich blood from L heart to all lung tissue except alveoli *arise from aorta entering lungs at hilus *branches along w/bronchi/bronchioles 2. bronchial veins - drains CO2-rich blood from larger bronchi & lung root structures *merge (anastomose) w/ pulmonary veins carrying O2-rich blood back to L heart *creates an arteriovenous shunt
Explain the relationship between respiratory volumes and respiratory capacities.
-Respiratory volumes - measured air volume (ml) that can or cannot be exchanged during breathing -Respiratory capacities - contained air volume calculated by adding together two or more respiratory volumes
Describe causes and pathological features of respiratory disorders: restrictive lung diseases, COPD (emphysema, bronchitis), asthma, and lung cancer.
-Restrictive lung disease - characterized by ↓ lung volume + ↓ effectiveness of inspiration *Effect is a loss of lung tissue or chest wall expansion 1. intrinsic diseases destroy lung (alveolar) tissue *pnuemoconiosis - occupational silicon, asbestos, cobalt dust inhalation or drugs causes inflammation followed by fibrosis *idiopathic pulmonary fibrosis - fibrosis of an unknown cause 2. extrinsic diseases affect pleura, chest wall, or innervation -Chronic obstructive pulmonary diseases (COPD) causes a permanent change is lung anatomy 1. emphysema - alveolar sacs are destroyed w/ a corresponding loss of elasticity around bronchiole airways/alveolar walls 2. chronic bronchitis - long-term cough w/ mucus hypersecretion clogs an already narrowed airway most people have a combination of both conditions -Asthma - characterized by acute episodes of airway inflammation w/ hyperreactive response *another obstructive disorder, but unlike COPD asthma is a reversible disorder *see coughing, wheezing, shortness of breath (dyspnea) -Pathology: *bronchoconstriction - smooth muscle in conducting zone airways constricts *airways become inflamed & swollen *produces excessively thick mucus -Lung cancer results in uncontrolled growth of lung tissue *involves either bronchial, bronchiole, or alveolar epithelium *cigarette smoking causes most lung cancers *nonspecific symptoms makes early detection difficult -Process: *cavitation - lung tissue collapses as abnormal cells divide wildly around bronchioles pushing against adjacent aveolar structures
Order sequence of lymph flow from lymphatic capillaries to venous blood return.
-Similar to blood capillaries but are noncontinuous, more permeable, & exhibit flap-like minivalves 1. minvalves are formed between ends of adjacent endothelial cells where they overlap each other (one-way swinging door) 2. collagen filaments anchors overlapping cell's end attaching it to surrounding connective tissue (prevent collapse) -IF entry mechanism: *minivalve flaps open as newly formed IF fluid causes increase interstitial pressure *flaps close when interstitial pressure ↓ as "old" IF enters & flows upward into lymphatic vessels
Explain general function of mucosa-associated lymphatic tissue. List tissues that comprise MALT.
-Small mucous membrane-bound lymphoid aggregates found mainly in digestive system *includes tonsils, Peyer's patches*, appendix *represents most extensive component of body's lymphoid tissue *also present in respiratory system organs (e.g. bronchiole walls, nose) & urogenital system
Describe structure/function of spleen, thymus, and tonsils.
-Spleen- *Structure- Soft, blood-containing organ located on left-side below diaphragm, borders left stomach *single large splenic artery/splenic vein enters/exits, respectively at hilum *largest lymphoid organ *Functions: *lymphocyte proliferation site *immune surveillance/response *cleanses blood of "old blood cell" debris *other functions include: storing RBC breakdown products, fetal RBC production site, stores blood platelets (33%) -Thymus- *Bi-lobed organ directly beneath sternum & above heart, important in formative years (infant to adolescent) *starts decreasing in size after puberty → atrophies in adults *Function: *site where naïve T cells learn how to perform self/non-self determinations to become immunocompetent T cells *Structure: 1. cortex - densely packed T cells +scattered macrophages 2. medulla - fewer lymphocytes + whorled thymic corpuscles (sites producing regulatory T cells preventing autoimmunity) -Tonsils- *simplest lymphoid organs forming a lymphatic tissue ring around pharynx *infolding of epithelial tissue overlying tonsil masses forms blind-ended crypts that trap/destroy bacteria/particulate matter
Explain functions of lymphoid cells: lymphocytes (T cells, B cells), macrophages, dendritic cells, and reticular cells.
-T cells - perform self-nonself recognition process, activated T-cells attack/destroy foreign cells -B cells - differentiate into antibody-producing plasma cells when activated by T cells and/or macrophages -macrophages - phagocytize foreign substances, help activate/ recruit T cells by "presenting" Ag to T lymphocytes -dendritic cells - long-lived antigen-presenting cell (APC) stimulating either immune response or tolerance -reticular cells - fibroblast-like cells producing a reticular network to support immune cells located in lymphoid organs
Compare/contrast venous blood pressure to arterial blood pressure.
-Venous BP is steady changing little during cardiac cycle *driving pressure in venous system is only ~ 15 mm Hg -Arterial BP reflects two factors of arteries close to heart: elasticity and blood volume.
Describe structure and functions of venules, veins, and venous sinuses. Explain why veins are called capacitance vessels.
-Venules - formed where several capillaries unite (merge) (avg. lumen ID = 20 um) *postcapillary venules - smallest venules only composed of endothelium + a few associated pericytes *extremely porous vessels, allow fluids/inflammatory WBCs to pass from bloodstream into tissues *larger venules have one or two layers of smooth muscle in tunica media *also display a thin tunica externa -Veins - formed where several venules converge (merge) *has a greater diameter than an artery at same body level *called capacitance vessels (blood reservoirs) since they can contain 60-65% of blood supply* at any one time *see all three tunics: *tunica interna - single endothelial layer *tunica media - thin, vena cavae expressing greatest amount of smooth muscle *tunica externa - thick, consists of collagen fibers + elastic networks -Venous sinuses - specialized, wide/flattened veins w/ extremely thin walls *heart coronary sinus *venous sinuses
Describe the adaptation used to return low pressure lymph to venous blood.
-Very low pressure system that lacks a pump, under less pressure than most veins *lymphatic vessels are referred to as low-pressure conduits -Uses similar methods as veins to help propel lymph *nearby skeletal muscle contractions, numerous valves, change in thoracic cavity size -Additional "help" mechanisms: 1. pulsations of large nearby arteries 2. smooth muscle in walls of lymphatic trunk/thoracic ducts contract regularly
Describe the structure of the respiratory membrane.
-air-blood barrier w/ gas on one side & blood on other side -made of alveolar wall (epithelial-side) + capillary wall (endothelial-side) + their fused basal laminas
Differentiate between arteries, veins, & capillaries on a functional basis.
-arteries - carry blood away from heart diverge/branch into smaller vessels -capillaries - smallest vessels for gas, nutrients, & waste exchange substance transfer = blood > interstitial space > tissue cells (nearby) -veins - carry blood towards heart converge/join into larger vessels
Define the terms atmospheric pressure, intrapulmonary pressure, intrapleural pressure, and transpulmonary pressure.
-atmospheric pressure (Patm) - pressure from surrounding air -intrapleural pressure (Pip) - pressure in pleural space -intrapulmonary pressure (Ppul) - pressure in lung alveoli -transpulmonary pressure - difference between Ppul & Pip keeps lung airspaces open
Discuss pressure differences in systemic circulation starting at the aorta and ending at the right atrium.
-cut vein - slow, even blood flow (oozing) -lacerated artery - fast, spurting blood flow (pulsatile) -resistance increases as arteries diverge and pressure is gradually lost all along arterial circulation. -blood pressure diminishes more than capillary beds -resistance decreases as blood returns back to the heart occurs through merging veins.
Define the term transpulmonary pressure.
-difference between Ppul & Pip keeps lung airspaces open *pleural infusion - excess pleural fluid causes a more positive Pip, which translates into decrease lung size during inhalation *↓ transpulmonary pressure
Differentiate between diffuse lymphatic tissue and lymphatic follicles (nodules).
-diffuse lymphoid tissue - loose association of lymphoid cells & reticular tissue found in almost all body organs *location: mucosal membranes (e.g., digestive system, esophagus) -lymphoid follicles (nodules) - well-organized solid, spherical bodies consisting of tightly packed reticular elements & cells *location: stomach, intestines, larger lymphoid organs like spleen
List the functions of the nasal cavity and identify its structures.
-divided by a midline nasal septum composed of septal cartilage & vomer bone -vestibule - area superior to nares lined w/ sebaceous/sweat glands & hair follicles *vibrissae - hairs filtering out large particles from inspired air -roof/floor - defined by ethmoid-sphenoid bones, hard/soft palates -posterior nasal apertures - marks end of nasal cavity/beginning of nasopharynx -conchae - scroll-like areas extend medially from lateral walls, covered w/ mucosal tissue, reclaims moisture during expiration
Explain why low capillary pressure is desirable.
-does not rupture fragile, thin-walled continuous capillaries *increase BP will rupture kidney fenestrated capillaries, which are under higher pressure (↑R) than continuous capillaries -allows creation of interstitial fluid (IF) from blood plasma leaky capillaries
Describe arterial elasticity and its relationship to blood volume.
-elasticity - conducting artery's ability to stretch (compliance) -blood volume - amount of blood forced into elastic arteries at any one time
Explain how intrapulmonary pressure varies with inspiration and expiration but reaches equilibrium with atmospheric pressure.
-falls during inspiration & rises during expiration -Ppul will eventual reach equilibrium with Patm -alveolar pores play a big part in pressure equalization process
Define the terms inspiratory capacity, functional residual capacity, vital capacity, and total lung capacity.
-inspiratory capacity (IC) - total air amount that can be inhaled after a normal tidal expiration -functional residual capacity (FRC) - air volume remaining in lungs after normal tidal expiration -vital capacity (VC) - total amount of exchangeable air, a max. expiration following a max. inspiration -total lung capacity (TLC) - total amount of exchangeable & nonexchangeable air sum of all lung volumes
Define the terms lacteal and chyle.
-lacteals - lymphatic capillaries only present in small intestine villi -absorb digested "milky" fat nutrient chyle (fatty lymph) delivering it to bloodstream
Describe laminar flowing of blood and how turbulence affects it.
-laminar flow (streamlining) - relative speed/position of blood in different areas of a blood vessel cross section remains constant *changes in smooth endothelial lining causes increase resistance (R) -turbulence from vessel lesions interrupt laminar flow dramatically increasing resistance
Describe special adaptations that help veins return blood to the heart.
-large-diameter lumens - offer little resistance to blood flow -valves - prevent blood backflow especially in lower limbs, composition resemble heart semilunar valves
Recall the forces contributing to a negative intrapleural pressure
-lung recoil (collapsing force): alveolar recoil during exhalation -thorax expansion (enlarging force): chest wall recoil during inhalation
Describe the process of pulmonary function testing.
-measures amount (mL) of air inhaled/exhaled by tested individual *varies w/ exercise, age, gender, weight and/or disease
Define the terms positive pressure and negative pressure.
-negative respiratory pressure = Ppul < Patm *at sea level, Ppul < 760 mm Hg -positive respiratory pressure = Ppul > Patm *at sea level, Ppul > 760 mm Hg
Discuss the effect of inflammation on lymphatic capillary permeability.
-non-inflammatory periods - interstitial space proteins easily enter lymphatic capillaries (but not blood capillaries) -tissue inflammation - lymphatic capillaries open more to absorb larger particulate matter *cell debris, microbes, cancer cells are carried to specialized lymphatic tissue called lymph nodes for examination/removal *microbes & cancer cells can uses lymphatics to enter blood & spread
Describe origins/destinations of plasma fluid, interstitial fluid, and lymph fluid.
-plasma fluid - "forced out" of distal capillaries, becoming interstitial fluid (interface) -interstitial fluid - enters lymphatic capillaries, becomes lymph -lymphatic vessels - returns lymph fluid to blood circulation
Discuss the structural relationship between alveoli and pulmonary capillaries.
-pulmonary capillaries surround each alveolus - part of pulmonary circuit
Define pulsatile, systolic pressure, diastolic pressure, pulse pressure, and mean arterial pressure.
-pulsatile (throbbing)-rise/fall of aortic BP -Systolic pressure - peak pressure during ventricular contraction (120mm Hg) -Diastolic pressure - lowest pressure during ventricular relaxation (80mm Hg) -pulse pressure - difference between systolic/diastolic pressures -mean arterial pressure (MAP) - average arterial pressure propelling blood to tissues/organs
Recall the respiratory zone structures.
-respiratory bronchioles - smallest bronchiole subdivision connecting a terminal bronchiole to an alveolar duct -alveolar ducts - tiny ducts connecting respiratory bronchioles to alveolar sacs -alveolar sacs - terminal clusters of alveoli (vs. single alveolus) *air route = terminal bronchioles > respiratory bronchioles > alveolar ducts > alveolar sacs
Differentiate between olfactory and respiratory mucosae.
-respiratory mucosa- lined w/ seromucus glands & goblet cells moist, high water content humidifies entering air -olfactory mucosa- contains smell receptors
Differentiate between respiratory and conducting zones, both structurally and functionally.
-respiratory zone - sites of gas exchange* *includes respiratory bronchioles, alveolar ducts, & alveoli -conducting zone - rigid conduits (tubes) that must be filled first for air to reach gas exchange sites *includes nose, nasal cavity, pharynx, trachea, & numerous bronchi/bronchioles *cleanses air of impurities *warms/humidifies air
Describe the structural changes that occur as conducting zone structures become smaller.
-terminal bronchioles - < 0.5 mm in dia., subdivide distally into respiratory bronchioles w/ alveoli *terminal bronchioles mark end of conducting zone
Define tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume.
-tidal volume (TV) - air volume exchanged during normal inhalation & exhalation -inspiratory reserve volume (IRV) - air volume that can be forcibly inspired after a normal tidal inspiration -expiratory reserve volume (ERV) - air volume that can be forcibly exhaled after a normal tidal expiration -residual volume (RV) - air volume remaining in lungs after a maximal exhalation
Define the terms tunic and lumen as they relate to blood vessels.
-tunic- layers -lumen- the opening
Describe how vasodilation and vasoconstriction affect blood flow (F)
-vasoconstriction - narrows blood vessel lumen ID -vasodilation - widens blood vessel lumen ID
Describe venous sinuses, venous anastomoses, atrial anastomoses and ateriovenous anastomoses. Identify their common locations.
-venous anastomoses - most common type seen on back of hands/feet, rarely blocked -arterial anastomoses - collateral channels in joints, heart, brain, abdominal organs -arteriovenous anastomoses - vascular shunt of metarteriole-thoroughfare channel, seen in digestive/urinary tissues
Differentiate between true and false vocal cords.
-vestibular folds (false vocal cords) - mucosal folds superior to true vocal cords, closes glottis during swallowing *no role in sound production -vocal folds (true vocal cords) - two strong pearly-white elastic tension-bearing ligaments enclosed by vestibular folds
Identify two reasons for alveolar pores.
1. act as an alternate air route for alveoli w/ collapsed bronchioles 2. allows air pressure throughout lung to be equalized
Differentiate between anatomic dead space, alveolar dead space and physiologic dead space.
1. anatomic dead space - measures air volume (~150 ml) required to fill conducting zones that does not participate in gas exchange *only 350 ml out of 500 ml TV inspired air reaches alveoli 2. alveolar dead space - measures damaged alveoli are unable to participate in gas exchange *disease process causes alveolar destruction 3. physiologic (total) dead - total volume of respiratory tract that is not functionally involved in gaseous exchange *sum total of anatomic + alveolar dead spaces
List the body regions served by lymph nodes.
1. cortex - outer region, contains same lymphoid follicles seen in diffuse lymphoid tissue/lymphoid nodules *germinal centers - center of an activated follicle* loaded w/ dividing B cells + Ab producing plasma cells (terminal B cells) *outer follicle area houses transient (traveling) T cells + resident dendritic cell 2. medulla - inner region, central core of lymph node *medullary cords - thin cortical extensions separated by lymph sinuses, contains B cells + T cells *lymph sinuses - large capillary-like spaces w/ crisscrossing reticular fibers separating medullary cords, contains phagocytic macrophages + reticular cells
Recall the two main functions of lymph nodes.
1. filtration - macrophages sort through filtered lymph to destroy microbes & remove cellular debris 2. immune system activation - activated B/T cells mount an attack against non-self substances (e.g., cancer cells)
Describe structural features of lymphatic capillaries, lymphatic collecting vessels, lymphatic trunks & lymphatic ducts.
1. lymphatic capillaries - microscopic, permeable, blind-ended vessels "weaving" through capillary beds/tissues 2. lymphatic collecting vessels - formed where several lymphatic capillaries merge *similar to veins since they posses all 3 tunics but are very thin-walled, have more valves, & anastomose more 3. lymphatic trunks - formed by a union of several lymphatic collecting vessels draining large body regions, named for body areas served: *subclavian trunks (L/R) *jugular trunks (L/R) *bronchomediastinal trunks (L/R) *lumbar trunks (L/R) *intestinal trunk (unpaired) 4. lymphatic ducts - two large thoracic region ducts located between both subclavian/jugular veins returning lymph to blood a. right lymphatic duct - drains right arm/thorax/side of head b. thoracic duct - drains left arm/thorax/side of head + lower limbs *cisterna chyli - small, dilated sac located in lower right abdomen created by junction of 3-lower body trunks, gives rise to thoracic duct
Discuss what is meant by the lymphatic system's two semi-independent arms.
1. meandering network of lymphatic vessels returning both lymph & "leaked" proteins back into blood *helps maintain body water volume balance 2. scattered lymphoid tissues/organs strategically located throughout body *resident site for immune system responder phagocytes & lymphocytes
Recall 3 tracheal layers and describe composition of each.
1. mucosa - single layer of ciliated epithelium w/ scattered goblet cells 2. submucosa - connective tissue deep to mucosa w/ seromucous glands 3. adventitia - outermost connective tissue layer embedded w/ 20 C-shaped rings made of hyaline cartilage
Recall tonsil names/locations.
1. palatine tonsils - posterior end of oral cavity, either side 2. lingual tonsils - lie at base of tongue 3. pharyngeal tonsil* - posterior wall of nasopharynx 4. tubal tonsils - surround openings of auditory tubes into pharynx
Order the first 3 branching of the bronchi and recall alternate names.
1. primary (main) bronchus 2. secondary (lobar) bronchi 3. tertiary (segmental) bronchi
Describe the 4 processes of respiration. Identify body areas where each process occurs.
1. pulmonary ventilation - moving air in/out of lungs (breathing) 2. external respiration - gas exchange between lungs/blood 3. transport - moving O2 /CO2 between lungs & tissues 4. internal respiration - gas exchange between blood/tissues
List three factors aiding venous blood return.
1. respiratory pump - inspiration decreases thoracic pressure, aspirates (sucks) blood towards right atrium from thoracic vein 2. muscular pump - local skeletal muscle contractions "milk" blood in thin-walled deep veins back towards heart *valves prevent backflow from lower body regions 3. smooth muscle - sympathetic activation promotes tunica media muscle vasoconstriction *venous blood volume is reduced while blood is "pushed" towards heart faster
Identify the gross structures of the lungs.
1. root - site of vascular/bronchial attachments to mediastinum 2. hilus - indentation where pulmonary/systemic blood vessels enter/exit lungs along w/ bronchi, nerves, & lymphatics 3. costal surfaces - lung surfaces contacting ribs 4. apex - narrow superior tip 5. base - broad inferior surface resting on diaphragm 6. cardiac notch - left lung concavity that accommodates heart 7. left lung - separated into 2 lobes by oblique fissure 8. right lung - separated into 3 lobes by oblique/horizontal fissures 9. bronchopulmonary segments - each lung contains 10 segments, 1 for each tertiary (segmental) bronchi 10. lobule - smallest subdivision of lung visible to eye
Explain the functions of the different alveolar cell types, macrophages.
1. type I alveolar cells - single layer squamous epithelium making up alveolar walls, permits gas exchange by simple diffusion *secrete angiotensin converting enzyme (ACE) 2. type II alveolar cells - scattered cuboidal epithelium cells *secrete surfactant & antimicrobial PROs
Describe structural/functional features of all 3 vessel tunics.
A. Tunica intima (tunica interna): 1. endothelial layer - single layer of flattened epithelium* lining lumen of all blood vessels *starts at heart endocardium, provides a smooth uninterrupted inner surface that decreases friction w/ increased blood flow 2. subendothelial layer - basement membrane + loose connective tissue supporting lumen endothelium only present in vessels > 1 mm in diameter B. Tunica media: (bulk of vessel wall) 1. smooth muscle layer - regulated by ANS sympathetic nervous system vasomotor fibers + hormones (e.g., norepinephrine) *causes changes in lumen internal diameter (ID) that affects both blood pressure (BP) & blood flow (F) a. vasodilation - effects smooth muscle relaxation → ↑lumen ID b. vasoconstriction - effects smooth muscle contraction → ↓lumen ID 2. elastin sheets - allows vessel expansion & subsequent recoil C. Tunica externa (tunica adventitia): 1. loose collagen fibers - protect, reinforce, anchors vessels 2. nerves - control smooth muscle 3. elastic fibers - expand/recoil 4. lymphatic vessels - lymph return 5. vasa vasorum (vessel-of-vessels) - tiny system of external blood vessels found in larger veins/arteries *"feeds" external vessel layers while lumen blood nourishes internal layers *originates from a branch off of an artery
Describe blood pressure differences in aorta, arteries, arterioles, capillaries, venules, veins, and venae cavae.
Aorta has the largest and it decreases down the list to almost nothing at the venae cavae
Recall the relative portions of blood volume in the circulatory system compartments.
Arteries and arterioles- 15% Pulmonary blood vessels- 12% Heart- 8% Capillaries- 5% Veins and Venules- 60%
Define the terms bronchial tree, bronchus, and bronchioles.
Bronchial tree - consists of multiple branching airways, each getting progressively smaller moving towards alveoli Bronchi - main air passageway into lungs, 2 major subdivisions branch off from trachea at carina Bronchioles - 4th order or smaller bronchi* less than 1mm in diameter differing from bronchi:
Recall body tissues that do not contain lymphatic vessels.
CNS, bones, teeth, bone marrow, cartilage
Define the terms and capillary bed and microcirculation.
Capillary beds - concentration of capillaries supplying blood to a specific body part microcirculation - blood flow through capillary beds
Characterize the lymphatic system as a whole.
Lymphatic system - extensive fluid drainage network that helps (1) balance body fluid levels, (2) defend body against infections *major component of immune system
Define the terms perfusion & closed circulation.
Perfusion- pumping of a fluid through an organ or tissue through a closed system of vessels *includes both blood & lymphatic fluid Closed circulation- fluids are going to be lost to surrounding areas if it`s not pumped on closed circuit
Describe both short-term and long-term blood pressure regulations mechanisms.
Short-term control involves changes in peripheral R/CO Long-term control involves changes in blood volume that are renal-mediated *direct - alters water volume independent of hormones *indirect - renin, ADH, aldosterone effect sodium/water reabsorption
Explain why the trachea contains incomplete (C-shaped) hyaline cartilage rings.
allows the trachea to contract and expand
Explain how blood is propelled through arteries while the heart is in diastole.
arteries expand increasing pressure and then recoil to decrease pressure moving the blood along in a pulsating manner when the heart is at diastole.
Describe how muscular arteries reduce pulsations.
because they don`t expand and recoil like elastic arteries do
List three factors influencing systemic blood pressure.
cardiac output, peripheral resistance (R), & blood volume
Discuss the effects of decreased blood pressure on heart activity (ESV, EDV).
decrease blood pressure causes cardiovascular center to increase vasoconstriction, increases CO (HR xSV)
Correctly order the route of different types of blood vessels starting at the heart and returning blood to the heart.
heart elastic arteries (largest) muscular arteries (large) arterioles (small) capillaries (smallest) venules (small) veins (larger) vena cavae (largest) heart
Recall which 4 organs cooperate to ensure adequate blood pressure.
heart, blood vessels, kidneys, & brain (CNS) control
Describe how the respiratory mucosa warms and humidifies inspired air.
high water content humidifies entering air; rich in superficial capillaries/thin-walled veins, warms entering air
Explain why a blood pressure gradient is necessary for blood circulation.
necessary to keep a high to low blood pressure to keep vessels from having too much pressure that they burst
Differentiate between voice pitch and voice loudness.
pitch - determined by vocal cords length/tension *higher pitch results from increase cord tension with faster vibrations loudness - depends upon force (velocity) which air passes across vocal cords *loud sounds are a result of strong vibrations with increase air volume passing cords
Define the term respiration.
process of exchanging oxygen/carbon dioxide between atmosphere & tissue cells
Recall the type of blood vessel where the steepest blood pressure change occurs.
steepest BP change occurs in arterioles since small ID offers most resistance (R) to blood flow (F)
Differentiate between continuous capillaries found outside the brain and those making up the blood-brain barrier.
tight junctions are in betweeen all endothelium which means no intracellular clefts
Define the term anastomoses.
union or joining together of blood vessels in certain body areas
Differentiate between true capillaries and a vascular shunt.
vascular shunt - mechanism to divert blood fluid, consists of a metarteriole & thoroughfare channel true capillaries - 10-100 capillary branches off a metarteriole delivering blood to local tissues, merge at thoroughfare channel
Explain how the larynx and its associated structures produce sounds.
vocal cords vibrate/control air flow being expelled from lungs; speech occurs during intermittent release of expired air that alternately opens/closes glottis
