CBIO2210 Week 7 Notes
CBIO2210 Week 7 Notes CBIO2210
Popular in Anatomy and Physiology II
Popular in Anatomy
This 10 page Class Notes was uploaded by Elise Weidner on Tuesday March 1, 2016. The Class Notes belongs to CBIO2210 at University of Georgia taught by Rob Nichols in Spring 2016. Since its upload, it has received 25 views. For similar materials see Anatomy and Physiology II in Anatomy at University of Georgia.
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Date Created: 03/01/16
CBIO2210 Notes 2/23/16 Top Hat Questions 1. According to Frank-Starling, stroke volume is most closely related to… o End diastolic volume 2. Negative inotropic agents would include all of the following except o Norepinephrine o Hypocalcemia o Hyperkalemia o Acidosis 3. Hypertension can cause (pick 2) o Reduced stroke volume o Reduced afterload (wrong because causes increased afterload) o Increased end-systolic volume 4. An increase in vessel diameter is called ______ As a result of this, the resistance in the vessel_____ o Vasodilation, decreases o Vasodilation, increases o Vasoconstriction, increases o Vasoconstriction, decreases Chart continued Systolic-pressure blood puts on vessel (cardiac function) Diastolic- pressure the vessel puts on blood (vascular function) o Function of elastic recoil of vessel Physiology of Circulation Blood ﬂow: volume of blood ﬂowing through a vessel (or a whole system of vessels) o equal to CO o proportional to pressure gradient o inversely proportional to resistance Blood Pressure: the force that blood exerts on the vessel wall of the vessel that it’s in o pressure gradient causes ﬂow Flow directly proportional to pressure gradient and inversely proportional to resistance (formula) most pressure in Aorta (*IMAGE* and formula) pressure gets lower and lower the farther the blood gets from aorta o heart does not push the blood away, it is just going to a place of lower pressure Resistance: opposition to ﬂow; function of the friction between blood and vessel walls o a.k.a., TPR o Resistance factors: viscosity (↑ vis. ➙ raises R) vessel length (↑ v.l. ➙ lowers R) vessel diameter (↑ v.d. ➙ lowers R) Mean Arterial Pressure (MAP) Arterial BP is a function of the force with which the heart ejects blood and the elastic recoil of the elastic arteries near the heart These two factors result in: o systolic pressure (a cardiac factor) o diastolic pressure (an arterial recoil factor) Pulse pressure (PP) = Systolic Pressure – Diastolic Pressure Since BP ﬂuctuates with each heartbeat, MAP is the average force that drives blood ﬂow o MAP = ⅓(PP) + DP o MAP = ⅓(SP - DP) + DP o ((120-80)/3) + 80 = 93.3 mm Hg o Notice how low the MAP becomes in veins…this decrease in pressure is the reason the blood goes towards veins Venous Return (blood coming back to right atrium needs help) “So, if veins are so low pressure, how does blood even get back to the heart?” Can kind of control/ affect first two but not last one 1. Respiratory “pump” o 1. decreased intrathoracic pressure during inspiration o Taking deep breath increases slightly the overall cardiac output 2. Muscular “pump” o 1. skeletal muscles around veins o 2. venous valves ensure one-way ﬂow o When muscles contract squeezes veins and because of the valves in the veins, the blood gets pushed up to the heart (makes you feel good when you exercise) 3. Smooth muscle in tunica media (provides ANS control) Circulatory Shock Any condition in which cardiac output is inadequate to meet the tissue demands of the body Point of pressure gradient is in capillaries (only ones that have walls thin enough for diffusion of nutrients and oxygen out and waste and CO2 in) Signs: o low BP (hypotension) o rapid HR (tachycardia) o poor “end-organ” perfusion(blood flow through the organ) (confusion, LOC, low urine output) Causes: o cardiogenic: CO is low due to myocardial infarction o low/poor venous return: CO is low because not enough blood is returning to heart (low preload) Pressure in vessels is inadequate to force blood into the capillaries (perfusion) o cardiogenic (do to heart attack) o poor venous return: (traumatic injury/loss of blood) hypovolemic (loss of volume) vascular (normal volume) (lost no blood, when blood vessels vasodilate) neurogenic anaphylactic (result of allergy, drop in BP because vessels vasodilate) septic (infection of the blood-usually bacterial) strep and staff both cause vasodilation if get in blood Blood Vessel Categories System of tubes for ﬂuid delivery that begins and ends with the heart arteries capillaries veins Vessels and Vessel Walls Tunica Intima (deepest) o endothelium (tissue type?) o basement membrane o for capillaries, there’s essentially nothing more than those 2 layers o in arteries only, there’s an elastic layer between the basement membrane and the next layer (the internal elastic lamina) o in veins only, there are valves that extend from the endothelium Arteries and Arterioles 3 branches of aortic arch (ABCs know them from lab) Elastic (conducting) arteries o closest to heart o largest lumen, least resistance (ﬁrst contribution to afterload) o pressure reservoirs (elastic recoil) o longer we live lose more elasticity Muscular (distributing) arteries o thickest tunica media(smooth muscles that vasoconstrict or vasodilate) : most inﬂuenced by ANS providing autonomic control of BP o carry blood into speciﬁc organs o acetylcholine causes vasodilation o epinephrine and norepinephrine cause vasoconstriction in these vessels Arterioles o smallest arteries, no elastic laminae or tunica externa o greatest control over BP o feed into capillaries Elastic Arteries are Pressure Reservoirs During ventricular systole, elastic arteries nearest the heart absorb the energy of the ejected blood o stretch like rubber bands During ventricular diastole, their recoil helps to “conduct” (or carry away) the blood further along o recoil keeps blood moving even during diastole Capillaries (do not memorize 4 routes for what goes in and out) “exchange vessels” o O2, CO2, waste, nutrients move in/out Fenestrated Capillaries Found where large amounts of materials are rapidly ﬁltered kidneys small intestine Capillary Beds Woven network of capillaries within tissues Precapillary sphincters regulate ﬂow into “true” capillaries o allows micromanagement of volume in capillary bed o controls routing of blood o made of smooth muscle, micromanage individual blood flow Extremes shown in diagram; most commonly beds are in a dynamic state of bypass CBIO 2210 2/25/16 *skip capillary exchange sections for test, don’t need to know it* Respiratory System Anatomy Chapter 22 Functions Primary Function: o Oxygenate blood for (and remove CO2 produced by) cellular respiration This is one of the mechanisms for controlling blood pH (Co2 not so much O2) Secondary functions that support the primary: o maintain an airway for ventilation o filter and clean incoming air o warm and moisten incoming air o recapture the heat and moisture of outgoing air 4 Processes of Respiration: Purpose of Pulmonary (lungs) Ventilation (breathing) o Bring air in to the pockets (alveoli) which have capillaries so that diffusion can happen (gas exchange/external respiration) External respiration o Respiration does not mean breathing, it means gas exchange o O2 going into the blood, CO2 coming out Transport o Done by circulatory system (the blood) Internal Respiration Basic Anatomy Upper respiratory tract and lower respiratory tract important for knowing illnesses Tracheobronchial Tree Air tubes consisting of 3 layers: o mucosa (epithelium) (one he wants to focus more on) o submucosa (connective tissue) o adventitia (serous) May be wrapped by layers of smooth muscle (but these are not consistent throughout) o The smooth muscle constricts May contain cartilage/rings o …what is the function of this cartilage? Structure, maintains airway by keeping the tubes open o C shaped so the esophagus can expand Carina-place where trachea splits (official end of trachea) Respiratory Mucosa ciliated pseudostratified columnar epithelium the cilia wave back and for in a rhythm goblet cells secrete mucus (contains a protein and water and fatty acids) the mucus get pushed by cilia up the trachea to the underside of the vocal cords and then drains down back side of esophagus o mucociliary escalator Bronchi Three levels o Primary (main) Left and right o Secondary (lobar) 3 right 2 left o Tertiary lead to bronchopulmonary segments (each lung has about 10 of these segments) Bronchioles (means little tubes) <1 mm diameter (very small) *no cartilage rings* cuboidal epithelium(getting thinner!) mucus very thick to prevent infections Terminal bronchioles o Have no further braches before they become a respiratory bronchiole Everything going through the conduction zone, after this it begins to be thin enough to exchange gas Respiratory Bronchioles Officially the beginning of the “respiratory zone” (locations of gas exchange) Terminate in pulmonary lobule Lobule consists of 3 or 4 alveolar ducts, each leading to an alveolar sac (don’t need to know the differences between these) Alveoli Simple squamous epithelium Stretch and expand as you breathe in This is the goal to get the air to here Air experiences 23 divisions from Trachea to bronchi *look at cross sectional area of all the bronchioles in chart* bronchioles-Primary contributors to airway resistance(on chart) Alveolar Structure Have elastin bands surrounding each alveolus to let them expand when we breathe Contains 3 cell types o Type I cells Simple squamous cells Make up wall (bricks) o Type II cells Part of wall too Secrete surfactant o Alveolar macrophages The Respiratory Membrane Respiratory membrane: very thin membrane that is the cite for gas exchange/diffusion because it gets pressed up against the blood cells o Illnesses can alter the thickness of the membrane which makes it difficult to get O2 in or CO2 put Fluid with surfactant lines the entire alveolar surface Creates fluid boundary between air and the cells Respiratory membrane has 3 layers: o alveolar epithelium o capillary endothelium o shared basement membrane “dust” cells Respiratory System Physiology: Ventilation Mechanics of Breathing (Ventilation) 2 phases: o inspiration (breathing in) o expiration (breathing out) Gases move from high pressure to low pressure 2 ways that air can be made to move into and out of the lungs o Change pressure in chest or pressure of whole atmosphere…easier to just alter own chest cavity How do the lungs alter pressures to accomplish inspiration/expiration? o Change volume of thoracic cavity which changes pressure Boyle’s Law Robert Boyle o Wanted to make a vacuum pump Robert Hooke o Robert Boyle’s assistant o Looked at cork and named cells o made piston which made vacuum and discovered Boyle’s Law “Pressure varies inversely with volume” basically: o ↑ V ↓ P o ↓ V ↑ P So, like the vacuum pump… Changes in the volume of the thoracic cavity cause changes in the pressures in the thoracic cavity The lungs are contained in a cage formed by the ribs, sternum and vertebrae The lungs are inflated and deflated by increasing and decreasing the size of the thoracic cavity. The size of the thoracic cavity is altered primarily by contracting and relaxing the diaphragm and external intercostals.