Sistemas Circulatorios: Anatomía y Funcion - Prof. Ramos, Apuntes de Biología

¡Descarga Sistemas Circulatorios: Anatomía y Funcion - Prof. Ramos y más Apuntes en PDF de Biología solo en Docsity! ACUC (A) Arthropod Extracellular fluid (hemolymph) of arthropods percolates through tissues and enters the heart through openings called ostia. (8) Mollusk In mollusks, a system of vessels drains the intercellular spaces and retums hemolymph to the heart. (C) Annelid worm In annelids, muscular hearts pump blood through a system of closed vessels. Sites of exchange of materials between blood Hearts and interstitial (Connecting vessels) fuid LIFE 10e, Figure 50.1 0 2014 Sinauer Associates, Inc. O IN IND Ml Oxygenated El blood [7] Deoxygenated blood | Bulbus ps Atrium Fish have a heart with four chamber:s: the sinus venosus, Sinus venosus an atrium, a ventricle, Ventricle and the bulbus arteriosus. Systemic capillaries LIFE 10e, In-Text Art, Ch. 50, p. 1028 (1) 0 2014 Sinauer Associates, Inc.  O NI) O Oxygenated blood Lung capillaries Deoxygenated S mM blood Right aorta Mixed blood : <Q Left atrium (RS Wi | ll Left aorta 7 Y Right atrium de Ventricle In the reptilian 3-chambered heart, the ventricle is partly divided by a septum, which directs oxygen- ated blood to the body Systemic and deoxygenated capillaries blood to the lungs. LIFE 10€, In-Text Art, Ch. 50, p. 1029 (2) 0 2014 Sinauer Associates, Inc.  RO IND O Oxygenated Lung capillaries blood Ml Deoxygenated Right blood aorta | Mixed blood Left aorta Crocodilians have completely Loft divided ventricles, but they can AULA selectively shunt blood to the pulmonary or systemic circuits Left through a connection between ventricle the two aortas. Systemic capillaries LIFE 10e, In-Text Art, Ch. 50, p. 1030 (1) O 2014 Sinauer Associates, Inc. O INN) ] Oxygenated Lung blood capillaries E] Deoxygenated blood E | Left Birds and mammals ZA > LEY H ventricle have four-chambered Right hearts. Their pulmonary UNS ventricle and systemic circuits are yo totally separate. X > —— Systemio capillaries LIFE 10e, In-Text Art, Ch. 50, p. 1030 (2) O 2014 Sinauer Associates, Inc. Figure 50.4 Measuring Blood Pressure ¡The cuff is inflated beyond the point that shuts off all blood flow. Pressure in the cuff is gradually lowered until the sound of a pulsing flow of blood through the constriction in the artery is heard. At this time, pressure in the cuff is just below the peak systolic pressure in the artery. Pulsing LIFE 10e, Figure 50.4 0 2014 Sinauer Associates, Inc. sounds 3 Pressure is further lowered until the sound becomes continuous. At this time, the cuff is just below the diastolic pressure in the artery. This person's blood pressure is 120/70. Pulsing sound gives way to smooth “whoosh” of blood flow ATC AECA El Once threshold is reached, a major influx of Ca?+ generates an action potential. A slow influx of first Na, then Ca?* causes a gradual depolarization of pacemaker cells. 3 Action potential EJ Opening of K* channels allows K* to Mmuesiolal exit and the A cal cell repolarizes. Membrane potential (mV) dh o -100 1 1 L 0 0.15 0.30 (B) L-type Na+ Ca?2+ channels channels o T k+ channels Ttype 2 |] Ca2+ channels o L y 1 0 0.15 0.30 Time (seconds) Relative membrane permeability LIFE 10€, Figure 50.5 2014 Sinauer Associates, Inc. Figure 50.6 The Autonomic Nervous System Controls Heart Rate — Control +10 Normal resting heartbeat rate A Membrane potential (mV) Threshold | | 5 100 200 300 400 500 600 Time (msec) Control recording shows When NE is applied, the rate When ACh is applied, A O that the membrane of depolarization of the the rate of depolarization potential of pacemaker membrane potential is slower. Time between cells gradually increases. Time between action potentials depolarizes after an action potentials decreases increases and the heart action potential is fired. and the heart rate increases. rate slows down. LIFE 10e, Figure 50.6 0 2014 Sinauer Associates, Inc. ACUC E igor lolo lE=T14] LIFE 10e, Figure 50.10 0 2014 Sinauer Associates, Inc. Q, R, and S together correspond to P corresponds to the depolarization and contraction T corresponds to the the depolarization of the ventricles. relaxation and repolar- of the atrial muscle. ization of the ventricles. 0.5 ECG (mv) o -0.5 High Arterial pressure Low aJoJselg ajoJselg eJoJselg PARRAS “Lub” “Dup” Time (seconds) Y The sounds heard through a stethoscope occur at the beginning and end of systole.  ID US E 14 E e Bluefin 100 9 12 e Albacore a E 10 o Yellowfin “ 80 3 É 2 S “5 60 6 X 5 9 40 x 4 Ñ 2 a S 2 320 a E o 0 | 1 1 ] J o 0 ] | 1 1 | J Ó 0. 5 10 15 20 25 30 35 0. 5 10 15 20 25 30 3 Temperature (*C) Temperature (*C) LIFE 10e, Working with Data 50.1, Figure A 0 2014 Sinauer Associates, Inc.  e U 1 The Composition of Blood Blood is withdrawn from the arm, placed in a test tube, and centrifuged. 100% — Components Water 7 Functions Solvent z ? / 50% — ba LA Hematocrit > 7 Enthrocytes (red blood cells) 7] Components e ES ; y Y Number per 4-6 million N pl of blood X Transport 1 Functions oxygen and N carbon dioxide LIFE 10e, Figure 50.11 (0 2014 Sinauer Associates, Inc. Plasma portion Salts Sodium, potassium, calcium, magnesium, chloride, bicarbonate Plasma proteins Albumin Fibrinogen Immunoglobulins Transported by blood: e Nutrients (e.g., glucose, vitamins) + Waste products of metabolism + Respiratory gases Osmotic balance, Osmotic balance, (O, and CO,) pH buffering, regulation pH buffering, clotting, + Hormones of membrane potentials immune responses e Heat Cellular portion Leukocytes Platelets (white blood cells; see Chapter 42) (cell fragments) Basophil Eosinophil Neutrophil Lymphocyte Monocyte - SD . ==> Ca a E WD < 250,000- 5,000-10,000 400,000 Destroy foreign cells, produce antibodies; Blood roles in allergic responses clotting Figure 50.13 Anatomy of Blood Vessels (A) Because veins operate under low pressure, some veins Arteries have many : O yl have valves to prevent elastin fibers and backflow of blood smooth muscle e. y) y (see Figure 50.16). fibers, allowing = y them to withstand high pressures. artery artery Capillaries Mean blood Total area velocity (cm?) (cm/sec) Total area (cm?) Low SS Large Small Arterioles Capillaries Venules Veins arteries arteries LIFE 10e, Figure 50.13 (0 2014 Sinauer Associates, Inc. Figure 50.14 A Narrow Lane "| Red blood cells must pass through capillaries in single file. > Capillary walls Nucleus of | endothelial cell y Endothelial Capillary walls consist of a single layer of endothelial cells. Fluid can squeeze out the spaces between the cells. Inside capillary LIFE 10e, Figure 50.14 0 2014 Sinauer Associates, Inc. Figure 50.15 Starling's Forces (4) Fluid is squeezed out of the Fluid is pulled back into the capillary by blood pressure. capillary by osmotic pressure. Blood Osmotic Blood Osmotic pressure pressure pressure pressure (40) (25) (16) (25) mm Hg mm Hg Blood pressure 40 Blood pressure 16 Osmotic pressure -25 Osmotic pressure -25 Net outward force 15 Net inward force SS) (B) 50 Net driving force for _ fluid to leave capillary 2 Blood pressure - / E 25 o 3 + | S Osmotic Net driving force for a pressure fluid to reenter capillary 0 LIFE 10e, Figure 50.15 0 2014 Sinauer Associates, Inc. UI Oi RL O Blood flow through a capillary bed is controlled by the constriction of smooth muscle in the arteries and arterioles. Capillary —L£o y Precapillary sphincters can open in response to low O,, low pH, or cytokines... Throughfare vessel Muscle fibers (cells) ...Or they can shut off blood supply to the capillary bed. LIFE 10€, Figure 50.18 0 2014 Sinauer Associates, Inc. Figure 50.19 Control of Blood Pressure through Local and Systemic Mechanisms ACUC E or lEr Om Tov: Higher brain centers Chemoreceptors in * Emotion medulla signal high e Anticipation e Stress SOS Y Pco» in blood. Medullary cardiovascular [ero] Lg or 1 08 Norepinephrine Acetylcholine qa Decrease Epinephrine heart rate and Kidney Increased arterial pressure heart rate and arterial pressure Baroreceptors in Chemoreceptors on aorta and carotid artery aorta and carotid arteries are activated when are activated when blood pressure rises. blood Po falls. LIFE 10e, Figure 50.20 0 2014 Sinauer Associates, Inc.