Cardiovascular system

2017 ◽  
Author(s):  
Mark Harrison
Keyword(s):  
Blood Pressure ◽  
Emergency Medicine ◽  
Cardiovascular System ◽  
Body Fluid ◽  
Cardiac Cycle ◽  
Colloidal Solutions ◽  
Pharmacological Manipulation ◽  
System P ◽  
Body Fluid Homeostasis ◽  
Crystalloid Solutions

This chapter describes the pathophysiology of the cardiovascular system as it applies to Emergency Medicine, and in particular the Primary FRCEM examination. The chapter outlines the key details of the control of blood pressure and heart rate, cardiac output, blood flow, cardiac cycle, ECG, pharmacological manipulation of the heart, shock, oxygen delivery and consumption, body fluid homeostasis, crystalloid solutions, colloidal solutions, and exudates and transudates. This chapter is laid out exactly following the RCEM syllabus, to allow easy reference and consolidation of learning.

Cardiovascular system

2011 ◽  
pp. 443-462
Author(s):  
Dr Mark Harrison
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Cardiovascular System ◽  
Cardiac Cycle ◽  
Peripheral Circulation ◽  
Pharmacological Manipulation ◽  
System P

2.1 Control of blood pressure and heart rate, 445 2.2 Control of heart rate, 446 2.3 Cardiac output (CO), 447 2.4 Measurement of cardiac output (CO), 450 2.5 Blood flow peripherally, 451 2.6 The cardiac cycle, 454 2.7 ECG, 458 2.8 Pharmacological manipulation of the heart and peripheral circulation, ...

scholarly journals Arterial baroreflex regulation of muscle sympathetic single-unit activity in men: influence of resting blood pressure

2020 ◽  
Vol 318 (4) ◽  
pp. H937-H946 ◽  
Author(s):  
Anthony V. Incognito ◽  
Milena Samora ◽  
Andrew D. Shepherd ◽  
Roberta A. Cartafina ◽  
Gabriel M. N. Guimarães ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Single Unit ◽  
Cardiac Cycle ◽  
Single Units ◽  
Arterial Baroreflex ◽  
Baroreflex Control ◽  
Pharmacological Manipulation ◽  
Operating Range ◽  
Resting Blood Pressure ◽  
Spike Firing

The arterial baroreflex has dominant control over multiunit muscle sympathetic nerve activity (MSNA) burst occurrence, but whether this extends to all single units or is influenced by resting blood pressure status is unclear. In 22 men (32 ± 8 yr), we assessed 68 MSNA single units during sequential bolus injections of nitroprusside and phenylephrine (modified Oxford). Sympathetic baroreflex sensitivity (sBRS) was quantified as the weighted negative linear regression slope between diastolic blood pressure (DBP) and single-unit spike firing probability and multiple spike firing. Strong negative linear relationships ( r ≥ −0.50) between DBP and spike firing probability were observed in 63/68 (93%) single units (−2.27 ± 1.27%·cardiac cycle−1·mmHg−1 [operating range, 18 ± 8 mmHg]). In contrast, only 45/68 (66%) single units had strong DBP-multiple spike firing relationships (−0.13 ± 0.18 spikes·cardiac cycle−1·mmHg−1 [operating range, 14 ± 7 mmHg]). Participants with higher resting DBP (65 ± 3 vs. 77 ± 3 mmHg, P < 0.001) had similar spike firing probability sBRS (low vs. high, −2.08 ± 1.08 vs. −2.46 ± 1.42%·cardiac cycle−1·mmHg−1, P = 0.33), but a smaller sBRS operating range (20 ± 6 vs. 16 ± 9 mmHg, P = 0.01; 86 ± 24 vs. 52 ± 25% of total range, P < 0.001) and a higher proportion of single units without arterial baroreflex control outside this range [6/31 (19%) vs. 21/32 (66%), P < 0.001]. Participants with higher resting DBP also had fewer single units with arterial baroreflex control of multiple spike firing (79 vs. 53%, P = 0.04). The majority of MSNA single units demonstrate strong arterial baroreflex control over spike firing probability during pharmacological manipulation of blood pressure. Changes in single-unit sBRS operating range and control of multiple spike firing may represent altered sympathetic recruitment patterns associated with the early development of hypertension. NEW & NOTEWORTHY Muscle sympathetic single units can be differentially controlled during stress. In contrast, we demonstrate that 93% of single units maintain strong arterial baroreflex control during pharmacological manipulation of blood pressure. Interestingly, the operating range and proportion of single units that lose arterial baroreflex control outside of this range are influenced by resting blood pressure levels. Altered single unit, but not multiunit, arterial baroreflex control may represent changes in sympathetic recruitment patterns in early stage development of hypertension.

scholarly journals Breakdown of blood pressure and body fluid homeostasis in heart transplant recipients

1996 ◽  
Vol 27 (2) ◽  
pp. 375-383 ◽  
Author(s):  
Randy W. Braith ◽  
Roger M. Mills ◽  
Christopher S. Wilcox ◽  
Gary L. Davis ◽  
Charles E. Wood
Keyword(s):  
Blood Pressure ◽  
Heart Transplant ◽  
Body Fluid ◽  
Transplant Recipients ◽  
Fluid Homeostasis ◽  
Body Fluid Homeostasis ◽  
Heart Transplant Recipients

Urinary system

2021 ◽  
pp. 497-534
Keyword(s):  
Body Fluid ◽  
Obstructive Uropathy ◽  
Extracellular Fluid ◽  
Mechanisms Of Action ◽  
Urinary Continence ◽  
Renal Tubules ◽  
Urinary System ◽  
Bladder Control ◽  
System P ◽  
Body Fluid Homeostasis

The ‘Urinary system’ chapter opens with a description of the urinary tract morphology (kidney, ureters, bladder) and its histology. Renal function is considered, including glomerular filtration, the role and regulation of the renal tubules in producing dilute and concentrated urines, and the mechanisms of action of diuretic drugs. The function of the kidney in body fluid homeostasis (extracellular fluid volume and osmolarity, pH) is then discussed, and the regulation of kidney function explored, including bladder control and urinary continence. Finally, renal failure and obstructive uropathy are discussed as examples of renal pathology.

scholarly journals Integration of detailed modules in a core model of body fluid homeostasis and blood pressure regulation

2011 ◽  
Vol 107 (1) ◽  
pp. 169-182 ◽  
Author(s):  
Alfredo I. Hernández ◽  
Virginie Le Rolle ◽  
David Ojeda ◽  
Pierre Baconnier ◽  
Julie Fontecave-Jallon ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Fluid ◽  
Blood Pressure Regulation ◽  
Core Model ◽  
Pressure Regulation ◽  
Fluid Homeostasis ◽  
Body Fluid Homeostasis

Normal function of the cardiovascular system

2018 ◽  
Author(s):  
Manish Kalla ◽  
Neil Herring
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cardiovascular System ◽  
Cardiac Cycle ◽  
Normal Function ◽  
Cardiac Physiology ◽  
Local Blood Flow ◽  
System P ◽  
Vascular Physiology ◽  
Flow Capillary

This chapter discusses normal function of the cardiovascular system, including cardiac physiology (the cardiac cycle, ECG, blood flow and heart sounds, control of cardiac output), vascular physiology (control of local blood flow, capillary transfer), integrated cardiovascular control,

Abstract 017: Optogenetic Activation of OVLT Neurons Stimulates Water Intake and Produces a Sympathetically-Mediated Increase in Arterial Blood Pressure

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Sean D Stocker ◽  
Sarah S Simmonds
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Arterial Blood Pressure ◽  
Water Intake ◽  
Body Fluid ◽  
Frequency Dependent ◽  
Fluid Homeostasis ◽  
Direct Activation ◽  
Arterial Blood ◽  
Body Fluid Homeostasis

The organum vasculosum of the lamina terminalis (OVLT) plays a pivotal role in body fluid homeostasis and arterial blood pressure (ABP) regulation. The OVLT lacks a complete blood-brain-barrier and responds to an array of circulating factors such as NaCl and angiotensin II. Lesion of the anteroventral third ventricular region which includes the OVLT attenuates or reverses several forms of salt-sensitive hypertension. However, there is limited evidence to demonstrate that direct activation of OVLT neurons alters body fluid homeostasis or elevates ABP. To address this question, Male-Sprague-Dawley rats (300-350 g) received an injection of rAAV9-CamKII-hChR2(H134R)-EYFP (10 12 particles/mL, 200nL) into the OVLT. A fiber optic cannula (200μm) was implanted 300μm dorsal to OVLT. Approximately 2-3 week later, optogenetic activation of OVLT neurons (10ms pulse, 50% duty cycle, 30 min) produced frequency-dependent increases in water intake (1Hz: 1.0±0.5mL; 5Hz: 4.2±0.6mL; 10Hz: 8.0±1.8; 20Hz: 10.2±2.1mL, n=4, P<0.05). In separate experiments, optogenetic activation of OVLT neurons produced a frequency-dependent increase in mean ABP (1Hz: 1±1 mmHg; 5Hz: 3±1mmHg; 10Hz: 7±1mmHg; 20Hz: 13±1mmHg, n=4, P<0.05) and heart rate (1Hz: 3±6 bpm; 5Hz: 15±5bpm; 10Hz: 40±12 bpm; 20Hz: 62±14bpm, n=4, P<0.05). Pretreatment with the vasopressin antagonist Manning Compound (10ug/kg, IV) did not affect these responses. However, pretreatment with the ganglionic blocker chlorisondamine (5mg/kg, IV) abolished the pressor (20Hz: 1±1 mmHg, P<0.01) and tachycardic (20Hz: 4±7 bpm, P<0.05) responses to activation of OVLT neurons. Finally, in vivo single-unit recordings demonstrate that optogenetic activation produced frequency-dependent increases in cell discharge of OVLT neurons responsive to either intracarotid injection of hypertonic NaCl (0.3M NaCl, 50μL over 10 s, n=6) or angiotensin II (100ng over 10s, n=3). Collectively, these data provide evidence that direct activation of OVLT neurons stimulates thirst and produces a sympathetically-mediated increase in ABP.

Cardiovascular system

2017 ◽  
Author(s):  
Mark Harrison
Keyword(s):  
Heart Failure ◽  
Emergency Medicine ◽  
Cardiovascular System ◽  
Cardiac Glycosides ◽  
Antiplatelet Drugs ◽  
Beta Adrenoceptor ◽  
System P ◽  
Antianginal Drugs ◽  
Beta Adrenoceptor Blockers

This chapter describes the pharmacology of the cardiovascular system as it applies to Emergency Medicine, and in particular the Primary FRCEM examination. The chapter outlines the key details of cardiac glycosides, diuretics, antiarrhythmics, beta-adrenoceptor blockers, hypertension and heart failure, nitrates and antianginal drugs, sympathomimetics, anticholinergics, anticoagulants, antiplatelet drugs, fibrinolytics, and lipid-regulating drugs. This chapter is laid out exactly following the RCEM syllabus, to allow easy reference and consolidation of learning.

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