# The Basic Physiology Of Cardiac Output And Its Measurement Essay

Length: 1958 words (5.6 double-spaced pages)

Rating: Better Essays

#### Essay Preview

egin{equation}
DO_{2} = CO imes CaO_{2}
end{equation}\

where\
CO denotes cardiac output and \
\$ CaO_{2} \$ denotes oxygen content of arterial blood.\

The oxygen content can be calculated by the formula:\

egin{equation}
CaO_{2} = (1.36 imes Hb imes SaO_{2} )+ ( 0.0031 imes PaO_{2})
end{equation}\

Where \
Hb denotes haemoglobin,\
\$ SaO_{2} \$ denotes saturations from pulse oximetry,\
\$ PaO_{2} \$ denotes arterial oxygen tension and\

A major determinant of oxygen delivery, as noted earlier, is the cardiac output. I will discuss the basic physiology of cardiac output and its measurement in further detail now.\

subsection{Cardiac output}
Cardiac output (CO) is the amount of blood pumped out of the heart in a minute. This is a product of the heart rate per minute and the stroke volume (blood volume per heart beat). Cardiac output is usually expressed as cardiac index (CI) (CO per unit body surface area). Cardiac index is crucial to ensure oxygenation of tissues. The normal range of CI in humans is between 3.5-6 l/min/\$ m^{2} \$. Studies by Starling on dogs were the first to describe the parameters that affect CO.\
According to Frank-Starling 's law, the force of contraction of cardiac muscle is directly proportional to the length of stretch. Blood fills the ventricle during diastole and stretches the cardiac muscle. Consequently, the amount of blood contained in the ventricle at end of diastole - the end diastolic volume - determines the length of stretch of the cardiac muscle which in turn determines the cardiac index.cite{Patterson:1914wka}cite{Starling:1927vt}\
The increase in force of contraction as a function of stretch is a non-linear curve. Therefore, the stroke volume initially increases with ...

... middle of paper ...

...duct guide.cite{Phillips:2009tz}}
label{uscom curve}
end{minipage}

subsection{Oxygen consumption}
Oxygen consumption depends on cellular respiration. The amount of oxygen utilised by the cells to generate ATP - in the electron transport chain in the mitochondria - is the ultimate determinant of consumption. Therefore oxygen consumption can act as a marker of the mitochondrial function and the functional status of cells. Other surrogate measures like mixed venous saturations, lactate and extit{\$ pCO_{2}\$} difference have also been used.\
The oxygen extraction rate (OER) is the ratio of oxygen consumption to oxygen delivery. The OER is utilised to analyse oxygenation of tissues.\

egin{equation}
OER = {frac {VO_{2}} {DO_{2}}}
end{equation}\

Where\
OER denotes oxygen extraction rate,\
\$ VO_{2} \$ denotes oxygen consumption and \
\$ DO_{2} \$ denotes oxygen delivery.\

## Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

## A Study Of Nervous Systems, Anatomy And Physiology Essay

- Question 6-The approach that fascinates me the most is neuroscience; furthermore, neuroscience is the study of nervous systems, anatomy and physiology. Neuroscience is preoccupied with both the organization of the system in humans, animals and their purposes. Neuroscience proposes a body of information that serves as an infrastructure for comprehending how cognitive operations are conveyed. Cognitive neuroscience focuses on cognitive processes, which are visual, object recognition, attention, memory, problem solving and language (Friedenberg and Silverman, 2012)....   [tags: Human brain, Brain, Nervous system]

Better Essays
2105 words (6 pages)

- Exercise Physiology This study assessed heart rate, blood pressure, and pulse oximeter readings at rest and during exercise. The heart rate (HR), blood pressure (BP), and oximetery measurements provide better insight into the inner workings of the human body. In using the results of the assessment, one can determine the affects that rest and exercise have on the cardiac system. Heart rate is described as the rate of the cardiac cycle. Heart rate is measured in beats per minute (bpm). A well conditioned heart is able to pump large amounts of blood with each beat....   [tags: Assessment Health Study]

Better Essays
1335 words (3.8 pages)

## Minute-to-Minute Urine Flow Rate Variability: A New Renal Physiology Variable

- Urine output is a time-honored measure of the patient’s effective blood volume (EBV) and a surrogate for tissue perfusion. Urine output is typically measured at one-hour intervals and expressed in milliliters per hour (ml/h). Because small volumes are difficult to measure, initial information becomes available only 20-30 minutes after catheter insertion by extrapolating to one full hour. This extrapolation can result in considerable over- or underestimation. Lately digital urine-meters were developed as a nursing tool to reduce urine output reading errors reaching 30%....   [tags: Medicine]

Better Essays
2297 words (6.6 pages)

## A Basic Principle Of Quality Measurement Essay

- Data Gathering Data will be obtained from human resources/risk management regarding the number of patient falls and number of staff injuries, adjusted for census, which were due to patient transfers. This information is obtained from incident and industrial injury reports. A reduction in both the number of injuries and days offs as a result of those injuries, as well a reduction in the number of patient falls during transfers would be expected in a successful program. The best measure of falls is one that can be compared over time within a hospital unit to see if care is improving....   [tags: Statistics, Arithmetic mean, Mean]

Better Essays
772 words (2.2 pages)

## Bios The Basic Input / Output Service Essay examples

- BIOS the Basic Input/Output Service is what allows you’re your CPU to communicate with all the other devices on your computer. BIOS is a program that that stores the information the CPU needs to communicate with the devices connected to the computer. The problem with BIOS is where to store it can’t be contain in the operating system, the hard drive, or RAM, so that leaves us with only one option ROM. ROM (Read Only Memory) is a special type of chip which stores programs called services, ROM is like RAM but unlike RAM it is nonvolatile and except for a few exceptions the information stored there cannot be changed....   [tags: BIOS, Personal computer, Floppy disk]

Better Essays
732 words (2.1 pages)

## The Effect Of Exercise On Exercise Physiology Essay

- My exposure to exercise physiology is far from conventional. Rather than engaging it as an academic hobbyist, I was drawn to it out of necessity and utility in the U.S. Army. Rather than following anachronistic military physical training, I took it upon myself to learn more about exercise science. What started as tool for my job soon turned into my passion. I understood how exercise physiology was more than a foray into the underpinnings of strength and conditioning, but something that had a meaningful purpose in a very tangible way....   [tags: Physical exercise, Obesity, Exercise physiology]

Better Essays
788 words (2.3 pages)

## Essay on Benchmarking and Performance Measurement

- Bench marking is setting some standard to the level of products and services being produced or offered to customers while still minimizing costs. The role of benchmarking is providing a reference point. The discipline of bench marking is focused on analyzing, identifying, studying and adopting best practices in an organization like customer satisfaction, product quality, throughput and implementing the findings. Performance measurement is the regular collection, reporting and analyses of resources used, work produced and whether the specific intended objectives were realized....   [tags: performance measurement, management]

Better Essays
1367 words (3.9 pages)

## Essay on The Anatomy And Physiology Course At Kings College London

- I am applying for a place on the Human Anatomy and Physiology course at Kings College London. My interest reemerged during the last semester of my undergraduate studies at the University of the Arts London where I studied BA Animation and I was to brainstorm internship locations, produce a creative curriculum vitae and sidereel. A major production opportunity emerges biannually and as much as I enjoyed watching my fellows work as entertainment, I surely didn 't want to choose the broad path towards that industry....   [tags: Human anatomy, Anatomy, Physiology, Biology]

Better Essays
1092 words (3.1 pages)

## Basic Physiology of a Neuron and How it Fires Essay

- Basic Physiology of a Neuron and How it Fires Describe the basic physiology of a neuron. Detail the manner by which neurons fire action potentials and how neurons communicate with one another across synapses. Outline the process of how an action petential occurs and hoe it propagates down an axon. Explain how chemical transmission occurs at synapses and how this allows neurons to activate of inhibit one another. [Picture from "Answer to Neuron Structure"] Neurons are the basic units of the brain....   [tags: Papers]

Better Essays
722 words (2.1 pages)

## Essay on Critique of an article from the Journal of Applied Physiology

- Critique of an article from the Journal of Applied Physiology "Effect of different protocols of caffeine intake on metabolism and endurance performance" Introduction In 2002, a group of Australian researchers published a paper entitled the "Effect of different protocols of caffeine intake on metabolism and endurance performance". Caffeine use during sporting events has become much more popular and has widely studied. The purpose of the research was to examine the work increasing (ergogenic) effects of differing regiments of caffeine on metabolism and performance while simulating the typical nutritional preparation an athlete would do for a race....   [tags: Physiology Journal Article Critique]

Better Essays
1108 words (3.2 pages)