Greg Ikonnikov and Dominique Yelle

Clin Anat.2009 Jan;22(1):99-113. Can J Anaesth.1993 Nov;40(11):1053-64.

An organized rhythmic contraction of the heart requires adequate propagation of electrical impulses along the conduction pathway. Of note, the impulses in the His-Purkinje system travel in such a way that papillary muscle contraction precedes that of the ventricles, thereby preventing regurgitation of blood flow through the AV valves.

Physiol Rev.2005 Oct;85(4):1205-53.

Heart Rhythm.2010 Jan;7(1):117-26.

Note: The different types of cardiac ion channels are discussed below, throughout the description of the phases of action potentials in different cardiac cells.

Physiol Rev.2005 Oct;85(4):1205-53.

Action potential: electrical stimulation created by a sequence of ion fluxes through specialized channels in the membrane (sarcolemma) of cardiomyocytes that leads to cardiac contraction.

The action potential in typical cardiomyocytes is composed of 5 phases (0-4), beginning and ending with phase 4.

Pharmacol Ther.2005 Jul;107(1):59-79. Drugs.2007;67 Suppl 2:15-24. (The funny current)

Table 1. Cardiac cell types displaying pacemaker behavior.

Pacemaker

Location

Inherent rate (beats per minute, BPM)

Sinoatrial (SA) node

Right atrium (RA) at junction with superior vena cava (SVC)

60-100 BPM

Atrioventricular (AV) node

RA at posteroinferior area of interatrial septum

40-60 BPM

Purkinje fibers and ventricular cardiomyocytes

Throughout the ventricles

20-40 BPM

The sequence of events for pacemaker action potential:

Nature.2002 Jan 10;415(6868):198-205.

Excitation-contraction coupling represents the process by which an electrical action potential leads to contraction of cardiac muscle cells. This is achieved by converting a chemical signal into mechanical energy via the action of contractile proteins.

Calcium is the crucial mediator that couples electrical excitation to physical contraction by cycling in and out of the myocytes cytosol during each action potential.

Main contractile elements:

Regulatory elements:

The initial influx of Ca2+ into myocytes through L-type Ca2+ channels during phase 2 of the action potential is insufficient to trigger contraction of myofibrils. This signal is amplified by the CICR mechanism, which triggers much greater release of Ca2+ from the sarcoplasmic reticulum.

As with myocyte contraction, this process is synchronized with the electrical activity of the cell.

Adv Physiol Educ.2011 Mar;35(1):28-32.

Continue reading here:
Physiology of cardiac conduction and contractility ...

An Online Examination of Human Anatomy and Physiology

Animated Text Narrations and Quizzes to Explain the Structures and Functions of the Human Body Systems

Subject Areas

Skeletal System

Muscular System

Muscle Physiology

Nervous System

Circulatory System

Respiratory System

Urinary System

Histology Websites

System Quizzes

More:
Human Anatomy and Physiology - GetBodySmart

Nov. 4 - Fall Seminar Series: Dr. Juan Song

Nov. 18 - Fall Seminar Series: Dr. Ana Maria Dragoi

Dec. 2 - Fall Seminar Series: Urska Cvek, Sc.D., M.B.A.

Dec. 16 - Fall Seminar Series: Dr. Xiuping Yu

Physiology is the study of how biological systems perform their functions to maintain the steady-state internal environment of living organisms. We can study these processes at the genetic, cellular, organ system or whole-animal level. Our departmental name reflects the increasing application of molecular biology techniques in the understanding of physiological function. Understanding the basic concepts of physiological control of organ systems in the human body is key to identifying regulatory processes during organ dysfunction and disease states which, in turn, may elucidate a novel approach in therapeutic intervention.

Faculty members of the Department of Physiology maintain active research programs covering a wide range of topics with emphasis on:

Microvascular Physiology

Inflammation

Cancer Biology

Stroke and Other Ischemic Disorders

Oxidative and Redox Signaling

Endothelial Cell Biology

Diabetes Pathophysiology

Platelets and Thrombosis

Mechanisms of DNA Damage & Repair

The Department of Molecular and Cellular Physiology is committed to the advancement and dissemination of knowledge in the physiological sciences through the support of basic research and the training of new biomedical scientists in its physiology graduate program. This department has a strong commitment to the continued development and expansion of interactive research programs including cell and molecular biology that are nationally and internationally competitive. The emphasis on maintaining a strong reputation in research serves to ensure a stimulating and nurturing environment for producing the next generation of well-trained and highly competitive biomedical scientists who are dedicated to obtaining a Ph.D. in biomedical sciences. Our integrative approach allows for an in-depth understanding of relevant biomedical issues of clinical importance at the molecular, cellular, organ, and whole-body levels.

Contact us to learn more about the graduate school in biomedical sciences and other opportunities related to the graduate school physiology program.

Graduate Program

We are now accepting applications for the 2016/17 academic year. If you are interested in learning more about our Physiology Ph.D. program for the 2016/17 academic year, please click the "Apply Here" button to go directly to our preliminary graduate program inquiry form.

Ph.D. Program Ojectives

Click Here to Visit LSU Health Shreveport website!

Read the rest here:

Graduate Physiology, PHD Biomedical Sciences, Cell and ...

The leading text on human physiology for more than four decades

For more than four decades, Ganongs Review of Medical Physiology has been helping those in the medical field understand human and mammalian physiology. Applauded for its interesting and engagingly written style, Ganongs concisely covers every important topic without sacrificing depth or readability and delivers more detailed, high-yield information per page than any other similar text or review.

Thoroughly updated to reflect the latest research and developments in important areas. Ganongs Review of Medical Physiology incorporates examples from clinical medicine to illustrate important physiologic concepts.

See the rest here:

Ganong's Review of Medical Physiology 25th Edition ...

Dear Friend,

A re you looking to learn anatomy and physiology?

You're about to discover the most spectacular gold mine of human anatomy & physiology materials and diagrams ever created for commercial sale.

I'm about to share with you everything you'll ever need to know about human anatomy, physiology and drug therapy, complete with diagrams, courses, lesson plans, quizzes and solutions. I'll provide an effective and painless way to learn or review anatomy and physiology, from the chemical level through the entire organism

No matter whether you're a

My name is Dr. James Ross and I've been teaching human anatomy and physiology for more than 18 years. I hold a Ph.D. in Integrative Physiology, which I completed in 1992, and started writing for popular magazines and journals.

I was recently a nominee in the poster prize at the British Neuroendocrine Society annual conference held on 15th and 16th September 2008 at the University of Briston. In 2004, I founded the "InnerHealth" training school for paramedics and nurses in Pennsylvania.

But more importantly, since 1996, I've helped thousands of students, practitioners and junior doctors learn and master the complex topics of anatomy quickly and easily.

You see, once an expert explains to you how to actually do it...in language you can easily understand...this is almost as easy as...eating lunch.

The secret is in following proven lessons, mastering the subject one step at a time - At your own speed with detailed illustrations. This is closest thing to joining a full time medical course that will cost you over thousands of dollars. Sounds good? Then read on ..

Cover Hundreds of Medical Topics Spanning Over 3000+ Pages

Award Winning Course Previously Only Sold To Medical Professionals

Each Lessons Ends With Key Facts, Revision Tests + Solutions To Reinforce Learning and Pinpoint Weaknesses

Detailed Illustrations With Labels To Aid Your Comprehension - And Boost Your Retention

Idiot Proof Coverage Of Every Region & System In The Body and Identify Specific Muscle Groups and Their Functions

Simple Explanations of Cell Structures & Body Tissue and Review Key Anatomy & Physiology Concepts

Perfect For Medical Practitioners, Students, Educators, Anatomists, Sports Trainers, Injury Law Attorneys, Chiropractors, Therapists, Nurses and Paramedics

No Prior Medical Training Is Required

Computer Printable So That You Can Read On The Go

Compatible With Both Windows And Mac

This Ultimate Award Winning Human Anatomy Course is unsurpassed in conveying complex anatomical & pathological information.

Take a fascinating journey inside the mysterious hidden wonders of the body via pages of structural information and beautifully detailed anatomical images to find answers to questions.

All structures and musculature are modeled and labeled including nerves, deep and superficial muscles, blood supply, skeletal structures and unique features for each individual body parts. Each topic is linked via references with test quizzes and this provides the best way to learn and understand human anatomy and the body.

This is honestly the most complete ultimate home study course in human anatomy and physiology course you'll ever find on the Internet. With over 3000+ pages coupled with detailed illustrations and diagrams, it blows other similar courses away.

If you are a student, you'll save yourself YEARS of research. Pursuing a career as a healthcare professional? No problem - this hands on course gets you up to speed in anatomy and physiology facts in a focused step by step manner. And thats not all!

Boost Your Grades with The Best-Selling Medical Illustrated Course!

Learn about Human Anatomy or Physiology without spending giant amounts of money on expensive courses. This easy to follow primer with quick study guides helps you understand the intricacies of the body and how all its system work together. So what does this mean for you?

Find out how human muscles, nerves, bones,organs, glands, connective tissue and more, function and communicate with each other

Discover the molecular-level workings of your glandular, genitourinary, digestive, cardiovascular, and other systems

Conquer comparative and cellular physiology

Get complete answer explanations for all problems

Modules are clearly presented, easy to follow and thorough in content

Learn MORE in less time with the most enjoyable human anatomy course

But that's just part of the story. Lets take a closer look at the main components in this course:

System Component #1:

System Component #2:

System Component #3:

It is simply impossible to list everything down since it is too big but here is brief overview at some of the contents. This is just ONE of the many modules in this component

Note: Click On Each Image To View Larger Illustration:

Click On Each Image To Zoom In

Lesson 1: Introduction to Basic Human Physiology

Lesson 2: Physiology of Cells and Miscellaneous Tissues

Lesson 3: Envelopes of the Body

Lesson 4: The Skeletal System

Lesson 5: Physiology and Actions of Muscles

Lesson 6: The Human Digestive System

Lesson 7: The Human Respiratory System and Breathing

Lesson 8: The Human Urinary System

Lesson 9: The Human Reproductive (Genital) System

Click On Each Image To Zoom In

Lesson 10: Cardiovascular and Other Circulatory Systems of the Human Body

Lesson 11: The Human Endocrine System

Lesson 12: The Human Nervous System

Lesson 13: The Special Senses

Lesson 14: Some Elementary Human Genetics

Ear-Eyes-Nose Injuries

Musculoskeletal System

Nursing Care Related to the Musculoskeletal System

Anatomy and Physiology Related to Clinical Pathology

AND MANY MORE! (over 3000+ PAGES with full illustrations)

What this boils down to is that you're getting the most comprehensive human anatomy & physiology course available. This leaves no stone unturned.

Remember, this is just ONE module out of the hundreds in this component. It is simply too huge to list them all.

Pharmacology continues to be among the most dynamic of the biomedical sciences and as such, it included as a component in this amazing home study course.

Drug Dosage and Therapy

Oral and Maxillofactal pathology

Pharmacology I

Pharmacology II

Principles of Epidemiology and Microbiology

AND MANY MORE! (over 3000+ PAGES with full illustrations

Frankly, I didn't even delve into the details of every single module as I do not want to overwhlem you.

You'll find out about drugs affecting the central nervous system, autonomic and cardiovascular drugs, drugs used to prevent and treat infections, lymphatic systems, cardiac and vasodilator drugs and so much more.

Let me tell you, though, that what I've shown here is VERY conservative in number. The actual contents of this course is jam packed with a gargantuan amount of knowledge that has been scrupulously researched.

This tome of knowledge is right there...just waiting for you to open ...

LIST OF ILLUSTRATIONS

1-1 Regions of the human body 1-2 Anatomical position and medial-lateral relationships 1-3A The sagittal plane 1-3B The horizontal plane. 1-3C The frontal plane . 1-4 A "typical" animal cell (as seen in an electron microscope) 1-5 Planes of the body (exercise 14) 1-6 Directions (exercise 15). 1-7 Directions upon members (exercise 16). 1-8 A "typical" animal cell (exercise 18). 2-1 Epithelial cells. 2-2 Types of epithelial tissues 2-3 Types of muscle tissue 2-4 A neuron. 2-5 A synapse 3-1 The integument and related structures. 3-2 The integumentary derivatives (appendages) 3-3 A bursa--the simplest serous cavity 4-1 A mature long bone (femur) 4-2 A "typical synovial joint"--diagrammatic 4-3A Anterior view of the human skeleton 4-3B Posterior view of the human skeleton 4-4 A typical vertebra (superior and side views) 4-5 The human thorax with bones of the shoulder region 4-6 The human skull (front and side views) 4-7 A general pattern of the upper and lower members 4-8 The human scapula and clavicle (pectoral girdle) 4-9 The humerus, radius, and ulna 4-10 The human hand 4-11 The bony pelvis (two pelvic bones and sacrum). 4-12 The femur, tibia, and fibula (anterior views) 4-13 The human foot 5-1 Skeletal and facial muscles, anterior view. 5-2 Skeletal and facial muscles, posterior view 5-3 Types of lever systems 5-4 A simple pulley (the human knee mechanism)

5-5 The skeleto-muscular unit (arm-forearm flexion (3rd class lever system)) 6-1 The human digestive system 6-2 Anatomy of the oral complex. 6-3 Section of a tooth and jaw. 7-1 The human respiratory system 7-2 Supralaryngeal structures. 7-3 The larynx. 7-4 Infralaryngeal structures ("respiratory tree") 8-1 The human urinary system. 8-2 A section of a human kidney 8-3 A "typical" nephron 8-4 The human female genital system 8-5 The human male genital system (continued) . 9-1 Scheme of blood vessels 9-2 The human heart.. 9-3 Scheme of heart valves. 9-4 Cardiovascular circulatory patterns 9-5 Main arteries of the human body 9-6 Main veins of the human body 9-7 The human lymphatic system 10-1 The endocrine glands of the human body and their locations.. 11-1 A "typical" neuron . 11-2 A synapse 11-3 A neuromuscular junction. 11-4 The human central nervous system (CNS) . 11-5A Human brain (side view). 11-5B Human brain (bottom view) 11-6 A cross section of the spinal cord. 11-7 A schematic diagram of the meninges, as seen in side view of the CNS 11-8 A "typical" spinal nerve, with a cross section of the spinal cord 11-9 The general reflex arc 11-10 A horizontal section of the eyeball 11-11 Cellular detail of the retina. 11-12 A frontal section of the human ear 11-13 The labyrinths of the internal ear. 11-14 Diagram of the scalae 11-15 Diagram of semicircular duct orientation ..

Click On Each Image To Zoom In

If you're a student or researcher, these diagrams would be a lifesaver.

The good news is, you pretty much don't have to do any work at all. All the hardwork has been extensively done for you. These comprehensive illustrations are all detailed and labelled.

This is like having your own walking human encyclopedia.

Cells and Tissues | Skeletal | Muscular | Digestive | System | Respiratory | Urinary | Reproductive | Cardiovascular | Endocrine and Nerves | Human Genetics and Senses

+

Drug Dosage and Therapy | Oral and Maxillofactal Pathology |Pharmacology | Epidemiology | Microbiology

Award Winning Home Study Course As Seen On The Martha Stewart Show!

See why I call this the "ultimate" home study course? But you know, I'm going to make it even easier...

And here's what I haven't told you...for the next 100 27 members only:

As if that's not enough, you'll also be glad to know that I'm throwing in an time limited bonus.

"Nursing & Paramedics Masterclass" is an exclusive course that covers all the fundamental materials ways to get started in the industry, even if you're new to this. As always, it contains detailed images and illustrations to guide you step by step along the way.

This is only available to members who order in the next 24 hours only so download it now before it's gone!

BONUS: Nursing & Paramedics Masterclass

Click On Image To Enlarge

That's right, I'll give you everything you'll ever need to know about nursing, paramedics and EMT.

Go here to see the original:

The #1 Human Anatomy and Physiology Course | Learn ...

Mechanics of Breathing

This explanation of the physiology of breathing shows how our health improves through the conscious connected breathing that we do in Transformation Breathwork.

Humans need a continuous supply of oxygen for cellular respiration, and they must get rid of excess carbon dioxide, the poisonous waste product of this process. Gas exchange supports this cellular respiration by constantly supplying oxygen and removing carbon dioxide. The oxygen we need is derived from the Earth's atmosphere, which is 21% oxygen. This oxygen in the air is exchanged in the body by the respiratory surface. In humans, the alveoli in the lungs serve as the surface for gas exchange.

Gas exchange in humans can be divided into five steps:

Other factors involved with respiration are:

Structure of the Human Respiratory System

The Nose - Usually air will enter the respiratory system through the nostrils. The nostrils then lead to open spaces in the nose called the nasal passages. The nasal passages serve as a moistener, a filter, and to warm upthe air before it reaches the lungs. The hairs existing within the nostrils prevents various foreign particles from entering.Different air passageways and the nasal passages are covered with a mucous membrane. Many of the cells which produce the cells that make up the membrane contain cilia. Others secrete a type a sticky fluid called mucus. The mucus and cilia collect dust, bacteria, and other particles in the air. The mucus also helps in moistening the air. Under the mucous membrane there are a large number of capillaries. The blood within these capillaries helps to warm the air as it passes through the nose. The nose serves three purposes. It warms, filters, and moistens the air before it reaches the lungs. You will obviously lose these special advantages if you breath through your mouth.

Pharynx and Larynx - Air travels from the nasal passages to the pharynx, or more commonly known as the throat. When the air leaves the pharynx it passes into the larynx, or the voice box. The voice box is constructed mainly of cartilage, which is a flexible connective tissue. The vocal chords are two pairs of membranes that are stretched across the inside of the larynx. As the air is expired, the vocal chords vibrate. Humans can control the vibrations of the vocal chords, which enables us to make sounds. Food and liquids are blocked from entering the opening of the larynx by the epiglottis to prevent people from choking during swallowing.

Trachea - The larynx goes directly into the trachea or the windpipe. The trachea is a tube approximately 12 centimeters in length and 2.5 centimeters wide. The trachea is kept open by rings of cartilage within its walls. Similar to the nasal passages, the trachea is covered with a ciliated mucous membrane. Usually the cilia move mucus and trapped foreign matter to the pharynx. After that, they leave the air passages and are normally swallowed. The respiratory system cannot deal with tobacco smoke very keenly. Smoking stops the cilia from moving. Just one cigarette slows their motion for about 20 minutes. Thetobacco smokeincreases the amount of mucus in the air passages. When smokers cough, their body is attempting to dispose of the extra mucus.

Bronchi - Around the center of the chest, the trachea divides into two cartilage-ringed tubes called bronchi. Also, this section of the respiratory system is lined with ciliated cells. The bronchi enter the lungs and spread into a treelike fashion into smaller tubes calle bronchial tubes.

Bronchioles - The bronchial tubes divide and then subdivide. By doing this their walls become thinner and have less and less cartilage. Eventually, they become a tiny group of tubes called bronchioles.

Alveoli - Each bronchiole ends in a tiny air chamber that looks like a bunch of grapes. Each chamber contains many cup-shaped cavities known as alveoli. The walls of the alveoli, which are only about one cell thick, are the respiratory surface. They are thin, moist, and are surrounded by several numbers of capillaries. The exchange of oxygen and carbon dioxide between blood and air occurs through these walls. The estimation is that lungs contain about 300 million alveoli. Their total surface area would be about 70 square meters. That is 40 times the surface area of the skin. Smoking makes it difficult for oxygen to be taken through the alveoli. When the cigarette smoke is inhaled, about one-third of the particles will remain within the alveoli. There are too many particles from smoking or from other sources of air pollution which can damage the walls in the alveoli. This causes a certain tissue to form. This tissue reduces the working area of the respiratory surface and leads to the disease called emphysema.

Breathing

Breathing consists of two phases, inspiration and expiration. During inspiration, the diaphragm and the intercostal muscles contract. The diaphragm moves downwards increasing the volume of the thoracic (chest) cavity, and the intercostal muscles pull the ribs up expanding the rib cage and further increasing this volume. This increase of volume lowers the air pressure in the alveoli to below atmospheric pressure. Because air always flows from a region of high pressure to a region of lower pressure, it rushes in through the respiratory tract and into the alveoli. This is called negative pressure breathing, changing the pressure inside the lungs relative to the pressure of the outside atmosphere. In contrast to inspiration, during expiration the diaphragm and intercostal muscles relax. This returns the thoracic cavity to it's original volume, increasing the air pressure in the lungs, and forcing the air out.

External Respiration

When a breath is taken, air passes in through the nostrils, through the nasal passages, into the pharynx, through the larynx, down the trachea, into one of the main bronchi, then into smaller bronchial tubules, through even smaller bronchioles, and into a microscopic air sac called an alveolus. It is here that external respiration occurs. Simply put, it is the exchange of oxygen and carbon dioxide between the air and the blood in the lungs. Blood enters the lungs via the pulmonary arteries. It then proceeds through arterioles and into the alveolar capillaries. Oxygen and carbon dioxide are exchanged between blood and the air. This blood then flows out of the alveolar capillaries, through venuoles, and back to the heart via the pulmonary veins. For an explanation as to why gasses are exchanged here, see partial pressure.

Gas Transport

If 100mL of plasma is exposed to an atmosphere with a pO2 of 100mm Hg, only 0.3mL of oxygen would be absorbed. However, if 100mL of bloodis exposed to the same atmosphere, about 19mL of oxygen would be absorbed. This is due to the presence of haemoglobin, the main means of oxygen transport in the body. The respiratory pigment haemoglobin is made up of an iron-containing porphyron, haem, combined with the protein globin. Each iron atom in haem is attached to four pyrole groups by covalent bonds. A fifth covalent bond of the iron is attached to the globin part of the molecule and the sixth covalent bond is available for combination with oxygen. There are four iron atoms in each hemoglobin molecule and therefore four heam groups.

Oxygen Transport -

In the loading and unloading of oxygen, there is a cooperation between these four haem groups. When oxygen binds to one of the groups, the others change shape slightly and their attraction to oxygen increases. The loading of the first oxygen, results in the rapid loading of the next three (forming oxyhemoglobin). At the other end, when one group unloads it's oxygen, the other three rapidly unload as their groups change shape again having less attraction for oxygen. This method of cooperative binding and release can be seen in the dissociation curve for hemoglobin. Over the range of oxygen concentrations where the curve has a steep slope, the slightest change in concentration will cause hemoglobin to load or unload a substantial amount of oxygen. Notice that the steep part of the curve corresponds to the range of oxygen concentrations found in the tissues. When the cells in a particular location begin to work harder, e.g. during exercise, oxygen concentration dips in that location, as the oxygen is used in cellular respiration. Because of the cooperation between the haem groups, this slight change in concentration is enough to cause a large increase in the amount of oxygen unloaded.

As with all proteins, hemoglobin's shape shift is sensitive to a variety of environmental conditions. A drop in pH lowers the attraction of hemoglobin to oxygen, an effect known as the Bohr shift. Because carbon dioxide reacts with water to produce carbonic acid, an active tissue will lower the pH of it's surroundings and encourage hemoglobin to give up extra oxygen, to be used in cellular respiration. Hemoglobin is a notable molecule for it's ability to transport oxygen from regions of supply to regions of demand.

Carbon Dioxide Transport - Out of the carbon dioxide released from respiring cells, 7% dissolves into the plasma, 23% binds to the multiple amino groups of hemoglobin (Caroxyhemoglobin), and 70% is carried as bicarbonate ions. Carbon dioxide created by respiring cells diffuses into the blood plasma and then into the red blood cells, where most of it is converted to bicarbonate ions. It first reacts with water forming carbonic acid, which then breaks down into H+ and CO3-. Most of the hydrogen ions that are produced attach to hemoglobin or other proteins.

Internal Respiration

The body tissues need the oxygen and have to get rid of the carbon dioxide, so the blood carried throughout the body exchanges oxygen and carbon dioxide with the body's tissues. Internal respiration is basically the exchange of gasses between the blood in the capillaries and the body's cells.

The respiratory center is gray matter in the pons and the upper Medulla, which is responsible for rhythmic respiration. This center can be divided into an inspiratory center and an expiratory center in the Medulla, an apneustic center in the lower and midpons and a pneumotaxic center in the rostral-most part of the pons. This respiratory center is very sensitive to the pCO2 in the arteries and to the pH level of the blood.The CO2 can be brought back to the lungs in three different ways; dissolved in plasma, as carboxyhemoglobin, or as carbonic acid. That particular form of acid is almost broken down immediately by carbonic hydrase into bicarbonate and hydrogen ions. This process is then reversed in the lungs so that water and carbon dioxide are exhaled. The Medulla Oblongata reacts to both CO2 and pH levels which triggers the breathing process so that more oxygen can enter the body to replace the oxygen that has been utilized. The Medulla Oblongata sends neural impulses down through the spinal chord and into the diaphragm. The impulse contracts down to the floor of the chest cavity, and at the same time there is a message sent to the chest muscles to expand causing a partial vacuum to be formed in the lungs. The partial vacuum will draw air into the lungs.

There are two other ways the Medulla Oblongata can be stimulated. The first type is when there is an oxygen debt (lack of oxygen reaching the muscles), andthis produces lactic acid which lowers the pH level.The Medulla Oblongata is then stimulated. If the pH rises it begins a process known as the Bohr shift. The Bohr shift is affected when there are extremely high oxygen and carbon dioxide pressures present in the human body. This factor causes difficulty for the oxygen and carbon dioxide to attach to hemoglobin. When the body is exposed to higher altitudes the oxygen will not attach to the hemoglobin properly, causing the oxygen level to drop and the person will black out. This theory also applies to divers who go to great depths, and the pressure of the oxygen becomes poisonous. These pressures are known as pO2 and pCO2, or partial pressures. The second type occurswhen the major arteries in the body called theaortic and carotid bodies, sense a lack of oxygen within the blood and they send messages to the Medulla Oblongata.

Various marine mammals have been found to have adapted special abilities which help in their respiratory processes, enabling them to remain down at great depths for long periods of time. The Weddell seal possesses some amazing abilities. It only stores 5% of its oxygen in its lungs, and keeps the remaining 70% of its oxygen circulating throughout the blood stream. Humans are only able to keep a small 51% of their oxygen circulating throughout the blood stream, while 36% of the oxygen is stored in the lungs. The explanation for this is that the Weddell seal has approximately twice the volume of blood per kilogram as humans. As well, the Weddell seal's spleen has the ability to store up to 24L of blood. It is believed that when the seal dives the spleen contracts causing the stored oxygen enriched blood to enter the blood stream. Also, these seals have a higher concentration of a certain protein found within the muscles known as myoglobin, which stores oxygen. The Weddell seal contains 25% of its oxygen in the muscles, while humans only keep about 12% of their oxygen within the muscles.

Not only does the Weddell seal store oxygen for long dives, but they consume it wisely as well. A diving reflex slows the pulse, and an overall reduction in oxygen consumption occurs due to this reduced heart rate. Regulatory mechamisms reroute blood to where it is needed most (brain, spinal cord, eyes, adrenal glands, and in some cases placenta) by constricting blood flow where it is not needed (mainly in the digestive system). Blood flow is restricted to muscles during long dives and they rely on oxygen stored in their myoglobin and make their ATP from fermentation rather then from respiration.

Read the original here:

Mechanics of Breathing - Breathing in Joy

Learn about the human body from the inside out

Every year, more than 100,000 degrees are completed in biologyor biomedical sciences. Anatomy and physiology classes are requiredfor these majors and others such as life sciences andchemistry, and also for students on a pre-medtrack. These classes also serve as valuableelectives because of the importance and relevance of this subject'scontent. Anatomy and Physiology For Dummies, 2ndEdition, appeals to students and life-learners alike, as acourse supplement or simply as a guide to this intriguingfield of science.

With 25 percent new and revised content, including updatedexamples and references throughout, readers of the new edition willcome to understand the meanings of terms in anatomy and physiology,get to know the body's anatomical structures, and gain insight intohow the structures and systems function in sickness and health. * New examples, references, and case studies * Updated information on how systems function in illness and inhealth * Newest health discovers and insights into how the bodyworks

Written in plain English and packed with dozens of beautifulillustrations, Anatomy & Physiology For Dummies is yourguide to a fantastic voyage of the human body.

Link:

Amazon.com: Anatomy and Physiology For Dummies ...

Quiz Bowl and Timed Test were retired at the end of summer 2013. Quiz Bowl had always been buggy, as many people had pointed out, and it had become difficult to maintain. It also used technology that doesnt work on a lot of newer computers or tablets. Timed test depended on a browser add-on that both Microsoft and Apple have encouraged users to remove for security concerns. For these reasons, we took these two quizzes down at the end of the month. Thanks to everyone who has shown support for them, and we hope you continue to use the other quizzes on this site!

Looking for the Image Bank? We moved it up to the main Anatomy and Physiology page, which has all kinds of other cool resources.

Conference for High School Anatomy and Physiology Instructors - October 17 and 18, 2014 - Minneapolis, MN. Contact Murray Jensen for details.

Excerpt from:

Anatomy and Physiology Learning Modules - CEHD - U of M

Fulfillment by Amazon (FBA) is a service we offer sellers that lets them store their products in Amazon's fulfillment centers, and we directly pack, ship, and provide customer service for these products. Something we hope you'll especially enjoy: FBA items qualify for FREE Shipping and .

If you're a seller, Fulfillment by Amazon can help you increase your sales. We invite you to learn more about Fulfillment by Amazon .

Read this article:

Human Physiology: An Integrated Approach (7th Edition ...

Sign In Sign up

Before we can start your download, please take a moment to join our community of 26,653,454 academic researchers.

Connect

Connect

Sign up with email

We're sorry. There were some errors with your registration:

Read more:

Human Physiology | Malik Adeel Umer - Academia.edu