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Chordae tendineae and papillary muscles

This photo shows the inside of the heart with the main muscles labeled.
In this frontal section, you can see papillary muscles attached to the tricuspid valve on the right as well as the mitral valve on the left via chordae tendineae. (credit: modification of work by “PV KS”/flickr.com)

The walls of the ventricle are lined with trabeculae carneae    , ridges of cardiac muscle covered by endocardium. In addition to these muscular ridges, a band of cardiac muscle, also covered by endocardium, known as the moderator band    (see [link] ) reinforces the thin walls of the right ventricle and plays a crucial role in cardiac conduction. It arises from the inferior portion of the interventricular septum and crosses the interior space of the right ventricle to connect with the inferior papillary muscle.

When the right ventricle contracts, it ejects blood into the pulmonary trunk, which branches into the left and right pulmonary arteries that carry it to each lung. The superior surface of the right ventricle begins to taper as it approaches the pulmonary trunk. At the base of the pulmonary trunk is the pulmonary semilunar valve that prevents backflow from the pulmonary trunk.

Left atrium

After exchange of gases in the pulmonary capillaries, blood returns to the left atrium high in oxygen via one of the four pulmonary veins. While the left atrium does not contain pectinate muscles, it does have an auricle that includes these pectinate ridges. Blood flows nearly continuously from the pulmonary veins back into the atrium, which acts as the receiving chamber, and from here through an opening into the left ventricle. Most blood flows passively into the heart while both the atria and ventricles are relaxed, but toward the end of the ventricular relaxation period, the left atrium will contract, pumping blood into the ventricle. This atrial contraction accounts for approximately 20 percent of ventricular filling. The opening between the left atrium and ventricle is guarded by the mitral valve.

Left ventricle

Recall that, although both sides of the heart will pump the same amount of blood, the muscular layer is much thicker in the left ventricle compared to the right (see [link] ). Like the right ventricle, the left also has trabeculae carneae, but there is no moderator band. The mitral valve is connected to papillary muscles via chordae tendineae. There are two papillary muscles on the left—the anterior and posterior—as opposed to three on the right.

The left ventricle is the major pumping chamber for the systemic circuit; it ejects blood into the aorta through the aortic semilunar valve.

Heart valve structure and function

A transverse section through the heart slightly above the level of the atrioventricular septum reveals all four heart valves along the same plane ( [link] ). The valves ensure unidirectional blood flow through the heart. Between the right atrium and the right ventricle is the right atrioventricular valve    , or tricuspid valve    . It typically consists of three flaps, or leaflets, made of endocardium reinforced with additional connective tissue. The flaps are connected by chordae tendineae to the papillary muscles, which control the opening and closing of the valves.

Questions & Answers

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Sentamu
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Shubham
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Sentamu
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zahruuzh Reply
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state and explain 20 radiology uses
ILYAS Reply
what are chemicals in anatomy and physiology?
Mike Reply
what can I do to find it easy for me in anatomy and physiology course
Mike
study up on the basics of the periodic chart, learn bones and muscles attachments, and learn muscles. Those take the longest to memorize. After that it should be a little easier.
Toni
what are the two types of body cells
Jennifer Reply
what is malnutrition
Claire
malnutrition refers to faulty nutrition resulting from malabsorption,poor diet or overeating. Sometimes too these food do not contain all the six food nutrients in their right proportion.
Yakubu
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Claire
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Baigwa
gud
Budumari
What's the difference between radiology and radiology
gabriel
Nothing! Radiology it means the study or using of radiation in medical science it can be 1.diagnose or treatment diagnosed radiology! x- ray. ultrasound. ct-scan. mammogram. MRI. 2. treatmen- radiation oncology, like Cobalt 60. and nuclear medicine
Larry
what is X-ray?
Nissar
X-ray is type of light that make it possible to see inside any object. as human body
KUNDAN
How the nervous system develops
ayiesher Reply
From the cells at the back of an embryo
Mma
breifly explain anatomy of thorax
Hadiza Reply
How many region the rib is divided
Konneh
how many bon of human being
Nura
206
John
how to study for the skeletal system
ryaisha
and anatomy
ryaisha
I really need sources immediately
ryaisha
I printed out all the different bones. Put them in the see through protective sheaths and got dry erase markers. I could right on them and erase to help me learn to spell the names of markings and bones.
Toni
Or go to a book store, Barnes and Noble(doesn't have to be this) and they have coloring books for anatomy. $16. Really helpful.
Toni
okay thanks and are what study tools you use to study the materials and get a better understanding
ryaisha
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ryaisha
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Roopa
I prefer diagrams, pictures that lay out each step with the information in each step. For Example: how action potential creates muscles to move. A pictured diagram gives me a better understanding of how each piece plays a role in each step of the process.
Toni
Also for basics, such as memorizing vocab. Flash cards are great. Don't become discouraged if you don't get them all right the first times through. The more you go through them, your brain will remember pieces of information from each and help you to pull out the information 😉
Toni
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ryaisha
what is the functions of the lips in human
Momboi Reply
could I say sensation?
Sovilace
kissing
Obrian
for protection
Omar
Lips assist in speech and eating
Cindy
Too many easy questions. Which bones are the axial and appendicular? What are the abbreviations for TEE, TTE, AED, A-Mode, B-Mode, and LTH? What is the difference between hypothalamus and thalamus? Where is the parathyroid located? How many True Ribs do we have?
Sovilace Reply
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Inam
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okello Reply
anatomy is scientific study of body structures and how they relate to each other
Skeater
Are there other functions of the nucleolus apart from synthesis of RNA and formation of ribosomes
Peninah Reply
plays a role in cell response to stress
airiz
what is angle of auscultation
Bryan Reply
Anatomy which is the study of the human body structure has a couple of reasons it is been studied It helps to discover genetic disease cytology And histology which is the study of tissues Physiology is the study of function of the human cells It helps to know how the different body part works Its helps to know how part of the brain works And lastly It gives the essential to understand more about anatomy
Stephen Reply
describe the external features of a spinal cord
okoche Reply
Spinal nerves emerge in pairs, one from each side of the spinal cord along its length. The cervical nerves form a plexus (a complex interwoven network of nerves—nerves converge and branch). The cervical enlargement is a widening in the upper part of the spinal cord (C 4–T 1). Nerves that extend in
Inam
Hormones regulate certain target cell responses. These can include which of the following?
Nazareth Reply
describe the external features of spinal cord
okoche

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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