Collapse of Industrial Civilization Civilizations are living organisms striving to survive and develop through predictable stages of birth, growth, maturation, decline and death. Cultural memes are a much more significant driver of human evolution than genetic evolution.
Photograph of a human heart Computer-generated animation of a beating human heart Location and shape Real-time MRI of the human heart The human heart is in the middle of the thoraxwith its apex pointing to the left. A double-membraned sac called the pericardium surrounds the heart and attaches to the mediastinum.
The upper part of the heart is located at the level of the third costal cartilage. Because the heart is between the lungsthe left lung is smaller than the right lung and has a cardiac notch in its border to accommodate the heart.
The atria open into the ventricles via the atrioventricular valves, present in the atrioventricular septum. This distinction is visible also on the surface of the heart as the coronary sulcus.
Similarly, the left atrium and the left ventricle together are sometimes referred to as the left heart.
It forms the atrioventricular septum which separates the atria from the ventricles, and the fibrous rings which serve as bases for the four heart valves.
The interatrial septum separates the atria and the interventricular septum separates the ventricles. Heart valves With the atria and major vessels removed, all four valves are clearly visible.
The white arrows show the normal direction of blood flow.
Frontal section showing papillary muscles attached to the tricuspid valve on the right and to the mitral valve on the left via chordae tendineae. One valve lies between each atrium and ventricle, and one valve rests at the exit of each ventricle.
Between the right atrium and the right ventricle is the tricuspid valve. The tricuspid valve has three cusps,  which connect to chordae tendinae and three papillary muscles named the anterior, posterior, and septal muscles, after their relative positions. It is also known as the bicuspid valve due to its having two cusps, an anterior and a posterior cusp.
These cusps are also attached via chordae tendinae to two papillary muscles projecting from the ventricular wall. These muscles prevent the valves from falling too far back when they close. As the heart chambers contract, so do the papillary muscles. This creates tension on the chordae tendineae, helping to hold the cusps of the atrioventricular valves in place and preventing them from being blown back into the atria.
The pulmonary valve is located at the base of the pulmonary artery. This has three cusps which are not attached to any papillary muscles.
When the ventricle relaxes blood flows back into the ventricle from the artery and this flow of blood fills the pocket-like valve, pressing against the cusps which close to seal the valve. The semilunar aortic valve is at the base of the aorta and also is not attached to papillary muscles.
This too has three cusps which close with the pressure of the blood flowing back from the aorta. A small amount of blood from the coronary circulation also drains into the right atrium via the coronary sinuswhich is immediately above and to the middle of the opening of the inferior vena cava.ASSISTED COLONIZATION is the intentional movement and release of an organism outside its indigenous range to avoid extinction of populations of the focal species..
ECOLOGICAL REPLACEMENT is the intentional movement and release of an organism outside its indigenous range to perform a specific ecological function..
See the 3-fold chart immediately below for distinctions between three forms of. The Philosophy of Social Science. The philosophy of social science can be described broadly as having two aims. First, it seeks to produce a rational reconstruction of social science. Even though it is a dark subject,it is always uplifting to see the good hearts commenting here.
This is a very powerful article Dane,thank you a million times over for the battle you chose to wage.
Course Area: Not a general education course Designations: Formative Experiences This accounting internship is designed for College of Business students who desire to gain real-world experience in the accounting field through on-the-job practice.
Mr. Kingsworth, you have quite the ability to give me goosebumps and make me question everything I do. As a college student studying forestry, while engaging myself in environmental and sustainability “movements,” your essays have often sent me into crises of faith, causing me to .
Mirror and Metaphor: Images and Stories of Psychological Life [Robert D. Romanyshyn, Jan Hendrik Van Den Berg, David LeRoy Miller] on benjaminpohle.com *FREE* shipping on qualifying offers. Edition statement taken from text, page 4 of cover.