Health, Illness, and Optimal Aging- Biological and Psychological Perspectives
Chapter 6: Aging of the Internal Organ Systems
Basic Anatomy and Physiology
-The cardiovascular system is the body’s main transportation system.
-It sends supplies such as fluids, nutrients, hormones, oxygen, and antibodies to tissues
in the body while at the same time removing waste products such as carbon dioxide
and hydrogen ions.
-The system is composed of the heart, blood vessels (arteries, arterioles, capillaries,
veins and venules), and blood. In general, arteries carry blood away from the heart, and
veins carry blood to the heart.
-Blood is a highly complex fluid composed of water, red and while blood cells, and
platelets, as well as nutrients such as fat globules, carbohydrates, and proteins.
-It is perfused by gases such as oxygen, carbon dioxide, and nitrogen.
-Blood also carries electrolytes, to help maintain the acid/base balance, and a host of other
chemicals, including hormones, neurotransmitters, and various other peptides necessary
to regulate homeostasis, cognition, movement, and every other function of the body.
-The heart is the centre of the circulatory system.
-It is located behind the chest wall, in a slightly canted position, with the midsection
somewhat to the left of the sternum, or breastbone.
-It is enclosed in a fibrous sac called the pericardium.
-The left and right sides of the heart each have two upper chambers (atria), which collect
the blood, and two lower chambers (ventricles), which pump the blood to the lungs and
the rest of the body. Anatomically, the atria are thin-walled; the walls of the ventricles
are thicker and more muscular, as they do the long-distance pumping.
-The right and left sides of the heart each serve as a pump.
-Oxygen-poor blood is collected in the right atrium from the large veins of the body,
the superior and inferior vena cava.
- From there it flows to the right ventricle and is pumped via the pulmonary arteries
into the capillary system of the lungs for carbon dioxide and oxygen exchange.
-Oxygen-rich blood is sent via the pulmonary veins to the left atrium, from there it
flows to the left ventricle and is pumped out through the aorta.
-The blood from the aorta flows into the large arteries and then to the smaller arteries,
arterioles, and the capillaries.