Please enable JavaScript.
Coggle requires JavaScript to display documents.
CARDIO VASCULAR SYSTEM (HEART (LAYERS OF HEART WALL (Epicardium: is the…
CARDIO VASCULAR SYSTEM
HEART
PERICARDIAL MEMBRANE
fibrous pericardium: made of D.I.C.T located from the roots of large vessels, keeps heart in place, keeps the heart from of over filling.
SEROUS PERICARDIUM: serous membrane made of simple squamous epithelium and areola connective tissue, it is a double layer of parietal and visceral pericardium.
parietal pericardium: it is the outer layer of the serous pericardium and adheres to the inner surface of the fibrous pericardium.
visceral pericardium: also called epicardium lies on the heart and considered part of the heart wall.
pericardial cavity: a space between the two serous membrane and has a thin film of serous fluid to reduce friction between the heart and its surrounding organs
LAYERS OF HEART WALL
Epicardium: is the visceral layer of serous pericardium composed of loose connective tissue of elastic fibers and adipose tissue
Myocardium: forms the bulk of the heart, consist of cardiac muscles tissues and its the layer that actually contracts. has intercalated disc which is a desmosome-like structure that helps to hold the connection together, has gap junctions for electrical signals for movement of ions
Endocardium: made of simple squamous epithelium and areola C.T, inner lining of the heart wall and covers the valves
VALVES
ATRIOVENTRICULAR VALVE: right and left valves between the atria and ventricles which open to let blood from the atria into the ventricles.
SEMILUNAR VALVES: located the pulmonary trunk and ascending aorta that prevent the backflow of blood into the ventricles
CONDUCTION SYSTEM
-
-
SINOATRIAL (SA) NODE: pace maker that sets the heart rate, it generates electrical signal that spreads through myocardium of atria to contract. After the atria contract, signal is then sent to the ATRIOVENTRICULAR (AV) NODE, the AV node has a short delay which allows for the ventricles to fill. the signal travels through the AV bundle, right and left bundle branches then to the purkinje fibers.
BLOOD VESSELS
ARTERIES
ELASTIC ARTERIES: are the largest arteries near the heart like the aorta and its branches, carries oxygen rich blood, has a large lumen, they have large lumen which allows it to absorb the high pressure from the heart pump.
MUSCULAR ARTERY: has more muscle compared to the others relative to size, takes blood to organs or part of organs, they can constrict or dilate to decrease or increase blood flow
ARTERIOLES: smallest of the arteries, tunica media is about 1-2 layers of smooth muscles, can constrict or dialate
VEINS
VENULES: smallest of the veins, much like capillaries, has 1-2 layers of smooth mucles
VEINS: are the blood vessels that carry oxygen poor blood toward the heart, relative to arteries, has larger lumen to carry large volume of blood, has smaller tunica media but larger tunica externa which prevents the collapse of the vessel and to withstand trauma since it is superficial to arteries.
CAPILLARIES
CONTINUOUS: most common, found in CNS, lungs, skin, smooth and skeletal muscles, has intercellular cleft that makes them somewhat leaky.
FENESTRATED: has pores, found in places with high rate of exchange like small intestines, kidneys, choroid plexus, endocrine glands
SINUSOID: large and winding, for large ion exchange, protein with whole cell, found in liver red bone marrow, spleen
BLOOD
CELLS: not close together, has extracellular matrix called the plasma
ERYTHROCYES: loose many organelles including the nucleus before release into the blood stream, biconcave in shape which gives it a large surface area for easy take up of oxygen or to give it away, contains hemoglobin the binds with oxygen. most abundant of the blood cells
LEUKOCYTES: less abundant relative to erythrocytes, has different types like eosinophils, basophils, monocytes, neutrophils and lymphocytes. it plays a role in immunity
THROMBOCYTES: not cells, pieces of cytoplasm from megakaryocytes involved with blood clotting
PLASMA: liquid part of blood made of 90% water and over 100 different molecules and nutrients like ions, minerals, vitamins, hormones, lipids, amino acids etc.
-