Cardiovascular System: a closed system used for transportation. (Heart: A…
Cardiovascular System: a closed system used for transportation.
Blood Vessels: transportation system
Capillary:only one layer thick, consist only of a Tunica intima, purpose is to allow gas exchange through the cell walls.
Veins: blood vessels that carry deoxygenated blood back to the heart accept for one exception the pulmonary veins. They are made of three layers like the artery however the Tunica intima is structured differently and the Tunic Media is smaller
Tunica Intima: internal layer of blood vessel, does not have the internal elastic membrane in the vein
Endothelium: deep to Tunica media, consists of simple squamous epithelial
Tunica Media: much thinner than artery muscle walls, typically collapse when sliced for histology slides
Tunica Externa: outer layer, consists of collagen fibers
Artery:carry oxygenated blood away from the heart accept for the coronary arteries. They are made of thick walls consisting of the tunica intima, tunica media, and tunica externa.
Tunica Media: middle layer of blood vessel, thick made of smooth muscle
Tunic Externa: outer layer, consists of collagen fibers
Tunica intima: internal layer of the blood vessel
Endothelium: deep to internal elastic membrane consisting of simple squamous epithelium
Internal elastic membrane: elastic tissue surrounding the outer layer of the tunica intima found only in the artery
A muscular organ which pumps blood throughout the body.
Layers of heart wall: there are 3 layers, they are composed of connective tissue
Myocardium: middle layer, composed of muscle fibers which allows it to contract assisting in moving blood through the valves of the heart.
Endocardium: a smooth membrane which lines the chambers inside the heart
Epicardium: external layer, a serous membrane that protects the heart and prevents friction as it pumps
Microscopic Anatomy of Myocardium
Cardiac muscle cell: found between sarcolema and muscle of cardiac muscle
Intercalated disk: Distinct markings to cardiac muscle which connect cardiac cells together. Junctions are found on these disks.
Gap junctions:protein lined tunnels that pass the signal to contract through
T-tubules: indentations in the sarcolemma on the A and I bands where the tubes run deep into muscle cell between cross channels.
Sarcolema: plasma membrane which wraps around muscle
Sarcoplasmic reticulum: smooth endoplasmic reticulum loosely wrapped around, thick solid lining the edge of T-tubules
nucleus: single nucleated muscle, contains majority of genetic material
Myofibrils: are similar to skeletal muscle, but fewer in number
Facia adherence: desmisome like structures, similar to a zipper.
Fibrous pericardium: loose-fitting, superficial layer, made of dense lose connective tissue, protects the heart.
Serous pericardium: deep, consists of two layers, made or areolar connective tissue. Between the two layers is serous fluid which prevents friction.
parietal pericardium: outer layer of serous.
visceral pericardium: layer attached directly to the heart, is almost transparent.
Heart valves: there are 4 valves, both valves which divide the chambers consist of cordae tendineae and are attached to the wall by papillary muscles.
tricuspid valve: allows blood to flow from the right atrium into the right ventricle
aortic semilunar valve: separates the left ventricle from the aorta. Prevents blood from flowing back into the left ventricle after it is pumped out into the blood vessel
mitral valve: also known as bicuspid valve allows blood to flow from the left atrium to the left ventricle
pulmonary semilunar valve: separates the right ventricle from the pulmonary trunk. Prevents back flow of blood.
Conduction system of heart: pacemaker, determines the period of time between the hearts contraction and rest (diastole=80 and systole=120)
Sianoatrial node (SA): sets the pace of the heart beat located in the right atrium, not visible to the eye. Communicates through gap junctions sending electrical signals.
Atrial ventricular node (AV): signal delays for a short time to allow blood to fill the chambers. Once filled the message is passed first to the AV bundle of his where it branches in the interventricular septum and separates into bundle branches which travel to the apex and papillary muscles. These lead to perkinji fibers which contract the heart.
Blood: bodily fluid that delivers necessary substance throughout the body.
plasma: transports O2 and CO2 , mostly erythrocytes, has a buffy layer consisting of leukocytes.
Erythrocytes: small, bioconcave disks, lack nucleus, contain hemoglobin.
Leukocytes: white blood cells, slightly larger than red blood cells, contain nucleus, lack hemoglobin.
Neutrophils: highest number of white blood cells, Contain numerous nucleus or a horse shoe shaped nucleus.
Lymphocyte: Nucleus covers most of the cell, only a small half shaped moon space is left uncovered, not typically very easy to find
Basophils: Nucleus is buried deep to granules.
Monocytes: monstrous sized white blood cells
Eosinophils: Extra nucleus (2) and extra granules, not typically very easy to find
Thrombocytes: tiny red blood cells, also called platelets.