circulatory system Flashcards
It pumps and directs blood cells and substances carried in the blood to all tissues of the body.
circulatory system
it propels blood through the system
heart
series of vessels efferent from the heart that become smaller as they branch into the various organs, carry blood to the tissue.
arteries
the smallest vessels
capillaries
sites of C02, O2, nutrients, and waste product exchange between blood and tissue.
capillaries
together with the smallest arterial and venous branches carrying blood to and from them, capillaries in amost every organ form a complex network of thin anastomosing tubule called
microvasculature/ microvascular bed
veins
Result from convergence of venules into a system of larger channels that continue enlarging as they approach the heart, toward which they carry blood to pump again.
the internal surface of all components of the blood and lymphatic system is lined by a single layer of squamous epithelium called
endothelium
how many chambers of the heart that contracts rhythmically pumping blood through the circulation
4
propels blood into the pulmonary and systemic circulation
right and left ventricle
receives blood from the body and pulmonary vein
right and left atria
The wall of all 4 heart chamber consist of 3 major layers
internal endocardium
middle myocardium
external epicardium
endocardium consists of
a very thin inner layer of endothelium and supporting connective tissue, a middle myoelastic layer of smooth muscle fibers and connective tissue, and a deep layer of connective tissue called the subendocardial layer
subendocardial layer merges with
myocardium
lined by endothelium
endocardium
1 layer of simple squamous epithelium
endocardium
the thickest layer of the heart
myocardium
myocardium, consists
mainly of cardiac muscle with its fibers arranged spirally around each heart chamber. Because strong force is required to pump blood through the systemic and pulmonary circulations,
the myocardium is much thicker in the
walls of the ventricles, particularly the left, than in the atrial walls
The epicardium is a
simple squamous mesothelium supported by a layer of loose connective tissue containing blood vessels and nerves
layer of the heart that has lots of adipose tissue
epicardium
The epicardium corresponds to the
visceral layer of the pericardium, the membrane surrounding the heart.
Where the large vessels enter and leave the heart, the
the epicardium is reflected back as the parietal layer lining the pericardium.
During heart movements, underlying structures are cushioned by
deposits of adipose tissue in the epicardium
friction within the pericardium is prevented by lubricant fluid produced by both layers of
serous mesothelial cells
has selective permeability, has antithrombogenic properties, serves as diapedesis for leukocytes, seccrete variety of paracrine factors for vasodilation, constriction, and growth of adjacent cells.
endothelium
diapedesis
how leukocytes migrate and moves out of the blood vessels and go to diff tissues
pulmonary vein
oxygenated blood
pulmonary arteries carry
doexygenated blood
major tissue types in 3 layers of the heart
cardiac muscle
Branches of the heart’s impulse-conducting system, consisting of modified cardiac muscle fibers, are also located in the subendocardial layer.
endocardium
seen in the Subendocardial layer
purkinje fibers
part of electrical conducting system of heart
purkinje fibers
2 layers of pericardium
outer visceral and inner parietal
fibro serous sac that surrounds the heart and the roots of the great vessel
pericardium
pericardium consist of
serous pericardium and fibrous pericardium
serous pericardium consist of ___ which lines the inside of fibrous pericardium
outer parietal layer
visceral layer adherens to the
surface of the heart
gitna ng parietal and visceral layer
perichardial cavity
endocardium corresponds to
visceral layer of serous perichardium
Dense fibrous connective tissue of the cardiac skeleton forms part of the
interventricular and interatrial septa, surrounds all valves of the heart, and extends into the valve cusps and the chordae tendineae to which they are attached
cardiac skeleton functions
■ Anchoring and supporting the heart valves
■ Providing firm points of insertion for cardiac muscle
■ Helping coordinate the heartbeat by acting as electrical insulation between atria and ventricles
between ventricle
interverticular septa
bet. atria
interatrial septa
pacemaker
SA node/sinoatrial node
system
SA node/sinoatrial node provide electrical signal—> atrioventricular node—> bundle of HIS (atrioventricular bundle) —>subendocardial conducting netwrok (purkinje fibers)
Conducting system of the heart
located within a subendocardial layer and adjacent myocardium are modified cardiac mucle cells that are responsible for rythmic contraction.
conducting system of the heart consist of specialized myocardial tissue in the
right atrium
Both parasympathetic and sympathetic neural components innervate the ___. Ganglionic nerve cells and nerve fibers are present in the regions close to the SA and AV nodes, where they affect heart rate and rhythm, such as during physical exercise and emotional stress
heart
fight or flight response
sympathetic
rest and digest response
parasympathetic
modify (not dictate) heart rate and rythm
sympathetic and parasympathetic neural component
Stimulation of the parasympathetic division (vagus nerve) ____, whereas stimulation of the sympathetic nerve ____
slows the heartbeat
accelerates activity of the pacemaker
Between fibers of the myocardium are afferent free nerve endings that register
pain, such as the discomfort
carotid massage
stimulate vagus nerve
pale staining fibers, larger than adjacent contractile muscle fibers
purkinje fibers
Walls of all blood vessels except capillaries contain
smooth muscle and connective tissue in addition to the endothelial lining.
capilliary only has
endothelium
The amount and arrangement of these tissues (smooth mucle and CT) in vessels are influenced by ________, primarily blood pressure, and metabolic factors reflecting the local needs of tissues
mechanical factors
The endothelium is a specialized epithelium that acts as a semipermeable barrier between two internal compartments:
the blood plasma and the interstitial tissue fluid.
