IPHY 3410 - Chapter 10: Cardiovascular System

arteries

carries blood AWAY from heart

veins

carry blood TOWARD the heart

pulmonary circuit

route between heart and lungs that allow blood to pick up oxygen

systemic circuit

route between heart & tissues of the body (other than the lungs) that brings oxygen out to cells

transposition of great arteries

aorta and pulmonary trunk are switched. blood leaving RV never get to the lungs, blood leaving LV would travel to lungs

major purpose of pericardium

anchor the heart to surroundings.

layers of pericardium superficial to deep

fibrous pericardium, serous pericardium (parietal, visceral, pericardial cavity), myocardium, endocardium

fibrous pericardium

Touch outer layer of sac that anchors heart and prevents overfilling; dense irreg CT

serous pericardium

serous membrane around heart

parietal layer of serous pericardium

inner layer of sac, secretes serous fluid

visceral layer of serous pericardium

outer layer of heart, secretes serous fluid (=epicardium)

pericardial cavity laayer of serous pericardium

space btwn parietal & visceral; filled w/ serous fluid

myocardium

cardiac muscle tissue

endocardium

simple squamous epith

Superior & Inferior vena cava

large veins that return deoxygenated blood from body

Tricuspid (R. atrioventricular) valve

separates right atrium from right ventricle

Chordae tendineae

Dense reg CT that attaches cusps of tricuspid valve to ventricle wall via papillary muscle

papillary muscle

projection of cardiac muscle

pulmonary semilunar valve

separates right ventricle from pulmonary trunk (artery)

pulmonary veins

return oxygenated blood to heart from lungs

Bicuspid/mitral (left atrioventricular) valve

separates left atrium from left ventricle

aortic semilunar valve purpose

separates left ventricle from aorta

how do tricupsid and bicupsid valves work

open at rest, pressure then pushes fold back to atrium, chordae tendineae pull valves from pushing too far back into atrium

Pulmonary & Aortic Semilunar valves

•Valve cusps resemble pockets

•Blood pushes them open when ventricles contract

•When ventricles relax, blood fills pockets and forces valve

closed

how do semilunar valves work

valves open w blood flow, and fall back down w gravity

heart murmur

Noise in heart caused by blood leaking past closed valve

mitral valve prolapse

most common; weakness in collagen of valve or chordae tendinae

mitral stenosis

narrowed opening between valves, may be caused by calcium deposits or illness

characteristics of cardiac muscle

striated, connected by intercalated discs.

some cells adapted to conduct impulse instead of contracting

fascia adherens

desmosome like connections, provide strength

how are intercalated discs arranged

zig zags

Sinoatrial (SA) node

in RA, initiates an electrical impulse

inherent rhythmicity - pacemaker

Only in RA

internodal pathway

carries impulse away from SA node to AV node

atrioventricular (AV) node

delays impulse before it is passed on to ventricles

fibrous skeleton

collagen barrier between atria and ventricles that prevent an electrical impulse from passing

pathway of nerve impulse in the heart

SA node (pacemaker) —> internodal pathway —> AV node (bundle of His) —> bundle branches —> purkinje fibers

how do atria vs ventricles contract

atria:top to bottom; ventricles: bottom to top

cardiac cycle - phase 1 (atria contract)

atrial: systolic

ventricles: diastolic

AV valves: open

SL valves: closed

cardiac cycle - phase 2 (ventricles contract)

atrial: diastolic

ventricles: systolic

AV valves: close

SL valves: open

cardiac cycle - phase 3 (all 4 chambers rest)

atrial: diastolic

ventricle: diastolic

AV valves: open

SL valves: closed

systole

contraction (forcing blood out)

diastole

relaxation (filling w blood)

what supplies the cardia muscles w an external blood supply

right and left coronary arteries

artherosclerosis

build up of plaques which causes narrowing of an artery.

most common cause of arteriosclerosis (any hardening of arteries)

arteriosclerosis

ay hardening of arteries

myocardial infarction (heart attack)

result of blood not reaching cardiac muscle tissue (thrombus formed, tissues become ischemic)

thrombus

blood clot

ischemic

restriction in blood supply resulting in O2 and glucose deprivation in tissues

Tx for artherosclerosis

balloon angioplasty w stent

coronary bypass

new artery taken and goes around the old blocked vein, blocked vein isn’t removed, new artery just goes around it.

what do lymph vessels

transport lymph (fluid accumulated in tissues), ONE WAY, same organization as blood vessels

layers of vessel walls? superficial to deep

tunica externa (w/ vaso vasorum), external elastic membrane, tunica media, subendothelial layer, endothelium lumen

tunica intima

endothelium (simple squamous) and subendothelial layer (loose areolar CT)

tunica media

smooth muscle arranged circularly to allow for vasoconstriction

tunica externa

loose areolar CT

vaso vasorum

blood vessels that run through the layer of tunica externa to supply cells of vessel wall w blood.

how are arterial walls different from vein walls

Thicker and stronger, they have more elastic fibers; they r under higher pressure. Veins also have valves

what part of the wall forms the valves in veins

tunica intima

circle of flow from and back to heart

heart —> elastic artery —> muscular artery —> arteriole —> capillary —> venule —> medium vein —> large vein —> heart

elastic arteries

largest, branches near heart.

high concentration of elastin in tunica media. (regulates BP)

muscular arteries

supply organs and skeletal muscles

tunica media has less elastin and more smooth muscle. (more control)

sheets of elastin support and surround muscle (internal and external elastic membrane)

arterioles

branches of musclar arteries

constrict and dilate quickly

larger: all 3 tunics and elastic lamina

smaller: tunica media and endothelium only

capillary beds

diameter of about one RBC

lack tunica media and externa (thin for diffusion)

metarteriole

passage of blood cells in capillaries from arteriole to venules, always open

precapillary sphincters

smooth muscle cells, regulate RBCs - open/close

capillary characteristics

thin walls

endothelium: simple squamous epithelium

basement membrane: CT

3 types of capillaries

continuous, fenestrated, sinusoidal

continuous capillary

most common type (skeletal muscles, skin, nervous system)

tight junctions (least leaky)

fenestrated capillary

found where there is a high rate of exchange (digestive organs)

fenestrations

complete basement membrane

intercellular clefts

areas where there is no cell junction

fenestrations

pores thru endothelial cells

sinsoidal capillary (discontinuous)

leakiest

allows passage of large materials

large intercellular cleft and incomplete basement membrane

fewer tight junctions

some locations: spleen, bone marrow, lymph nodes

venules

smallest, drain capillaries

medium veins

drain venuels

large veins

drain large regions back towards heart

varicose veins

most commonly affect veins that r superficial on lower leg

failure of valves allow blood to pool, stretched veins and causes misshapen vessels

formed elements (cellular components)

erythrocytes (RBCs)

buffy coat - leukocytes (WBCs) + platelets

~46% of blood volume

plasma (extracellular matrix)

55% blood volume (mostly water)

contains dissolved solutes: wastes, nutrients, hormones

proteins: albumin and fibrinogen

albumin

bind above solutes

fibrinogen

needed for blood clotting

hemophilia

erythrocyte characteristics

mature red blood cell

anucleate and no organelles

anareobic - use glycolysis for E

97% hemoglobin

bioconcave - large surface area

3-4mo lifespan

hematopoiesis (hemopoiesis)

new RBCs form from stem cells in red bone marrow

Fe needed to make new cells

anemia

lower than normal number of RBCs to carry O2 to body

due to low levels of iron which leads to fewer RBCs

fewer RBCs to transport O2 to cells

also caused by blood loss and menstruation

leukocytes (WBCs)

complete cells, diapedesis (can squeeze thru capillary walls), immune response

platelets

blood clotting, cell fragments of larger megakaryocyte

what kind of antigens does type A blood have

A antigens only

what kind of antigens does type B have

B antigens only

what kind of antigens does type AB have

both A and B antigens

what kind of antigens does type O have

neither A or B

Rh factor

Rh is a protein that is either present (+) or absent (-) on erythrocytes unlike A or B antibodies, Rh antibodies are able to pass thru the pacenta and attack the fetus.

prob is mother is Rh-