A & P Lecture Exam 1

Hematocrit Components and Precents

Erythrocytes: 37-52%

Buffy Coat: 1%

Plasma: 47-63%

Plasma Components

mixture of water, proteins, nutrients (vitamins, cholesterol), electrolytes (90% Na+), nitrogenous wastes, hormones, and gases (dissolved O2 and CO2)

Albumin

smallest and most abundant plasma protein, regulates liquid amount in blood, blood pressure, flow and fluid balance, formed in the liver

osmolarity of blood

total molarity of dissolved particles that can’t pass through blood vessels, to high means blood absorbs water increasing blood pressure, when too low blood leaves too much water in the tissue (edema)

globulins

provide immune system functions, alpha and beta are made in the liver and gamma are free floating antibodies produced by plasma cells

fibrinogen

precursor of fibrin, plasma protein, formed in the liver

hemopoiesis

red bone marrow makes all formed elements from hemocytoblasts

erythrocyte function and structure

lose all organelles, no mitochondria so they don’t use the O2 they are moving, no nucleus so there is no reproduction, flexible membrane for durability and resilience, high surface area/volume ration, lives 120 days

hemoglobin

each has 4 heme groups that binds 1 O2 to its Fe,

factors increasing hematocrit

male (higher androgen amount), higher elevation, low body fat, high exercise

erythropoisis

kidney detects low erythrocytes and produces erythropoietin to stimulate the red bone marrow, hemocytoblasts with a nucleus gets smaller, becomes a hemoglobin sac and losses its organelles and nucleus, takes 3-5 days

iron absorption

vitamin C helps turn it to Fe2+, attached to cells to be transferred from the stomach into the liver until it is needed

erythrocyte death and recycling

macrophages in spleen hydrolyze goblins into amino acids, remove heme and separate iron which is reused, heme is lost (bilirubin into urine, bile from gallbladder into brown feces)

pernicious anemia

autoimmune attack of stomach tissue leading to inadequate vitamin B12 absorption, newborns

aplastic anemia

compete cessation of erythropoiesis, radiation of red bone marrow for leukemia

anemia effects

lethargic, shortness of breath, tissue death (necrosis) of high O2 using organs (brain, heart, kidneys, spinal cord), osmolarity is reduced (edema)

agglutinogens

antigens on surface of blood cells that activates an immune response, distinguish self from foreign matter

agglutinins

antibodies in blood plasma, gamma globulins secreted by plasma cells that bind to antigens and mark for destruction

agglutination

clumping when antibodies hold on to blood antigens, blocks small blood vessels, release hemoglobin

hemolytic disease of the newborn

when the mom is - and the first baby is + the mom will start producing Anti-D antibodies after birth that would attack a second + baby

neutrophil

aggressive antibacterial, rise in response to bacterial infection efficient phagocytosis

eosinophil

parasitic infections (malaria), collagen disease, allergies, release enzymes to destroy large parasites

basophils

increases with chickenpox, sinusitis, diabetes, secretes histamine (vasodilator) and heparin (anticoagulant)

lymphocytes

destroy cancer and virally infected cells, activates and coordinates other immune cells with antigens, secretes antibodies and provides immune memory

monocytes

increases with viral infections and inflammation, phagocytize pathogens and debris, activates other immune cells, can leave blood for tissue and turn into macrophages

leukopoiesis

myeloblasts form granulocytes, monoblasts form monocytes, lymphoblasts form lymphocytes, stored and released from red bone marrow

leukocyte life cycle

granulocytes are released after 8 days and live for 5 days, monocytes leave in 20 hours turn into macrophages and live for several years, lymphocytes provide long-term immunity and are continuously recycled from blood to tissue fluid to lymph to blood

platelets

secrete vasoconstrictors, stick together to form platelet plug for small breaks, secrete procoagulants (clotting factors), attract neutrophils and monocytes, secrete growth factors that stimulate mitosis for repair, circulate for 5-6 days

extrinsic pathway

factor 3 is released by damaged tissue, cascade is VII, V and X

intrinsic pathway

platelets release factor XII, cascade is XI, IX, VIII, X

common pathway

factor X activates thrombin to convert fibrinogen to fibrin which is crossed linked by XIII

Fibrinolysis

break down of a clot, factor XII forms kallikrein enzyme which makes plasmin to dissolve the fibrin holding the clot

prevention of inappropriate clotting

platelets can’t stick to blood vessels only to collagen fibers that are exposed when there is damage to blood vessels, thrombin dilution by bloods continuous flow, antithrombin deactivate thrombin when it moves away from the clot, heparin keeps some blood flow to injury to bring building materials

hemophilia

hereditary diseases with deficiencies of a clotting factor, A missing factor VIII, B missing factor IX, C missing factor XI, treated with transfusion of plasma of clotting factors

thrombosis

abnormal clotting in a unbroken vessel

thrombus

unmoving blood clot, mostly likely in leg veins of inactive people due to less circulation

embolus

anything traveling in the blood vessels that can block them

pericardium

double-walled sac that encloses the heart to allow the heart to beat without friction

parietal pericardium

superficial outer layer of connective tissue

visceral pericardium

inside layer of the heart, epicardium when talking about the layers of the heart, adipose thick layers in some places, coronary vessels travel through this layer

endocardium

slippery inner lining of the heart, covers valve surfaces and is continuous with endothelium of blood vessels

myocardium

layer of cardiac muscles proportional to work load, spirals

atrioventricular sulcus

separates atria and ventricles on the outside, filled with coronary blood vessels and cushioned with adipose

pectinate muscles

internal ridges in right atrium and auricles to help direct blood flow into ventricles

trabeculae carneae

internal ridges in both ventricles the could prevent walls from sticking together from hydrogen bonds

right atrioventricular (AV) valve

three cusps (tricuspid), from right atria to right ventricle, first

left atrioventricular (AV) valve

two cusps (bicuspid), from left atria to left ventricle, enters second

chordae tendineae

connect AV valves to papillary muscles on ventricle floor to prevent them from flipping or bulging into the atria

pulmonary semilunar valve

control flow from right ventricle into the pulmonary trunk (artery going to the lungs)

aortic semilunar valve

controls flow from the left ventricle and the aorta (brings blood to the body)

pericardium

double walled sac the encloses the heart

epicardium

membrane covering the heart, adipose thick in some places, coronary blood vessels travel through this layer

endocardium

slippery inner lining of the heart and blood vessels, covers valve surfaces and is continuous with endothelium of blood vessels

myocardium

layer of cardiac muscle, spirals to wring out blood

fibrous skeleton of the heart

framework of collagenous and elastic fibers the provide structural support and attachment for cardiac muscles, electrical insulation between atria and ventricles to protect each other allowing for correct timing of contraction

pectinate muscles

internal ridges of myocardium in right atrium and both auricles, helps direct blood flow in the ventricles

trabeculae carneae

internal ridges in both ventricles that may prevent walls from sticking together after contraction

right AV valve

three cusps valve, between right atria and right ventricle, blood enters first

left AV valve

have two cusps, between left atria and left ventricle, blood enters second

pulmonary semilunar valve

controls blood flow between right ventricle and pulmonary trunk, open and closes because of blood flow and pressure

aortic semilunar valve

opening between left ventricle and aorta, open and closes because of blood flow and pressure

intercalated disc

joins cardiomyocytes end to end, electrical synapses, allows cells to contract together

mechanical junctions

tightly joins cardiomyocytes via transmembrane proteins of desmosomes that has an anchor in both cells that go through the intercalated disc, prevents contracting myocytes from being pulled apart

electrical junctions (gap junctions)

allows ions to flow between cells so myocardium of either the atria or ventricles contract in uniform

sinoatrial (SA) node

modified cardiomyocytes that depolarizes spontaneously which causes the other cells to contract, in right atrium near the base of the superior vena cava, stimulates two atria to contract almost simultaneously

atrioventricular node

electrical gateway to the ventricle, creates a delay that allows the ventricle to fill before it contracts, located right of the AV valves at the lower end of the interatrial septum

atrioventricular bundle (bundle of His)

forks into right and left bundle branches, pass through interventricular septum towards apex

Subendothelial conducting networks (Purkinje fibers)

nerve like process that spread through the ventricular myocardium, bottom contracts before top pushing the blood up

pacemaker potential

gradual depolarization up from -60mV due to slow Na+ inflow

depolarzation of pacemaker

when the membrane potential reaches -40 mV, fast Ca2+ and Na+ channels open peaking potential at 0 mV, then K+ channels open and K+ leave the cell causing repolarization

depolarization and contraction of generic myocytes

Na+ channels open in a positive feedback loop, Na+ close when voltage reaches +30 mV, Ca2+ slowly enters to prolong depolarization of membrane (plateau), Ca2+ transported out of the cell and K+ channels open creating a rapid outflow of K+ and return to -90mV

P wave

SA node fires, atria depolarizes and contracts

QRS complex

ventricular depolarization, complex shape due to difference in thickness and shape of two ventricles

ST segment

between the end of ventricular depolarization and the beginning of ventricular repolarization (systole), plateau

T wave

ventricular repolarization and relaxation

ventricle contraction controlling the AV and semilunar valves

when the ventricle relaxes internal pressure falls allowing the AV valves to open and blood to flow in, when the ventricle contracts, the AV valve closes and pressure pushes the semilunar valves open

S1 heart sound

louder and longer “lubb” occurs with the closure of the AV valves

S2 heart sound

softer and sharper, “dubb”, closure of the semilunar valves because the closure is gentler

S3 heart sound

rarely heard, “wosh” opening of left AV valve and filling of left ventricle

end-diastolic volume

amount when each ventricle is done filling, 130mL

isovolumetric contraction

ventricle begin to contract but do not eject blood

stroke volume

amount of blood the comes out during ejection, 70 mL

ejection fraction

percent that comes out during contraction, 54%, higher in healthier people

end-systolic volume

amount of blood left after contraction

isovolumetric relaxation

blood from aorta and pulmonary trunk breifly flow back closing semilunar valves

quiescent period

when all four chambers for relaxed (diastole)

cardiac output

amount ejected by each ventricle in 1 min, heart rate x stroke volume, increases with fitness

unbalanced ventricle output effects

right ventricle exceeds left so fluid accumulates in pulmonary tissue, left ventricle exceeds right so fluid accumulates in systemic tissue

autonomic nervous systems affects on the heart

does not initiate heartbeat but modulates rhythm and force, sympathetic system adrenergic by releasing norepinephrine which increases Ca2+ inflow and depolarizes SA node

acetylcholine (ACh)

started by the vagus nerve to slow down heart rate, opens K+ gates in the nodal cells

vagal tone

vagus nerve is always firing telling the hearth to slow down to lower blood pressure, lowers it from 100 bpm

baroreceptors

pressure sensors in the aorta and internal carotid arteries

chemorecptors

in aortic arch, carotid arteries, medulla oblongata, sensitive to blood pH, Co2, and O2

arteries

carry blood away from the heart

veins

carry blood to the heart, stores most blood in the body, thinner less muscular and elastic tissue, subjective to low blood pressure

capillaries

connect smallest arteries to smallest veins, gasses, nutrients, waste, and hormone pass, absent in tendons, ligaments, epithelia, cornea, and lens

tunica interna

lines blood vessels and is exposed to blood, secretes chemicals that stimulate dilation or constriction of the vessel, slippery, covers collagen fibers

tunica media

larger is arteries, smooth muscle, collagen, and elastic tissue, strengthens vessels and prevents rupture, regulates diameter

tunica externa

loose connective tissue the often merges with neighboring blood vessels, nerves, or organs, anchors vessels and contains small nerves and vessels

vasa vasorum

small vessels that supply blood to outer art of big transporting vessels