exam 2 cardiovascular and blood vessels

Heart

pump and propels blood between lungs and tissues

-oxygenated and deoxygenated

Heart inclusions and what do they do?

arteries, veins, and capillaries serve as tubes for blood to travel

pulmonary circuit

blood flows between heart and lungs

deoxygenated blood leaves heart and RBC pick up oxygen in lungs

What does the pathway of the pulmonary circuit include

includes flow exiting right ventricle to entering left atrium

systemic circuit

blood flows between body tissues and heart

oxygenated blood leaves heart and deoxygenated blood returns from the body tissues

what does the pathway of the systemic circuit include?

includes flow from left atrium to aorta body

heart anatomy - base

posterior

heart anatomy - apex

leans toward left hip

heart anatomy - size

3 by 4 inches

heart anatomy location

sits on superior portion of diaphragm

anterior to vertebral column

posterior to sternum

most of heart to left of midline

Heart coverings

pericardium

• fibrous pericardium

• serous pericardium

The surrounding pericardium around the heart….

double walled sac around heart

composed of serous, and fibrous pericardium

fibrous pericardium

dense connective tissue

protects and anchors to surrounding structures

prevents overfilling

serous pericardium

serous membrane

2 layers separated by fluid filled pericardial cavity

serous pericardium 2 layers

parietal

visceral

parietal - serous pericardium layer

outer/middle lines inner surface

visceral - serous pericardium layer

heart epicardium

on external heart surface

Heart tissue layers

epicardium

myocardium

endocardium

epicardium

visceral layer of serous pericardium

myocardium

thick cardiac contractile tissue

well supplied with blood vessels

endocardium

inner linning of e.t

lines chambers and covers valves

Heart chambers

Atria(atrium) R/L

Ventricles R/L

Atrian (atrium)

upper 2 chambers

blood ENTERS

receives

Ventricles

Lower 2 chambers

blood LEAVES heart

exits

Auricles R/L

floppy region over atria

expands to allow increased volume

Atrioventricular valves

valves between atria and ventricles

Atrioventricular valve inclusions

Tricuspid valve - right

Bicuspid valve - left

chordae tendineae

collagen strings supporting valve cusps

Pulmonary semilunar (SL) valve

between right ventricle and pulmonary trunk to pulmonary arteries

Aortic semilunar (SL) valve

between left ventricle and aorta

What do SL valves do?

They open and close when pressure in ventricles fluctuate

Cardiac muscle contractions - 3 differences from skeletal muscles

Autorhthmicity

Heart muscle acts as a unit or NOT at all

long absolute refractory period which prevents tetanic contractions so heart doesn’t stop pumping

many mitochondria so uses aerobic respiration

Autorhthmicity

can depolarize (contract) spontaneously and continuously (1% of cells)

does not need nervous system stimulation

Cardiac muscle cells

striated, short branched, interconnected, 1-2 central nuclei

cardiac muscle cell inclusions

Big mitochondria ( 25-35% bigger in volume)

intercalated discs

gap junctions

functional syncytium

Intercalated discs

junctions between muscle cells

gap junctions

allow ions to pass from cell to cell

functional syncytium

cardiac muscles cells acting as 1 unit

pectinate muscle

muscle in right atrium and R/L auricles

Fossa ovalis

oval depression in right atirum

remnant of fetal structure foramen ovale

ligamentum arteriosum

remnant of fetal structures ductus arteriosus

trabeculae carnae

irregular ridges in ventricle muscle walls

papillary muscle

cone - shaped muscles anchoring chordae tendineae

Interatrial septum

divides right an left atria

interventricular septum

divides ventricles

anterior and posterior interventricular sulcus

groove between two ventricles

Cardiac veins

collect blood from heart capillary beds

cardiac vein inclusions

great cardiac vein

middle cardiac vein

small cardiac vein

coronary sinus

great cardiac vein

located in anterior interventricular sulcus

middle cardiac veins

located in posterior interventricular sulcus

small cardiac veins

located in inferior margin of heart

coronary sinus

empties into right atrium

coronary circulation

blood supply to heart cardiac muscles cells

delivered when heart is relaxed

coronary arteries (branch off aorta)

left coronary artery

right coronary artery

anastomoses

Left coronary artery

blood to left chambers and anterior walls of ventricles

left coronary branches into

anterior interventricular a

circumflex a

right coronary artery

blood to the right chambers and posterior walls of ventricles

right coronary a branch into

R. marginal a

posterior interventricular a

anastomoses

interconnections (give alternative routes)

junction between arteries to provide collateral circulation for heart muscle

AV valve location

in between artium and ventricle

AV valve function

move blood from atria to ventricles

AV valve cause of open and close

pressure from the atria open/ pressure from ventricle close

AV specific names and structures

Tricuspid and bicuspid valve

SL valve Function

move blood from ventricles to aorta and pulmonary trunk

SL valve cause of open and close

pressure from ventricle open and pressure from atria closed

SL valve specific names and structures

pulmonary semilunar valve

aortic semilunar valve

Cardiac conduction system ( electrical system in the heart)

Sinoatrial node (SA node)

Internodal pathway

Atrioventricular node AV node

AV bundle

Subendorcardial conducting network

Subendocardial conducting network

completes pathway through interventricular septum, heart apex, and superiorly into ventricular wall

contacts from bottom to top, pushing blood up and out the heart

Sinoatrial node SA node

pacemaker

noncontractile cells in right atrial wall

average 70-80 beats/min

sinus rhythm (determines heart rate)

Internodal pathway

path of impulses )contraction=depolarization) from SA to AV node

atrioventricular node (AV node)

located in interatrial septum superior to tricuspid valve

allows atria to completely contract before ventricle

junctional rhythm

junctional rhythm

HR from AV node 40-6- beats / min

AV bundle

located superior interventricular septum

creates electrical connection between R/L bundle branches

Non- functioning conduction system

If SA node doesnt work - AV node takes over

If SA and AV nodes dont work - subendocardial (short term fix) conducting network takes over

BUT end result is always decreasing heart rate

extrinsic innervation of heart

Heart beat modified by and ANS by cardiac centers in medulla oblongata

extrinsic innervation of heart - sympathetic

Increase rate and force

extrinsic innervation of heart - parasympathetic

decrease rate

extrinsic innervation of heart - cardioacceleratory center (CAC)

SNS will increase HR

affects SA, AV nodes, heart muscle, coronary arteries

extrinsic innervation of heart- cardioinhibitory center (CIC)

PNS will decrease HR

affects SA, and AV nodes via vagus nerves

arrhythmias

bradycardia

tachycardia

fibrillation

bradycardia

slow heart rate

less that 60 beats a minute

tachycardia

fast heart rater

more than 100 beats a minute

fibrillation

rapid, irregular contraction of heart

electrocardiogram

records electrical activity in heart (cells=myocardium)

a measurement

waves

P = atrial depolarization

QRS complex

T

p=atrial depolarization causes what?

depolarization causes action potential to spread from SA node (60-100 bpm) to atria to create atrial contraction (systole)

QRS complex

negative to positive to negative wave

ventricular depolarization

action potential spreads interventricular septum

T

repolarization of ventricles

wave is wider because slower process

do atria repolarize

yes, its not powerful but when repolarized its happening behind QRS wave, but you wont be able to see or read it

abnormal waves can be

too long

too short

come to soon

come to late

mechanical events - cardiac cycle -events during 1 complete heart beat

atrial systole and diastole followed by ventricular systole and diastole systole and diastole ( series of pressure and blood volume changes)

systole

contraction

diastole

relaxation

Phases of cardiac cycle

physics of pressure (P) and volume (V) changes related to cardiac cycle

phases of cardiac cycle inclusions

ventricular filling

isovolumetric contraction

ventricular ejection

isovolumetric relaxation

ventricular filling

takes place mid to late diastole

AV valves are open

pressure low

80% of blood passively flows into ventricles

isovolumetric contraction

atria relax - ventricles begin to contract

rising ventricular pressure closes AV valves

very end of stage the SL valves are forced open

ventricular ejection

ventricles contract, high pressure

blood into aorta and pulmonary trunk

SL valves open

Isovolumetric relaxation

early diastole

ventricles relax

atria relaxed and filling

low pressure

blood in aorta and pulmonary trunk closes SL valves

Heart sounds

Auscultation

Two sounds (lub dup)

Lub

dup

heart murmurs

Auscultation

listening to sounds in body

Two sounds (lub Dup)

heart valves closing

paise indicates heart relaxation