BIO 202 Exam 2 Cardiovascular and Lymphatic systems

pulmonary circulation

blood vessels that carry blood to and from alveoli of lungs for gas exchange (right side of heart)

systemic circulation

transports blood to and from the rest of the body (left side of heart)

heart location

mediastinum, between lungs

base of heart

broad superior portion of the heart

apex of heart

inferior end, tilts to the left, tapers to point

pericardium

Covering over heart and large
blood vessels

Fibrous pericardium

Outer layer, that surrounds
double-layered serous
membrane

Parietal pericardium

Deep to fibrous pericardium;
outer layer of serous
membrane

Visceral pericardium

Inner layer of serous
membrane; attached to surface
of heart; also called the
epicardium

three layers of the heart

epicardium, myocardium, endocardium

Epicardium

Outer layer; also called visceral pericardium; thin layer.

myocardium

Middle layer; composed of cardiac muscle tissue; thickest layer
-mostly comprised of cardiac muscle

endocardium

inner layer; forms inner lining of all heart chambers; thin layer.

coronary sulcus

divides atria and ventricles

anterior/posterior interventricular sulci

-separates right and left ventricles
-contains blood vessels of cardiac muscle

interatrial septum

wall between atria

interventricular septum

thicker walls between ventricles

atrioventricular valves (AV)

fibrous valves that connect atria to ventricles and only permit blood flow in one direction

right atrium

receives blood from superior and inferior vena cava

Superior vena cava

opens to posterior portion of right atrium, delivering blood from head, neck, upper limbs and chest

inferior vena cava

posterior/inferior delivers blood from rest of trunk, viscera and lower limbs

coronary sinus

superior and inferior vena cava drain into this

right ventricle

blood travels from right atrium through tricuspid valve to get to this chamber

tricuspid valve

found between the right atrium and right ventricle, right AV valve

Chordae Tendineae

"heart strings"
-free end of each cusp is attached, determines main position and tension of valves, prevents backflow of blood into the atrium

papillary muscle

attach to cusps of AV valves via chordae tendineae
-prevents inversion or prolapse of valves in systole

Trabeculae Carneae

Prevent suction that would impair heart's ability to pump efficiently

pulmonary trunk

carries blood from the right ventricle to the lungs

pulmonary semilunar valve

heart valve opening from the right ventricle to the pulmonary artery

pulmonary veins

Deliver oxygen rich blood from the lungs to the left atrium

left atrium

Chamber that receives oxygenated blood from the pulmonary veins and pumps it into systemic circulation.

mitral valve

fount between the left atrium and the left ventricle
-aka bicuspid valve (left AV valve)

left ventricle

receives oxygen-rich blood from the left atrium
-thickest walls (needs more force to pump blood out to the rest of the body)

aortic valve

heart valve between the left ventricle and the aorta

ascending aorta

Branches off the left ventricle; carries oxygen rich blood to parts of the body above the heart

aortic arch

a curved blood vessel from which arteries branch to the head and neck.

brachiocephalic trunk

The first large artery arising from the aortic arch. It carries oxygenated blood to the neck, head, and right forelimb.

left common carotid artery

middle artery arising from aortic arch, supplies left side of head and neck

left subclavian artery

Third branch of the aortic arch that distributes blood to the left arm

decending aorta

travels to all lower body, to the capillary level, then to Venules, then to Veins, and ultimately into Superior Vena Cava and the Inferior Vena Cava

regurgitation

failure of valves
-causes backflow of blood into atria
-Systolic Heart Murmur

prolapse

valves open backwards

Angina pectoris

partial obstruction of coronary blood flow can cause chest pain, pain caused by ischemia (restricted blood flow), often activity dependent

Myocardial infarction

complete obstruction causes death of cardiac cells in affected area, pain or pressure in chest that often radiates down left arm

Myogenic

heartbeat originates within heart

Autorhythmic

regular, spontaneous depolarization

components of cardiac conduction system

Sinoatrial node (Pacemaker), Atrioventricular node, Atrioventricular bundle, Bundle branches, Purkinje fibers

pacemaker cells

heart cells that regularly produce spontaneous electrical impulses

myocytes

contractile cells

SA node

pacemaker, initiates heartbeat, sets heart rate

AV node

electrical gateway to ventricles
-brief delay so atria can contract before ventricles

AV bundle

pathway for signals from AV node
-right and left bundle branches: divisions of AV bundle that enter interventricular septum

purkinje fibers

upward from apex, spread throughout ventricular myocardium in order to maximize ventricular ejection

autorhythmic/automaticity

regular, spontaneous depolarization

Cardiac action potential

-myocytes: Resting potential -90mV
-voltage gated Na+ channels open and depolarizes rapidly and Na+ rushes in rapidly
- voltage gated Na+ channels close when action potential reaches +30mV
-slow leak Ca+ channels open and binds to SR which results in a contraction (Plateau phase)
-Ca+ channels close and K- channels open
-rapid reflux of K+ returning into the cell results in repolarization

role of calcium ions

20% required for contraction, arrival of ion triggers release of \____ion reserves (80%) from SR slow \_____channels close and intracellular \______ absorbed by SR or pumped out of the cell

plateau phase

extends the absolute refractory
period of the cardiac muscle cell
-cardiac muscle cell can't create another action potential
-allows for sustained contraction

pacemaker cell action potential

-K+ channels close; Na+ leak channels open (depolarization)
-Ca+ channels open
-Ca+ channels close, slow leak K+ channels open
-K+ permeability increases and calcium levels decrease (repolarization)

funny current

Na+ leak channels, generating a slow inward flow of Na+ ions into the cells of SA node

significance of slow polarization

allows for complete contraction and allows for pacemaker potential

ventricular heart cell

resting potential: -90mV
-stimulus from neighboring cardiocyte
-threshold: -75mV
-plateau brought on by calcium
-fast depolarization
-K+ causes repolarization

pacemaker heart cells

resting potential: -60--70mV
-funny current causes depolarization
-threshold: -40--50mV
-no plateau
-slow depolarization
-K+causes repolarization

differences between skeletal AP and cardiac AP

gap junctions allow cardiac cells to be linked allowing for synchronization of cell contraction, cardiac cells "self excitable" allow for contraction of adjacent cells through the heart, length of absolute refractory period:
cardiac (250 ms) muscle cell (2-5 ms)
-prevents heart from getting tired and sore

Electrocardiogram (ECG)

recording of electrical changes that occur in the myocardium during the cardiac cycle

p-wave

atrial depolarization

p-r interval

delay of av node

qrs complex

ventricular depolarization

q-t interval

ventricular depolarization into repolarization

t-wave

ventricles depolarize

atrial systole

atrial contract
-av valves open
-semilunar valves closed
-SA node fires
-atria depolarize (p-wave_)

early ventricular systole

atria relax, ventricles contract
-AV valves forced closed
-semilunar valves still closed
-atria repolarize
-ventricles depolarize
-qrs complex
-no ejection of blood yet

late ventricular systole

atria relax, ventricles contract
-av valves remain closed
-semilunar valves forced open
-rapid ejection of blood
-less pressure

early ventricular diastole

atria and ventricles relax
-AV and semilunar valves closed
-atria begin passively filling with blood

late ventricular diastole

atria and ventricles relax
- atria passively fill with blood
-as AV valves open semilunar valves are closed
-ventricles repolarize (t-wave)

Ectopic foci

region of spontaneous firing (not SA)

Arrhythmia

abnormal cardiac rhythm
-heart block
-bundle branch block
-total heart block (damage to AV node)

heart block

failure of conduction system

Long QT syndrome

ventricles are not repolarizing fast enough

ST segment ELEVATION

injury (myocardial infarction)

ST segment DEPRESSION

ISCHEMIA(reduced blood flow through a coronary artery)

systole

contraction

diastole

relaxation

Sinus rhythm

-set by SA node at 60 - 100
bpm
-adult at rest is 70 to 80
bpm (vagal inhibition)

Auscultation

listening to sounds made by body

S1

First heart sound
-louder and longer "lubb", occurs with closure of AV (tricuspid and bicuspid) valves

S2

Second heart sound
-softer and sharper "dupp" occurs with closure of semilunar valves (aortic and pulmonary valves)

S3

Blood flow into ventricles

S4

- Atrial contraction (atrial kick)
Rarely heard in people \> 30

cardiac output

amount of blood ejected by ventricle in one minute
-can increase with fitness and decrease with disease
-CO\=HR*SV

pulse

surge of pressure in an artery

tachycardia

resting adult HR above 100 bpm
-caused by stress, anxiety, drugs heart disease or increase in body temp

Cardiac Reserve

Difference Between A Persons Maximum And Resting CO
-can increase with fitness and decrease with disease

bradicardia

resting adult HR below 60 bpm
-in sleep and endurance trained athletes

Chronotropy

increase or decrease in HR
-positive agents: increase in HR (caffeine, nicotine and catecholamines)
-negative agents: decrease in HR

cardiac center

medulla oblongata

Cardioacceleratory center

sympathetic
-cardiac nerves to SA node, AV node and myocardium
-norepinephrine involved
-can increase HR up to 230 bpm (limited by refractory period of SA node)
-SV and CO decrease (less filling time- very inefficient)

Cardioinhibitory center

parasympathetic
-stimulates vagus nerve (right-SA node)(left- AV node)
-secretes acetylcholine that binds to muscarinic receptors
-nodal cells hyperpolarized
-HR slowed
-severed vagus nerve (intrinsic rate 100 bpm)
-maximum vagal stimulation decreases stimulation decreases HR to as low as 20 bpm

Neurotransmitters

Camp 2nd Messenger
•Catecholamines (NE And Epinephrine)
•Potent Cardiac Stimulants

chronotropic chemicals

Neurotransmitters, drugs, hormones, electrolytes

stroke volume

governed by preload, contractility and afterload