Heart 1

what pumps blood through heart

contraction of cardiac muscle

Functions of the heart (1)

generating blood pressure

What generates blood pressure

contractions of the heart generate blood pressure, which is moving blood through the blood vessels

Heart Function (2)

Routing Blood

what does the heart seperate and ensure through routing blood

seperates pulmonary and systemic circulation and ensures that blood flowing to tissue has an adqueate levels of O2

Heart Functions (3)

ensuring one way blood flow

what causes a one-way flow

valves

Heart Functions (4)

Regulating Blood supply

How does it regulate blood supply

the rate and force of contractions change to meet the metabolic needs of tissues, which vary based on rest, exercise, and changes in body positions

Pericardium

surronds the heart has two layers

Superficial fibrous pericardium

tough fibrous connective tissue that anchors heart within the thoracic cage.

Deep serous pericardium

a thin, two-layered, lubricated membrane forming a closed sac around the heart, crucial for reducing friction during cardiac contractions.

what does the deep serous pericardium consist of

fibrous pareital layer and epicardium

Epicardium (Visceral)

layer of simple squamous epithelium that lines surface of heart

Epicardium

1 thin superficial cell layer forming a smooth external surface and superficial adipose.

Myocardium

Thick middle layer of cardiac muscle tissue responsible for the hearts ability to contract

Endocardium

Deepest layer composed of simple squamous epithelium and connective tissue. The endocardium forms the smooth, inner surface of the heart chambers.

the right side of the heart pumps blood through what

pulmonary circulation

what is pulmonary circulation

which carries blood to the links, where CO2 from the blood into the lungs and O2 diffuses from the lungs into the blood

what side does pulmonary circulation return blood to

left side

what does the left side of the heart pump through

systemic circulation

what does systemic circulation do

which delvers O2 and nutrients to all the remaining tissues of the body.

from the systemic circulation tissues what happens

CO2 and other waste products are carried back to the right side of the heart.

coronary circulation

provides blood flow to the heart via coronary artery

blood returns to the right atria how

cardiac veins

After aorta what is a pathway back to the superior and inferior cava

body tissues

After aorta what is pathway back to the right atrium

coronary arteries to heart tissue to cardiac veins and coronary sinus.

electric properties of the heart

Special cardiac pacemaker cells begin at the Sinoatrial (SA) node

Membrane Potenial

what are responsibile for the rapid depolarzation phase

VG Ca2+ channel

What allows NA to enter the cell when it is negative

a new NA channel called a leak or funny channel

what is spiking in the graph

Ca2+ depolarzation

what comes before the Ca2+

Na+ slow influx

What drops after the Ca2+

K+ repolarzation

Electrocardiogram

measures electrcial activies of heart

with each beat what happens

eletrical impulse is sent to squeeze muscle and pump blood.

a normal heartbeat on the ECG shows what

rate and rhythm of the contractions in the upper and lower chambers.

P Wave

atrial depolarzation

QRS Complex

ventricular depolarzation

T Wave

ventricular recovery/repolarization/rest

Commotio Cordis

s a phenomenon in which a sudden blunt impact to the chest stops the heart (cardiac arrest)

what is the most common theory for commoto cordios

physical disruption of cardiac plasma membrane causes abnormal ion conductance.

How are heartbeats controlled (1)

Intrinsic regulation (done by cardiovascular system itself without neural or hormonal regulation.)

How are heartbeats controlled (2)

Extrinsic regulation (Involves neural and hormonal control).

Intrinsic regulation of the heart

This is happens due to cardiac muscle cells stretching and generating more force upon contraction.

Starlings Law

states that the stroke volume of the heart increases in response to an increase in the the volume of blood in the ventricle- before

contraction.

How does starlings law happen

This is done by cardiac muscle fibers stretching . Remember muscle fibers are elastic, meaning they spring back to their regular shape after being stretch.

If BP increases, Volume in ventricle increases, and muscle fibers stretch what happens

Stretch muscle fibers contract with more force, This increases the volume of blood ejected (stroke volume) which increases blood

pressure

how are heart rate and blood pressure externally regulated

neurons and hormones

what are baroreceptors and chemoreceptors

specalized sensory neurons

sensors in heart detect what and send where

detect changes and send to CNS

Regulation of heart rate (1)

baroreceptors and chemoreceptors send sensory neurons to CNS

Regulation of heart rate (2)

sensory nerve fibers sent to CNS

Regulation of Heart rate (3)

CNS send parasympatheic and sympathetic nerve fibers back to heart

Regulation of Heart Rate (4)

sympatehic nerves fibers are sent to cardiac nerves while parasympathetic nerve fibers are sent to Vague nerves

Regulation of heart rate (5)

if sympatheic nerve fibers are not sent to cardiac nerves they go to adrenal gland.

Homeostatsis of blood pressure if BP increases (1)

Receptors and control center: Baroreceptors in the carotoid arteries and aorta detect an increase in blood pressure

Homeostatsis of blood pressure if BP increases (2)

Receptors and Control center: the cardioregularty center in brain detect a decrease in sympathetic stimulation of the heart and adrenal medulla increases parasympatheic stimulation of heart.

Homeostatsis of blood pressure if BP increases (3)

Effectors/Reponse: The SA Node and cardiac muscle decrease activity and heart rate and stroke volume decrease (BP restored).

Homeostatsis of blood pressure if BP decreases (1)

Receptors and control center: Baroreceptors in the carotoid arteries and aorta detect an decrease in blood pressure

Homeostatsis of blood pressure if BP decreases (2)

Receptors and Control center: the cardioregularty center in brain detect a increase in sympathetic stimulation of the heart and adrenal medulla decrease parasympatheic stimulation of heart.

Homeostatsis of blood pressure if BP decreases (3)

Effectors/Reponse: The SA Node and cardiac muscle increase activity and heart rate and stroke volume increase (BP restored).