APK2100C UF EXAM 4

Right Heart is part of the ___________________ circuit.

Pulmonary Circuit: carry blood to and from the lungs

Left Heart is part of the ___________________ circuit.

Systemic Circuit: pumps blood to the entire body

The Heart is served by the ________________ vessels in the _______________ circuit.

Coronary; Systemic

The Location of the Heart

~Thorax: superior portion of ventral body cavity

~Mediastinum

~Midsternal Line

~Sits on Diaphragm (skeletal muscle): fused with connective tissue

~Upside down, backward leaning cone

The Apex of the heart is on the ____________ side and points _______________.

left; anteriorly (left ventricle)

The Base of the heart lies on the ___________ _____________.

Right Atria

The heart is surrounded by __________________.

Pericardium

The Pericardium is

a fibrous sac of connective tissue that surrounds the heart and helps it to adhere to surrounding structures

The 3 Layers of the Heart Wall are the:

1. Epicardium

2. Myocardium

3. Endocardium

Epicardium

~outer layer of the heart wall

~continuous with visceral layer of pericardium

~simple squamous epithelium

Myocardium

Cardiac Myocytes (Muscle Tissue)

Endocardium

~deepest layer of heart wall

~lines the chambers and covers the valves

~simple squamous epithelium

The Pericardial Cavity

is filled with fluid to allow lubrication between the heart and pericardium

The 3 Layers of the Pericardium are the:

1. Fibrous Pericardium

2. Parietal Pericardium

3. Visceral Pericardium

Fibrous Pericardium

adheres to the diaphragm and root of large vessels

Parietal Pericardium

connects to inner surface of fibrous pericardium

Visceral Pericardium

the same as epicardium (continuous with outer heart wall layer)

The Cardiac Skeleton

~gives the general framework of the heart

~connective tissue

Cardiac Muscle Bundles

~ideal for directing blood flow

~as muscle cell contracts, muscle squeezes and rings the structure

The Atria are separated by the ___________________________.

Interatrial Septum

The Atria

~receive blood

~superior

~smaller

The Ventricles are separated by the ____________________.

Interventricular Septum

The Ventricles

~pump blood

~inferior

~larger

The Coronary Sulcus separates _________________ and _________________.

Atria; Ventricles

The Anterior and Posterior Interventricular Sulci hold ________________.

Major coronary vessels

The Right and Left Auricle

~surround atria

~ear like structure

~expand volume of atria

The Superior and Inferior Vena Cava

dump deoxygenated blood into the right atria.

The Aorta

sends oxygenated blood through the systemic circuit to the whole body except the lungs.

The Pulmonary Trunk

~sends blood to the lungs/pulmonary circuit

~receives blood from the right ventricle

The Pulmonary Trunk bifercates into the

right and left pulmonary arteries.

The 2 Right and Left Pulmonary Arteries/ Trunks

~carry deoxygenated blood away from the heart, out of the right atrium and to the lungs

~bifercate

The 4 Pulmonary Veins

carry oxygenated blood from the lungs into the left atrium

Where can you find the coronary sinus?

between the atria and ventricles on the posterior side of the heart

The Coronary Sinus

~drains venous blood from the heart

~dumps blood back into right atrium

~once oxygenated blood from coronary vessels have supplied the heart, deoxygenated blood drains through the coronary sinus

~sits in coronary sulcus

~receives blood from great cardiac vein

Pectinate Muscles

~parallel ridges of muscle tissue

~atria

~anterior inner wall of atria

~allow for stronger contractions

Crista Terminalis

~groove like structure that borders the openings of the inferior and superior vena cava

~right atrium

~origin for pectinate muscles

Fossa Ovalis

~remnant of the foramen ovale of the fetal heart

~opening through the interatrial septum that closes after birth

~atria

Trabeculae Carnae

~ridge like structures

~ventricles

~"beams of meat"

Papillary Muscles and Chordae Tendinae

~work together to prevent back flow of blood

~allows unidirectional blood flow from atria to ventricles

AV (atrioventricular) Valves

allow blood flow from the atria to the ventricles

Semilunar Valves

~prevent back flow from pulmonary trunk to heart

~found between aorta/ pulmonary artery and the ventricles

The Left Ventricle is bigger because

it pumps to the systemic circuit and requires more pressure

The Tricuspid Valve

~AV Valve

~Right Side of the heart

The Bicuspid Valve

~AV Valve

~Mitral Valve

~Left Side of the Heartb

The Pulmonary Valve

~receives blood from right ventricle

~semilunar valve

~lies between right ventricle and pulmonary artery

The Aortic Valve

~receives blood from left ventricle

~between left ventricle and aorta

~semilunar valve

Diastole

relaxed ventricles

Systole

~contracted ventricles

~spurt blood into pulmonary trunk/ aorta

Anastemoses

alternate route for blood flow

Coronary Veins

take deoxygenated blood away from the heart

Electrical Conduction Through the Heart

Note: there are NO NERVES in the heart, electrical impulse comes directly from heart

1. SA Node (pacemaker): generates impulse, top of right atria

2. AV Node (also a pacemaker): momentary pause, bottom of right atria

3. AV Bundle (bundle of his): connects electric impulse of atria to ventricles, found in interventricular septum

4. Bundle Branches: impulse gets sent to bundle branches which take signal through inner ventricular septum, split of AV bundle, move towards apex of heart

5. Purkinje Fibers: stimulate muscle cells to contract within ventricles, curve away from apex of heart. Excites myocardium of ventricular walls and causes heart to pump

Atherosclerosis

blood flow is blocked inside arteries from fatty deposits

Angina Pectoris

chest pain from lack of oxygen in heart muscle

Myocardial Infarction (Heart Attack)

blocked artery causing stoppage of blood flow

Parasympathetic impulses are sent to SA Node through this nerve

Vagus Nerve

The Flow of Blood

~IVC and SVC with deoxygenated blood enters Right Atrium

~Travels through Tricuspid Valve to Right Ventricle

~Travels through the Pulmonary Trunk to get to the Pulmonary Circuit/Lungs

~Oxygenated blood comes back from Pulmonary Veins and enters the Left Atrium

~Left Ventricle sends blood to the systemic circuit.

This scientists believed blood flowed through only one set of veins with a single pump

Galen

Blood Flow Through Vessels

heart, arteries, arterioles, capillaries, venules, veins, heart

for example: blood travels from right ventricle into pulmonary arteries into arterioles, into capillaries in the alveoli, into venules and into pulmonary veins back to the heart

The Tunica Externa is larger in ____________.

Veins

The Tunica Media is larger in ______________.

Arteries to Regulate Blood Pressure

The Layers of Blood Vessel Wall

1. Tunica Intima

2. Tunica Media

3. Tunica Externa

Tunica Intima

~endothelium

~continuous with endocardium (deepest layer of heart wall)

~simple squamous epithelium

Tunica Media

~smooth muscle and elastic fibers

~allows for contraction of lumen

Tunica Externa

~connective tissue

~collagen fibers

~protects veins

~adheres vessels to a structure so they are not freely moving

Capillaries

~the point between arteries and veins

~allow gas exchange

Vessels are hollow ______________.

organs

The Vessel with a larger lumen

Vein

Arteries carry blood _____________ from the heart.

away

Most arteries carry _____________ blood, but pulmonary arteries carry ________________ blood.

oxygenated; deoxygenated

Three Types of Arteries

1. Elastic

2. Muscular

3. Arterioles

(biggest to smallest)

Elastic Arteries

~elastin

~large lumen

~used in large arteries ex. aorta

Muscular Arteries

~thick tunica media (muscle)

~maintains blood pressure by slightly contracting

Arterioles

~smallest arteries

~lead to capillaries

Arteries get ____________ as they branch away further from the heart.

smaller

Arterioles autonomically regulate blood flow through

vasoconstriction and vasodilation

Smooth Muscle Tone

allows for vasoconstriction and vasodilation and the regulation of blood flow in the arterioles

Capillaries

~composed of only 2 layers: endothelium and basement membrane

~tiniest blood vessels

~allow single file passage of red blood cells in order to increase surface area and increase the uptake of nutrients

Capillary Beds

grouping of capillaries that branch from the main vessel

Precapillary Sphinters

~band of smooth muscle that guards the entrance to every capillary

~control by reducing or stopping the blood flow that travels through capillaries

~prevent blood from flowing into capillaries

ex. when you are exercising you do not need as much blood flow to kidneys so blood flows directly from arteriole to venule in that capillary bed, but skeletal muscles need more oxygen and blood during exercise so sphinters are open

Metarteriole

first part of vessel traveling throuhg the capillary bed

Thoroughfare Channel

transitionary vessel from arteriole to venule

Capillary Permiability

1. Diffusion

2. intercellular Clefts

3. Pinocytotic Vessels

4. Fenestrations

Diffusion

passive movement of small particles to higher to lower concentration

Intercellular Clefts

gaps between endothelial cells

Pinocytotic Vessels

endocytosis

Fenestrations

holes through epithelial cells

Blood Brain Barrier

~exception to capillary permeability

~completely sealed by tight junctions

~glucose may be shunted in

Types of Capillaries

1. Continuous

2. Fenestrated

3. Sinusoidal

Continuous Capillaries

~most common

~least permeable

~pinocytotic vessels

~intercellular clefts

Fenestrated Capillaries

~fenestrations (pores)

~pinocytotic vessels

~intercellular clefts

~occurs in places of active filtration (kidneys, small intestine)

Sinusoidal Capillaries

~most permeable

~incomplete basement membrane

~allows large particles such as proteins and cells to pass

~occurs in special locations (liver, bone marrow, spleen)

Veins carry blood ___________ the heart.

away

Veins usually carry ______________ blood toward the heart, nit the pulmonary veins carry _____________ blood.

oxygen-poor; oxygen-rich

The veins store the majority 65% of the blood because

it is a low pressure system because it is farther away from the heart

Blood Flow Through Veins

post capillary venules -->

venules -->

veins

Veins work against gravity in 2 ways:

1. Valves

2. Skeletal Muscle Pumping

Skeletal Muscle Pump

~skeletal muscles contract to push blood up a vein

~allows venous blood to travel back up veins

Venous Valves are located in

The Limbs

Varicose Veins

~caused by damage to venule/ vein walls. or valves

~standing too long

~skeletal muscle pump goes wrong

~spider veins are a smaller version

Anastemoses are more common in

veins and joints