Biology 1410 Lecture Notes UNIT 12

The heart is in a space between lungs within thoracic cavity which is called

mediastinum

double-walled sac surrounding heart =

Pericardium

Pericardium has ??? layers

three

outermost layer = ??? connective tissue

dense irregular

• outermost layer = dense irregular connective tissue

• anchors to surrounding structures e.g. diaphragm, great vessels (aorta, vena cava, etc)

fibrous pericardium

serous pericardium is composed of:

parietal pericardium, visceral pericardium

are both parietal pericardium, visceral pericardium 2 layers – epithelial & connective?

Yes 

• connected to fibrous pericardium

• pericardial sac
  what is this 

parietal pericardium

• fused to heart surface, so is part of heart wall
  what is this? 

visceral pericardium

between pericardial layers = pericardial cavity with ??? fluid (lubricates) this prevents friction and damage to the heart 

serous

The heart wall has three parts 

epicardium
myocardium
endocardium

Whats a = cardiac muscle

arranged in spiral/circular pattern, reinforced with connective tissue

myocardium

Whats a = visceral pericardium

epicardium

Which two are a simple squamous epithelium and connective tissue

epicardium, endocardium

What lines inner surface of heart and ALL blood vessels

epithelium named endothelium

Four chambers of the heart

Right Atrium

Left Atrium

Right Ventricle 

Left Ventricle 

Three major veins connected to the right atrium that carry deoxygenated blood into the chamber

1. inferior vena cava (carries blood from body below heart)

2. superior vena cava (carries blood from body above heart)

3. coronary sinus (carries blood from the myocardium)

4 veins carry oxygenated blood into the left atrium from the lungs:

1. left pulmonary veins

2. right pulmonary veins

• 1 artery, the ??? exits the right ventricle and then divides to form 2 pulmonary arteries (left and right). These carry deoxygenated blood towards the lungs.

pulmonary trunk

• 1 artery, the ???, exits the left ventricle and carries oxygenated blood to all organ systems.

aort

Septa (separate chambers)

1.what separates atria
2.what separates ventricles

1. Interatrial septum

2. Interventricular septum

Cardiac (Fibrous) Skeleton

fibrous connective tissue separating ??? & ???

atria & ventricles

Cardiac (Fibrous) Skeleton

provides firm attachment point for ??? muscles

cardiac

Cardiac (Fibrous) Skeleton

forms solid rings around heart valves, base of ??? and ??? that provide structural support for these structures and hold them in place.

aorta, pulmonary trunk

Cardiac (Fibrous) Skeleton

provides electrical insulation – prevents simultaneous contraction of ??? and ???

atria, ventricles

for one way flow of blood…

Valves

For Atrioventricular (AV) valves there are two..

1. bicuspid (mitral) valve

2. tricuspid valve

Which valve is between right atrium and right ventricle

tricuspid valve

Which valve is between left atrium and left ventricle

bicuspid (mitral) valve

which valve has 2 sheet-like cusps

bicuspid (mitral) valve

which valve has 3 sheet-like cusps

tricuspid valve

prevent eversion of cusps

Chordae tendineae

Chordae tendineae (strings of connective tissue) that attach atrioventricular valve cusps to papillary muscles that project from the…

 ventricular myocardium.

Semilunar valves

3 cup-like cusps each
aortic separates ???
pulmonary separates ???

aortic separates left ventricle & aorta

pulmonary separates right ventricle & aorta

Cardiac Muscle Cells

includes two cell types

Contractile cells
Conduction System cells

forms majority of myocardium

Contractile cells

forms remainder of the myocardium

Conduction System cells

striated (myofibrils with sarcomeres)

has sarcoplasmic reticulum & T-tubules

are these similarities or differences 

similarities

branched (myofibrils with sarcomeres)

uninucleated (single nucleus)

intercalated discs = region where two fibers meet

contain anchoring and gap junctions

are these similarities or differences 

differences

cardiac muscle cells that are ??? to produce and conduct electrical impulses – DO NOT CONTRACT

modified 

Conduction System cells have many ??? that help electrical signals to spread very quickly

gap junctions

The five parts of the conduction system cells

atrioventricular (AV) node
Atrioventricular Bundle (Bundle of His)
Atrioventricular (AV) Bundle Branches
sinoatrial (SA) node
Purkinje fiber

At the base of right atrium

atrioventricular (AV) node

• in right atrium at base of superior vena cava

• generates impulses the fastest – sets pace

sinoatrial (SA) node

• superior part of interventricular septum

• electrically connects atria to ventricles

Atrioventricular Bundle (Bundle of His)

Carry impulse to apex (bottom tip) of heart

Atrioventricular (AV) Bundle Branches

• terminal fibers in ventricles (not found in atria) that carry signals from apex upward to all parts of the ventricle

• Note: electrical signal spreads from conduction system to contractile cardiac cells then they contract

Purkinje fibers

General structure of blood vessels (there are 4)

Tunica externa
Tunica media
Tunica intima/interna
Lumen

which two general structure of blood vessels
have connective tissue

Tunica externa
Tunica media (elastic fibers

which general structure of blood vessels has smooth muscle

Tunica media

which general structure of blood vessels is endothelium – simple squamous epithelium and continuous with endocardium

Tunica intima/interna

which general structure of blood vessels contains blood and (not a layer) 

Lumen 

carry blood AWAY from heart (does NOT refer to oxygenated or deoxygenated blood)

Arteries (the reason it says does not because arteries in general and veins in general do both since our whole body needs oxygen too

large conducting arteries exiting the heart

elastic arteries

smaller distributing arteries

muscular arteries

• elastic CT in all 3 layers

• largest arteries (near heart)

• e.g. aorta

elastic arteries

• a LOT of smooth muscle

• most arteries

• e.g. coronary artery

muscular arteries

little arteries regulate blood flow + blood pressure

Arterioles

What allow exchange of gases + nutrients and most have gaps between cells that allow exchange of fluid + solutes with the interstitial fluid (inside fluid)

Capillaries

In the Capillaries its made of endothelium (once cell layer) + basement membrane this is….

ONLY TUNICA INTIMA 

What collect blood from capillaries and is made of intima(endothelium) with thin media / externa layers 

Venules 

What carry blood INto heart?

veIN

veins can have ??? valves that prevent back flow of blood

one-way

veins have more connective tissues but less smooth muscle than arteries what is this called?

thin media

do veins have large lumen?

yessss

For Circulatory Routes blood confined to heart + blood vessels is called 

closed 

For Circulatory Routes for 2 routes (pulmonary + systemic) is called

double

In adult circulation this is for oxygenation of the blood

Pulmonary circulation

Pulmonary circulation carries blood from ??? ventricle to lungs via pulmonary arteries (deoxygenated blood) 

right

Do pulmonary arteries only carry deoxygenated blood?

YES

In the pulmonary circulation what picks up oxygen in the lungs

capillaries

In the pulmonary circulation what carries blood from lungs to left atria

pulmonary veins

What does pulmonary veins only carry?

oxygenated blood

What is for delivery of oxygenated blood to all other tissues

Systemic Circulation

In the systemic circulation what carries blood from left ventricle to organs

aorta

Does aorta only carry oxygenated blood?

Yes

In the systemic circulation organs take up oxygen from blood what does this

capillaries

In the systemic circulation what carries blood from organs to right atrium

superior and inferior vena cava

superior and inferior vena cava do they only carry deoxygenated blood?

Yes

overall route is left ventricle to right atrium =

systemic circulation (besides all of the other places it goes to organs/systems)

What are four places the systemic circulation goes too

cerebral = brain
hepatic = liver
coronary = heart
bronchial = parts of respiratory system 

In fetal circulation fetus gets what two things and i guess takes a one thing out to mothers blood 

oxygen(o2) nutrients from + expels wastes to mothers blood

In fetal circulation fetus where is the exchange site

placenta 

In the placenta does the mother and fetus mix blood to get nutrients 

NO but they’re close together 

In fetal circulation fetus differences from adult circulation…
carries oxygenated blood from placenta to vena cava 

umbilical vein (towards the fetal heart)

In fetal circulation fetus differences from adult circulation…
??? + ??? are late to develop and their functions are handled by maternal organs 

lungs and liver 

3 shunts that allow most blood to bypass these organs (minimal blood flow to these organs for nourishment/ growth).. does jobs of lungs and lier

ductus venosus
foramen ovale
ductus arteriosus

in the ductus venosus what connects to the inferior vena cava

umbilical vein

umbilical vein only carries ???
inferior vena cava only carries ???

umbilical vein only carries oxygenated blood
inferior vena cava only carries deoxygenated blood 

in the ductus venosus it permits most of the ??? blood coming from placenta to bypass the liver capillaries 

oxygenated

in the ductus venosus oxygenated and deoxygenated blood mixes in ??? and enters fetal right atrium

inferior vena cava

What is the hole in interatrial septum and allows blood to move from the Right to Left atrium

foramen ovale

in the forman ovale it bypasses the ???

uninflated fetal lung (HOW?? since the fetus is not breathing no gas exchange is happening lol) 

What connects to pulmonary trunk and aorta in fetus and also bypasses the uninflated fetal lung 

ductus arteriosus

When do all shunts normally become closed?

following birth

what returns mixed blood to placenta

umbilical arteries(away from fetal heart)

higher viscosity than H20
pH 7.35 - 7.45
4-6 L in an adult 

What are the characteristics of this 

BLOOD 

plasma (matrix) makes up ??? - ??? of blood volume

~55-60%

plasma is fluid portion with ???

solutes (what plasma is composed with)