Chp 14 - Cardiovascular System

What is the Cardiovascular System responsible for

movement of blood & everything it carries throughout animal’s body

The Cardiovascular System is considered a ___ system

• closed system

• no external openings

Arteries

carry blood away from heart

Veins

carry blood toward the heart

capillaries

form transition between arteries & veins

2 parts of the Cardiovascular System

1. pulmonary (lung) circulation

2. systemic (body) circulation

Which side of the heart controls the pulmonary (lung) circulation

right side

Right side of heart receives ___ blood from throughout the animal’s body

deoxygenated

Right side of heart pumps blood into the ___ where it becomes oxygenated

lungs

Which side of the heart controls the systemic (body) circulation

left side

the left side of the heart receives __ blood from the lungs

oxygenated

Heart is located in the middle of the thoracic cavity in the ___

mediastinum

mediastinum

space between 2 lungs

mediastinum is bounded by the thoracic cavity ___ (direction)

cranially

mediastinum is bounded by the diaphragm ___ (direction)

caudally

mediastinum is bounded by the sternum ___ (direction)

ventrally

mediastinum is bounded by the spinal column ___ (direction)

dorsally

The heart is located between the ___ when viewing a standing animal

elbows

Base of heart

rounded cranial end

apex of heart

more pointed caudal end

Angle of heart in an animal

doesn’t sit straight along the median plane

Base is shifted to the ___ and faces more ___ (direction)

right; dorsally

Apex is shifted to the ___ and sits more ___ (direction)

left; ventrally

heart is contained in a fibrous sac called ___

pericardium

2 parts of pericardium

1. pericardial sac

2. serious periardium

pericardial sac

• fibrous sac

• little loose 

• not elastic

2 membranes of serious pericardium

1. parietal layer

2. visceral layer

parietal layer of serious pericardium

smooth, moist serous membrane

parietal layer of serious pericardium lines the ___

pericardial sac

viseral layer of serious pericardium lies directly on the ___

surface of the heart

pericardial space

area between the 2 serous membranes

pericardial space is filled with ___

pericardial fluid

pericardial fluid

• lubrictaes 2 membranes

• prevents friction as they rub together during relaxations & contractions of the heart muscle

Layers of the heart: superficial to deep

1. epicardium

2. myocardium

3. endocardium

epicardium is another name for the ___

visceral layer of the serous pericardium

myocardium layers

• middle

• thickest

• muscle

myocardium is made up of ___ muscle

cardiac muscle

papillary muscles

• inside surface of myocardium

• ridges & nipple like projections

what is the papillary muscles covered by

endocardium

2 advantageous characteristics of the myocardium

1. autorhythic

2. doesn’t fatigue

what tissue is endocardium made of

thin flat simple squamous epithelium

endocardium is continuous with the ___ that lines the blood vessels

endothelium

How many chambers or cavities are in the heart

4

Names for the heart chambers

1. 2 atria

2. 2 ventricle

The two atria chamber walls form part of the ___ of the heart

base of the heart

The wall of the left ventricle chamber walls forms the ___ of the heart

apex of the heart

interatrial septum

separates the left & right atrium

interatrial septum is a continuation of the

myocardium

Atria retrieves blood from ___ that carry blood to heart

large veins

How are atria identified on the outside of the heart

by their auricles

auricles

• blind pouches

• come off the main part of atria

• look like ear flaps

auricle means

earflap or ear

Why is the myocardium not very thick

only has to contract with enough force to move blood into ventricle

Left & right ventricles are separated by the ___

interventricular septum

interventricular septum is a continuation of the ___

interatrial septum

what makes up the Atrioventricular septum

interatrial septum + interventricular septum

interventricular groove

area of interventricular septum visible on the outside of the heart

what does the interventricular groove contain

• coronary (heart) blood vessels

• frequently filled with fat

The right ventricle pumps blood to the pulmonary circulation through the ___

pulmonary artery

The left ventricle pumps blood to the systemic circulation through the ___

aorta

Why is the right ventricular wall thinner than the left ventricular wall

blood from right ventricles doesn’t have very far to go

Why is the left ventricular wall thicker than the right ventricular wall

• left ventricular wall has the most work to do pumping blood to the rest of the animal’s body

• contract with greater force

4 one-way valves that control blood flow through the heart

1. aortic valve

2. mitral valve

3. pulmonary valve

4. tricuspid valve

atrioventricular valves (AV valves)

located between atria & ventricles

The right atrioventricular valves consists of ___ flaps of endothelium

3 flaps (cusps)

tricuspid valve

Valve between the right atrium and the right ventricle.

What prevents the tricuspid valve from opening backward into the atrium

collagen fiber cords

chordae tendineae

Connect the pointed ends of the flaps or cusps to the papillary muscles in the ventricles

collagen fiber cords are attached to the edge of what two things in the wall of the right ventricle

1. each cusp

2. papillary muscles

The left atrioventricular valves consists of ___ flaps of endothelium

2 flaps (cusps)

semilunar valves

two valves that control blood flow out of the ventricles & into arteries

semilunar valves shape

• 3 cusps

• each resembles a crescent moon

Two semilunar valves

1. pulmonary valve

2. aortic valve

Pulmonary valve

• Right semilunar valve

• blood from the right ventricle flows through it into the pulmonary circulation

aortic valve

• left semilunar valve 

• blood from the left ventricle flows through it into the aorta

aorta

• largest elastic artery

• beginning of systemic circulation

where is the skeleton of the heart located

between atria & ventricles

what is the skeleton of the heart made up of

4 dense connective tissue rings

4 primary functions of skeleton of the heart

1. Separates atria and ventricles​

2. Anchors heart valves​

3. Point of attachment for myocardium​

4. Electrical insulation between atria and ventricles

skeleton of the heart is equivalent to the ___ in cattle

Os cordis in cattle

Coronary arteries

Supply the walls of the heart with oxygenated blood.

Coronary arteries branch off the ___ just past the ___ valve

aorta; aortic valve

which part of the heart gets the largest blood supply from the Coronary arteries

left ventricle

After the blood from the Coronary arteries has passed through the capillaries in the myocardium, it enters the ___

coronary veins

coronary sinus

channel that drains the blood from the coronary Vein into the right atrium

external motor stimulation

• nerve supply to the heart

• accomodate for the increased oxygen stimulation to certain tissues

nerve fibers terminate primarily in the ___ near the area of cardiac muscle cells

right atrium

vena cava

largest vein that brings deoxygenated blood from the systemic circulation to the heart

cardiac cycle

• cycle of atrial and ventricular contraction and relaxation​

• produces 1 heartbeat

sinoatrial node 

area of cardiac muscle cells that automatically generate impulses that trigger each heart beat

where is the sinoatrial node located

in the wall of the right atrium

at rest, a cardiac muscle cell is ___

polarized

polarized cardiac muscle cell - sodium and calcium ions are located on the ___ membrane of the cell

outer membrane

polarized cardiac muscle cell - potassium ions are located ___ of the cell

inside

For the cardiac muscle cell to contract it must ___

depolarize

Sodium and calcium ions move from the ___ to the ___ of the cell

exterior → interior

Potassium ions move from the ___ to the ___ of the cell

interior → exterior

during contractions, the cardiac muscle cell is ___

depolarized

How does the impulse generated from the sinoatrial node travel through the heart

from base →apex →base again

the impulse generated from the sinoatrial node passes through ___ of the wall of the atria

muscle fibers