Cardiovascular System - The Heart

Question 1

Define: Endothelium

Answer 1

simple squamous endothelium lining the inner aspect of the heart and blood vessels

Question 2

Define: Tunica Intima

Answer 2

internal layer of the vessel wall

Question 3

Define: Tunica Media

Answer 3

middle layer of the vessel wall

Question 4

Define: Tunica Adventitia

Answer 4

Outer layer of the vessel wall

Question 5

Define: Endocardium

Answer 5

inner heart layer

simple squamous epithelium

loose CT (subendothelial CT)

Purkinje Fibers (nuclei, intercalated disks)

closest to lumen/heart chamber

Question 6

Define: Myocardium

Answer 6

Muscle Heart layer

Cardiac Muscle

Fibrous Skeleton

contains: contractile cardiocytes myoendocrine cardiocytes, nodal cardiocytes

Question 7

Define: Epicardium

Answer 7

outer heart layer

Loose CT

Adipose Tissue

larger blood vessels, coronary arteries and veins

Question 8

All muscle does:

Answer 8

movement → sliding filaments, actin and myosin

Question 9

Arrangement of Skeletal and Cardiac Muscle

Answer 9

lined up to form striations

Question 10

Arrangement of Smooth Muscle

Answer 10

no regular arrangement → no striations

Question 11

Cardiac Muscle Organization

Answer 11

Sarcolemma with opening to T tubule

lateral component of intercalated disc

Z Line

T Tubule

Gap Junctions

Macula Adherens

Fascia Adherens

Transverse component of intercalated disc

Question 12

Define: Intercalated Disks

Answer 12

Can think of structure as series of steps

desmosomes provide strength

gap junctions are there for electrical continuity

found in border between cells

Question 13

What is different about Cardiac Muscle from Skeletal and Smooth Muscle?

Answer 13

it is striated

central nuclei

intercalated disk

branching myocytes

Question 14

Ventricular Walls are thicker than…

Answer 14

atrial walls

Question 15

Walls of the aorta are thicker than…

Answer 15

the walls of the vena cava

Question 16

How does blood flow through the heart to the lungs?

Answer 16

Blood enters heart through right atria from vena cava → heart contracts → sends to right ventricle → heart contracts → blood moves to lungs

Question 17

How does blood move from the lungs to the heart?

Answer 17

Blood flows from lungs through the pulmonary veins to the left atria → heart contracts → enters left ventricle → heart contracts → goes through aorta to rest of the body

Question 18

Why is there more pressure in the arch of the aorta?

Answer 18

to send blood through the body

Question 19

Where are valves located in the heart?

Answer 19

valves between atria and ventricles and arteries

valves prevent back flow

Question 20

Define: Pericardium

Answer 20

external layer to outer epicardium

next to adipose tissue

Question 21

What is the order of the layers of the heart from inner to outermost?

Answer 21

Endocardium

Myocardium

Epicardium

Pericardium

Question 22

What are the 3 layers of the heart?

Answer 22

Endocardium

Myocardium

Epicardium

Question 23

Define: Contractile Cardiocytes

Answer 23

contract to pump blood through the circulation

Question 24

Define: Myoendocrine Cardiocytes

Answer 24

producing atrial natriuretic factor

Question 25

Define: Nodal Cardiocytes

Answer 25

specialized to control the rhythmic contraction of the heart

located in the SA node at the superior vena cava → right atrium junction

located in the AV node → present under the endocardium of the interatrial and interventricular septa

Question 26

Which has a thicker myocardium, the ventricle wall or the atrial wall?

Answer 26

the ventricle wall

Question 27

Define: Fibrous Skeleton

Answer 27

collagen fibers that provide structure

function similarly to tendons → provide stable platform for contraction

muscle moves while fibrous skeleton stays still

Question 28

Define: Valves

Answer 28

extensions of the fibrous skeleton covered in endothelium

3 layers (AV Valve) → ventricularis, fibrosa, spongiosa

Question 29

Define: Ventricularis

Answer 29

Valve layer

dense irregular CT

Faces Ventricle

Question 30

Define: Fibrosa

Answer 30

Valve Layer

Dense irregular CT; internal

continuous with fibrous skeleton

interior of valves → middle layer

Question 31

Define: Spongiosa

Answer 31

valve layer

loose ct

faces atrium → more cells fewer fibers

Question 32

Define: Chordae Tendinae

Answer 32

connect the valve to the papillary muscle to help regulate opening and closing

Question 33

Heart Conducting System

Answer 33

• Coordinated Action
  
  • impulses initiate in SA node → pacemaker cells
  • transmitted to AV node (takes over as pacemaker if SA is damaged)
  • further transmitted through bundle of His and Purkinje fibers to ventricular walls

Question 34

Why do Purkinje Fibers stain lighter?

Answer 34

due to their glycogen content

Question 35

What is the overall purpose of the circulatory system?

Answer 35

it delivers nutrients throughout an organism, and removes waste

Question 36

The central part of the circulatory system is…

Answer 36

the heart

Question 37

The heart has a specialized type of muscled called….

Answer 37

cardiac muscle

Question 38

The cardiac muscle is connected to a…., which…

Answer 38

fibrous skeleton, which extends to form valves that regulate the direction of blood flow

Question 39

A specialized network of electrical connections….

Answer 39

transmits signal for the SA node to the AV node to the ventricles