CIRCULATORY SYSTEM PT 1 - HEART Flashcards Preview

T1 PHYSIOLOGY > CIRCULATORY SYSTEM PT 1 - HEART > Flashcards

Flashcards in CIRCULATORY SYSTEM PT 1 - HEART Deck (59):
1

Describe the size/positioning/inferior attachment of the Heart.

- Size of a fist
- Middle of the mediastinum with 2/3rds of mass on the left
- Attached to diaphragm inferiorly

2

The inferior portion of the heart is called?

Apex

3

The superior portion of the heart is called?

Base

4

Define Mediastinum.

Mass of organs between Lungs

5

Name the structures that border the Mediastinum.

Superior: 1st rib
Inferior: Diaphragm
Anterior: Sternum
Posterior: Vertebrae

6

What are the structures that make up the Mediastinum?

Trachea
Esophagus
Thymus/Lymph Nodes
Heart

7

What is Pericardium? Name the layers.

A two-layered CT membrane surrounding Heart
Fibrous and Serous

8

Describe Fibrous Pericardium.

A inelastic, dense irregular CT holding Heart in place and allows movement

9

Describe Serous Pericardium.

Deep to Fibrous, forming a double layer around Heart

10

Describe the Parietal Layer of the Serous Pericardium.

Outer layer fused to Fibrous Pericardium

11

Describe the Visceral Layer of the Serous Pericardium.

aka. Epicardium
Inner layer attached to Heart muscle

12

What is the Pericardial Cavity?

Space between the Parietal and Visceral layer filled with pericardial fluid to reduce friction

13

Name the layers that make up the Hearts walls. From superficial to deep.

Epicardium
Myocardium
Endocardium

14

Describe the Epicardium layer.

aka. Visceral layer of Serous Pericardium
Outer layer of simple squamous epithelium and CT with a smooth, slippery texture

15

Describe the Myocardium layer.

Cardiac muscle tissue - site of contractions

16

Describe the Endocardium layer.

Deep layer providing a smooth lining for chambers and valves

17

Describe Endothelium.

Simple squamous epithelium lining cavities of heart, blood and lymph vessels. Found in Endocardium layer

18

What is a Septa?

Dividing walls in heart

19

What does the Interatrial Septum divide?

Divides 2 Atria

20

What does the Interventricular Septum divide?

Divides 2 ventricles

21

What is the function of Veins?

Carry blood towards Heart

22

What is the function of Arteries?

Carry blood away from Heart

23

Explain the blood flow function of the Right Atrium.

- Receives blood from 3 veins
- Exits through the Tricuspid Valve (Right A-V Valve)
- Into the Right Ventricle

24

Name the 3 veins entering the Right Atrium.

Superior Vena Cava
Inferior Vena Cava
Coronary Sinus

25

Explain the blood flow function of the Right Ventricle.

- Receives blood from Right Atrium
- Ejects through Pulmonary Semilunar Valve
- Into the Pulmonary Trunk
- Suppling R and L Pulmonary Arteries (Lungs)

26

Explain the blood flow function of the Left Atrium.

- Receives blood from 4 veins (from lungs)
- Exits through Bicuspid/Mitral Valve (Left A-V Valve)
- Into the Left Ventricle

27

Explain the blood flow function of the Left Ventricle.

- Receives blood from Left Atrium
- Ejects through Aortic Semilunar Valve
- Into the Aorta and Coronary Arteries

28

What are Chordae Tendinae?

Tendon-like cords on the cusps of the AV Valves

29

What is the function of Papillary Muscles?

Prevents valves from opening in opposite direction

30

Explain the opening and closing of the Atrioventricular Valves (Tricuspid and Bicuspid Valves).

- Blood flow into the Atriums causes pressure which opens the AV Valves into the Ventricles.
- AV Valves closes when ventricles contract

31

Explain the function of the Pulmonary/Aortic Semilunar Valves.

- Ventricles contract opening the Pulmonary and Aortic Valves into the Arteries
- Once ventricles relax, left over blood will flow into the cusps of the semilunar valves

32

What is the "Lub" sound from the Heart?

Sound of AV Valves closing

33

What is the "Dub" sound from the Heart?

Sound of Semilunar Valves closing

34

Explain the Pulmonary Circulation Pathways.

- 'Right side of the Heart'

- Deoxygenated blood enter Right Atrium
- Pumped into Right Ventricle
- Up into the Pulmonary Arteries (Lungs)
- Deoxygenated blood rid CO2 for O2 in Lungs
- Oxygenated blood from Lungs enter the Left Atrium via 4 Pulmonary Veins

35

Explain the Systemic Circulation Pathways.

- 'Left side of the Heart'

- Oxygenated blood enter Left Atrium from Lungs
- Pumped into Left Ventricle
- Up into Aorta and out to body tissues
- Tissues use O2 and releases CO2 making it deoxygenated, which eventually goes in Right Atrium

36

Describe Coronary Circulation.

Heart provides own circulation, with coronary arteries encircling the Heart, and receiving blood supply in between beats

37

Describe Autorhythmic Fibres?

Self-excitable cardiac muscle cells generating own APs
- Sets rhythm of APs for contactions
- Form a conducting system

38

Explain the Conducting System of the Heart.

A pathway at which APs progress through the heart

39

List the sequence of an AP through the Heart (Conduction System).

SA Node (Sinoatrial Node)
Atria
AV Node (Atrioventricular Node)
B. of His
B. Branches
Purkinje Firbres
Ventricles

40

Describe the Sinoatrial Node (SA Node).

Repeatedly generates APs causing atrial contraction and ejection of blood into the AV node

41

Describe Atrioventricular Node (AV Node).

Causes ventricular contraction and ejection of blood into the arteries

42

Define Cardiac Cycle

All events associated in one heart beat

43

Define Systole.

Contraction phase

44

Define Diastole.

Relaxation phase

45

Define Heart Rate and average HR.

- Heart beats in 1 min
- Avg. HR 72bpm

46

Define Strike Volume and average SV

- Blood ejected from each ventricle with each beat
- Avg. SV 70mL

47

Define Cardiac Output and average CO.

- Heart rate x Stroke Volume
- 5L/min

48

Define Cardiac Output.

Amount of blood ejects per minute

49

What are the factors that regulate HR?

ANS
Hormones/Ions
Other Factors (age/sex/fitness/body temp.)

50

The control centre in the _______________ gets input from sensory receptors and high brain centres to regulate HR.

Medulla Oblongata

51

An increased SyNS, will __________ HR

Increase

52

An increased PaNS, will __________ HR

Decrease

53

Which Hormones/Ions increase HR and contractility?

- Epinephrine/Norepinephrine
- Thyroid
- Calcium

54

Which Hormones/Ions is needed for normal APs, and elevate blood levels and decrease HR?

Sodium and Potassium

55

What 3 factors help maintain equal stroke volume?

Preload
Contractility
Afterload

56

Define the Frank-Starling Law.

Degree of stretch = Greater contraction

57

Define the Preload factor that helps maintain equal stroke volume.

Amount of stretch equals to volume of blood that fills the ventricles at the end of diastole (end diastolic volume)

58

Define the Contractility factor that helps maintain equal stroke volume.

Strength of contraction at given Preload

59

Define the Afterload factor that helps maintain equal stroke volume.

Pressure in ventricles must overcome pressure in vessels before semilunar valves can open