Anatomy of the Heart (complete) Flashcards Preview

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Flashcards in Anatomy of the Heart (complete) Deck (32):
1

What are the functions of the cardiovascular system?

1) Distributes dissolved gases & nutrients
2) Removes metabolic waste
3) Control temp, O2 supply, pH, ionic composition
4) quickly adapts to changes in conditions and metabolic demands

OVERALL: to maintain homeostasis (*really important*)

2

What are the three parts of the CV system?

1) Heart
2) Blood
3) Vasculature

3

Describe the heart as a dual pump

Left side:
higher pressure, serves the systemic circulation

Right:
lower pressure, serves pulm circulation

No direct connection between right and left sides

4

Why is the right and left heart relationship described as a series?

- Because they're not directly connected
- Output of left/right sides must be closely matched

5

Describe pulmonary circulation

- Low pressure
- Single pathway through a single set of capillary beds

6

Describe systemic circulation

- Higher pressure
- Multiple pathways from heart to systemic beds

7

Describe what it means when that systemic circulation is arranged in parallel

- Blood only goes to one part of the body and then goes straight back to the heart
- Changes in flow/demand in one organ does not directly affect others
- Blood flow to different organs regulated independently to match metabolic demand

8

What are the 4 chambers of the heart?

- L/R Atria
- L/R Ventricles

9

Describe the purpose of the ventricles

- Main pumpers!
- Left: supplies higher pressure systemic circulation --- BIGGER & THICKER than right
- Left also does more work --- uses more O2

10

Describe the purpose of the atria

- Small "primer" chambers
- Supply blood to ventricles
- Have thinner walls than ventricles

11

What are the 4 vessels of the heart?

1) Vena Cavae
2) Pulmonary a.
3) Pulmonary v.
4) Aorta

12

What are the 4 valves of the heart?

1) Tricuspid
2) Pulmonary
3) Mitral
4) Aortic

13

Where is the tricuspid valve located?

Between RA and RV

14

Where is the pulmonic valve located?

Between RV and Pulm a.

15

Where is the mitral valve located?

Between LA and LV

16

Where is the aortic valve located?

Between LV and aorta

17

Describe the heart valves

- One-way
- Pressure operated
- Passive

No contractile fibers in valve

18

Describe the blood flow pathway through the heart

S/IVC => RA (contraction, ^ pressure) => Tricuspid valve opens => RV (contraction) => pulmonic valve opens => pulmonary circulation (artery then vein) => LA (contraction) => mitral valve opens => LV (contraction) => aortic valve opens => aorta => blood circulation

19

What are the major types of blood vessels?

- Aorta
- Arteries
- Arterioles
- Capillaries
- Veins/venules
- Vena cavae

20

Describe the aorta

- Single outlet from left side of heart
- Dampens pulsatile pressure

Diameter: ~25mm

21

Describe arteries

- Thick walled, resist expansion
- Distributes blood to organs

Diameter: ~0.2 to 6.0mm

22

Describe arterioles

- Thicker walls than arteries (more smooth muscle)
- Highly innervated, sensitive to hormones, metabolites
- Primary site of regulation of vasculature resistance

Diameter: ~10 to 70 microm

23

Describe capillaries

- Smallest vessels
- Walls => single cell layer of endo cells

Diameter: <10 microm

24

Describe venules, veins

- Thin walls => similar diameter to arteries
- Holds most of blood volume
- Low pressure
- Has one-way valves to ensure blood flows in one direction

25

Describe the vena cavae

- Two branches: superior and inferior
- Large diameter (25-30 mm)
- Very low pressure

26

Describe the arrangement of microcirculation

- Arterioles to venules (AKA capillaries)
- Capillaries are site for gas, nutrient and waste exchange
- Blood flow determined by pressure gradients
- Blood flow regulated by arterioles and pre-cap sphincters

27

Describe the function of the lymphatic system

- Returns fluid from interstitial space to blood
- Depends on interstitial pressure
- Lymph vessels are low pressure, have one-way valves

28

What are the membranes/walls of the heart? From outside to in

- Epicardium
- Myocardium
- Endocardium

29

What encloses the entire heart?

The pericardium!

A fluid-filled membranous sac

30

Describe the atrioventricular valves

Tricuspid & mitral

- Between atria and ventricles
- Have chordae tendons
- Attach to papillary muscles in ventricles (stabilize/prevent prolapse of valves)

31

Describe the semilunar valves

Pulmonic & aortic

- Between ventricles and great arteries
- No chordae tendons

32

What are pre-capillary sphincters?

Smooth m. bands at junction of arteriole and capillary