L26: The Heart Flashcards
1
Q
what do blood vessels consist of ?
A
- arteries
- capillaries
- veins
2
Q
role of arteries
A
carry blood AWAY from heart (mostly oxygenated blood)
3
Q
role of capillaries
A
- supply body cells with nutrients and oxygen
- take waste products away
4
Q
role of veins
A
RETURN blood to heart (mostly deoxygenated blood)
5
Q
what is the heart
A
muscular organ that pumps blood through blood vessels
6
Q
what is blood
A
- fluid connective tissue that is transported in the cardiovascular system
7
Q
what separates the left and right side of the heart?
A
a muscle wall called the septum
8
Q
what does the right heart deal with?
A
- oxygen poor blood
- is a low pressure system (pulmonary circulation)
9
Q
what does the left heart deal with?
A
- oxygen rich blood
- high pressure system (systemic circulation)
10
Q
where is the heart located?
A
- left of the body midline; posterior to the sternum in the mediastinum
11
Q
where is the right atrium and ventricle located?
A
more anteriorly
12
Q
where is the left atrium and ventricle located
A
more posteriorly
13
Q
what is the mediastinum?
A
- space between sternum (ventral), vertebral column (dorsal), lungs (right&left lateral), and diaphragm (caudal)
14
Q
what is the fibrous (tough) pericardium? what is it attached to?
A
- sac of fibrous connective tissue that envelopes the heart
- attached to great vessels and diaphragm
15
Q
what does the serous (delicate) pericardium consist of?
A
- parietal pericardium
- visceral pericardium
16
Q
where is the parietal pericardium located
A
- parietal layer lines inside of fibrous pericardium
17
Q
where is visceral pericardium located
A
- visceral layer directly covers outer surface of heart
18
Q
where is the pericardial cavity
A
- between 2 serous layers and contains fluid film
19
Q
which muscles are smaller, cardiac or skeletal?
A
cardiac muscle tissue
20
Q
what does cardiac muscle tissue contain?
A
- myofibrils
- sarcomeres (striated)
21
Q
where do cardiac muscle tissue interconnect
A
at intercalated discs
22
Q
how do cardiac muscles contract
A
- spontaneously
- without neural input
23
Q
what innervates cardiac muscle tissue
A
autonomic nervous system
24
Q
role of pulmonary circuit
A
- pumps blood from right heart through pulmonary vessels, to lungs, and back to left side of heart
25
role of systemic circuit
- pumps blood from left heart, through systemic vessels in peripheral tissues, and back to right heart
26
what separates atria
- interatrial septa
27
what separates ventricles
interventricular septa
28
what do you find within septa?
the fibrous skeleton of the heart (dense irregular connective tissue)
29
how does the fibrous skeleton anchor heart valves?
forming supportive rings
30
what ensures that muscle impulses are times properly?
electrical insulation between atria and ventricles
31
what provides a rigid framework for the attachment of cardiac muscle tissue
fibrous skeleton of the heart
32
what prevents valves from being pushed back to the atria?
papillary muscles and chordae tendineae
33
papillary muscles are relaxed and chordae tendineae slack when??
bicuspid and tricuspid valves are open
34
papillary muscles are contracted and chordae tendineae taut when?
bicuspid and tricuspid valves are closed
35
what kind of blood does the right atrium receive and from where?
- deoxygenated blood from systemic circulation via 3 blood vessels (coronary sinus, superior vena cava, inferior vena cava)
36
which valve does the right atrium convey blood into the right ventricle?
tricuspid valve (3 cusps)
37
which nodes does the right atrium contain?
SA and AV nodes
38
what kind of blood does the left atrium receive and from where?
- oxygenated blood from pulmonary circulation via four pulmonary veins
39
how is the left atrium separated from the left ventricle?
by bicuspid valve (2 cusps)
40
what are the relevant internal features of the left atrium?
- valve of foramen ovale
| - auricle contains musculi pectinati
41
role of the hearts 3 major sulci?
separate the four chambers, and major coronary blood vessels occupy these sulci
42
what occupies heart grooves (sulci)
- coronary blood vessels
| - filled with fat (adipose tissue)
43
what shape is the coronary (atrioventricular groove)?
crown shaped
44
what shape is the interventricular groove?
loop shaped
45
what do atrioventricular and interventricular grooves contain
adipose tissue and coronary blood vessels
46
what surrounds and cushions coronary vessels?
"fat depot" in epicardium
47
what is viewed as a cardiac risk marker
increased epicardial adipose tissue
48
where do coronary arteries originate
- base of aorta (superior to aortic valve)
49
difference between roles of coronary arteries/veins
coronary arteries: supply oxygen and nutrient to heart muscle
coronary veins: drain the blood
50
what is the coronary sinus, role?
- biggest cardiac vein
| - collects blood from all cardiac veins, drains blood into right atrium
51
where are the coronary sinus, great and small cardiac veins located?
in the coronary (atrioventricular) groove
52
middle cardiac vein located?
posterior interventricular groove
53
comparison of roles of great/small/middle cardiac veins?
great: drains left heart
small: drains right heart
middle: drains interventricular septum
54
role of sinoatrial node?
- initiation of heartbeat
| - pacemaker (controls pace for cardiac activity)
55
where does the SA node signal travel to
the AV node
56
role of AV node
- slows down activation/contraction of ventricles
57
from AV node, the signal travels along the?
AV bundle
58
from the AV bundle, the signal travels to?
the ventricles via the purkinje fibers
59
define systole?
contraction
| - a chamber ejects blood
60
define diastole
dilation/relaxation
| - chamber fills with blood
61
characteristics of relaxation period
- all 4 chambers in diastole
- low pressure in ventricles
- blood flows from atria to ventricles
- ventricles fill passively to 75%
62
characteristics of relaxation period
- all 4 chambers in diastole
- low pressure in ventricles
- Dupp: 2nd heart sound
- blood flows from atria to ventricles
- ventricles fill passively to 75%
63
what occurs during atrial systole
atria contract and push last 25% of blood volume into ventricles
64
what occurs during ventricular systole
- ventricular contraction forces AV valves shut
- Lubb: 1st heart sound
- pressure builds and forces semilunar valves open
- blood ejected
65
what percentage of australians aged 65+ is affected by irregular and rapid heart beat
5%
66
what causes atrial fibrillation
'extra' electrical impulses disrupting SA node activity
67
what does atrial fibrillation result in
chaotic atrial contractions at faster rates than ventricles
68
impact of sympathetic/parasympathetic innervation on the heart?
sympathetic: speeds up
parasympathetic: slows down heart activity
69
what is the first organ to fully develop in the embryo
heart
70
when and why does foramen ovale close
- closes at birth
- due to reversal of pressure difference between atria with dilation of pulmonary vasculature
- traces remain as fossa ovalis
