#3 Lecture Flashcards
1
Q
What is diffusion necessary of
A
To get nutrients in and waste out of cells
2
Q
What do you need to get diffusion to work
A
Need surface area on cell membrane to allow exchange gases and nutrients to occur via diffusion
3
Q
A
4
Q
Is diffusion a slow process?
A
yes, it puts limits on body form, where organisms must have
1) small body
2) thin anatomy
3) use circulatory system
5
Q
What cavities in thin anatomy help facilitate diffusion
A
Gastrovascukar
- does both digestion and circulation
6
Q
Circulatory system
A
Employ bulk flow of specialized circulatory fluid to distribute needed materials through the body quickly and efficiently
7
Q
What does circulatory systems connect
A
Connect exchange surfaces where diffusion exchanges occur and materials transferred
8
Q
Gas exchange of cardiovascular systems
A
- deliver oxygen for cellular respiration
- remove carbon dioxide for cellular respiration
9
Q
Energy balance of cardiovascular systems
A
- deliver nutrients from digestion and absorption
- remove waste products to excretory organs
10
Q
Osmotegulation/ communication of cardiovascular system
A
Carry water, ions, and hormones throughout body
11
Q
Is diffusion the fundamental process for how essential molecules enter and exit cells
A
Yes
12
Q
High pressure/low pressure of diffusion
A
High pressure (high O2)
- red blood cells constantly bring more O2 from lungs
Low pressure(low O2)
- cells always depleting O2 via cellular respiration
13
Q
Circulatory fluid
A
Blood in human system
- carries gases/nutrients/molecukes
14
Q
Tubes of cardiovascular
A
Blood vessels in closed circuit
Arteries >capillaries >. Veins
15
Q
Muscular pump of cardiovascular
A
The heart
Provides force to move blood
16
Q
Does blood flow in one direction
A
Yes
17
Q
Arteries
A
Carry blood from the heart, by branching into arterioles and capillaries
18
Q
Capillaries
A
Infiltrate tissues and organs thus allowing diffusion of molecules into cells
19
Q
Veins
A
Capillaries merge into venules/veins to carry blood towards the heart
20
Q
Double circulatory system
A
Blood goes to lungs, back to heart and is pumped again to tissues in body
-pulmonary and systemic circuit
21
Q
Pulmonary circuit of double circulatory systems
A
Circuit of blood vessels that goes from heart to lungs to heart
22
Q
Systemic circuit of double circulatory systems
A
Circuit of blood vessels that goes from heart to organs/tissues to heart
23
Q
Oxygen levels in pulmonary circuit of arteries and veins
A
Arteries- low oxygen
Veins= high oxygen
24
Q
What causes blood to travel in one direction
A
Heart valves
25
What does the right heart deal with
Pushing blood to pulmonary circuit
26
What does the left heart deal with
Pushing blood to systemic circuit
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Coronary circuit
Supplies oxygen to heart muscle tissue
- left coronary artery leaves aorta then right coronary artery leaves aorta
- branch into additional arteries then capillaries
- merge into veins
- veins converge on coronary sinus
- coronary sinus enters right atrium
28
Where is heart located
Between lungs, posterior to sternum, anterior to vertebral column, superior above diaphragm
- within mediastinum membrane that encodes medial cavity of thorax
- 2nd-5th rib pointing left
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Where do great vessels enter
Top area
30
What is heart made of
Cardiac muscle
- fatigue-resistant
-tetanus-resistant
-auto-excitatory
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Atria
Chamber where blood enters heart
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Ventricle
Chambers that contract to pumps blood out of heart
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Two superior atria where blood enters into heart via veins
Right atria: low O2 blood returns from systemic circuit
Left atria: high O2 blood returns from pulmonary circuit
34
Two inferior ventricles where blood exits heart out arteries
Right ventricle: low O2 boood sent to pulmonary circuit
Left ventricle: high O2 blood sent to systemic circuit
35
Does left ventricle have thicker myocardium
Yes, because it has to push blood through the larger systemic circuit
36
Does atria or ventricle contract first
Atria then ventricles
37
Cardiac cycle
Rhythmic heart contraction and relaxation
38
Contraction
Pumping phases called systole
39
Relaxation
Filling phases called diastole
40
Atrioventricular valves
Regulate blood flow between atriums and ventricles
- tricuspid: right atrium to right ventricle
- Mitral: left atrium to left ventricle
41
Semilunar valves
Control blood flow to great vessels
- aortic valve: left ventricle to aorta
- pulmonary valve: right ventricle to pulmonary artery
42
Three flaps of tricuspid and 2 flaps of mitral(bicuspid) valve
Endocardium and connective tissue
43
What are atrioventricular anchored by
By tendons in ventricles
44
What does chordate tendineae do in atrioventricular valves
Attach in ventricles and papillary muscle
- when papillary muscle contracts w ventricles , chordate tendineae tighten resisting back flow, prevent eversion
45
Pulmonary valves
Control blood flow to pulmonary trunk and pulmonary circuit
46
Aortic valve
Control blood flow to aorta and systemic circuit
47
How do semilunar valves open
Pressure of ventricle contraction opens them
- shape pushes them closed during backflow
48
Are there valves for veins entering into atria
No valves protecting both vena cava and pulmonary veins
- there is atrial contraction that constricts opening to these vessels
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Unidirectional blood circulation
Depends on proper coordination of valves
50
Systole
When ventricles are contracting
51
Diastole
When ventricles are relaxing
52
How is contraction controlled
Cardiac conduction, pacemaker cells rhythmically self depolarize
53
Pacemaker cells (cardiac conduction)
Special cardiac cells that are non contractile and self excited (undergo automatic depolarization)
- unstable resting potential
- voltage slips to threshold
- AP passed via gap junctions
- pacemaker reset and repeat
54
Sinoatrial (SA) node (cardiac conduction)
First pacemaker region that begins the action potential relay through neighboring gap junctions
55
Atrioventricular node (cardiac conduction)
Second region of pacemaker cells: smaller size and fewer gap junctions causes a pause between atria and ventricles contraction
56
What do pacemakers send through fiber network
Rhythmic AP
57
58
59
Do cardiac conduction cells contract?
No , instead have connected fiber form, lack striating
Myocardial cells
60
What do intrinsic cardiac conduction network in the heart trigger?
Trigger action potential in contractile myocardium
- fibers move quickly/sequentially
- depolarization sent through gap junctions and spread to contractile cells
- depolarization begins at special nodes
61
62
2 types of myocardium cells (cardiac conduction)
Contractile - depolarize in response to neighbor AP
Non contractile- some auto depolarize rhythmically
63
Is contractile or non contractile cells stable?
Contractile have stable resting potential
64
Unstable members potential = (pacemakers cells)
Auto rhythmic AP
65
1) pacemaker potential stage
- begin at hyperpolarization of -60mV
- I channels are open, allowing NA/K to cross membrane
- Na is slowly allowed to enter cell that Kevan leave
- + charge inside cell slowly increases
- + charge reaches -40mV threshold
66
2) depolarization
- Imchannels are closed, at the voltage
- voltage gates Ca2+ channels open, allowing Ca2+ to enter
- depolarization of membrane triggers AP
- rise between +5 to +20 mV
- at this voltage Ca2+ begin to close
67
3) repolarization
- Ca2+ channels close at these positive membrane voltages
- voltage gated K channels open, allowing K+ to leave cell
- bring membrane potential back into negative ranges
- repolarizes cell to -60mV
- cause K channels to close and I channels to open
68
Does the auto rhythmic generation of AP repeat?(pacemaker cells)
Yes
69
Heart rate can be modulated by
Changing permeability to,ions
70
Do pacemaker cells set heart rate?
Yes with SA node dominating due to its speed
71
How can heart rate be increased
Increased or decreased via ANS
72
what does parasympathetic do to heart rate
Decrease heart rate
Increase permeability to K+
73
What does sympathetic do to heart rate
Increase heart rate
Increase permeability to Na+ and Ca2+
74
Contractile cardiac cells AP steps
1. Resting potential
2. Rapid depolarization
3. Plateau phase
4. Repolarization
75
1) resting potential (contractile cardiac cells AP)
- stable resting potential I’m contractile cells
- resting potential of cell is very low at -90mv
- voltage change comes from neighboring cells
Non contractile: Ca2+
Contractile cells: Na+/Ca2+
76
2) rapid depolarization (contractile cardiac cells AP)
- threshold is quickly reached by influx of Ca2+ or Na+ from gap junctions of neighbors
- fast gates Na channels open massively / quickly
- positive feedback loop thus causes rapid depolarization
- fast gated Na channels also close quickly
77
3) plateau phase ( contractile cardiac cells)
- slow Ca2+ channels have delayed opening
- slow Ca2+ channels do not begin to open until +30mV
- more positive charge (Ca2+) enters cell
- meanwhile fast K channels open to offset Ca2+ influx
- Ca2+ in/some K+ out balance prolongs AP
78
4) repolarization (contractile cardiac cells AP)
- slow Ca2 channels close stops influx of positive Ca2
- slow K channels open to release much more K+
- rapid loss of K+ from inside cell resets resting potential
- at -90mV, slow K+ channels now close resettingg cycle
79
What does unique lateral prevent
Prevent tetanus in cardiac muscle
80
Action potential and contraction period are much longer in…
Cardiac muscle
- skeletal: AP= 2ms, contraction= 15-100
-cardiac: AP= 200ms, contraction 200
81
Plateau ensures that …(contractile cardiac cells AP)
1) long contraction to empty chambers
2) long absolute refractory period
82
What does long refractory period prevent
The heart from cramping due to repeated stimulus
83
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85
Lymphatic system
Other circulatory network
- recovering fluid leaked from capillaries
- transporting leukocytes
86
As blood vessels branch, they will…
Decrease in diameter/sizewhich..
- increase surface area
- increase resistance
87
What do we have in the smallest size capillaries
We have proportionally most surface area and most resistance
88
89
Sites of maximum surface area, capillaries have the ….
Most resistance, which is where blood is slowest
90
Regions closer to heart are under ….
Higher pressure which decreases the further you get from the heart
- receive less “push” from pump
- so veins need valves to return blood
91
Width and composition of the tunics depends on
Size and role of blood vessel
92
Anastomoses
Connections between blood vessel
- merging/ branching networks of vessels (outside of capillary beds) that can provide alternative paths of blood flow
93
Anastomoses can be connections between…
-arteries to arteries
- veins to veins
- arteries to veins
94
Anastomoses serve as ..
Redundant backup routes for blood flow to important regions
- example: circle of Willis , regions of coronary circuit
95
Coronary circuit> heart blood vessels also have
Vascular anastomoses
96
Pathway hepatic portal system
After passing intestines, blood stops at liver
-pathogens and toxins are absorbed with nutrients
- so blood needs to go through detoxication and purification
-
97
98
How many capillary beds in hepatic portal system
2 capillary beds which filters blood before going back towards the heart
99
Where do capillary beds reemerge in the hepatic portal system
Remerge into hepatic veins that go to the inferior vena cava
100
Process of fetal circulatory system
- high O2 blood enters from placenta, through umbilical vein
- umbilical vein bypass liver and kidney, goes directly into inferior vena cava through ductus venosus
- there it mixes with “very low O2” to make “moderate O2” in inferior vena cava
- moderate O2 from inferior vena cava mix w very low O2 from superior vena cava to make low O2 in right atria
101
Where can blood bypass in Fetal circulatory system
Bypass the pulmonary circuit by passing directly between right and left atria through foramen ovale
102
What can happen to blood that enters the pulmonary artery? (Fetal circulatory system)
Blood that does enter the pulmonary artery can also be shunted into aorta via the ductus arteriosus
103
All blood circulating in the fetal cardiovascular system is …(fetal circulatory system)
Lower O2 levels with some being sent back to mom via the umbilical arteries in order to be oxygenated
104
After birth what happens to fetal circulatory system
Process immediately begin to close holes and shunts
105
Names of holes that close in fetal circulatory system
-umbilical vein> round ligament of liver
- ductus venosus> ligamentum venosum
- foramen ovale> fossa ovalis
- ductus arteriosus > ligamentum arteriosum
- umbilical arteries > destroyed or ligaments
106
