EXAM 1: Intro & Cardiovascular System Flashcards
1
Q
Does passive transport require energy
A
No!
2
Q
Does active transport require energy
A
yes
3
Q
Diffusion is an example of ____ transport
A
passive
4
Q
Diffusion requires…
A
a concentration gradient
- results movement of articles from high to low concentration
5
Q
what is osmosis
A
the diffusion of water across a membrane
- dependent on amount of dissolved “stuff” in water
6
Q
water diffuses from where is concentration is 1._____ to where its concentration is 2.______
A
- HIGH (dilute solute)
- LOW (concentrated solute)
7
Q
Examples of molecules that can transport straight through a membrane
A
small molecules
lipophilic molecules
8
Q
example of molecules that utilize facilitated diffusion to transport across a membrane
A
- partially charged molecules
- moderately sized molecules
- sugars, vitamins, amino acids
9
Q
example of molecules that require a pump to diffuse across a membrane
A
ions, charged, and very large molecules (proteins)
10
Q
what are affarent neurons
A
neurons that carry info from skin/organs to the nervous system
11
Q
what are somative afferent neurons
A
somatic is external environment (skin) to the nervous system
12
Q
what are visceral afferent neurons
A
carries info from internal (organs) to nervous system)
13
Q
what are chemoreceptors vs. mechanoreceptors vs. proprioceptors
A
chemo: detect chemicals
mechano: physical deformaties
proprio: limb positions
14
Q
what are efferent neurons
A
neurons that carry information from the CNS to the target tissue (aka motor)
15
Q
what are somatic efferent neurons
A
brings information to the muscle
16
Q
what are visceral efferent neurons
A
brings information to internal organs
17
Q
what are interneurons
A
neurons that are involved in processing in the CNS
18
Q
what are neurotransmitters
A
chemical messengers, neurons communicating
19
Q
what are endocrine glands
A
secrete hormones into the blood stream
20
Q
what are hormones
A
chemical messengers, released systemically
21
Q
what are target cells
A
cells that have hormone receptors
22
Q
does active transport move against or down the concentration gradient
A
against (requires energy/ATP)
23
Q
does passive transport move against or down the concentration gradient
A
down the gradient ( no energy/ATP needed)
24
Q
what is the difference between positive and negative feedback loops
A
neg - response opposes stimulus (homeostasis)(more common)
pos - process that accels itself
25
what is th erole of dorsal root ganglion in a neural circuit
sensory neuron cell bodies
26
what is the role of an autonomic ganglion in a neural circuit
postganglionic autonomics
27
what are the types of tissues
epithelial, connective, muscle, and neural
28
what two tissue types make up membranes
epithelian and connective
29
what are the two types of muscle tissue
smooth - not organized into sacromeres
cardiac - heart,does have sacromeres
30
what are the functions of the cardiovascular system
transport, protection, regulation
31
what are some examples of the function of transport in the cardiovascular system
- nutrients, oxygen to cells throughout the body
- metabolic wastes to lungs and kidneys for removal
- hormones to target tissue (cells)
32
ways the the cardiovascular carries out the function of protection
- white blood cells, antibodies, proteins circulate via blood and defend body against foreign microbes/toxins
- clotting factors protect from blood loss after injuries
33
how does the cardivasular system regulate the body
- regulates… body temperature, fluid pH, water conent of cells, blood pressure
34
All cardiovascular functions are acheived by blood pumping through two circuits:
1. Pulmonary
2. Systemic
35
the heart is in a region of the thoracic cavity called the…
mediastinum
36
Where is the mediastinum located
between two pleural cavities that house the lungs
37
the inferior tip of the heart is called the…
apex
38
the superior border of the heart is called the…
base
39
the membranes of the heart create a double-walled sac called the..
pericardium
40
what is the fibrous pericardium
think outer layer, provides protection
- connected to parietal layer
41
what is the serous pericardium
thin inner double layer
- parietal layer (tightly connected to fibrous pericardium) AND continuous with the…
- visceral layer (on top of cardiac tissue)
42
the relationship between the heart and the pericardial cavity can be linked too…
a first pressed into the center of a partially inflated balloon
43
membranes of our body consist of
loose connective tissue plus epithelial tissue
44
what does mucous line
Lines the passages to the outside world
Hollow organs
45
What does serous line
The interior cavities of our body
-covers thoracic and abdominal organs
46
What are the three different major layers of tissue in the heart wall
Epicardium
Myocardium
Endocardium
47
What is the epicardium the same as
The same as the visceral layer of the pericardium
48
What is the myocardium
Middle muscular layer forming atria and ventricles
Composed of cardiac muscles
Also includes blood vessels and nerves
49
What is the endocardium
Covers all inner surfaces
Composed of simple squamous epithelial tissue and underlying areoler tissue
50
What are the atria
Thin-walled muscle
Auricles are extension of atria that hold extra blood
Pump blood to ventricles
51
What are the two ventricles
Thick-walled muscle
52
Where does the right ventricle pump blood two
Lungs
53
Where does the left ventricle pump blood to
The body
54
What vessels carry blood to the atria
Veins
- Superior vena cava
- inferior vena cava
- Pulmonary veins
55
What vessels carry blood away from the ventricles
Arteries
- aorta
- pulmonary trunk leading to left and right pulmonary arteries
56
Both the left and right pulmonary veins enter the…
Left atrium
57
Both the superior and inferior vena cava enter the…
Right atrium
58
Blood flow between chambers or arteries is regulated by…
Fibrous valves
59
What are the two types of valves
AV and semilunar
60
What valves are between the atria and ventricles
Right atrioventricular valve
Left atrioventricular valve
61
What valves are between ventricles and arteries
Pulmonary valve and aortic valve
62
What separates the ventricles
Inter-ventricular septum
63
Blood flow to the atria
- superior and inferior vena cava (from the body) —> right atrium
- pulmonary veins (from lungs) —> left atrium
64
From the atria, how does blood travel to the ventricles
- right atrium pumps blood through the right AV valve (tricuspid) to the right ventricle
- left atrium pumps blood through the left AV valve (bicuspid) to the left ventricle
65
Where does blood flow from the ventricles
- right ventricle —> pulmonary trunk (to lungs)
- left ventricle —> aorta (to body)
66
Right structures are oxygen-________
Poor
67
Left structures are oxygen-_______
Rich
68
The valves are a part of the _________ __________ of the heart
Fibrous skeleton
69
The fibrous skeleton consist of
Dense irregular connective tissue
70
What are the four main functions of the fibrous skeleton
- Control of blood flow through the heart
- Structural support for the heart
- Gives the muscle cells something to pull against
- Electrical insulation between chambers helps regulate the heartbeat
71
AV valves consist of
Cusps of dense irregular connective tissue
72
Valve cusps are attached to _____ ______ by ______ _____
Papillary muscles
Chordae tendineae
73
Semilunar valves consist of
Three cusps of dense irregular connective tissue with no muscular attachment
74
Backflow of blood from arteries fills cusps and results in
Semilunar valves closing
75
Coronary arteries deliver blood ____ heart tissue
TO
76
Coronary veins drain blood _____ heart tissue
FROM
77
What are the two types of cardiac cells
Working cardiomyocytes (muscle)
Conductive cardiomyocytes (pacemaker cells)
78
Factors of working cardiomyocytes
Striated, branched, can be excited by conductive cardiomyocytes and can excite each other, can contract
79
What are factors of conductive cardiomyocytes (pacemaker cells)
Function in spontaneously initiating and communicating action potentials
80
What are the three types of muscle tissue
Skeletal
Cardiac
Smooth
81
Which type of muscle tissue is in the heart
Cardiac
82
What are intercalated discs
A collection of proteins that connect cardiac cells at branch points
83
What are two structural components
1. Desosomes
2. Gap Junctions
84
What are desmosomes
- provide a physical connection
- allows muscle cells to pull on each other without damaging membrane
85
What are gap junctions
- provide cytoplasmic connection
- made of proteins that are non-specific, leak channels
- allows sodium to diffuse between cells during depolarization
- results in excitation of neighboring cells and propagation of action potentials
86
Conductive and working cells initiate and help regulate a _______
Heartbeat
87
How do the conductive and working cells initiate and regulate heartbeats
Causes an action potential to initiate in atria, down the ventricles base and then up the ventricle sides
88
What does the conduction system include
Sinoatrial node
Atrioventricular node
Atrioventricular bundle
Purkinje fibers
89
What are considered the main pacemaker and where are they located
the SA node, in the right atria
90
What does the depolarization of SA node cells result in
Excitation (then contraction) of surrounding muscle cells in the atria only
- excited 60-100 times per minute
- electrical signal can pass to neighboring cardiomyocytes of atria
- electrical signal cannot pass directly into ventricles due to fibrous skeleton
91
Do the SA node cells have a stable RMP
NO
This results in pacemaker potential
92
What channels allow cations to diffuse in the cell during pacemaker action potentials
Leak-like channels
- these channels result in depolarization to threshold WITHOUT neuronal excitation = auto-rhythmic
93
What happens after the conductive cells reach threshold
Ions travel via gap junctions and excite surrounding cardiomyocytes
94
A sustained contraction (and extended refractory period) is due to
slow-opening calcium channels
95
Step 1 of an action potential of a ventricular muscle (contractile cell): Rapid depolarization
Cause Na+ entry
Duration 3-5 msec
Ends with: Closure of voltage-regulated (fast) sodium channels
96
Step 2 of an action potential of a ventricular muscle (contractile cell): The Plateau
Causes Ca2+ entry
Duration: ~175 msec
Ends with: Closure of slow calcium channels
97
Step 3 of an action potential of a ventricular muscle: repolarization
Cause: K+ loss
Duration: 75 msec
Ends with: Closure of slow potassium channels
98
Does ventricular muscle have a stable resting membrane potential or a threshold?
Stable RMP
No threshold
99
The AV node is the _____ _____ into the ventricles
“Electrical Gateway”
(Only way to get from atria to ventricles)
100
What do atrioventricular (AV) node cells do
SLOW (to let the atria finish contracting) and conduct the action potential to additional conductive cells of the ventricles
- if the SA node fails, conductive cells in the atria and AV node can take over pacing (40-80 times per minute)
- conduct the action potential to the base of the ventricles
101
What is the function of the atrioventricular bundle
If all higher pacing systems fail, the bundle branches can pace at 40-60 times per minute
102
What do purkinje fiber cells do
Conduct the action potential to muscle cells of the ventricle walls
- if all higher pacing systems fail, purkinje cells can pace at 20-40 times per minute
103
The following events occur during contraction
- cells of the SA node trigger an action potential
- action potential passes through the two atria, causing contraction
- this is also called atrial systole (diastole is relaxed)
- action potential depolarizes the cells of the AV node
- this is also called ventricular systole
- action potential propagates down the AV bundle cells
- action potential propagates throughout the ventricles, causing contraction from bottom up (toward the major vessels)
- process begins again… and again… and again…
104
What do Electrocardiograms (ECG) measure
Small changes in voltage between the heart and the rest of the body
- NOT the same as an action potential, but a result of ion movement during ALL action potentials of a heartbeat
105
(IN ECGs) Electrical signal _____ contractions by _____
Precedes
Milliseconds
106
What are the three parts of the ECGs
P wave, QRS and T wave
107
What happens during the P wave
Atria muscle depolarize
- atria contract at PR segment
108
What happens during the QRS segment of the ECG
Ventricle depolarize
- ventricle contract at ST segment
109
What happens during the T wave of the ECG
Ventricles repolarize
110
What are the steps of ECG and Heart Contraction
1. Atria begin depolarizing
2. Atrial depolarization complete
3. Ventricular depolarization begins at apex and progresses superiorly as atria repolarize
4. Ventricular depolarization complete
5. Ventricular repolarization begins at apex and progresses superiorly
6. Ventricular repolarization complete; heart is ready for next cycle
111
For a fixed volume of fluid pressure depends on the..
Volume of the space it occupies
Large space = lower pressure
Small space = high pressure
- as the size of the space changes so does the pressure
- think of heart chambers as a space containing fluid
112
What will happen to blood flow if there is no pressure difference
It will stop flowing
113
Relaxation relates to diastole or systole
Diastole
- space of the chamber increases, volume of the fluid is the same
114
Contraction relates to diastole or systole
systole
- space of the chamber decreases, volume of the fluid is the same
115
What is phase 1 of the cardiac cycle
The Quiescent Period
116
What is phase 2 of the cardiac cycle
Atrial Systole
117
What is phase 3 of the cardiac cycle
Isovolumetric contraction
118
What is phase 4 of the cardiac cycle
Ventricular Ejection
119
What is phase 5 of the cardiac cycle
Isovolumetric relaxation
120
What happens during phase 1/the quiescent period of the cardiac cycle
- aka ventricular filling phase
- atria/ventricles are in diastole
- pressure in vessels is higher than pressure in chambers
- blood fills from veins, through atria and to ventricles
- ventricles contain about 90mL of blood at this point
- some blood was leftover in ventricules from previous contraction
- NOT maximum capacity of ventricle
- SA node cells are depolarizing (not to threshold, yet)
121
What happens during Phase 2 of the cardiac cycle (Atrial Systole)
- SA node depolarizes to threshold
- triggers action potential across the atria
- the atria contract (systole)
- pressure is greater in the atria compared to ventricles
- blood is forced into the ventricles
- ~40 mL more blood
- 90 mL + 40mL = 130 mL total
- END-DIASTOLIC VOLUME (EDV)
122
What happens during phase 3 of the cardiac cycle (Isovolumetric contraction)
- Atria enter diastole (lower pressure than veins)
- begin refilling with blood
- Ventricles depolarize and begin to contract (in early systole
- Pressure increases in the ventricle
- Blood forces the AV valves closed
- Makes first heart sound
- Blood DOES NOT leave the ventricles (?)
123
During what phase of the cardiac cycle does the first heart sound (S1) occur
Phase 3: Isovolumetric Contraction
124
What happens during phase 4 of the cardiac cycle (ventricular ejection)
- Ventricles fully contracted (in full systole)
- Pressure in ventricles is greater than pressure in arteries and atria
- forces pulmonary/aortic valves open while AV stay closed
- blood leaves through arteries
- only ~70 mL of blood leaves (stroke volume)
- ~60mL left behind
- END-SYSTOLIC VOLUME (ESV)
- Atria are still in diastole (lower pressure than veins)
- continue to fill with blood
125
What happens during phase 5 of the cardiac cycle (Isovolumetric relaxation)
- ventricles repolarize and relax (in diastole)
- pressure decreases in ventricle
- pressure in pulmonary artery and aorta is greater
- blood tries to flow back, but valves shut and prevent this
- Makes second heart sound (S2)
- Both sets of valves are still closed so volume of blood in ventricles does not change
- Isovolumetric relaxation
- As ventricles continue to relax, pressure drops. When ventricular pressure is lower than atrial pressure, AV valves open
126
During what phase does the second heart sound occur
Phase 5: Isovolumetric relaxation
127
What is cardiac output
The amount of blood pumped by the left ventricle in one minute
- Heart rate (bpm) X Stroke volume (mL/beat)
- can be altered by increasing or decreasing stroke volume
128
What are 3 main factors affecting stroke volume
Preload
- strength of cardiac tissue prior to contraction
Contractility
- strength of myocardiocyte contraction
After load
- pressure required to eject blood to arteries
