Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

biol 364 > circulation pt1 > Flashcards

circulation pt1 Flashcards

(100 cards)

Start Studying
1
Q

what process do unicellular organisms and some small metazoans use to transport molecules?

A

they lack circulatory systems and rely on diffusion to transport molecules

diffusion can be rapid over small distances, but is very slow over large distances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how do large animals move fluid through their bodies?

A

bulk flow or convective transport

bulk flow: fluids move from high pressure area to low pressure area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

major function of circulatory systems

A

(depends on the organism)
transport oxygen, carbon dioxide, nutrients, waste products, immune cells, signaling molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

circulatory systems move fluids by…

A

increasing the pressure of the fluid in one part of the body, causing fluid to flow down pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

3 main components of a circulatory system

A

pump or propulsive structures (e.g. heart)
system of tubes, channels or spaces
fluid that circulates through the system (blood)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

3 types of pumps

A

CHAMBERED HEARTS with contractile chambers
SKELETAL MUSCLE (squeeze on vessels to generate pressure)
PULSATING BLOOD VESSELS (peristalsis- rhythmic contractions of vessel wall pumps blood)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what to one-way valves do?

A

help ensure unidirectional flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

4 types of fluid that are circulated

A

BLOOD (in closed circulatory system)
HEMOLYMPH (in open circulatory system)
INTERSTITIAL FLUID (extracellular fluid, directly bathes tissues)
LYMPH (fluid that circulates in the lymphatic system, secondary circulatory system of vertebrates)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does the lymphatic system do?

A

carries lymph that has filtered out of the vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

in open circulatory systems, fluid comes in direct contact with tissues in spaces called…

circulating fluid and interstitial fluid are…

A

sinuses
(all hemocoels are sinuses)

not separated (mixed)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

in closed circulatory systems, circulatory fluid remains within vessels and does NOT….

circulating fluid and interstitial fluid are…

A

come in direct w/ the tissues, molecules must diffuse across vessel wall

separated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

order of vessels blood goes through in one circulatory cycle, starting from when it leaves the heart

A

aorta
arteries
arterioles
capillaries
venules
veins
vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

sponges, cnidarians and flatworms lack a circulatory system but have mechanisms for…

A

propelling fluids around their bodies

(ciliated cells in sponges and flatworms)
(muscular contractions of the body wall pump in cnidarians)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

describe the circulatory system in polychaetes and oligochaetes (Annelids)

A

circulate interstitial fluid with cilia or muscular contractions of body wall

open in polychaetes
closed in oligochaetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe the circulatory system in molluscs

A

all have hearts and some blood vessels
most have open system

cephalopods have closed systems w/ 2 branchial hearts and 1 systemic heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

describe the circulatory system in crustaceans

A

all have one or more heart and some blood vessels
all have open systems
some control over distribution of blood flow in body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

describe the circulatory system in insects

A

open circulatory system
multiple contractile hearts along dorsal vessel

hemolymph enters from ostia and leave from arteries and aorta

tracheal system for gas transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

describe the circulatory system in urochordates (tunicates)

A

open circulatory system
tubular heart at base of digestive tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe the circulatory system for cephalochordates (lancelets)

A

closed system with a few open sinuses
tubular heart at base of digestive tract and pulsatile blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe the circulatory system in vertebrates

A

all have closed systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what was the circulatory system first evolved for

A

to transport nutrients to body cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

closed systems evolved independently in jawed vertebrates, cephalopods and annelids
what are some of the advantages

A

increased blood pressure and flow
increased control of blood distribution
can allow for high metabolic rates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how does the circulatory system fit into O2 delivery?

A

pump blood to where & when it is needed (both loading and unloading)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are 2 ways tissues can obtain more O2 with relation to the circulatory system?

A

heart pumps more blood per unit time

tissues extract more O2 from capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is the equation for O2 uptake?
O2 uptake = Q (CaO2 - CvO2) CaO2= content of O2 in arterial blood (carrying capacity) CvO2= content of O2 in venous blood
26
describe the circulatory plan/ blood flow of vertebrates
- muscular chambered heart contracts to increase the pressure of the blood and flow away from heart in arteries - blood flows from arteries to arterioles within tissues then to capillaries - capillaries merge to form venules which then merge into veins - veins carry blood to heart
27
what is the site of diffusion of molecules between blood and interstitial fluid?
capillaries
28
what are the three layers of blood vessel walls
TUNICA INTIMA (internal lining: smooth, epithelial cells) TUNICA MEDIA (middle layer: smooth muscle + elastic connective tissue) TUNICA EXTERNA (outermost layer: collagen)
29
why do arterial vessels have much more muscle/ layers/ are thicker
blood close to the heart is leaving with high pressure the muscles help reinforce the vessel walls and dampen pressure oscillations
30
characteristic of capillaries 3 types
- lack tunica media and tunica externa CONTINUOUS (cells held together by tight junctions, in skin + muscle) FENESTRATED (cells contain pores, specialized for exchange, in kidneys + endocrine organs + intestine) SINUSOIDAL (few tight junctions, most porous for large protein exchange, in liver + bone marrow)
31
describe the circulatory system in jawed vertebrates
all have a closed system structure depend on respiratory strategy water-breathing fish: SINGLE CIRCUIT, some have accessory hearts in tail air-breathing tetrapods: PULMONARY CIRCUIT (right side of heart) + SYSTEMIC CIRCUIT (left side of heart)
32
the 2 in-series capillary networks in closed single-circuit systems
respiratory capillaries and systemic capillaries
33
describe resistance to blood flow in gills and tissues in a single-circuit, closed circulatory system
additive (Ohm's law)
34
describe the fish heart
2 CONTRACTILE CHAMBERS: atrium + ventricle (contract in sequence + generate enough blood pressure to propel blood around entire body) 2 OTHER CARDIAC CHAMBERS: SINUS VENOSUS- elastic chamber, collects venous blood, SINOATRIAL region contains CARDIAC PACEMAKER BULBUS ARTERIOSUS- elastic chamber connected to aorta, dampens pressure oscillations
35
describe the double-circuit, closed circulatory system
right atrium + right ventricle pump deoxygenated blood to pulmonary circuit left atrium + left ventricle pump oxygenated blood to systemic circuit
36
what is the benefit of a double-circuit, closed circulatory system?
the 2 pumps can create different blood pressures, but their flow output must be the same
37
why do we want high pressure in systemic system
because there are lots of organs to circulate through and therefore high resistance
38
why do we want low pressure in pulmonary system
there is shorter distance to travel through lung is delicate, if pressure is too high, capillaries can be easily damaged or blood can enter the lung (in the lung, there is no tissue on the other side of capillary wall to prevent capillary from rupturing)
39
what is the equation for bulk flow? what is Poiseuille's equation?
Q= deltaP / R Q= deltaP * pi * r^4 / 8Ln L=length of tube n= viscosity of fluid
40
what is the advantage of arranging organs/ tissues in parallel
resistance in series: Rt= R1 + R2... resistance in parallel: (1/Rt)= (1/R1) + (1/R2) less resistance will be experienced in a parallel system
41
what is the formula for flow?
Q= V/t volume of fluid transferred per unit time
42
equation for blood velocity
v=Q/A Q= flow A= cross-sectional area of the channels if total cross-sectional area of capillaries is very large-> velocity slow -> long time for diffusion
43
why do you want low velocity in capillaries?
need to give RBCs enough time for efficient O2 unloading
44
which vessels have the highest/lowest total cross-sectional area? velocity?
highest A: capillaries lowest A: aorta and vena cava highest v: aorta and vena cava lowest v: capillaries
45
4 main parts of vertebrate hearts
PERICARDIUM: sac of connective tissue surrounding heart, space between parietal and visceral layers has lubricating fluid to prevent wear and tear EPICARDIUM: outer layer of heart continuous w/ visceral pericardium, contain nerves that regulate heart and coronary arteries MYOCARDIUM: layer of heart muscle cells (cardiomyocytes) ENDOCARDIUM: innermost layer of connective tissue covered by epithelial cells, in contact w/ blood
46
what is the function of coronary artery
provides oxygenated blood to the heart myocardium is oxidative; has high O2 demand
47
2 types of myocardium where are they mostly found?
COMPACT: tightly packed SPONGY: loosely connected mammals have mostly compact myocardium fish and amphibians have mostly spongy myocardium, but active fish (tuna) have more compact
48
what does spongy myocardium allow for?
much greater surface area for gas exchange. blood going through the blood are deoxygenated (single circuit) but spongy myocardium can obtain the leftover O2 spongy myocardium are arranged as TRABECULAE that extend into chambers
49
4 chambers of fish heart, in order of venous to arterial
sinus venosus atrium ventricle bulbus arteriosus
50
chambers in amphibian hearts which atria does oxygenated and deoxygenated blood go into?
2 atria, 1 ventricle, conus arteriosus pulmonary vein-> left atrium deoxygenated blood from body-> right atrium
51
what helps prevent mixing of oxygenated and deoxygenated blood in ventricle of amphibian heart?
trabeculae of spongy myocardia
52
what is the function of the spiral fold in conus arteriosus?
direct deoxygenated blood to pulmocutaneous circuit and oxygenated blood to systemic circuit
53
chambers in the reptile heart
2 atria, 3 interconnected ventricular compartments blood from left atrium goes to cavum arteriosum first
54
what are the ventricular compartments in the reptile heart? where do they lead to?
(connected to right atrium and cavum arteriosum) cavum venosum-> systemic aorta (left and right) cavum pulmonale-> pulmonary artery cavum arteriosum
55
describe the pathway of oxygenated blood from lungs through the reptile heart
oxygenated at lungs-> left atrium-> cavum arteriosum -> cavum venosum-> left or right aorta-> body
56
describe the pathway of deoxygenated blood from body through the reptile heart
deoxygenated blood at body-> right atrium-> cavum pulmonale-> pulmonary artery-> lungs
57
describe right-to-left shunt in reptile hearts
deoxygenated blood bypasses pulmonary circuit and re-enters systemic circuit
58
describe left-to-right shunt in reptile hearts
oxygenated blood reenters pulmonary circuit (sent back to lung) aids oxygen delivery to myocardium in right heart
59
how is shunting in crocodile hearts facilitated?
pulmonary artery closes cog valve and prevents blood flow
60
describe the crocodile heart
2 atria + 2 ventricle blood from lungs enter left atrium-> left ventricle-> right aorta-> foramen of Panizza connects right aorta to left aorta-> body-> right atrium + ventricle-> pulmonary artery or left aorta pulmonary artery is in right ventricle
61
what does the anastomosis between the left aorta and right aorta do?
allows left aorta and right aorta to equilibrate blood
62
in birds and mammals, what are the ventricles separated by
intraventricular septum
63
what are the valves in the birds and mammal hearts?
AV valves: between atria and ventricles semilunar valves: between ventricles and arteries (pulmonary or aortic)
64
2 phases of the cardiac cycle
systole (contraction) diastole (relaxation)
65
describe the cardiac cycle in mammals
2 atria contract simultaneously pause 2 ventricles contract simultaneously atria and ventricles relax while the heart fills w/ blood
66
how and when are ventricles filled in birds and mammals
ventricles fill passively during ventricular diastole (atrial contraction adds a little blood to ventricles) ventricular diastole-> negative pressure in ventricle-> pressure in atrium higher
67
how is the ventricle filled in fish and some amphibians
filled by contraction of atrium bc they have lower blood pressure, atrium filling is reduced, need pressure to push blood to ventricle
68
why does the left ventricle contract more forcefully and develop higher pressure to pump blood?
bc it pumps to body (systemic system) longer distance + more resistance
69
why does right ventricle contract less forcefully?
bc less pressure is needed to pump blood through the lungs
70
why is resistance in pulmonary circuit low?
bc of high capillary density in parallel-> large cross-sectional area (also bc of low pressure, to protect blood vessels of lung and prevent edema)
71
sequence of AV valve and semilunar valve open/close on left side of heart
AV valve close semilunar valve open semilunar valve close AV valve open
72
what controls cardiac contractions (3)
neurogenic pacemakers (invertebrates) myogenic pacemakers (rhythm generated in myocytes, vertebrates + some invertebrates) artificial pacemakers (rhythm generated by device)
73
in vertebrates, what produces rhythmic depolarizations? what is a feature they have to ensure coordinated contractions?
cardiomyocytes (do not require nerve signal) cardiomyocytes are electrically coupled via gap junctions to ensure coordinated contractions (action potential passes directly from cell to cell)
74
where is the pacemaker in fish, amphibians, reptiles, birds + mammals
fish: sinus venosus tetrapods: sino-atrial node (SA node)
75
characteristics of pacemaker cells
derived from cardiomyocytes small w/ few myofibrils + organelles do not contract have unstable resting membrane potential that depolarizes until it reaches threshold and initiates an action potential
76
steps in terms of membrane potential changes to trigger an action potential
CELL DEPOLARIZES (permeability of K+ down-> open Na+ channels-> mV up permeability of Ca2+ up-> mV up) threshold reached (-40 mV) opens voltage-gated channels initiates action potential CELL REPOLARIZES permeability of K+ up-> mV down permeability of Ca2+ down-> mV down channels open at diff. mVs
77
what are the major differences between action potentials and pacemaker potentials?
depolarization is mainly done by Ca2+ instead of Na+ in pacemaker potential action potentials have hyperpolarization K+ repolarizes in both cases
78
stimulation of what nervous system INCREASES rate of pacemaker potentials
sympathetic nervous system
79
stimulation of what nervous system DECREASES rate of pacemaker potentials
parasympathetic nervous system
80
how can norepinephrine and epinephrine alter heart rate
norepinephrine (noradrenaline) from sympathetic neurons epinephrine (adrenaline) from adrenal medulla (triggered by sympathetic neuron) increase heart rate by opening more Na+ and Ca2+ channels more depolarization-> more AP
81
how can acetylcholine alter heart rate?
acetylcholine from parasympathetic neurons more K+ channels open-> hyperpolarize pace maker cells-> more difficult to reach threshold-> less AP-> heart rate slowed
82
2 ways depolarization travels through the heart
specialized conducting pathways directly between cardiomyocytes
83
how do depolarizations travel by specialized conducting pathways
with modified cardiomyocytes lack contractile proteins spread action potential rapidly throughout myocardium can undergo rhythmic depolarizations
84
how do depolarizations travel directly between cardiomyocytes
cardiomyocytes are electrically connected via gap junctions electrical signals can pass directly from cell to cell
85
how does AP cause cardiomyocyte contraction
action potential from adjacent cell voltage gated Ca2+ channel open and Ca2+ enter cell Ca2+ triggers release of Ca2+ from sarcoplasmic reticulum (most Ca2+ come from the SR) Ca2+ binds to troponin to initiate contraction
86
how does relaxation of cardiomyocyte happen
when Ca2+ unbinds from troponin Ca2+ is pumped back into the sarcoplasmic reticulum for storage Ca2+ exchanged w/ Na+ and Ca2+ exits cell Na+ gradient maintained by Na/K ATPase
87
what is the conducting pathway in the mammalian heart for atria contraction
SA node depolarizes, depolarization spreads via internodal pathway AV node delays signal, depolarization spreads through atria via gap junction atria contract
88
why does the AV node need to delay the signal
so atria can contract before the ventricle does
89
what is the conducting pathway in the mammalian heart for ventricle contraction
depolarization spreads through bundles of His and Purkinje fibers depolarization spreads upwards through ventricle ventricle contract
90
how do action potentials in cardiomyocytes differ from those in skeletal muscle or pacemakers
there is a plateau phase in cardiomyocyte action potentials plateau phase: extended depolarization that lasts as long as the ventricular contraction
91
what is the plateau phase caused by? what is the function of the plateau phase?
caused by Ca2+ entry via L-type channel prevents tetanus (prevents muscle contraction from occurring again before it recovers)
92
what is the difference between skeletal muscle and cardiac muscle in terms of relation between action potential and conttraction
skeletal muscle: does not have time to recover/relax when action potentials are fired very rapidly cardiac muscle: plateau phase of action potential ensures that heart muscle relaxes before next contraction (plateau phase extends until peak of muscle contraction)
93
what is an electrocardiogram? describe the kinds of waves you would see
composite recording of action potentials in cardiac muscle shows net change, not directional P wave: atrial depolarization QRS complex: ventricular depolarization T wave: ventricular repolarization
94
how are electrical and mechanical events correlate in the heart
electrical events initiate contractile events
95
what mechanical event do each of the waves found on a ECG initiate
P wave initiates atrial contraction and atrial blood pressure peak QRS complex initiates ventricular contraction and ventricular blood pressure peak T wave initiates ventricular relaxation (it is a repolarization) energy in aorta is slowly released
96
what is end-systolic volume and end-diastolic volume how do we find the cardiac stroke volume
ESV: volume of blood in ventricle after contraction EDV: volume of blood in ventricle before contraction cardiac stroke volume = EDV - ESV
97
does a heart beat fully empty the human ventricle?
no but there is also no need to bc increasing BPM is more effective to get more cardiac output
98
why does blood aortic blood pressure decrease during diastole?
to have negative pressure to bring blood into the chamber
99
equation for cardiac output what does it tell us
cardiac output = HR * SV volume of blood pumped per unit time HR= rate of contraction (beats per minute) SV= volume of blood pumped with each beat (= EDV-ESV)
100
how can cardiac output be modified
by regulating heart rate and/or stroke volume heart rate: modulated by autonomic nerves and adrenal medulla stroke volume: modulated by various nervous, hormonal, and physical factors

biol 364 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions