Chapter 25 Flashcards
what has the greatest effect on the flow of liquid through a tube?
Radius of the tube
In crustacean circulatory systems, deoxygenated blood from the tissues enters the heart via ?
ostia
In a mammal, blood pressure is lowest in the ___.
veins
The hearts of vertebrates are myogenic, meaning that
the impulse to contract originates within the muscle tissue.
The QRS complex arises from
ventricular depolarization.
Which vessels of the systemic vascular system have the highest total cross-sectional area?
Capillary beds
In _______, there is no separation of oxygenated and deoxygenated blood at the heart.
a teleost fish
Flow rate equals the difference in blood pressure between the entry of the vascular system and the exit vessels, divided by ____ _____.
vascular resistance
The chambers of the teleost fish heart are what?
the sinus venosus, atrium, ventricle, and bulbus arteriosus.
In the human heart, oxygenated blood is carried from the lungs to the heart by the ____.
pulmonary veins
Among nonavian reptiles, crocodilians are unique because they have a ?
complete ventricular septum.
Mean blood pressure in the brain of a standing person _______ the blood pressure at the heart.
lower than
Cardiac output is directly proportional to
heart rate x stroke volume
In which of the following vessels is there a lack of pressure pulse?
a. Large arteries, terminal arteries, and arterioles
b. Terminal arteries, arterioles, capillaries, and venules
c. Capillaries, venules, and veins
d. Venules and veins
e. Veins only
C
In a fish that has an air-breathing organ, the blood leaving the ABO mixes with what??
w/ systemic venous blood.
Which of the following statements comparing the circulatory systems in mammals and birds is true?
a. Birds have far smaller hearts per gram.
b. Mammals have, on average, higher systolic blood pressures.
c. Birds have a smaller cross-sectional area of capillaries per gram.
d. Mammals have a higher pressure systemic circuit.
e. Birds and mammals have essentially identical circulatory systems.
E
When a mammal exercises, oxygen delivery is increased by ???
- an increased blood flow.
- the extraction of more O2 per unit volume of blood that circulates.
- a lowering of resistance in the systemic vasculature.
Which of the following statements about squid is false?
a. Their systemic heart receives largely deoxygenated blood.
b. They have a systemic heart and two branchial hearts.
c. Their systemic heart is myogenic.
d. Blood enters the systemic heart from the gills.
e. Branchial hearts pump blood through the gills.
A
Which of the following statements about the insect circulatory system is true?
a. Insects have an open circulatory system and solely a diffusion-based system for delivering O2.
b. Insects have a closed circulatory system and a tracheal system for delivering O2.
c. Insects have an open circulatory system and a tracheal system for delivering O2.
d. Insects have an open circulatory system and a derived lung for delivering O2.
e. Insects have a closed circulatory system and solely a diffusion-based system for delivering O2.
C
Excessive protein in the blood plasma will _______ the loss of fluid through the capillaries.
decrease
what is a pressure driven mass flow of fluid that rapidly
transports oxygen, carbon dioxide, nutrients, wastes,
hormones, immune agents, heat and other commodities
throughout the body and that often provides a source
of hydraulic pressure for organ function.
circulatory system
A discrete, localized pumping structure, present in most animals with circulatory systems
Heart
Heart: Chambers surrounded by _____ (heart muscle) pump blood by alternating contraction (systole) and relaxation (diastole). Valves between chambers respond to _____.
myocardium, pressures
Blood flow through the heart is ____ ____ (mL/min) = heart rate (beats/min) x stroke volume (mL/beat)
cardiac output
Myocardium is supplied with O2 via _____ ____ if
myocardium is _____, or by luminal blood if it is ____.
coronary circulation, compact, spongy
\_\_\_\_\_ \_\_\_\_\_ may originate in pacemaker cells that are muscle cells (myogenic) or neurons (neurogenic), and moves through the heart in a controlled manner by \_\_\_\_
Myocardial depolarization, conduction
Control of heart rate and stroke volume can be ___, _____, _____ (Frank-Starling relation matching stretch to output)
nervous, hormonal,intrinsic
_____ is compact. Arteries carry blood ___from heart, veins carry blood ____ the heart.
compact, away, towards
blood in the pulmonary artery is _____
deoxygenated
Blood flow through the heart and the positions of
valves are determined by ?
relative pressures in the chambers
Blood generally flows from high to low pressure, but also has momentum if it is moving.
momentum
The A-V(atrioventricular node) valve opens when atrial pressure ____ ventricular pressure.
exceeds
The ____ valve opens when ventricular pressure
exceeds aortic pressure.
aortic
Isovolumetric contraction and relaxation are changes in
_____ ____ without changes in chamber volume,
and serve to build pressure in the ventricle.
myocardial tension
How does the heart muscle get its oxygen? who has both and what does octopus have ?
by coronary circulation (compact) or heart lumen (spongy myocardium)…. some fishes have both while octopus have coronary circulation.
Muscle cells of the heart must ____ and generate
_____ to contract and pump blood.
depolarize, AP
Depolarization originates from _____ cells that
can be either neurons or modified muscle cells, in
either ____ or ____ depolarization..
pacemaker, neurogenic, myogenic
Vertebrates have _____ depolarization, while
invertebrates often have _____ depolarization
(crustaceans and mollusks).
myogenic, neurogenic
Depolarization of the chambers must be coordinated
and controlled in order to ____ ____ effectively, and
occurs along specialized pathways, ___
systems, either neural or muscular.
pump blood, conducting
Among vertebrates (e.g. humans) the \_\_\_ system is specialized muscle cells.
conduction
The _____ is the pacemaker, with a fast endogenous rhythm that entrains the other muscle cells
SA node
The ___depolarize first, spreading excitation
to the A-V node
atria
the ____ has delayed excitation, allowing atria
to contract first.
A-V node
Depolarization spreads through the
myocardium by ?
electrical synpases.
Atria are already ____ when A-V depolarizes
repolarizing
Fiber bundles conduct ____ from ____ node to all
parts of ventricles rapidly.
depolarization, A-V
Crustaceans such as the lobster have _____
depolarization, in a cardiac ganglion of 9 cells.
neurogenic
One of neurons 6-9 acts as a ____ ___ and ____, and excites remaining neurons and muscle cells of the heart. Each muscle cell is ____.
cellular oscillator, CPG, innervated
Heart creates fluctuations in blood pressure, from ___
pressure (___ pressure) to ____ (____ pressure).
high,systolic, low,diastolic
Pressure gradients, kinetic energy, and gravitational potential energy all determine the ____ and ____ of blood flow
velocity and direction
Flow through a vessel is proportional to the difference in
pressure between the ends, and inversely proportional to the ____ _____
vascular resistance.
Vascular resistance _____ with increasing vessel length and with decreasing vessel radius to the ____ power. Flow is highly sensitive to changes in vessel radius.
increases, fourth
As blood moves through vessels, the ___ of blood
(resistance to flow) causes a loss of pressure as kinetic energy is converted to heat. Pumping blood is costly
viscosity
Gravity effects blood pressure by _____ effects.
fluid-column
Pressure of blood is ____ in proportion to the height of the blood in a column ____ it. This effect determines what?
increased, above,
how high a heart can pump blood.
Flow rate = (Pin - Pout)(π/8)(1/η)(r4/l)
Flow rate is much more sensitive to changes in
vessel ___ than vessel ___
radius, length
Circulation in Birds and Mammals:
Closed circulatory system, with vascular _____ cells lining all blood vessels.
endothelial
Circulation in Birds and Mammals:
Systemic and pulmonary circuits are connected in ___.
Systemic circuit is ___ pressure, pulmonary is __ pressure.
series, high, low
Circulation in Birds and Mammals:
____ dampen and reserve pressure generated by heart, and transport blood long distances from the heart. They are equipped with elastic walls with ___ muscle.
Arteries, smooth
Circulation in Birds and Mammals:
Arterioles are tiny arteries that ____ blood flow, by ___ control, to microcirculatory beds with densely
distributed capillaries, where most gas exchange occurs.
control,vasomotor
Circulation in Birds and Mammals:
Velocity and pressure drop in beds, due to what? Velocity picks up again in ___.
large total cross sectional area, veins
Circulation in Birds and Mammals:
Fluid is lost from systemic capillaries by _____, but
lower pressures prevent this in the pulmonary system
ultrafiltration
In birds and mammals, the heart is completely divided and the systemic and pulmonary circulations are in ___ with one another.
series,
Blood is delivered to cells in ?
microcirculatory beds
The beds consist of ____, ___ and ___
Flow is controlled in ___. Gas exchange occurs mainly in ___
artierioles, capillaries, and venules.
arterioles, capillaries
Microcirculatory beds have a huge collective _____
area, so blood velocity drops, _____ gas exchange at
the cells.
cross sectional, increasing
Pressure fluctuations (i.e. pulse) are damped in the _____
aterioles
Blood pressure drops in _____ and continues to
fall until blood reaches the ____.
terminal arteries, vein
Skeletal muscles and valves in veins help return
blood to ___
heart
One important consequence of a high pressure
circulatory system is ____
ultrafiltration
Fluid is forced out the ____ into the _____.This would be disastrous in the ____.
capillaries, tissues, lungs
Bird and mammal hearts have compact myocardia with coronary vessels providing ___.
oxygen
The heart has four chambers, with separated left and right
sides that pump blood through two systems in series: the high-pressure _____ system and the low pressure _____ system
systemic, pulmonary
Circulation in Fish
The heart has ___chambers in series.
four
Circulation in Fish
The heart pumps blood through the ___ and then the systemic circulation in series in most fish, thus blood passes through ___ capillary beds before returning to the heart.
gills, two
Circulation in Fish
T/F:When present, air breathing organs in fish are typically situated in parallel with the systemic circuit (unlike birds and mammals), and supplies the heart muscle with oxygenated blood (spongy myocardium).
t
Circulation in Fish
___ are an adaptation for myocardial oxygenation (new
view - Farmer) rather than aquatic hypoxia (traditional view).
Lungs
Circulation in Fish
____ can keep oxygenated and deoxygenated blood mostly separated and control how much blood goes to lungs, coordinating pulmonary blood flow with breathing bouts.
Lungfish
The heart receives _____ blood
deoxygenated
Air breathing organs (i.e. lungs) provide oxygen to ?
myocardium
Fish heart must pump blood through two
____, ____ and ___
capillary beds, branchial, system
Respiratory and systemic beds are in ____,
as in birds and mammals.
series
Cephalopod molluscs and some annelids have ____
circulatory systems
closed
Cephalapods have the same in series circulation of ____ and _____ structures as birds and mammals, and a heart for each (anatomically distinct hearts in cephalopods).
respiratory, systemic
In open circulatory systems, such as those of crustaceans,
blood travels through ____, _____ and ____ which are spaces between cells that lack epithelial lining.
lacunae, lacunar networks, sinuses
Blood vessels and capillaries are present in some parts of the body in some species with ___ circulatory systems
open
In open systems, blood flow rate can be high, due to ______ compared to closed systems.
low resistance
In some crustaceans with open circulation, ___ delivery is
comparable to that of fish of the same size.
o2
___ circulation is similar to birds and mammals.
Cephalopod
The left and right hearts or birds and mammals are analogous to ____ and _____ hearts
systemic, branchial
In open systems, blood empties into ____ or ____ between cells.
lacunae, sinuses
Insects meet their gas exchange demands with the air-filled _____ system, and hence have modest circulatory systems.
tracheal
In many species, the ___ aorta is the only blood vessel, and it empties into the lacunae.
dorsal
myogenic and neurgenic, spongy and
compact.
heart
Circulation in vertebrates
• Mammals and birds
• Fishes
• Amphibians and Reptiles
in series, left and right sides
evolution of lungs, spongy myocardium
parallel circulation
Circulation in invertebrates
• Closed circulatory systems
• Open circulatory systems
cephalopod molluscs
crustaceans and others
Arteries carry blood __________ the heart, while veins carry blood __________ the heart.
away, towards
T/F: A cephalopod, such as a squid, has an open circulatory system, like all invertebrates. if not why?
F, Cephalopods and some annelids have closed circulatory systems. Not all invertebrates have open systems.
In humans oxygenated blood from the lungs flows directly where?
To the heart and enters the left Atrium
The volume of blood pumped per unit of time is known as the
cardiac output
In the ECG the QRS complex is produced by the
depolarization of the myocardium of the two ventricles
The highest peak in the Electrocardiogram is produced during which phase?
R
When blood flows through the blood vessel it can best be described as behaving how?
The blood flows in concentric layers known as laminae and is the greatest near the center of the vessels
In fish which chamber of the heart is the source of the main blood propulsive force?
ventricle
A fish living in an environment where ions are easily obtained from the water (hard water) will have a __________ density of chloride cells than a fish living in water where ions are more difficult to obtain (soft water).
lower
Fish will develop a greater density of chloride cells when ions are more difficult to obtain from their environment.
Hyperosmotic urine has a U/P ratio __________, while hyposmotic urine has a U/P ratio __________. Isosmotic urine has a U/P ratio __________.
greater than 1… less than 1… equal to 1
T/F: Inorganic ions are mostly used to regulate cell volume, instead of organic molecules.
F; Organic molecules regulate cell volume
An organism which regulates its blood plasma while hyperosmotic to its environment as well as regulating when hyposmotic is called a
hyper-hyposmotic regulator
T/F: Both mammals and amphibians can reclaim water that is stored in the bladder.
F; Amphibians can reclaim water from the bladder, but mammals can not. In mammals, once the solution has left the kidneys and traveled to the bladder, it is lost to the system.
Evaporative water loss (EWL) is __________ for smaller land dwelling animals than larger ones. One way animals can reduce EWL is __________.
more of a concern…cooling exhaled air
An organism which regulates its blood plasma while hyperosmotic to its environment, but conforms when hyposmotic is called a.
hyper-isosmotic regulator
Most fish are __________ to a marine environment, while most invertebrates are __________ to a marine environment.
hyposmotic…isosmotic
________________ refers to survival while dried as fully as possible by desiccation of air or “remaining alive without water”.
anhydrobiosis
The heart of vertebrate regulates blood flow rate by changing ____(ml/beats) and ____(beats/min).
stroke volume and pumping rate
The valves of the heart are controlled by?
pressure differences
Arteries carry the ____ blood and veins carry ____
deoxygenated, oxygenated
How does the heart muscle of mammals obtain oxygen?
coronary circulation( not true for all vertebrates)
Heart pacemakers cells are often myocytes among vertes and neurons among invertebrate
myocytes, neruons
Membrane depolarization spreads throughout the vertebrate heart via ?
gap junction(electrical synapses)
Advantage of open circulatory system?
faster flow rate
Which invertebrates have closed circulatory systems?
cephalopod and mollusc
The systemic heart of cephalopods is functionally analogous to the ______ of birds and mammals.
left heart
