Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Mammalian Physiology > Slide 5b > Flashcards

Slide 5b Flashcards

1
Q

What is the heart responsible for?

A

Pumps deoxygenated blood to lungs and oxygenated blood to the rest of the body

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

What is a pericardium?

A

fluid filled sac for protection and lubricant for the heart to beat freely within.

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

What systems are related to the cardiovascular system?

A

digestive system (liver), urinary system (kidneys), pulmonary system (lungs), immune system (antibodies, clotting factors, immune cells flowing in blood for cells to use anytime), endocrine system (transport hormones to target sites)..

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

What happens when you get hot? besides sweating

A

vasodilation of blood vessels (enlarge = heat)

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

Which ventricle is larger?

A

left ventricle

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

What are atria?

A

upper two chambers of the heart

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

Describe the flow of de/oxygenated blood.

A

Deoxygenated blood flows from the right side of the heart to the pulmonary circulation and returned to the left atrium and then pumped out by the left ventricle.

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

What is the cardiac muscle called?

A

myocardium

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

Direction of flow of blood vessels?

A

arteries = away, veins= toward

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

Septum

A

tissue that separates low (on right) and high (on left side of heart) oxygen blood

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

How does blood return to the heart? What are the oxygen levels?

A

Via the inferior (below) and superior (coming from tissues above the heart) vena cava, the vena cava has the lowest amount of pressure in the body because it is farthest from the highest point of pressure which is the left atrium (when leaving the heart). Oxygen is removed and must be pumped out to the lungs via the right ventricle.

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

What is the right AV tricuspids valve for?

A

It separates right atrium from right ventricle and prevents blood from entering the right ventricle until the heart is contracted so there is no general leaking of blood. (blood only comes in one flow)

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

What happens during contraction of the right ventricle?

A

The contraction causes blood to push against semilunar valve which opens circulation to the lungs. Blood picks up oxygen and leaves carbon dioxide.

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

Where does oxygenated go from the lungs?

A

Comes through the left pulmonary veins and moves down though the atrium into the left ventricles. The pressure of contraction opens the valves to allow blood to move through the chambers.

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

What happens when the left ventricle contracts?

A

It forces the blood out the aorta where it then travels to the systemic circulation to oxygenate all the tissues in the body.

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

Describe the direction and movement of the blood flow in the heart.
http://s.hswstatic.com/gif/heart3b.jpg

A
  • one way flow of blood through the heart
  • controlled by sets of chambers and valves
  • describe de/oxygenated blood in the picture.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the resistance level for pulmonary and systemic circulation.

A

low resistance because it does not need to flow out to many tissues (just capillary bed and lungs). On the contrary, systemic circulation is high resistance and high pressure (going to all tissues and organs in body).

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

What are the main systemic veins that return blood to the body?

A

Inferior and superior vena cava are the main ones. While all veins are systemic veins as well.

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

Name the three portal vein systems.

A
  1. Hepatic portal vein: connects liver to digestive tract
  2. In kidneys
  3. connects the hypothalamus to the anterior pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the purpose of the portal systems? Please use examples.

A

They allow nutrients/substances to be transmitted without being lost to the external circulations. For example, liver and digestive tract allows liver to be a “detoxification” and doing it without them being released in the circulations. Kidneys allows direct exchange between nephrons (filtration units) and circulatory system = recapturing sodium or excretion of that.

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

Explain a low pressure, low resistance system and vice versa.

A

Blood from right side of heart to the lungs is a low pressure and low resistance system because it is only going through 1 capillary bed before reaching lungs. The blood flow from the left side of heart to the systemic circulation is high pressure and high resistance because must leave the heart with an enormous force to overcome the resistance. It is high pressure to push the blood through several capillary systems, becomes more and more narrow.

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

What is the relationship between resistance and diameter of blood vessels?

A

More narrow the blood vessel, the higher the resistance. (like a straw)

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

How to reduce the pressure of blood vessels?

A

Increase the diameter of blood vessels (decreases resistance) so that reduce the contraction of smooth muscle cells that line the blood vessel.

24
Q

What is the change in pressure as blood moves through different blood vessels in the body?

A

Aorta > arteries > arterioles> capillaries (starts to lose it here) > venules > veins > venae cavae

25
Q

How does the body deal with a sudden increase in blood pressure?

A

Tries to keep blood pressure constant for homeostasis. Regulate the flow of blood to appropriate organs (selective) for example: run, will not go to kidneys but increase the pressure for more blood flow to the muscles. It is done automatically.

26
Q

Affects on blood pressure?

A
  1. peripheral resistance dictated by the diameter
  2. blood viscosity
    For example, increase in blood viscosity, increases the pressure. If you’re dehydrated, you can increase the thickness which change the flows around the body and makes you vulnerable to blood clotting causing risk for stroke.
    Blood doping increases thickness. It used to be common among athletes because it increases oxygen carrying capacity for better performance. However, it increase chances for stroke.
    High plasma protein concentration is a risk for high blood pressure.
    Anemia (not having enough RBC: iron, bone marrow not making enough), bleeding out
27
Q

What are ways to control arterial blood pressure?

A
  1. Local control
  2. Total peripheral control : generally raises systemic arteriole pressure
    For example, an athlete drinks caffeine, eats a salty meal and is dehydrating, sweating, how does the body compensate on the level of blood vessels? The heart compensates for the drop in pressure by increase heart rate (beating more), body recognizes that it must increase the flow of blood so sends message to heart to beat more via nervous system. Although the person is hot, the body sends message to blood vessels to vasoconstrict to increase pressure throughout the system.
28
Q

What are the differences of right ventricular wall vs. left ventricular wall?

A

Right:
Left: does more work to pump so it is more muscular and further develop than right side.

29
Q

How is unidirectional blood flow achieved?

A

Via valves!
2 AV valves (left and right separating atria from ventricles): have chordae tendonae at the edges of the valve to prevet the evertion of valves (opposite flow) and are attached to capilli, they are little bits of muscles that open and contract for the opening of the valves.
Aortic and pulmonary valves: major arteries leave ventricles

30
Q

Name tricuspid and bicuspid valves.

A

Pulmonary valve, aortic and right AV valve: tricuspid

Left AV valve: biscupid

31
Q

Where semilunar valves?

A

Between ventricles and arteries. They are tricuspid valves. They have pressure exerted on them to open (when pressure of right ventricle is greater than the pressure in the aorta or pulmonary artery) and close when the pressure in the ventricle falls below the aortic (shows the blood has moved) and pulmonary pressure to prevent backflow.

32
Q

Describe the blood flow and valve action.

A

Blood returns to the heart and puts pressure on the AV valve (right), at the same time, there is atrial contraction so there’s more pressure on AV valves forcing blood into the ventricles and forces the valves to open. Once the ventricles are full, the blood exerts pressure onto the valves closing the valves. At this point, the ventricles contract and pushes the blood out to the pulmonary circulation. The contraction of the ventricules puts pressure on the semilunar valves and as the ventricle relaxes, reduces pressure in the ventricle and forces closure of the semilunar valves.

33
Q

What are the three layers of the heart wall and its location?

A
  1. Endocardium: inner lare of the epithelium
  2. Myocardium: middle later of cardiac muscle tissue
  3. epicardium: external membrane (made of connective tissue)
34
Q

What drives the action potentials in the heart?

A

There are two types of cells in the heart:
1- auto rhythmic cells (generate the action potential and causes contractile cells to contract)
2- contractile cells
The heart creates its own action potentials via auto rhythmic cells who specialize in initiating the action potential.

35
Q

What are the four major structures of the heart conduction system?

A
  1. Sinoatrial node (pacemaker)
  2. atrioventricular node
  3. AV bundle (bundle of His)
  4. purkinje system
36
Q

What happens during an irregular heart rate (in terms of the heart conduction system)

A

When the action potential is driven by something other than the SA node.

37
Q

What is a solution to arhythmia?

A

They sometimes restart the heart.

38
Q

Map out the electrical signal in the heart from start to end.

A

Starts: SA node because it is fastest to depolarize therefore they set the rate for the heat beat. Travels to AV node which slows down to allow complete contraction of the atria and complete filling of the ventricles before they contract. It travels down to the ventricles via the bundle of His and purkinje fibres and blood moves out the ventricles.

39
Q

How to set heart rate? Normal vs. abnormal.

A

Normal: SA nodes are fastes to depolarize then the AV node and purkinje fibres.
Abnormal: if heart/cells are damages, SA node is not driving heart rate anymore. It is derailed. Can be due to over consumption of caffeine: derail SA node cells and another cell type are now driving the heart rate. (ectopic focus), lack of sleep also causes this too, anxiety etc. body is telling you it is not good.
People who have pacemakers put in: they have permanent damage to the SA node so they cannot initiate own action potentials.

40
Q

What is needed for efficient pumping?

A
  1. atrial excitation and contraction must be complete which means must have the pause so that you have complete ventricle filling before contraction.
  2. excitation of cardiac muscles must contract as a coordinated unit
  3. atria contract together ventricle contract together synchronized.
41
Q

Map the conduction in the heart chambers.

A
  1. SA node: spread signal from right atrium to left atrium
  2. Pauses at the AV node: first allows complete filling of ventricles before contraction. It spreads down through the bundle of His and to the purkinje fibres.
42
Q

How do we spread the electrical conduction to 1% of auto rhythmic cells to the contractile cells?

A

The heart muscle is specialized that have intercalated disk which are specialized gap junctions of the heart. This allows electrical coupling between the two cell types. Auto rhythmic cells (SA node) generate action potential that travels through the tissues to the contractile cells through gap junctions. The movement of the ions causes those cells to depolarize.

43
Q

How do cardiac ARC differ from other muscles?

A

Smooth and skeletal muscles have remain at a RMP (resting membrane potential) but cardiac ARC do not. They are always drifting towards firing and returning down below rate: repeated cycles of drift and fire. It does occur through the opening of gates but they do not need stimulation from a motor neuron but will contract by itself auto rhythmically. Drive own action potential.

44
Q

How does the slow drifting and firing of ARC cells happen in comparison to other muscles and contraction cardiac cells?

A

Ions involved in ARC are different when compared to smooth and skeletal muscle contraction and cardiac contractile cells. The main ionic change driving slow drift to firing is the decrease in the permeability of cell membrane to potassium.
How is there this decrease that controls selective permeability? Channels. constant outward leak of K+ and inward leak of Na+ and Ca+.

  1. There is closing of potassium channels so less is moving out=decreased passive flux. (potential is changing from -60 to +10) Superimposed on that is sodium moving out. (quick)
  2. Pleateau
    Superimposed is inward leak of calcium. K+ outward leak is still low.
  3. The return to normal (“repolarization” phase) is the movement of potassium out of the cell once the peak of the membrane potential is reached. (fast outward leak)

So the movement of potassium is the driver behind self induced action potential primarily driven by change in potassium.

45
Q

What distinguishes cardiac contractile cells?

A

They differ from skeletal muscle because they have intercalated disks and it is not multi nucleated (single cells). They have a difference since they are a diad (t tubules and SR) rather than a triad (t tubules, SR, sarcolemma) in skeletal muscle. There is a different arrangement so absence of typical sarcomere contractile unit.

46
Q

What is a syncitium?

A

It is a mix of tissue types. (made of many different cell type)
The heart is mostly made of myocardium but also have the epithelium made of the inner lining and the connective tissue which are the membranes of the outer lining of the heart.
Essentially, the atria and ventricle are separate tissues so that the atria contract and then the ventricles do. They are a two system pump.
The atria and ventricle form separate types of syncitium.

47
Q

Compare the action potential of cardiac contractile cells and cardiac ARC. What are the differences and similarities?

A

Differences:
1. ionic mechanisms distinguished from skeletal muscles and ARC (nodal pacemaker cells).
- there is a plateau phase: there as extended contraction in another muscle type.
What other type? Smooth muscle.
2. RMP: -90 mV
-3. when cells are stimulated by ARC and ionic movement: there is an increase in permeability to sodium. Once peak has been reached at +30 mV, there is a shutting of sodium gates and opening of Calcium gates. Calcium is in excess in the ECF, it slowly moves into the contractile cells which prolongs the plateau phase of the action potential. Eventually, calcium gates close and potassium gates open and potassium moves out of the cell to return to the threshold.
key: prolonged action potential

48
Q

Describe action potentials of muscle profiles.

A

Skeletal muscles: fast and narrow
Smooth muscle: has a plateau
Cardiac muscle: has a plateau too

49
Q

Why is there a prolonged action potential (physiologically) in the cardiac contractile cells?

A

There needs completely filling and emptying of the heart which is related to the length of contraction. There needs to be a coordinated contraction that needs to keep contracting so there is enough pressure on the valves so they open up so that hte all the blood leaves the chambers.

50
Q

What sorts of things in the body influence the change in heart rate?

A
  • changing the level of electrolytes
    eg. illness: diarrhea= loss in electrolytes
    drugs: cortical steroids = tend to excrete a lot of potassium so might need potassium supplement
51
Q

What the connection between action potential and the molecular mechanisms to help it contract/relax for the cardiac muscles?

A

Action potential has traveled down through the cell via gap junctions. Calcium enters through L type channels. It causes local spark and is required to bind to tryponin which allows the large myosin head to bind the actin for contraction to occur. The calcium entrance causes increase because they released form SR stores and drives the binding of myofilaments.
For relaxing to occur in cardiac muscle, calcium needs to be removed out of the cell and back to the SR which require energy.

52
Q

What is the difference in molecular mechanisms of contraction/relaxation in cardiac and skeletal muscles?

A

The time when gates open.

53
Q

How does the refractory period in the heart compare to other muscles and why is it this way?

A

Refractory periods are much longer in the heart to avoid tetanus. Tetany = continual contraction which does not allow complete emptying and filling of the heart chambers. They have a long period where cells cannot be stimulated and contract.

54
Q

How does the body restore homeostasis in face of increased heart rate?

A

The heart is innervated by both ANS systems: Parasympathetic and sympathetic divisions. So even though nervous stimulation is not required for heart beat, it can still modify heart rate.
eg. parasympathetic control: SA initiates heart rate normally but input changed. parasympathetic system comes in via vagus nerve which sits on the trunk of the aorta which have aortic baroreceptors. If there is a rise in heart rate, the barorecepters sense it and feedback via the vagus nerve to the cardiac control centre which sends outgoing message which results in release of ACh which increase permeability to potassium. It makes the inside of the cell more negative because releasing more potassium which requires more stimulation to drive firing and contraction. This slows down heart rate and also acts on blood vessels for vasodilation.

55
Q

How does the body restore homeostasis during a decreased heart rate?

A

The sympathetic branch of nervous systems acts. There needs to be an increase blood flow. This can be done by stimulating ARC (SA node cells) which accelerates the inactivation of potassium channels so less potassium is leaving the cells (more positive in the inside) so the cells are more swifter to drift to action potential. Because of this heart beats more quickly and forcefully. It also has vasoconstriction effects.

56
Q

What are baroreceptors for?

A

They are stretch receptors on the aortic arch and carotid baroreceptors. They sense how much the tissues are being stressed. High heart rate, more stretch so sends a signal to slow down heart. If not stretched neough, sends signal to increase heart rate so there’s more pressure on receptors.

57
Q

Situation: Women horse so snake scared horse which scares her. What happens physiologically?

A

This increases her blood pressure where she activated fight or flight responds so the heart is beating faster. The baroreceptors sense that which feeds info back to the cardiac control in brain by the cranial nerves. The medulla oblongata sends signal to release ACh which works on the SA node cells. This hyper polarizes the cardiac muscle fibers which deceases the heart rate. More potassium is released out of the cell making them less swifter to drift to firing. This decreases the heart rate and the baroreceptors stop sending signal which stops sending ACh which is how homeostasis is restored. This is the feedback mechanism.

Mammalian Physiology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions