bio unit 4 Flashcards

1
Q

what do we require from the enviroment

A

nutrients and oxygen

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2
Q

how is the rate of diffusion o oxygen and nutrients limied and what is the solution

A

it is limited by distance

  • cardiovascular system for transoport of substances through the body
  • transported by flow of blood through circulatory system
  • bulk flow rather than diffusion
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3
Q

what are the materials transported from the external environment to tissues

A

nutreints, water, gases (especially o2)

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4
Q

between tissues of body

A

wastes, nutrients, hormones

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5
Q

from tissues to external environment

A

metabolic wasted, gases (especially CO2), heat

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6
Q

what is the cardiovascular system with components

A

series of tubes (blood vessels) filled with fluid (blood) and connected to a pump (heart)

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7
Q

what is he pericardium

A

it is part of the external anatomy of the heart, a tough membranous sac surroiing the heart, made up of epicardiu and parietal layer of pericardium with a small amount of fluid between them that acts as a lubricant

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8
Q

what are coranary atary

A

part of the external anatoy of the heart

  • nourisht he heart muscle with blood
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9
Q

what does the heart demand for

A

oxygen and this depends on adequete blood flow , if lacks then leads to hear attack (myocardial infraction)

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10
Q

what is the left atrium

A

part of the internal anotome, recieves oxyginated blood from the pulmonary veis and sends to left ventricle

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11
Q

what is the left ventricle

A

receives oxygenared blood from left atrium and sends to body, after going through body retuns back to the heart via superior vena cava (this cycle is called the systemic circuit)

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12
Q

right atrium

A

recieves deoxygiinated blodd from venae cavea and sends to right ventricle

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13
Q

right ventricle

A

recieves deoxygentated blood from the right atrieum and sends to lungs ( via pulmonary trunk)

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14
Q

what are valves and what are the two types of valves

A

ensure flow is unidirectional

Atriovetnriular valves (tricuspid and bicuspid)

semilunar valves (Aortic and pulmonary)

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15
Q

what is atrioventricular valves and what holds them

A

tricuspid and bicuspid

atached on ventrucular side to collagenous cord(chordinae tendineae (prevent valves from bieng pushed back into the atrium)

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16
Q

what is semulunar valves and what holds them

A

Aortic and pulmonary

  • prevent backflow into ventricles
  • the semilunar valves do not need cords to brace them because of thier shape
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17
Q

what are the two divisions of the path of blood flow and describe them

A

pulmonary circuit, blood vessels in the lungs and those that connect the lunds to the heart

systemic circuit, encompases the rest of the blood vessels in the body

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18
Q

describe the path of the two cardiovascular system divisions

A

page 92

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19
Q

what does the heart do to blood pressuse

A

increases it

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20
Q

what are the specialized cells of the heart

A

they are autorythmic cells (oacemaker cells) need then bc heart don’t get activated by the nervous system

located in sinoatrial node (SA node)

right atrium, near superioir vena cave,

and spontaneously generate action potentials withought input fom the nervous system

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21
Q

what is the membrane potential for pacemaker cells

A

have an unstable membrane potential that slowly drifts upwards from starting point og -60 mV until reaches threshold and iniates action potential

no resting membrane have special If channels

permeable to K+ and Na+

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22
Q

when membrane potential is negative:

A

Na+ influx > K+ efflux, net influx of + charge, slow depolarication of membrane

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23
Q

when membrane potential is positive

A

If channels close, Ca2+ channels open, contiend depolirzation, threshold reached, many Ca2+ channels open and rapid influx of Ca2+, steep depolarization phase of action potential

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24
Q

what happens during repolarization

A

at the end of depolarizaio the Ca2_ channels close and K+ channels open slowly;efflux of K+ causes repolarization

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25
Q

what is a major difference beween action potentials and pacemaker pottentials in the pacemaker cells

A

page 93

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26
Q

what modulates the rate of pacemaker potential

A

autonomic division

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27
Q

explain autnimoc division how heart rate increaases and decreases

A

page 95

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28
Q

what initiates the electrical excitation of the heart and does it spread

A

pacemaker/autorythmic cells initiate the electrical excitation of the heart, and speads to neibourgingh cardiac cells via gap juncions in the interalaed discs

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29
Q

explain the events of conduction

A

page 96

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30
Q

what is the electrocardiogram

A

it is used to obtain infromation of the heart and heart rate

records the electrical ativity at the surface of the skin using electrodes

measure the voltage differentials occuring diring the cardiac cycle, signle contraction-relaxation of mechanical events

3 leads to make einthoven’s triangle

now 12 ECG leads`

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31
Q

what are the 3 waves of an ECG

A

P wave - depolarzation of Atria
QRS complex - ventricular depolirazation
T wave - repolirization of ventricles

32
Q

talk about mechanical events and electrical events

A

mechanical events lag slightly behind electrical events

33
Q

what are the 2 segmensts of an ECG

A

P-R segment, atrial contraction
S-T segment, ventricular contraction, just after Q wave

34
Q

what is the cardiac cycle

A

the cardiac cycle is the period from one heart beat to the next and has two phases

  1. systole - contraction
  2. diastole - relaxation
35
Q

explain steps to cycle

A

page 100

36
Q

explain the sounds of the heart

A

lub - due to closing of AV valves
Dub - due to closing of semilunar valves

37
Q

liquids and gasses flow from….

A

high pressure to areas of lower preaser

38
Q

what happens when heart contracts

A

preassure increases, blood flows out of the heart to lower pressure areas

39
Q

End distolic volume (EDV)

A

maximumvolume in venricle - endo of ventricular filling

40
Q

End systolic volume (ESV)

A

minimum volume in ventricle, end of ventricular contraction

41
Q

cardiac output

A

the amount of blood pumped byy the heart in one minute

= heart ratexstroke volume

stroke volume = EDV-ESV

42
Q

factors influencing heart rate

A
  1. parasympathetic stimulation - decreses heart rate, via vagus nerve, ach
  2. sympathetic stimulation - increase heart rate, via great cardiac nerve, NE
  3. plasma epinephrine (from adrenal medulla) - increases heart rate
43
Q

factors influencing stroke volume

A
  1. parasympathetic stimulation - decrease conractililty
  2. sympathetic stimulation - increases contractility
  3. plasma epinephrine - increases contractility
  4. increased end-diastolic volume - increases stroke volume
44
Q

what is a blood vessels structure

A

hollow tube made of lumen (central cavity) and wall( made of layers)

45
Q

what are the walls of blood vessels

A

inner lining - endothelial celes make up the endothelium

elastic connective tissue

vascular smooth muscle - vasoconstriction (narrowing of vessel), vasodilation ( widening of the vessel)

fibrous connective tissue

46
Q

what are the types of blood vessels

A

artery - thick walled to withstand high pressure

arteriole smallest arteries

capillary - smallest blood vessel, exchange of material

venule - smallest veins

vein - transport blood at low pressure

47
Q

why does blood flow

A

because of a pressure gradient (deltap) between the arteries (p1-highest) and viens (p2-lowest)

flow is directly proportional to the pressure gradient

48
Q

explain the factors hat influence blood flow

A

page 106

49
Q

wheni is pressure increased or decreased

A

p inc when volume dec

p dec by friction (occurs beetween blood and walls of the blood vessel

50
Q

what is friction exerted by a tube

A

resistance

51
Q

how does resistance and pressure difference play a role i blood pressure

A

flow is inversely proportional to resistance

flow is proportional to pressure diff

52
Q

how is resistance determined

A

lenghth, radius and viscosity, chanches in radius most important

53
Q

what is blood presssure and what is the pulse

A

the driving pressure caused by the heart pumping, highest in arteries and lowest at point of return to the heart

pulse is increase in pressure caused when ventricles contract and push blood into aorta

54
Q

what are the two parts that make up blood pressure and how do you estimate it

A
  1. systolic pressure: time when the heart is contracting - highest arterial pressure
  2. diastolic pressure: time when the ventricle relaxes - lowest aterial pressure

estimated using sphygmomenomety, cuff and stethescope shi

55
Q

what is the mean arterial pressure (MAP)

A

since arterial pressure is pulsatile use a single value to represent driving pressure

MAP = diastolic p +1/3 (systolic P - diastolic P)

56
Q

what are the factors affecting MAP

A

cardiac output, changes in blood volume, peripheral resistance

57
Q

how is regulation of blood presssure

A

coordinated by CNA - a homeostatic reflex

58
Q

what does the bararoreceptors do for blood pressure

A

barororecetors are stretch sensetive mechanoreceptors found in vessel walls of the, corotid artery ( moniters blood pressure to brain) and Aorta (moniters blood pressure to body). and blood pressure is monterded though sensory input from them

59
Q

explain bararoreceptor reflex

A

page 109

60
Q

what is blood

A

circulating component of extracellular fluid responsible for carrying subsances around the body

61
Q

what are the 4 major compnents of blood

A

plasme - fluid portion of the blood
red blood cells - erythocytes
white blood cells - leukocutes
plaelets - thormbocytes

62
Q

red blood cell

A
  • biconcave in shape
  • most ubundant cells in blood
    -contain protien haemoglobin
  • major fnction of erythocytes is gas transport
  • humans, RBC’s lack a nucleas and mitochondria so no protien synthesis and no energy produced by oxidative phosphrylation
63
Q

white blood cells

A
  1. lyphocytes
  2. monocytes
  3. granulocytes (3 types)
    - nuetrophils
    -esunophils
    -basophils

macrophages and neutrophils are the professional phagocutes in the body

64
Q

platelets

A
  • involves in blood clotting
  • derived from megakaryocytes, pinch off and have no nucleus
65
Q

why haemoglobin synthesis

A

required for RBC function to transport oxygen

66
Q

explain haemoglobin synthesis

A

page 112

67
Q

bohr effect

A

A shift in haemoglobin saturation due to pH

68
Q

haematopoieis and where are all blood cells produced

A

blood formation

red bone marrow

69
Q

what are cells that arise from a single precursor, and what are thier typees

A

pluripotent hematopitc stem scell, uncommited stemm cells still capble of many fates and progenitor sells are committed to one or two cell types

70
Q

cytokines

A

small peptides/protiens secreted by one cell to send signals to another, chooses path for blood formation and splits them by factor

71
Q

leukposis

A

formation of leukocytes (white blood cells) that is regulated by the colony-stimulating factors (CSFs)

cytokines released by leukocyts regulate further leukocyte production

72
Q

colony-stimulating factors(CSFs)

A

CSFs are released by endothelial cells, morrow fibroblasts and white blood cells

induce cell division and cell maturation in stem cells

73
Q

thrombopoiesis, how they formed what they contain, when are they active

A

megakaryocytes are parent cells that produce platelets (thrombocytes)

growth and maturation are regulated by cytokine theombopoietin

platelets no nuclues but contain mitochindria, smooth ER and granules filled with clotting protiens and cytokines

platelets are always present in the blood, but active only when damage has occured to the walls of the circulotory system

74
Q

megakaryocyte

A

a polypoid cell with a lobed nuclues, parent cells that produce platelets (thrombocytes)

megakaryocyte resides in the bone marrow and extends is outer edges through the endothelium into blood stream

75
Q
A