chapter 18 extra

Question 1

heart generates what
and how is the heart structured

Answer 1

pressure that propels blood to to vessels
structured to keep 02 and de02 air separated

Question 2

heart is located where

Answer 2

mediastinum

Question 3

heart enclosed in double layer sac

Answer 3

pericardium- has 2 layers
1)superficial fibrous pericardium (protects, anchors, distension)
2) serous pericardium: 2 layers
-parietal (protect, anchors) and visceral (secretes fluid)

Question 4

whats in between parietal and visceral layers

Answer 4

pericardial cavity that has fluid that reduces friction between layers

Question 5

layers of heart:
1) epicardium
2) myocardium
3) endocardium

Answer 5

1) visceral layer of serous pericardium
2) bulk of heart, contracts, contain fibrous skeleton
3)reduces friction, lines heart

Question 6

heart chambers (4)

Answer 6

2 superior atria separated by interatrial septum
2 inferior ventricles separated by interventricular septum

Question 7

circuits

Answer 7

2 pumps connected in series
pulmonary: between right side of heart and lungs, pump for right ventricle, low pressure
systemic: between left side, pump for left ventricle, high pressure

Question 8

atria
RA
LA

Answer 8

receiving chambers of heart, receives blood from circuits
RA- receives de02 from systemic and sends blood to tricuspid, receives 3 vessels (IVC,SVC,CS)
LA: receives 02 blood from pulmonary circuit, receives 4 vessels (pulmonary veins)

Question 8

heart sounds

Answer 8

lup, dup; associated with valves closing, 1st sound is closing of AV valves and second is closing of SL valves

Question 9

ventricles
RV
LV

Answer 9

pump, cardiac muscle to generate pressure
RV- receives de02 from RA, pulm. circuit, tricuspid valve closes
LV- receives 02 from LA, systemic, mitral valves close, more muscular to pump blood further
both the same volume

Question 10

heart valves ensure

Answer 10

unidirectional flow of blood, open/close in response to pressure changes
2 AV valves
2 SL valves

Question 11

tricuspid valve open when RA pressure is; closed when RA pressure is

mitral open when LA pressure is; closed when LA pressure is

Answer 11

less than RV pressure, less than

less than RV pressure; greater than LV pressure

Question 12

pulmonary semilunar valve open when RV pressure is; closed when

aortic semilunar valve open when LV pressure is; closed when

Answer 12

less than pulmonary trunk, less

greater than aortic pressure, less

Question 13

coronary circulation

Answer 13

part of systemic
left coronary branches into inter ventricular tissue
and right branches into right marginal artery, cardiac veins collect blood from capillary beds

Question 14

great cardiac vein
middle cardiac veins
small cardiac vein

Answer 14

anterior inter ventricular sulcus
posterior inter ventricular sulcus
inferior margin

Question 15

angina pectoris
myocardial infarction

Answer 15

thoracic pain caused by deficiency
heart attack

Question 16

myocardium has cardiac muscle, what are the 2 types of cardiac muscle cells

Answer 16

auto rhythmic (1%)- send electrical signals, intrinsically control heart rate, spontaneous, electrically linked by gap junctions
contractile cells (99%), contract, shorten and generate pressure in response to depolarization

Question 17

fibrous skeleton between

Answer 17

atria and ventricles (electrically and physically separates them); attachment site for cardiac muscle, form rings that support valves

Question 18

cardiac muscle

Answer 18

striated, short, only in myocardium, have intercalated discs, mainly mitochondria

Question 19

intercalated disc

Answer 19

desmosome (mechanical connection between cardiac cells)
gap junction (electrical connection between cardiac cells)

Question 20

cardiac muscle contraction

Answer 20

no nervous system, contract as unit, triggers CA release from SR, long absolute refractory period

Question 21

what influences extrinsic

Answer 21

ANS and endocrine system, EP and throxyine, outside cardiac tissue, heart beat modified by ANS

Question 22

sympathetic
parasympathetic
cardioacceleratory
cardioinhibitary

Answer 22

increases rate and force
decrease rate
sympathetic, release in NE (inc in NE=inc in heart rate)
parasympathetic, ACH released, dec in heart rate, no effect on force, in charge

Question 23

decrease in cardioacc affect hr
ACH affect time between heart bets
vagotomy affect hr

Answer 23

slows down hr
inc time
inc hr

Question 24

CO

Answer 24

vol of blood pumped by each ventricle in 1 min, HR x SV; increases if SV and HR increase

Question 25

if heart rate increases time between beats filling time EDV will If heart rate decreases

Answer 25

all decrease all increase

Question 26

SV EDV ESV 3 main factors affecting SV

Answer 26

SV- volume ejected by ventricles, SV=EDV-ESV EDV- length of vessel diameter ESV- arterial bp 1)preload- most important, venous return, SV varies directly with preload 2)afterload 3)contractility- increased by sympathetic stimulation

Question 27

sympathetic activity activated by

Answer 27

emotional and physical stressors

Question 28

if aortic bp is high easy to open SL valves: as afterload inc, sv:

Answer 28

no dec

Question 29

ventricular filling isovolumetric contraction ventricular ejection isovolumetric relaxation

Answer 29

v. filling v volume=inc both ventricles= diastole AV valves= open SL valves= closed atrium pressure greater than ventricle p (only time) LV pressure less than aortic RV pressure less than PT pressure I. contraction v volume= static ventricle p= inc, ventricle in systole AV and SL valves closed atrial less than ventricle LV less than aortic RV less than PT v. ejection v volume= dec AV= open SL= closed ventricles in systole atrial less than ventricular pressire LV greater than aortic RV greater than PT i. relaxation v volume= unchanges v pressure= dec AV and SL valves= close ventricles in diastole atrial greater than ventricle LV less than aortic RV less than PT