BIO 2A03 2013: Lecture 7 Cardiovascular II
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JeevikaGoyalBIO 2A03 2013: Lecture 7 Cardiovascular II
Uploaded by
JeevikaGoyal8lC 2A03 - 2013
LecLure 7
Cardlovascular ll
~200,000
3m
4000-10,000
3-24m
3,000,000
7-8m
leukocyLes
leukocyLe
PemaLopoleuc sLem cell
8lood cells develop ln bone
marrow.
8egulauon of eryLhrocyLe producuon
3
Pb exhlblLs Lhe properLy of allosLerlc modulauon = blndlng aL one
slLe on a molecule aecLs blndlng aL a second slLe, usually by
changlng Lhe shape of Lhe molecule."
280 x 10
6
Pb molecules per 88C
Pb ls a LeLramer (M.W. ~ 68,000), composed of 4 slmllar unlLs
Lach unlL conslsLs of a heme" rlng sLrucLure, whlch blnds 1 C
2
& a polypepude chaln (globln) whlch blnds CC
2
, P
+
, phosphaLes, eLc.
llg 13-3, 16.3
8egulauon of eryLhrocyLe producuon
8lood componenLs are under ughL
reex (homeosLauc) conLrol.
8ed blood cell producuon occurs
prlmarlly ln .
Pave relauvely shorL ( ) llfe
span (compared Lo oLher verLebraLes).
-ApproxlmaLely recycled per day.
-breakdown occurs ln spleen and llver.
roducL= (yellow ln colour).
roducuon (eryLhropolesls) ls
prlmarlly regulaLed by Lhe
Pormone (LC).
lncreased release Lrlggered by Lo Lhe kldney.
SecreLed by speclallzed cells ln kldney.
bone marrow
120 days
1%
bilirubin
erythropoeitin
decreased O2 delivery
3
8egulauon of eryLhrocyLe
producuon
C
2
dellvery Lo kldneys
LC secreuon by kldneys
lasma LC
roducuon of rbc
ln bone marrow
8lood Pb
8lood C
2
carrylng capaclLy
8esLorauon of C
2
dellvery
llg 16-4, 13-4
1
1
2 2
3
3
4
4
8egulauon of eryLhrocyLe producuon
6
Ways Lo lncrease red blood cells
Plgh aluLude: 8lood doplng:
revlously sLored
rbc relnfused
LryLhropoleun:
1akes 3-4 weeks Lo
clear Lhe sysLem
Low C
2
sumulaLes
producuon
olycyLhemla: PemaLocrlL (rbc's) ls
Anemla: Low ablllLy for blood Lo carry C
2
1) Low 2) Low per rbc 3) boLh
Makes bloodow more dlmculL -
uenluons
too high
viscosity
RBC Hb
Monge's dlsease
hoLograph of a pauenL from Cerro de asco (4300 m) wlLh Chronlc
MounLaln Slckness, presenung cyanosls of Lhe llps and a Lyplcal color of Lhe
face.
8
2. LeukocyLes- eoslnophlls, basophlls, neuLrophlls, moncyLes,
lyphocyLes
-roduced ln bone marrow and lymphold ussue
- and cleanup funcuons
3. 8lood plaLeleLs - lmporLanL ln sLasls
-lormed by Lhe breakdown of wbc's
-lnvolved ln blood clomng
-lorm a plaLeleL plug"
8uy coaL"
8oLh of Lhese Lypes are cells are much less numerous ln Lhe
blood Lhan 88C's
defence
hemo
9
C (or l) =
2
8
C
C
8
1he fundamenLal law of Lhe clrculauon
.
.
A = pressure dlerence beLween 2 polnLs ln clrc sysLem
8
= LhaL lmpedes ow
= force/area exerLed by blood - generaLed by hearL conLracuons
Note: Not measured
directly but calculated
lnLernal ( ) LxLernal (lnLeracuon wlLh vessel )
change in P
R
friction
viscosity
wall
10
C (or l) =
A
8
1he fundamenLal law of Lhe clrculauon - ressure
.
A = MA- Cv
3
MA a average of ume
spenL ln each phase of a hearLbeaL.
ressure gradlenLs are whaL drlve blood ow.
ls Lhe overall pressure drlvlng blood lnLo ussues.
llg 13-2, 14-2
.where,
MA = mean arLerlal pressure
Cv = cenLral venous pressure
Cv
MA
- Cv
= 90 - 0 mmPg
1 systolic + 2 diastolic pressure
weighted
MAP
11
1herefore: 8 musL be ln
Lhe pulmonary clrculL
SysLemlc vs ulmonary ressures
A = MA- Cv
SysLemlc = 90 mmPg
ulmonary = 13 mmPg
8ecall: LhaL C = 3L/mln for
each clrculL
And: C = A / 8
llg 13-3
lower
12
Low pressure & reslsLance clrculL
1) revenL lLrauon ln lungs
3) Mlnlmlzes workload by
venLrlcle
Plgh pressure & reslsLance clrculL
1) Lnsure good uld lLrauon
ln sysLemlc caplllarles
2) 8apld shunung of blood 2) revenLs of blood
ulmonary
SysLemlc
llg 14-3
8lghL venLrlcle le venLrlcle
3) venLrlcle has hlgh work-
load
ressure dlerences
reecLed ln hearL
chambers
fluid
shunting
right
left
13
olseullle's Law
! #
$
% & '
8=
(' of blood vessels falrly consLanL
- (&) doesn'L change much under
normal condluons
- Lhe mosL lmporLanL facLor ln deLermlnlng
reslsLance
8 o
1
r
4
e.g. uecreaslng # by 2x
uecreases ow by 16x
WhaL deLermlnes vascular reslsLance?
L
r
C
4
Lh
power law
WlLh and decreased 1'C
WlLh and lncreased 1'C
consLanL
C =
A ,
8
C =
n r
4
8ql
A
n r
4
8 q L ,
8 =
14
8eslsLance vessels
Capable of acuve and passlve changes ln radlus
arLerloles & pre-caplllary sphlncLers
Addluon of reslsLances
ln serles
81 82
83
8
1
= 8
1
+ 8
2
+ 8
3
8eslsLance Lhan
any slngle 8
1/8
1
= 1/8
1
+ 1/8
2
+ 1/8
3
ln parallel
8eslsLance ls Lhan any slngle 8
8
1
=
1/8
1
+ 1/8
2
+ 1/8
3
1
81
82
83
13
MosL ma[or reslsLances are
arranged ln
orLal clrculauon an example of
reslsLance ln
llg 14-3
Caplllary neLworks are small vessels
arranged ln
Lven Lhough r ls small caplllary
LoLal reslsLance of caplllarles
ls noL huge
16
1oLal erlpheral 8eslsLance (18)
Comblned reslsLance of wlLhln Lhe
sysLemlc clrculL
8eslsLance across a neLwork of blood vessels depends on
reslsLance of all vessels
llow Lhrough neLwork varles wlLh reslsLance
vasoconsLrlcuon ln neLwork ! reslsLance !
ow
vasodllauon ln neLwork ! reslsLance ! ow
17
8elaung ressure CradlenLs and 8eslsLance ln Lhe
SysLemlc Clrculauon
llow = cardlac ouLpuL = CC
A = mean arLerlal pressure = MA
8 = LoLal perlpheral reslsLance = 18
llow = A /8
Cardlac CuLpuL (CC) = /