Unit 3 - Organisms exchange substances with their environment
All documents for this subject (186)
Seller
Follow
talhaahmed360
Content preview
The Circulatory System
Stretch iness of aor ta
crucial to
Heart Rate Stroke Volume
is
slowly Cardiac Output = ✗
flatten out blood pressure ( How
.
much blood is
The Cardiac Cycle % ejected per beat)
/ ←✗ ← , - --
%
Superior
I - - ,
" """ "
" "
"
• Both
a_a contract .
Pulmonary
-
Atria volume decreases . \
→ pressure in
.
This increases atria pressure .
aor taexceeds
ventricles ( valves
-
Blood flows from the atria into the close to prevent
backflow
)
ventricles .
← Vein
-
Backflow of blood into the veins is prevented by
closure of valves into the veins .
Ventricular systole
sinoatrial
Mitral
Both ventricles contract ]
'
node CSA node
Valve
-
The atrio -
ventricular values close
Left Aortic
Semi lunar valves in the
pulmonary artery
•
valve
and aorta open Pulmonary
.
-
Blood flows from the ventricles into the Valve
arteries .
Ventricular Diastole Tricuspid
Valve
Blood
xx -
Vessels
- - - -
%
Atria and ventricles relax
'
vessel characteristics
Blood flows from the reins the Inferior
through
-
Vena cava
• Thick and muscular wall high pressure)
atria and into the ventricles Arteries
.
tissue for recoil
• Elastic
for
The cardiac Muscle %
•
Folded endothelium stretching
1=-31--1 , - , -
% veins
•
Wider lumen than arteries
-
Cardiac muscle not
only contracts ,
but conducts electrical impulses in a similar
way
to nerve cells .
'
Valves to prevent backflow
•
It has branched fibres which assist the spread of electrical impulses .
-
It can function at lower
oxygen
levels than skeletal mivscle and has a higher tolerance for CO2 and lactic
.
One cell thick for short diffusion
capillaries pathway
levels
acid .
.
Capillary beds increase surface area
?⃝
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller talhaahmed360. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.67. You're not tied to anything after your purchase.