#3 Lecture Flashcards
What is diffusion necessary of
To get nutrients in and waste out of cells
What do you need to get diffusion to work
Need surface area on cell membrane to allow exchange gases and nutrients to occur via diffusion
Is diffusion a slow process?
yes, it puts limits on body form, where organisms must have
1) small body
2) thin anatomy
3) use circulatory system
What cavities in thin anatomy help facilitate diffusion
Gastrovascukar
- does both digestion and circulation
Circulatory system
Employ bulk flow of specialized circulatory fluid to distribute needed materials through the body quickly and efficiently
What does circulatory systems connect
Connect exchange surfaces where diffusion exchanges occur and materials transferred
Gas exchange of cardiovascular systems
- deliver oxygen for cellular respiration
- remove carbon dioxide for cellular respiration
Energy balance of cardiovascular systems
- deliver nutrients from digestion and absorption
- remove waste products to excretory organs
Osmotegulation/ communication of cardiovascular system
Carry water, ions, and hormones throughout body
Is diffusion the fundamental process for how essential molecules enter and exit cells
Yes
High pressure/low pressure of diffusion
High pressure (high O2)
- red blood cells constantly bring more O2 from lungs
Low pressure(low O2)
- cells always depleting O2 via cellular respiration
Circulatory fluid
Blood in human system
- carries gases/nutrients/molecukes
Tubes of cardiovascular
Blood vessels in closed circuit
Arteries >capillaries >. Veins
Muscular pump of cardiovascular
The heart
Provides force to move blood
Does blood flow in one direction
Yes
Arteries
Carry blood from the heart, by branching into arterioles and capillaries
Capillaries
Infiltrate tissues and organs thus allowing diffusion of molecules into cells
Veins
Capillaries merge into venules/veins to carry blood towards the heart
Double circulatory system
Blood goes to lungs, back to heart and is pumped again to tissues in body
-pulmonary and systemic circuit
Pulmonary circuit of double circulatory systems
Circuit of blood vessels that goes from heart to lungs to heart
Systemic circuit of double circulatory systems
Circuit of blood vessels that goes from heart to organs/tissues to heart
Oxygen levels in pulmonary circuit of arteries and veins
Arteries- low oxygen
Veins= high oxygen
What causes blood to travel in one direction
Heart valves
What does the right heart deal with
Pushing blood to pulmonary circuit
What does the left heart deal with
Pushing blood to systemic circuit
Coronary circuit
Supplies oxygen to heart muscle tissue
- left coronary artery leaves aorta then right coronary artery leaves aorta
- branch into additional arteries then capillaries
- merge into veins
- veins converge on coronary sinus
- coronary sinus enters right atrium
Where is heart located
Between lungs, posterior to sternum, anterior to vertebral column, superior above diaphragm
- within mediastinum membrane that encodes medial cavity of thorax
- 2nd-5th rib pointing left
Where do great vessels enter
Top area
What is heart made of
Cardiac muscle
- fatigue-resistant
-tetanus-resistant
-auto-excitatory
Atria
Chamber where blood enters heart
Ventricle
Chambers that contract to pumps blood out of heart
Two superior atria where blood enters into heart via veins
Right atria: low O2 blood returns from systemic circuit
Left atria: high O2 blood returns from pulmonary circuit
Two inferior ventricles where blood exits heart out arteries
Right ventricle: low O2 boood sent to pulmonary circuit
Left ventricle: high O2 blood sent to systemic circuit
Does left ventricle have thicker myocardium
Yes, because it has to push blood through the larger systemic circuit
Does atria or ventricle contract first
Atria then ventricles
Cardiac cycle
Rhythmic heart contraction and relaxation
Contraction
Pumping phases called systole
Relaxation
Filling phases called diastole
Atrioventricular valves
Regulate blood flow between atriums and ventricles
- tricuspid: right atrium to right ventricle
- Mitral: left atrium to left ventricle
Semilunar valves
Control blood flow to great vessels
- aortic valve: left ventricle to aorta
- pulmonary valve: right ventricle to pulmonary artery
Three flaps of tricuspid and 2 flaps of mitral(bicuspid) valve
Endocardium and connective tissue
What are atrioventricular anchored by
By tendons in ventricles
What does chordate tendineae do in atrioventricular valves
Attach in ventricles and papillary muscle
- when papillary muscle contracts w ventricles , chordate tendineae tighten resisting back flow, prevent eversion
Pulmonary valves
Control blood flow to pulmonary trunk and pulmonary circuit
Aortic valve
Control blood flow to aorta and systemic circuit
How do semilunar valves open
Pressure of ventricle contraction opens them
- shape pushes them closed during backflow
Are there valves for veins entering into atria
No valves protecting both vena cava and pulmonary veins
- there is atrial contraction that constricts opening to these vessels
Unidirectional blood circulation
Depends on proper coordination of valves
Systole
When ventricles are contracting
Diastole
When ventricles are relaxing
How is contraction controlled
Cardiac conduction, pacemaker cells rhythmically self depolarize
Pacemaker cells (cardiac conduction)
Special cardiac cells that are non contractile and self excited (undergo automatic depolarization)
Sinoatrial (SA) node (cardiac conduction)
First pacemaker region that begins the action potential relay through neighboring gap junctions
Atrioventricular node (cardiac conduction)
Second region of pacemaker cells: smaller size and fewer gap junctions causes a pause between atria and ventricles contraction
What do pacemakers send through fiber network
Rhythmic AP
