Circulatory System Flashcards
Functions of the Circulatory System
- transport
- defense
- regulation
Animals w/o circulatory systems
Why don’t single-celled protists have a circulatory system?
so small, easy to simply use DIFFUSION
What do single-celled and organisms with two cell layers use instead of a circulatory system? Why?
Diffusion only a short distance to diffuse to the cells of outer layer
Why does a flat worm have a flat body?
maximize exposure for gas diffusion through the skin
What is the Internal Fluid Environment in unicellular animals?
Cellular cytoplasm
What is the Internal Fluid Environment in Multi-cellular animals?
Internal fluid
What are the two types of Circulatory System?
- Open circulatory system
- Closed circulatory system
What is the difference between an Open and a Closed circulatory system?
- Open - heart pumps directly to surrounding organs; no vessels
- Closed - blood always enclosed in vessels
What organisms have an Open circulatory system?
insects, other arthropods, most mollusks
What organisms have Closed circulatory systems?
earthworms, squids, octopuses, vertebrates
What are the main parts of a Vertebrate Circulatory System?
- heart 2. vessels 3. blood
What does the heart consist of?
one or two atria one or two ventricles
What is the role of the atrium?
receive blood from the body
What is the role of the ventricle?
pump out blood from the heart
What are the different types of vessels?
- Arteries 2. Arterioles 3. Capillaries 4. Venules 5. Veins
Arrange the different types of vessels starting from the heart.
heart –> arteries –> arterioles –> capillaries –> venules –> veins –> heart
Describe the circulatory of the a fish.
simplest 2-chambered heart single blood circuit only has sinus venosus and conus arteriosus
Describe the circulatory system of amphibians .
3-chambered heart (2 atria, 1 ventricle) double blood circuit -pulmonary and systemic circuits
In an amphibian heart, which atria pumps deoxygenated blood from the organs?
RIGHT Left pumps deoxygenated blood from the skin and lungs.
In an amphibian heart, which atria pumps deoxygenated blood from the skin and lungs?
LEFT Right pumps deoxygenated blood from the organs.
Describe the circulatory system of reptiles.
3-chambered heart (except crocodiles) ventricle is partially divided double blood circuits -pulmonary and systemic circuits
Describe the circulatory in mammals and birds
4-chambered heart double blood circuit
What is the most efficient heart? Why?
MAMMALS & BIRDS There is no mixing of oxygenated and deoxygenated blood
Outline the path of blood in the human body.
Blood enters the RIGHT VENTRICLE from the right atrium. RV pumps blood out of the heart to the lungs via the PULMONARY ARTERIES Blood is oxygenated in the CAPILLARIES of the LUNGS Oxygenated blood is carried back to the LEFT ARTERY by the PULMONARY VEINS Blood is pumped to the LEFT VENTRICLE from the LA Blood is pumped the the body via the AORTA CAPILLARIES of the body carry out gas exchange in organs Blood flows back to the heart (RIGHT ATRIUM) via the ANTERIOR VENA CAVA and POSTERIOR VENA CAVA.
What is the Cardiac Cycle?
all activities of the heart in a single heartbeat.
How long does the Cardiac Cycle last?
0.8 seconds
Describe the activities of the cardiac cycle.
Atria and ventricle diastole allowing blood into the chambers. Atria systole and ventricle diastole forcing all blood into the ventricles. Atria diastole preparing for the next cycle while Ventricles systole pumping blood out of the heart and into arteries.
Differentiate Systole and Diastole
Systole - contract Diastole - relax
What is a CARDIAC OUTPUT?
amount of blood pumped per minute (heart rate)(stroke volume) Heart Rate - beats per second Stroke Volume - amount of blood pumped by LV in each contraction
What is the sound made by the heart? What do they signify?
“lub” -recoil of blood against closed atrioventricular (AV) valves “dub” -recoil of blood against semi-lunar valves
What is an Electrocardiogram and how does it work?
Detect currents from heart that is conducted through bodily fluids to the skin
Where do the electrical impulses of the heart come from?
the Pacemaker cells (SA node) in the right atrium
Outline the flow of electrical impulses in the heart
Pacemaker generates electrical signal Signals spread through Atria and delayed at the AV node Signals pass to heart apex Signals spread throughout the ventricles
What two nerves affect heart rate? What do they do?
SYMPATHETIC -speeds up pacemaker PARASYMPATHETIC -slows down pacemaker
Aside from the Sympathetic and Parasympathetic nerves, what also influences the pacemaker?
Hormones Body Temperature Exercise
How are blood vessels structured? Outer –> Inner
Tunica Adventia (connective tissue) Tunica Media (smooth muscle) Tunica Intima (endothelium)
What prevents blood from backflow of blood?
Closed valves in veins
What is the relationship between blood flow (velocity) and area?
Inverse relationship (increase in area = decrease in blood flow velocity)
In which blood vessel is the blood flow velocity the slowest? What is the benefit of this?
CAPILLARIES Slower blood flow allows more time for gas exchange
What is the relationship between blood pressure and blood flow?
Pressure is highest coming from the heart and lowest going back
What do we use to measure blood pressure?
Stigmanometer
How do we use a Stigmanometer?
What are some factors affecting Blood Pressure?
Exercise, Nutrition, Diet, Drugs
What are illnesses related to Blood Pressure?
HYPERTENSION -high blood pressure HYPOTENSION -low blood pressure
What are precapillary sphincters?
Sphincters that restrict blood flow to the capillary networks by relaxing or contracting
What is the fluid that flows out of the capillaries?
Interstitial fluid
What is the make up of blood?
55% Plasma 45% Cellular Elements
What is in Blood Plasma?
Water Ions Plasma Proteins Substances transported by blood
What makes up the Cellular Elements in blood?
Erythrocytes (RBC) Leukocytes (WBC) Platelets
Outline Blood Coagulation
Platelets are activated Chemicals are released to make platelets sticky forming a PLATELET PLUG Chemicals also turn PROTHROMBIN to THROMBIN THROMBIN turns FIBRINOGEN to FIBRIN Fibrin clot forms
What is the illness witht he inability to form blood clots?
Hemophilia
What are the 2 types of Hemophilia and how do they differ?
Hemophilia A -clotting from factor VIII deficiency Hemophilia B -clotting factor IX deficiency
