Animal Circulatory System Flashcards
1
Q
The circulatory consists of.. (3 things)
A
- blood vessels
- blood
- heart
2
Q
What is are the two(*) types of circulation in our “double circulatory system?”
A
We have a double circulatory system:
- pulmonary circulation
- carries blood to lungs and back to the heart
- systemic circulation
- carries blood through the aorta, through the body, and back to the heart
- *coronary circulation
- technically part of systemic circulation; supplies the heart muscle itself with blood as the rest of the blood pumping through the chambers does not actually supply it with nutrients.
3
Q
Features of arteries
A
- higher pressure because they take blood AWAY from the heart; smaller diameter than veins
- large, thick-walled, muscular, elastic
- almost always takes oxygenated blood, with the exception of the pulmonary artery that takes blood from the heart to the lungs. Because the blood needs oxygen from gas exchange, the pulmonary artery must take deoxygenated blood.
4
Q
Features of veins
A
- lower pressure because they take blood to the heart; larger diameter than arteries
- carry blood which contains waste and CO2. Exception is the pulmonary vein which takes oxygenated blood from the lungs to the heart
- largest vein is the vena cava; has very low blood pressure
- valves prevent backflow due to gravity
- venules - small veins, larger than capillaries, connect to major veins
5
Q
Features of capillaries
A
- the only blood vessels which allow for diffusion
- connect the arteries to the veins
- smallest vessels; microscopic; walls are one cell thick with no muscle or protective layers
6
Q
What is arteriosclerosis?
A
Arteriosclerosis; artery blockage and hardening
- plaque is formed from cholesterol buildup mixed with rogue calcium and causes restricted blood flow
- not necessarily caused by diet; often genetic and caused by other indirect sources
7
Q
What does the heart do (structure + functions)? What are its four chambers?
A
- keeps blood moving at about 1.5L a minute during rest (non elevated heart rate)
- Large organ; composed of
- cardiac muscle
- rich in mitochondria
- enclosed in a sac called the pericardium
- Four chambers in the heart;
- two upper atria (right and left)
- walls are thinner and less muscular
- two lower ventricles (right and left)
- walls are thicker and more muscular as they do more work
- two upper atria (right and left)
8
Q
What is the path that blood takes through the heart?
A
- blood enters through the right atrium as it’s low in oxygen
- It then crosses down into the right ventricle through the superior vena cava, still low on oxygen
- It takes the pulmonary artery through to the lungs so that the gas exchange can happen and oxygen can diffuse into the blood
- Coming back through the pulmonary veins (there are 4) into the left atrium, the blood is now oxygenated
- Crossing through the mitral valve, the blood will enter the left ventricle and then be pumped through the aorta to the rest of the body.
9
Q
valves
A
- valves prevent backflow in the heart
- mitral valve, aortic valve, tricuspid valve, pulmonary valve
10
Q
Atriums/Ventricles; which receives what blood?
A
- both atria fill at the same time
- right atrium receives deoxygenated blood
- left atrium receives oxygenated blood
- Both ventricles contract
- right ventricle contracts and pushes deoxygenated blood towards lungs
- against gravity through pulmonary arteries
- left ventricle contracts and forces oxygenated blood out of the heart through the aorta
- right ventricle contracts and pushes deoxygenated blood towards lungs
11
Q
What regulates the heartbeat?
A
- Main control: medulla oblongata (brain stem), which measures CO2 in the bloodstream
- force of blood from left ventricle into arteries is known as a pulse
- pacemaker (sinoatrial node), which is a group of cells at the top of the right atrium
- electrical impulse signals both atria to contract
- this triggers 2nd set of cells at the base of the right atrium to send messages to ventricles through nerves in the septum to contract
- EKG or ECG = electrocardiogram; a record of electrical changes in the heart
12
Q
What are the two types of blood pressure and what do they mean?
A
- Blood against vessels walls
- systolic pressure refers to:
- the pressure recorded in the arteries while the ventricles pump blood
- diastolic pressure refers to:
- the pressure recorded in the arteries while the ventricles fill with blood
- systolic pressure refers to:
- Normal pressure is 120/80
13
Q
What are coronary blood vessels?
A
Coronary blood vessels are a network of arteries and veins that provides oxygen and nutrients to the muscle cells of the heart and removes waste products.
14
Q
What is blood and what are its components?
A
Blood:
- The human body contains 4-6L of blood
- blood is a connective tissue!
- blood separates in a centrifuge!
Components:
- Red Blood Cells (RBC) = 45%
- Plasma = 54%
- water = 50%; proteins, antibodies, hormones = 4%
- White blood cells (WBC) + platelets = 1%
15
Q
How is oxygen transported through blood?
A
- Hemoglobin is a molecule which contains iron and is responsible for transporting oxygen into blood cells.
- loosely picks up oxygen in lungs, then loses it in areas of low oxygen (both due to diffusion)
- found mostly in RBC
