Lecture #5 Flashcards
What makes up the cardiovascular system (circulatory system)?
1- heart
2- blood vessels
3- blood
What is the blood composed of?
plasma, red blood cells, white blood cells and platelets
In addition to delivering nutrients and oxygen and taking away toxins and by products what does the cardiovascular system do?
- ensures homeostasis by its constant adjustment of heart rate and blood vessel diameter
- regulates the flow of blood containing oxygen and nutrients to the cells and CO2 and toxins from the cell
Name the different functions of the CVS?
- oxygen transport
- CO2 transport
- nutrient and waster product transport
- disease protection and healing
- hormone delivery
- body temperature regulation
describe how the CVS functions in oxygen transport?
- most essential function of the CVS
- inhalation: air enters the lung, o2 is absorbed through air sacs into the bloodstream, O2 rich blood is pumped through heart into the arterial circulation, in capillaries, o2 diffuses out of the blood into the cells or organs and tissues
describe the transport of CO2
- occurs during exhalation
- CO2 waste produced by cells is absorbed into the blood and transported to the lungs through venous circulation
- when O2 poor reaches lungs, CO2 diffuses through air sacs and is exhaled
Describe fn of nutrient and waste product transport. What are vitals nutrients?
- sugars, fats, vitamins, minerals, amino acids
- glucose is the body’s primary fuel to generate energy
- AA enable the body to manufacture new cells
how does the CVS function is disease protection and healing?
- serves as highway for disease-fighting cells and proteins and messengers of immune system
- white blood cells patrol and send chemicals through blood streams during infection
- also carries chemical messengers that attract cells to heal tissue that have been damaged due to injury or disease
How does CVS function in hormone delivery?
- hormones are produced by endocrine glans that affect distant organs
- CVS serve as transportation connection btwn endocrine glands and the organs or tissues they control
What does the pituitary gland, insulin and thyroid hormones control?
Pituitary gland hormones:
- control other endocrine glans (thyroid, ovaries, testes)
- directs childhood growth
insulin:
- produced by pancreas
- affects uptake and use of blood sugar through the body
thyroid hormones:
- affects metabolic rate of virtually every body organ tissue
- delivery through systemic
How does CVS work in regulatin body temp?
If body temp increases:
- Blood vessels close to the body and surface dilate
- the body rids itself of excess heat through the skin
If body temp lowers:
- surface blood vessels constrict to conserve body heat
Describe important elements of the heart?
- powerful muscular pump that generates force needed to circulate blood through the body
- beats about 72 beats/minutes depending on age, fitness and level of exertion
- about 5 L of blood is pumped through the heart’s chambers every minute
Name the different layers of the heart
- pericardium -> thick fibrous sac enclosing the heart, holds the heart in the middle of the chest
- myocardium -> cardiac muscle tissue that make up bulk of heart. generates contractibility
- endocardium -> inner most layer, cells are similar to endothelial cells that line blood vessels. provides protection to the valves and heart chambers
Name the heart structures?
- 2 halves separated by a septum
- right and left atrium -> receiving chambers for blood
- left and right ventricle -> main pumps of the heart, contraction forces blood out
What are the two pairs of valves that ensure blood flows in one direction through heart?
1- atrioventricular valves (AV valve)
- > on right side: triscupid (3 flaps)
- > on left side: bicuspid (mitral valve, 2 flaps)
- Semilunar valves -> located between a ventricle and its connecting artery (aorta or pulmonary)
- > prevents back flow of blood into ventricle
What is the AV valve on the right called?
tricuspid
What is the AV valve on the left called?
bicuspid
What is the main body’s artery that conducts blood from left ventricle to body>
the aorta
What prevents oxygenated blood from mixing with low oxygenated blood?
the fact that the left and right sides of the heart function in two different pathways
- pulmonary and systemic
Where does the right side of heart pump blood to?
- through pulmonary circuit, which transports blood to and from the lungs
- begins in right atrium as veins return deoxygenated blood from systemic
Where does the left side of the heart pump blood to?
- pumps blood through systemic circuit, transports blood to body tissies
- begins when the O2 rich blood enters the left atrium
Describe the pulmonary path
- right atrium -> AV valve (tricuspid) -> right ventricle -> pulmonary semilunar valve -> pulmonary trunk -> pulmonary arteries -> lungs - > pulmonary veins - > left atrium
Describe the systemic circuit
- left atrium -> AV valve (biscupid) -> left ventricle -> aortic semilunar valve -> aorta -> body tissues -> inferior/superior vena cava -> right atrium
what happens to coronary arteries when in resting conditions? during exertion?
- removes almost all oxygen from blood flowing into it
- coronary blood flow can increase up to 9 times that of the normal resting heart.
Describe the cardiac cycle
- 2 atria contract simultaneously as 2 ventricles relax
- > is a coordinated contraction and relaxation of the chambers of the heart
What is systole and diastole?
- contraction of the heart muscle -> pumps blood out of a chamber
- diastole -> relaxation of the heart muscle fills blood into a chamber
How can the heart beat?
- cluster of specialized cells in the SA node
- pace changes in response to activity or excitement
- affected by autonomous NS and certain hormones
Design of vessels?
- arteries (leaves heart) - arterioles - capillaries - venules - veins (return to heart)
What is the common feature of all vessels?
- lumen
- endothelium lining (makes it smooth for blood flow)
the greater the # of arterioles contracted the higher the ____
blood pressure
Primary function of arterioles?
- modify blood pressure and blood flow
What is the primary function of capillaries?
exchange of material between blood and body cells
What regulates the blood flow into capillaries?
a ring of smooth muscle called pre capillary sphincter
What re important differences between veins and arteries?
- lumens of veins are much larger than similarly sized arteries
- walls are much thinner
- > allows to hold a much larger volume
- > veins must be able to retunr blood to heart withouth heart pumping
What mechanisms assist the movement of blood from the lower body to the heart?
1- veins have valves, preventing backflow
2 - skeletal muscle contractions squeezes veins
3 - reduced pressure in thoracic cavity and increased pressure in our abdominal cavity from our breathing
What is the role of blood?
- regulate the body’s sytem
- help maintain homeostasis by stabilizing pH, temp, osmotic pressure, eliminating excess heat
- supports growth by distribution of nutrient, hormones and removing waste
Describe RBC and role
- erythrocytes carry O2
- hb is protein inside that bind O2
- RBC also removes CO2 from body
- made in bone marrow and usually live about 120 days.
What are problems with RBC?
- can be caused by an illness or lack of iron or lack of vitamins in diet
Role of WBC (leukocytes)? Types:
- help fight infection and other diseases
- made in bone marrow
- found in blood and lymph
types: granulocytes (neutrophils, eosinophils, basophils), monocyotes, lyphocytes (T cells or B cells)
function of platelets?
function in homeostasis by reacting to bleeding from blood vessel injury by clumping, initiating a blood clot
other blood functions?
- brings waste product to kidneys, liver which filters and clean blood and are important for the regulation of body temp.
