Unit 2 - Chapter 10 - Blood and Circulatory System Disorders Flashcards
(169 cards)
what is the function of blood
- transport oxygen and nutrients to all tissues
- remove waste products of cellular metabolism
- play a critical role in the bodys defenses/immune system and serve in maintaining abody homeostasis
how are blood and lumph transported throughout the body
through vessels and the pumping action of the heart
what type of system do the arteries, capillaries and veins constitute
a closed circulatroy system
how many types of circulations are there and what are they called
-2
- pulmonary circulation
- systemic circulation
expand on pulmonary circulation
- allows for the exchange of oxygen and carbon dioxide in the lungs
expand on systemic circulation
provides for the exchange of nutrients and wastes between the blood and the cells throughout the body
where do arteries transport blood to
- transport blood away from the heart into the lungs or to body tissues
what are arterioles and what do they control
- they are the smaller branches of arteries
- they control the amount of blood flowing into the capillaries in specific areas through the degree of contraction of smooth muscles in the vessel walls
what do precapillary sphincters determine
determine the amount of blood flowing from the arterioles into the individual capillaries, depending on the metabolic needs of the tissues
what do venules do
they conduct blood from the capillary beds toward the heart
what do larger veins do
they collect blood draining from the venules
what do valves in the veins do
they keep the blood flowing towards the heart
what are the 3 layers that make up the walls of arteries and veins
- tunica intimia
- tunica media
- tunica externa
expand on the tunica intimia
composed of endothelial cells
expand on the tunica media
layer of smooth muscle
expand on the tunica externa
layer of connective tissue and contains elastic and collagen fibers
what does the vasa vasorum consist of and what does it do
- tiny blood vessels that supply blood to the tissues of the blood vessel wall itself
what is autoregulation and provide an example
- a reflex adjustment in a small area of tissue or an organ, whcih varies depending on the needs of the cells in the area
- ex) localized vasodilation or vasoconstriction in arterioles
what can cause vasodilation
- a decrease in ph, an increase in co2, decrease in oxygen, release of histamine or increase in body temperature
what can cause vasoconstriction
- norepinephrine
- epinephrine
- angiotensin
what do capillary walls consist of and why
- consist of a single endothelial layer
- because it helps to facilitate the exchange of fluid, oxygen, co2, electrolytes, glucose, other nutrients and wastes between the blood and the interstitial fluid
what is the function of blood
- transport system
-defense mechanism (carrying wbc and antibodies) - promotes homeostasis
- controlling body temp
- contains clotting factors
how much blood does the human body contain and what is the % composition made of
- 5L
- 55% is water and its disolved solutes
- 45% is cells
what does hematocrit refer to
refers to the proportion of cells (rbc’s) in blood and indicates the viscosity of the blood
- males have higher hematocrit than females