exam 2 class 10 Flashcards
what is the equation for hemoglobin?
Hb + O2 ->HbO2
1 hemoglobin molecule can bind to how many oxygen molecules?
4
Hemoglobin bound to oxygen
oxyhemoglobin (HbO2)
Amount of oxygen bound to hemoglobin at any given is expressed as?
% saturation of Hb
If all binding sites on all hemoglobin molecules are occupied by oxygen
molecules then what?
the blood is 100% oxygenated, or saturated with oxygen
If half the available binding sites are carrying oxygen?
the hemoglobin is 50%
saturated, and so on
relationship between
and how much oxygen binds to hemoglobin in vitro
Oxyhemoglobin saturation curves
At normal alveolar and arterial (100 mm
Hg) how much hemoglobin is bound to O2?
98% of the hemoglobin is bound to O2
Above 60 mm Hg, hemoglobin is more than 90% saturated?
to maintain near-normal
levels of oxygen transport
having a higher
oxygen affinity than adult hemoglobin (HbA)
Fetal hemoglobin (HbF)
how long does it take for babies to automatically switch from producing
HbF to producing HbA?
2 years for the switch to be complete
Shift in Hb saturation curve that results from a change
in pH is called the?
Bohr effect
At a of 40 mm Hg (equivalent to a resting cell) and pH of 7.4, hemoglobin is about _______ saturated
75%
At the same if the pH falls to 7.2, the percent
saturation decreases to about 62%. Hb releases
______ more oxygen at pH 7.2 than they do at pH
7.4
13%
When does body undergo shifts in blood pH?
during exercise
Increasing temperature decreases ?
the affinity of Hb for O2
Carbon dioxide increases ____________________ and lowers ______________
-hydrogen ion concentration
-tissue pH
more CO2 in blood
lower pH
what is the inner lining of blood vessels made of?
thin layer of endothelium
walls of blood vessels are composed of?
(1) smooth muscle
(2) elastic connective tissue
(3) fibrous connective tissue
narrows the diameter
of the vessel lumen
vasoconstriction
widens the diameter
of the vessel lumen
vasodilation
arterioles, capillaries, small post capillary vessels (venules) are all called?
microcirculation
have a lining that contains pores that let only small molecules pass through. Nervous system, skin and lungs
Continuous capillaries
have larger openings between the cells that allow the quick exchange of substances. Kidneys,
small intestine and endocrine glands
Fenestrated capillaries
discontinuous, have even larger gaps and pores. Liver, spleen, lymph nodes, bone marrow and endocrine glands
Sinusoidal capillaries
what in the veins prevent backflow of blood
valves
When the skeletal muscles compress the veins, they force blood toward?
the heart (skeletal muscle pump)
contraction of the ventricles pushes blood into the elastic arteries causing them to stretch
ventricular contraction
elastic recoil in the arteries maintains driving pressure during ventricular diastole
ventricular relaxation
where is blood pressure the highest?
in the arteries
blood pressure decreases when?
blood flows through the circulatory system
Highest pressure in the
circulatory system created by the contraction of ventricles of heart
Systolic Pressure (SP)
Lowest pressure in the
circulatory system associated with the
relaxation of ventricles of heart
Diastolic Pressure (DP)
Abnormally high or low arterial blood pressure can be indicative of?
a problem in the cardiovascular system
blood pressure falls too low
hypotension
blood flow and oxygen
supply to the brain are impaired, and the person may become dizzy or
faint
hypotension
blood pressure is chronically elevated
hypertension
high pressure
on the walls of blood vessels may cause weakened areas to rupture and bleed into the tissues
hypertensive
rupture occurs in the brain
cerebral hemorrhage
cerebral hemorrhage and may cause
a stroke
rapid pressure increase that occurs when the left ventricle pushes
blood into the aorta can be felt as a
pulse or pressure wave
measure of the strength of the pressure wave,
is defined as systolic pressure minus diastolic pressure
pulse pressure PP
PP=?
SP-DP
Arterial pressure is pulsatile, so we use a single value
the mean arterial pressure (MAP)
MAP =?
DP + 1/3 (SP- DP)
Distribution of systemic blood varies according to?
the metabolic needs
of individual organs and is governed by a combination of local control
mechanisms and homeostatic reflexes
distribution of blood to tissues is represented as
(1) % of total flow
(2) Volume per 100 g of tissue per min
(3) Absolute rate of flow (L/min)
