PA Physiology Exam 1

purpose of the cardiovascular system

movement of substances

removal of wastes

body homeostasis

body protection

movement of substances

for cell growth and maintenance

nutrients and O2, cell building blocks, and electrolytes

removal of wastes

CO2, nitrogenous wastes, fixed acids, bilirubin

homeostasis

coordination of cellular activity, regulation of body temperature, pH, and hydration

negative feedback loop

hormones, heat, H2O, and buffers

body protection

Ab, complement proteins and WBC

blood chracterisitics

roughly 7% of body weight

plasma is 4%

cells are 3%

blood volume

5 liters

density of whole blood

1.06 g/mL

serum osmolality

275-295 mOsm/kg

helps determine distrubutuion of water between intracellular and extracellular compartments

salinity

normal saline solution is 0.9%^w/v NaCl

9 g or 154 mmol of NaCl per liter of solution

has about the same osmolality of blood

pH of blood

7.35-7.45

charge of blood

neutral

mean temperature of blood

38 C or 100 F

whole blood

natural unseparated state

plasma, RBC, WBC, and platelets

centrifusion of blood

3 layers are visible

top layers contains plasma, 55% of volume

thin middle layer called the buffy coat, contains white cells and platelets

bottom layer contains RBCs, 45% of volume, called hematocrit (Hct)

hematocrit

RBC fraction of blood

buffy coat

contains WBCs and platelets

plasma vs serum

plasma has clotting factors while serum does not

2 process of separating blood

• blood sample is collected into tubes containing an anticoagulant and then if the whole blood is spun down and cells and plasma are removed

• or blood is collected into tubes that promote clotting and then the fluid remaining after the removal of the clot is called serum

serum

plasma with the fibrinogen and most clotting factors removed

Albumin

serum protein

keeps fluids in vessels

albumin should be > globulins

charge of albumin

negative

where is albumin made

liver

Albumin in urine filtration

is limited due to its size and charge

hypoalbuminemia

liver disease and malnutrition or renal loss decreases production of albumin

increases capillary fluid loss which causes edema

albumin and osmotic pressure

major contributor to colloid osmotic pressure

helps regulate distribution of water between intravascular and extravascular spaces

colloid osmotic pressure

the pulling force exerted by large proteins in the blood plasma that draws water back into the blood vessels and helps keep fluid balance steady across capillary walls

hypoalbumenemia

increases fluid loss in the vessels and leads to edema

what does albumin carry

hydrophobic substances and binds cations

ex. steroids, thyroid hormones, and bilirubin

solution

particles that remain suspended in a liquid

colloid

proteins and large molecules are evenly dispersed without dissolving entirely

mixture

separates and keeps its own identity

globulins

a diverse collection of proteins that may be separated into 4 groups according to differences in their charge desnity that affect how they move in an electric field

four groups of globulins

alpha1, alpha2, beta1, and gamma-globulins

SPEP

serum protein electrophoresis

separates serum proteins based on their charge density

gamma globulins

the largest

broad, slow moving peak on SPEP

largely made up of antibodies

slowest globulin to migrate toward anode

anode

positive

negative charged particles move to it

catode

negative

positive charge particles migrate towards it

migration pattern in serum protein electrophoresis

albumins- the most in quantity and travel the furthest

alpha 1- least in quantity and travel the second furthest

alpha 2 - travels the third furthest

beta - travels the second least

gamma-globulins - travels the least, broadest group

alpha 2, beta, and gamma are all about the same quantities

what does it mean when a peak on a serum protein electrophoresis is narrow or broad

narrow- proteins are similar

broad- proteins are less similar

gamma- globulins are also called what

immunoglobulins

plasma

in addition to the preoteins found in serum, plasma contains fibrinogen and clotting factors

components of plasma

mainly water

ions

organic molecules

trace elements and vitamins

gasses

alpha and beta globulins job

transport iron, lipids, and fat soluble vitamins

fibrinogen

produced by the liver, essential in blood clotting

genes vs proteins amounts

many more proteins than genes because one gene can be modified to make many different types of proteins

formed elements

cells and cell fragments

RBC

WBC

granulocytes

agranulocytes

platelets (thrombocytes)

granulocytes

neutrophils

eosinophils

basophils

agranulocyte

lymphocyte

monocyte

amount of hemoglobin in males

13-17 g/dL

amount of hemoglobin in females

12-15 g/dL

hemoglobin

measure of most important characteristic of blood, ability to carry O2

hematocrit in males

40-52%

hematocrit in females

36-47%

hematocrit

quick and easy assessment of Hb content

mean corpuscular volume

MCV - corpuscular is interchangeable with cell

helps identify cause of RBC abnormalities

low mean corpuscular volume

microcytosis

anemias due to iron deficiency

small cells

high mean corpuscular volume

macrocytosis

anemia due to B12 or folate deficiency

large cells

red blood cell distribution width (RDW)

measure of variation in cell sizes

addresses whether there is a single population of relatively uniform cells

why would there be two peaks in a red blood cell distribution width (RDW)

blood transfusion

patients RBCs and then the donors RBCs

reticulocytes

0.5-1.5% of RBCs

young cells recently released

platelets

140-400 × 10³ microliters

turnover of RBC and reticulocyte replacement rate

1% of RBC per day so 1% of RBCs are reticulocytes

why does blood have a resistance of flow in vessles

because it is viscous

what makes blood viscous

η is most dependent on hematocrit

η

eta

the viscosity of the fluid

polycythemia

an increase in RBCs leads to an increase in hematocrit which creates blood that is too viscous so η is high

high η means what

more viscous blood

low η means what

less viscous blood

an increase in η can also cause what

and increase in systemic vascular resistance (SVR) which then increases the afterload on the heart, sludging, and leads to thrombosis and CNS effects

hematopoiesis

process of blood cell production

hematopoietic stem cells

all formed elements are derived from this single population

hematopoietic stem cells differentiate into

common myeloid progenitors and common lymphoid progenitors

common myeloid cells differenciate into what

megakaryocytes

erythrocytes

mast cells

myeloblast

common lymphoid progenitor cells differentiate into what

natural killer cell and small lymphocyte

what is the most numerous of the formed elements

RBCs

in adults where are RBCs made

the red marrow in flat bones, vertebrae, and proximal ends of long bones

erythropoietin (EPO)

a hormone produced primarily by the kidney in response to lowered tissue oxygenation to stimulate erythrocyte production

what stimulates erythopoietin release

factors that decrease renal tissue oxygen delivery

synthetic (EPO)

stimulate RBC production

physical features of RBCs

anucleate

biconcave discs with central pallor

central pallor makes up what diameter of a RBC

1/3 to ½ of its diameter

job of RBCs

carry O2 from lungs to tissues and CO2 from tissues to lungs

shape of RBCs is important why

increases surface area for gas exchange

is deformable to ease passage through capillaries

RBCs cytoskeleton

composed primarily of proteins actin and spectrin that maintains the cell shape giving it stability and yet flexibility needed for the cell to deform to fit through tight spaces

hereditary spherocytosis

a defect in spectrin so interferes with a normal cell shape

cells are spheroid

lack central pallor

appear small yet MCV is greater than normal

cells are unable to normally deform and so are prone to hemolysis

carbonic anhydrase in RBCs

important role in transportation of CO2 and buffering H+

there is a lack of mitochondria in RBC so how is energy produced

90% of the energy needed is generated anaerobically from glucose

glucose-6-phosphate dehydrogenase (G6PD)

an enzyme needed to maintain glutathione in its reduced state so that it is able to scavenge reactive oxygen species to protect RBC proteins, especially Hb

deficient glutathione leads to what

Hb denatures and creates Heinz bodies, cell membrane is damaged and then lysis occurs

G6PD deficiency is what kind of disorder

an X-linked recessive genetic disorder

G6PD causes what

hemolysis under oxidative stress such as exposure to some drugs, infection, and ingestion of fava beans

G6PD deficiency is usually

self limited

what population is G6PD most common in

African, Asian,a nd Mediterranean descent

Heinz body

bulge in RBC created by the denaturation of hemoglobin

bite cell

results from removal of Heinz bodies by the spleen

average erythrocytes life span

100-120 days

on average how many RBCs are replaced everyday

1%

how long are reticulocytes distinguishable for

1 day

reticulocyte structure

slightly larger than mature cells and slightly bluish (polychromatophilic) from residual RNA