body fluids and circulation Flashcards
outer layer of blood vessels
tunica externa ; fibrous connective tissue and collagen fibres
middle layer of blood vessels
tunica media ; smooth muscles and elastic fibres
tunics interna/intima
lining of thin squamous epithelium,yellow elastin fibres
function lf arteries
distribute blood from heart to body
function of veins
carry blood from body into heart
where is tunics media thicker
arteries
where are walls of blood vessels thicker
arteries
do arteries have valves
no
why is the heart called myogenic
because activities of heart are regulated by specialised nodal tissue
function of medulla oblongata in nervous control of hert
can moderate cardiac unction through ANS ; sympathetic and parasympatheic nerves modify the rate of depolarization
function of sympathetic nerves in nervous control
nerve endings release noradrenaline which accelerates heart beat, strength of ventricular contraction, cardiac output
parasympatheic nerve function
erve endings release acetylcholine, decreases heart beat, speed of action potential conduction, cardiac output
how do adrenal medullary hormones increase cardiac output
by release of adrenaline and noradrenaline
what type of tissue is blood
specialized fluid connective tissue
how do sponges and coelentratstes circulate water
through body cavities
what does blood contain
plasma, fluid matrix, formed elements
describe plasma
straw Coloured, viscous fluid
composition of plasma
constitutes 55% of blood, 90-92% is water
percentage of proteins present in blood
6-8%
major proteins present in blood
fibrinogen, albumin, globulin
fibrinogen function
clotting factor
globulin
defence mechanisms of body
albumin
osmotic balance
plasma also contains
minerals like Na+,Ca2+,Mg2+,HCO3-,Cl-, glucose, amino acids, lipids
nature of minerals present in blood
always in transit
in what form are coagulation factore present in blood
inactive form
what is plasma without clotting factors called
serum
formed elements of blood
erythrocyte’s,leucocytes,thrombocytes
most abundant lf all cell in blood
RBCs
how many RBCs are present in blood on avg
5 mil-5.5mil per mm³ of blood
in most mammals rbcs are
biconcave in shape, devoid of nucleus
oval shaped rbcs found in
camel and llama
why do rbcs lack nucleus and other organelles
to accomodate more space for haemoglobin
what enzyme does rbc contain
carbonic anhydrase
red coloured iron containing protein rbcs
haemoglobin
amt of haemoglobin per 100 ml of blood
12-16 gm
life span lf rbcs
120 days
graveyard of rbcs
spleen
where is rbcs formed in adults
bone marrow
formation of rbcs in embyo occurs in
yolk sac
formation of rbcs is called
erythropoeisis
formation lf blood is called
haemopoeisis
leucocytes are also called
wbcs
why are leucocytes colourless
they lack haemoglobin
are wbcs nucleated
yes
how many wbcs are found in blood
6000-8000 per mm³ of blood
life span lf wbcs
short lived
locomotion of wbcs
amoeboid
movement of leucocytes through pores in capillary walls
diapedesis
types of leucocytes
granulocytes, agranulocytes
types of agranulocytes
lymphocytes and monocytes
what percentage of lymphocytes are present in blood
20-25%
second most numerous type of leucocytes
lymphocytes
function lf lymphocytes
responsible for immune response of body
