Download Comparative Anatomy Circulation

Comparative
Anatomy
Circulation
Putting all cells in contact with the
surrounding environment!
Circulation

Organisms of small number of cells
 DO NOT need circulation structures
 ALL cells are in contact with environment
for food, gases, and waste removal

Organisms of Large Number of Cells
 need circulation structures due to not all
cells being in contact with the environment
 Substances made/collected in one part of
the organism are needed in another part.
 Transportation Structures are needed.
Protozoa
No Circulation
Structures
 Only one cell
 All cells in contact
with the
environment

Hydra
No circulatory
structures
 2-cells thick
 All cells in contact
with the
Environment

Planaria
No circulation
structures
 Yes, multi-celled,
but the organism is
flat.
 All cells are in
contact with
environment

Earthworm





Closed Circulatory
System
5 pairs of “hearts”
Dorsal blood vessel
(along back) - to
head
Ventral blood vessel
(along belly) - to tail
Branches off at each
segment and
connects both
top/bottom vessels.
Grasshopper





Open Circulation
System
“Heart”
Dorsal Blood Vessel
trickles through the
spaces between cells
(no blood vessels)
Returns back to heart.
Human





Closed Circulation
4-chambered Heart
Right - to Lungs
Left - to Body
Pathway:

Body, Rt. Atrium, Rt.
Ventricle, Lungs, Lt.
Atrium, Lt. Ventricle,
Aorta, Body

Arteries



AWAY from heart
carry oxygen-rich
blood
thick, elastic walls
to handle pressure

allow to expand
under pressure

Capillaries





smallest of blood
vessels
allow one blood cell
through at a time
material exchange
occurs here.
Unites arteries with
veins.
BP drops

Veins





TOWARDS Heart
collect blood after pass
through capillaries.
Thin walled, less
elastic
one-way valves
near Skeletal Muscles


help pump blood
back to heart.
Exercise is
important
Blood Pressure

Body sensors



too low - surrounding smooth muscles contract
too high - surrounding smooth muscles relax
Kidneys


too high - remove water
too low - re-absorb more water
Blood


4-6 liters of blood
45% of Blood




Red Blood Cells (RBC)
White Blood Cells
(WBC)
Platelets
55% Plasms
Red Blood Cells

Hemoglobin



Iron containing protein
that increases the
blood’s ability to carry
oxygen
Produced in Bone
Marrow
No Nucleus


Life span 120 days
Replace 1% each day
White Blood Cells




Do not contain
hemoglobin
Made in bone marrow
Have nuclei (long life many months / years)
Immunity Function

destroy foreign invaders
(bacteria, virus,
parasites, etc.)
Platelets


Blood Clotting proteins
reach cut, become
“sticky” and clump
together - clot forms