Bio 004, College of the Desert

Facilitates exchange of materials, providing a rapid long-distance internal transport system that brings resources close enough to cells for diffusion to occur.

Circulating fluid is pumped through open-ended vessels and flows out among the cells. - Example: arthropods (most invertebrates)

Circulating fluid is confined to vessels and is distinct from the fluid found around cells (interstitial fluid). Example: Some invertebrates, vertebrates.

• Open: Requires less energy in operation & maintenance and provides support during molting.

• 2. Closed: More efficient at moving materials in highly developed vertebrates.

• Contains both the heart and blood vessels.

• Atria - receive blood

• Ventricles - pump blood

• Arteries - carry blood from heart

• Arterioles - connect arteries to capillaries

• Capillaries - infiltrate every organ

• Venules - connect capillaries to veins

• Veins - carry blood to heart

• Blood is trans-ported through both pulmonary and systemic circuits.
• 1) Pulmonary circuit
• 2) Systemic circuit
• 3) Heart

• Muscular organ consisting of four chambers, pumping blood throughout body.
• 1) Atria: Collect blood returning to heart and pump it into ventricles; Ventricles – pump blood.
• 2) Ventricles: Pump blood out of heart to the other body organs; more powerful than atria.
• 3) Valves: Prevent backflow and keep blood moving in the correct direction.

Prevent backflow and keep blood moving in the correct direction.

Collect blood returning to heart and pump it into ventricles; Ventricles – pump blood.

• 1 complete cycle of pumping and filling

• Systole = contraction

• Diastole = relaxation

• Heart rate = number of beats/minute (60 – 80)

Sets rate and timing at which all cardiac muscle cells contract. Located in wall of rt. atrium.

(AV) node – relay which in-sures ventricles contract after atria (0.1 sec). Located in wall btw. rt. atrium & rt. ventricle.

• 1) Connective tissue with elastic fibers (outer).
• 2) Smooth muscle with elastic fibers (middle).
• 3) Endothelium (inner).

• Hydrostatic pressure that blood exerts against the walls of vessels which propels blood.

• *Much greater in arteries than veins

• *Gravity affects bp in larger land animals

• Blood Pressure

• Humans: heart - head = 0.35m, 27 mm Hg

• Giraffe: heart - head = 2.5 m, 250 mm Hg

• Dinosaurs: heart - head = 10 m, 760 mm Hg

• Rhythmic contractions of arteries caused by pressure of blood forced into arteries during systole.

• Systole = contraction (120).

• Diastole = relaxation (80).

• Liquid matrix with cells in suspension (90% water; 55% of blood composition.

• Plasma proteins – buffer, maintain osmotic balance, contribute to blood’s viscosity.

• 1) Most numerous (25 trillion
• / 5L).

• 2) Small (7 – 8.5 µm in
• diameter).
• 3) Function: Transportation
• 4) Anemia: An abnormally low number of
• red blood cells or amount of Hb.
• 5) Mammalian RBC’s lack nuclei
• & mitochondria (ATP generated by anaerobic metabolism).
• 6)
• Hemoglobin:
• Iron-containing
• protein that transports oxygen.

• Each Hb binds 4
• mols. of O₂
• Each RBC carries1
• bil. mols. of O₂

• 1)25 – 30 billion / 5L
• 2)Large, nucleated – 5 different types
• 3)Function: Spend majority of time patrolling for pathogens.
• 4)Leukemia: Cancerous lines of stem cells that produce WBC’s.

• 1. Fragments of cells (2 – 3 µm in diameter)

• 2. Lack nuclei.

• 3. Originate in bone marrow.

• 4. Function: Blood clotting.

• 1)
• Injuries trigger self-sealing ma-terials in blood to stop
• bleeding: Fibrin - active clotting factor. Platelets - recruited to plug bleed.

• 2) Thrombus: Formation of clot in
• absence of injury, coagulating inside a blood vessel.
• 3) Embolus: Traveling clot

• Disorders of the heart and blood vessels.

• 1)Account for more than 50% of US deaths.

• 2) Causes:

• a) Genetic predisposition

• b) Sedentary lifestyle

• c) Diet

• d) Smoking

Death of nervous tissue in the brain due to blockage or rupture of arteries in the head.

• Animal’s body part where gas is exchanged
• 1)Gas exchange occurs by diffusion.
• 2)Moist, thin with large surface area.
• 3)Larger in endotherms than ectotherms (metabolic activity).

• Extensions or outfoldings of the body’s surface in aquatic animals.

• Great amount of surface area

• Can remove 80% of dissolved O2 in water

• Air tubes branching through-out the body of insects.
• Trachea open to the outside
• Finest branches extend to surface of almost every cell.

• Restricted to

• a specific region – uses circulatory system to expand functions

• *Found in snails, spiders, and terrestrial vertebrates.

• 1) Breathing

• 2) Diaphragm