Functions of the Circulatory System
• Transport of…– Respiratory gases– Nutrients– Wastes– Hormones
• Defense from…– invaders– blood loss
Blood components
• Plasma• Yellow liquid
(90% water)
• Transports…– Food– Wastes– Hormones– Fibers , etc
Blood components
• Red blood cells
(erythrocytes)• Small, biconcave
cells without nucleus• Hemoglobin =
red pigment, gives ability to…
• Transport oxygen
Blood components
• White blood cells(leucocytes)
• Large, clear, ameboid, cells with nucleus & granules
• Fight infection (by phagocytosis)
Heart
• Pericardium – sac surrounding heart,
to prevent friction
• Chambers:• Atria (right & left) = receive blood • Ventricles (right & left) pump blood• Valves = prevent backflow of blood
– Between atria & ventricles– Between ventricles & arteries
Lymphatic System Function
• Series of vessels that collect fluids lost by blood and returns the blood to the circulatory system
• Main organs: – thymus, spleen. lymph nodes, lymph vessels
• Works in conjunction with the immune system
Lymph Organs
Primary function: – to trap and filter
microorganisms that may have invaded the body
(May become enlarged when many microbes are trapped, indicating illness)
Anatomy of the Respiratory System• Nasal cavity
– To warm, moisten and filter air
• Pharynx – Throat; for transporting
air and food
• Epiglottis – Cartilage flap; to prevent food
from entering lungs
• Larynx – voice box: voice pitch
controlled by… – tension & thickness of cords
Anatomy of Respiratory system• Trachea
– Windpipe; with cartilage rings to prevent collapse
• Within lungs:– Bronchi = 2 large branches– Bronchioles = smallest
branches into...– Alveoli =
tiny air sacs where gas exchange occurs
• Diaphragm – breathing muscle
Breathing
• Inspiration
– Diaphragm contracts, chest increases, pressure decreases, air comes in
• Expiration
– Diaphragm relaxes, chest decreases, pressure increases, air forced out
Types of Respiration
• External – Within lungs– Oxygen enters blood,
CO2 exits blood
• Internal – Within body tissues– Oxygen enters cells,
CO2 exits cells