Circulation and Respiration
Circulatory System
Functions
Blood Pressure Regulation
Facilitates exchange and transport of gases, nutrients and other materials throughout the body
Blood pressure too high: cardiac output decreases and blood vessels dilate
Blood pressure too low: cardiac output incresases and blood vessels constrict
Componenets
Cardiovascular System
Circulating Fluid (Blood)
Central Pump (Heart)
Vascular Network (Blood Vessels)
Types
Open (fluid circulates freely among cells)
Closed (blood stays within vascular network)
"Single" Circulation (one circuit)
"Double Circulation" (pulmonary and systemic circuits)
2-chambered heart
3-chambered heart
(mixing of oxygenated and deoxygenated blood in single ventricle)
4-chambered heart
(separation of oxygenated from deoxygenated blood between 2 ventricles)
Human Circulatory System
Pathway
Heart
(4 chambers separated by valves)
Left Atrium
(receives blood from pulmonary circuit
via pulmonary veins)
Right Atrium
(receives blood from systemic circuit
via superior and inferior vena cavae)
Left Ventricle
(pumps blood to systemic circuit
via aorta)
Blood Vessels
Capillaries
(fine, thin vessels that facilitate exchange
between blood and tissues via diffusion)
Venules / Veins / Vena Cavae
(thick vessels with valves that return blood
back to heart via skeletal muscle contractions)
Aorta / Arteries / Aterioles
(thick, elastic vessels that carry blood
away from heart under pressure)
Blood
Cellular Components
Plasma
Water
Dissolved Substances
White Blood Cells
(fight infection)
Platelets
(aid clotting by via fibrin)
Red Blood Cells
(carry oxygen via hemoglobin)
Right Ventricle
(pumps blood to pulmonary circuit
via pulmonary arteries)
Blood Flow
Cardiac Cycle
Blood Pressure (force on walls of blood vessels)
Phases
Systole: contraction phase
(atria pump blood into ventricles; ventricles pump blood out;
higher pressure)
Diastole: relaxation phase
(blood flows into atria from pulmonary and systemic circuits;
lower pressure)
Nodes
SA node
(natural pacemaker that sets tempo of heartbeat / pulse,
spreading from atria)
AV node
(relay point of electrical impulses
from atria to ventricles)
Normal: 120/80
High: over 140/90
Risk factors: aging, obesity, diabetes,
salt, alcohol, smoking, lack of exercise
Dangers: artherosclerosis, heart attack, stroke,
vision loss, kidney disease
Respiratory System
Arrhythmia (irregular heartbeat
that may need correction via artificial pacemaker)
Functions
(coordination with respiratory system)
absorb oxygen from environment
remove carbon-dioxide from body
oxygen transported from respiratory surface to tissues bound to hemoglobin in red blood cells
(needed for cellular respiration)
carbon-dioxide transported from tissues to respiratory surface
dissolved in plasma as bicarbonate ions
(waste product from cellular respiration)
Respiratory Surfaces
Tracheae
Gills
Skin
Lungs
Human Respiratory System
Upper Respiratory Tract
Pharynx
(epiglottis controls opening to windpipe)
Lower Respiratory Tract
Nasal Cavity
(nose hairs and mucus filter air)
Trachea
(ciliated cells and mucus filter air)
Bronchi
(left and right branches to lungs)
Larynx
(voice box makes sounds)
Bronchioles
(smaller branching passageways in lungs)
Alveoli
(air sacs provide large surface area for gas exchange with capillaries in lungs)
Lungs
Negative Pressure Breathing
Dangers from Smoking
Inhalation
Exhalation
diaphragm contracts and moves down
because chest volume increases, air pressure in chest cavity is lower than external air pressure
rib muscles contract and rib cage expands
air flows into lungs
diaphragm relaxes and moves up
because chest volume decreases, air pressure in chest cavity is higher than external air pressure
rib muscles relax and rib cage gets smaller
air flows out of lungs
smoke damages cilia lining respiratory tract
tar and toxins damage alveoli in lungs and can lead to cancer
may require supplemental oxygen or lung transplant