Download Chapter 42 / Internal Transport: Circulatory Systems I. Introduction A

Randa, Bio102
Chapter 42 / Internal Transport: Circulatory Systems
I. Introduction
A. General components
1. Blood--transport material; has pigments
2. Pumping organ (heart)--move blood through body
3. Spaces or blood vessels--carry blood to different parts of body
B. Types
1. Open
a. heart pumps blood into open space
b. blood re-enters heart through holes or open vessels
c. found in arthropods and mollusks
2. Closed
a. completely closed network of blood vessels
b. may or may not have heart
c. substances diffuse through vessels to surrounding cells
d. more efficient
e. found in cephalopods, annelids, chordates
3. No circulatory system
a. diffusion
--gas exchange through skin or pseudocoelom
--other systems move nutrients and wastes
--body movements important
b. gastrovascular cavity
--circulating fluid
--body movements important
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II. Blood -- Vertebrates
A. Plasma
1. Mainly water; also proteins, salts, gases, hormones, dissolved nutrients
2. Proteins
a. clotting
b. immune response
c. maintain proper fluid volume
d. maintain proper pH
B. Cells
1. Erythrocytes
a. biconcave disk
b. contains hemoglobin
c. lifespan ca. 120 days
2. Leukocytes
a. granular
1) neutrophils
2) eosinophils
3) basophils
b. agranular
1) monocytes
2) lymphocytes
leukemia = leukocyte cancer
3. Thrombocytes
a. play an important role in clotting for stoppage of bleeding
b. involves clotting factors
Hemophilia = one of clotting factors absent; inherited trait
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III. Blood Vessels
Artery: carries blood away from heart; muscular, elastic walls
Arterioles and Metarterioles: can vasoconstrict and vasodilate
Capillaries: smallest vessels
Venules and Veins: Carry blood toward the heart; have valves
IV. Heart
A. Number of chambers
valves, walls
atria: receive blood from body via veins
ventricles: receive blood from atria; pump blood into arteries
1. 2-chambered heart
1 atrium, 1 ventricle
e.g., fish
2. 3-chambered heart
2 atria, 1 ventricle
e.g., amphibians
3. Incomplete 4-chambered heart
2 atria, 2 ventricles partially separated
e.g., reptiles (except crocodiles)
4. 4-chambered heart
2 atria, 2 ventricles
separates blood flow into Pulmonary and Systemic Circuits
e.g., crocodiles, birds, mammals
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Know pattern of blood flow through 4-chambered heart.
B. Parts of the heart
pericardium
septum
AV valves
semilunar valves
C. Pacemaker of heart
1. conduction system that ensures rhythmic beating
2. specialized cardiac muscle tissue
3. rhythm results in 2 heart sounds--valve closures
pulse = expansion and elastic recoil of an artery
4. conduction of pacemaker → electrical activity
can record via EKG (ECG)
5. pacemaker regulated by nervous system
a. can function on its own but may adjust according to body’s needs
b. different effects of sympathetic and parasympathetic systems
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