Lecture 8A

Question 1

Animal body types that require circulatory systems

Answer 1

More complex multicellular organisms where some cells do not have easy access to the environment for exchange of materials.

Question 2

Open circulatory system and advantages/disadvantages

Answer 2

Heart; vessels; hemolymph
Not very energy intensive, but does not allow for cell targeting

Question 3

Closed circulatory system and advantages/disadvantages

Answer 3

Heart; vessels; blood
Allows targeting certain cells with more or less material, but is more energy intensive

Question 4

Hemolymph v. Blood

Answer 4

Hemolymph: equivalent to interstitial fluid; exists in an open circulatory system
Blood: in closed systems; specialized cells that carry oxygen, as well as interstitial fluid that allows for transport of hormones

Question 5

Number of heart chambers in fish

Answer 5

Two (AV)

Question 6

Number of heart chambers in amphibians

Answer 6

three (AVA)

Question 7

Number of heart chambers in birds

Answer 7

four (AVAV)

Question 8

Number of heart chambers in mammals

Answer 8

four (AVAV)

Question 9

Features of single circulatory system

Answer 9

Unoxygenated blood is pumped through the heart to the gill capillaries, where the blood is oxygenated. The blood then goes to body tissues, loses oxygen, and returns to the heart.

Question 10

Features of double circulatory systems

Answer 10

Have either a pulmocutaneous or pulmonary circuit and a systemic circuit. The blood is oxygenated in the pulmocutaneous/pulmonary circuit, then returns to the heart and is pumped to the systemic system where oxygen is delivered to the body cells.

Question 11

pulmocutaneous v. pulmonary circuits

Answer 11

Pulmocutaneous: seen in amphibians where exchange happens through the skin; circuit goes to both lung and skin capillaries
Pulmonary: seen in mammals and birds; goes to lung capillaries

Question 12

Systemic circuits

Answer 12

In double circulatory systems; brings oxygen to the cells in the body

Question 13

Atrium

Answer 13

Receives blood
Superior portion of heart
Right: unoxygenated blood
Left: oxygenated blood

Question 14

Ventricle

Answer 14

Sends blood
Inferior portion of heart
Right: unoxygenated blood
Left: oxygenated blood

Question 15

Valve

Answer 15

Structures that prevent blood from entering a chamber once it has been pumped out.

Question 16

Artery

Answer 16

Vessels that move away from the heart; pressurized from the heart

Question 17

Vein

Answer 17

Vessels that move towards the heart; have a valve system that is not pressurized; can flatten

Question 18

Capillary

Answer 18

Smallest blood vessels that perform the most exchange and exist between arteries and veins

Question 19

Sinoatrial (SA) node

Answer 19

Valve located in right atrium that is responsible for initiating the heartbeat (pacemaker)

Question 20

Atrioventricular (AV) node

Answer 20

Valve between atrium and ventricle that prevents blood from re-entering the atrium.

Question 21

Purkinje fibers

Answer 21

Spread an electrical signal from the apex of the heart to the ventricles; coordinates the constriction of the ventricles. Constriction moves from the apex to the top of the ventricles.

Question 22

Sinoatrial node cells

Answer 22

aka “pacemaker cells”
Group of cardiac cells known for automatically generating a regular electrical signal. Action potential is specialized to perform an action on a regular basis.
Coordinate atrium constriction

Question 23

Cellular structures that allow electrical signals (action potentials) to spread directly from one cardiac muscle cell to another

Answer 23

Intercalated discs

Question 24

Name and describe the three general types of capillaries

Answer 24

Continuous - Standard across the membrane; exchange
Fenestrated - holes; leaky
Sinusoidal - imperfect seals between vessel cells; very leaky

Question 25

Name the four major components of blood plasma and their functions

Answer 25

Water - Solvent
Ions (electrolytes) - Osmotic balance, pH buffer, regulation of membrane permeability
Plasma proteins - Osmotic balance, pH buffer, defense and immunity, lipid transport, blood clotting
Substances transported by blood - Nutrients, waste products, respiratory gases, and hormones

Question 26

Three categories of cellular elements found in the blood

Answer 26

Leukocytes (white blood cells), Platelets, and Erythrocytes (red blood cells)