biology chapter 5 Flashcards
protozoans
movement of gases and nutrients is accomplished by simple diffusion within the cell
cnidarians
have body walls that are two cells thick. All cells are in direct contact with either the internal or external environments so there is no need for a specialized circulatory system
arthropods
have open circulatory sytems in which their blood-like fluid (interstitial fluid) is in direct contact with the body tissues. The fluid is circulated primarily by body movements. Fluid flows through a dorsal vessel and into spaces called sinuses where exchange occurs
annelids
use a closed circulatory system to deliver materials to cells that are not in direct contact with the external environment
aorta
which branches into a series of arteries
capillaries
converge into venules, and eventually into veins, leading deoxygenated blood back toward the heart
right side of heart
pumps deoxygenated blood into pulmonary circulation (toward the lungs)
left side of heart
pumps oxygenated blood into systemic circulation (throughout the body)
atria
two upper chambers. Thin walled
ventricles
two lower chambers. Are extremely muscular
left ventricle
more muscular than the right ventricle because it is responsible for generating the force that propels systemic circulation and because it pumps against a higher resistance
atrioventricular valves
located between the atria and ventricles on both sides of the heart, prevent backflow of blood into the atria
tricuspid valve
the valve on the right side of the heart that has three cusps
mitral valve
valve on the left side of the heart that has two cusps
semilunar valves
have three cusps and are located between the left ventricle and the aorta (the aortic valve) and between the right ventricle and the pulmonary artery (the pulmonic valve)
heartbeat
made up by the systole and diastole
systole
is the period during which the ventricles contract
diastole
is the period of cardiac muscle relaxation during which blood drains into all four chambers
cardiac output
is defined as the total volume of blood the left ventricle pumps out per minute. = heart rate x stroke volume
heart rate
number of heartbeats per minute
stroke volume
volume of blood pumped out of the left ventricle per contraction
sinoatrial (SA) node
a small mass of specialized tissue located in the wall of the right atrium. It spreads impulses through both atria, stimulating them to contract simultaneously
autonomic nervous system
modifies the rate of heart contraction
arteries
are thick walled, muscular, elastic vessels that transport oxygenated blood away from the heart– except for the pulmonary arteries, which transport deoxygenated blood from the heart to the lungs
veins
are relatively thinly walled, inelastic vessels that conduct deoxygenated blood towards the heart– except for the pulmonary veins, which carry oxygenated blood from the lungs to the heart
capillaries
have very thin walls composed of a single layer of endothelial cells across which respiratory gases, nutrients, enzymes, hormones, and wastes can easily defuse. They have the smallest diameter of all three types of vessels; red blood cells must often travel through them single file
lymph nodes
are swellings along lymph vessels containing phagocytic cells (leukocytes) that filter the lymph, removing and destroying foreign particles and pathogens
plasma
is the liquid portion of the blood
erythrocytes (red blood cells)
are the oxygen carrying components of blood
oxyhemoglobin
when hemoglobin binds oxygen
leukocytes (white blood cells)
are larger than erythrocytes and serve protective functions
platelets
are cell fragments that lack nuclei and are involved in clot formation as well as wound healing
serum
the fluid left after blood clotting
humoral immunity
involves the production of antibodies
cell-mediated immunity
which involves cells that combat fungal and viral infection
lymphocytes
are responsible for both of these immune mechanisms
immunoglobulins
are complex proteins that recognize and bind to specific antigens and trigger the immune system to remove them
active immunity
refers to the production of antibodies during an immune response
passive immunity
involves the transfer of antibodies produced by another individual or organims
gamma globulin
the fraction of the blood containing a wide variety of antibodies, can be used to confer temporary protection against hepatitis and other diseases by passive immunity
skin
is a physical barrier against bacterial invasion
macrophages
engulf and destroy foreign particles
interferons
diffuse to other cells, where they help prevent the spread of the virus
antigens
are macromolecules that are foreign to the host organism and trigger an immune response
type AB blood
is the “universal recipient” as it has neither anti-A nor anti-B antibodies
type O blood
is considered to be the “universal donor”; it will not elicit a response from the recipient’s immune system since it does not possess any surface antigens
stem
is the primary organ of transport in the plant
vascular bundles
run up and down the stem
xylem
are thick-walled, often hollow cells located on the inside of the vascular bundle (towards the center of the stem). They carry water and minerals up the plant and their thick walls give the plant its rigid support
sapwood
what the outer layer of xylem is called
transpiration pull
as water evaporates from the leaves of plants, a vacuum is created which pulls water up the stem
capillary action
any liquid in a thin tube will rise due to the surface tension of the liquid and interactions between the liquid and the tube
root pressure
water entering the root hairs exerts a pressure which pushes water up the stem
phloem
are thin walled cells on the outside of the vascular bundle. They usually transport nutrients (especially carbohydrates produced in the leaves) down the stem
cambium
(two layers thick) are the actively dividing, undifferentiated cells which give rise to xylem and phloem.
fibrovascular bundle
composed of the phloem, cambium and xylem layers
gross structure of a woody stem
proceeding from the outside inwards, the following layers occur: epidermis (outer bark), cortex, phloem, cambium, xylem, and pith (tissue involved in storage of nutrients and plant support)
root
functions to absorb materials through the root hairs and anchor the plant
root hairs
are specialized cells of the root epidermis with thin-walled projections. They increase the surface area for absorption of water and minerals from the soil
meristem
refers to the actively dividing, undifferentiated cells of a plant
