Chapter
42
Animations
Study Guide
Unit 7: Animal Form and Function
Circulation and Gas Exchange
Review
Aquatic animals
have
for gas exchange.
Fishes
have a
-chambered heart with single circulation, while
amphibians
have a
chambered heart with double circulation.
Mammals have a
-chambered
heart
with double circulation, allowing for an
way of life.
Mammalian double
circulation
is regulated by
in the heart that direct one-way flow of blood.
The heart contracts and relaxes in a
cycle.
The contraction, or pumping, phase is called
; the relaxation, or filling, phase is called
. Blood
is generated in both
phases.
The
(SA) node, or
pacemaker,
sets the timing of contraction of all cardiac muscle cells.
The heart and lung are major organs of the
system
that supplies mammals with oxygen from the atmosphere.
Exercise:
The Human Respiratory System
Chapter
43
Animations
Study Guide
Unit 7: Animal Form and Function
The Immune System
Review
Animals have two major kinds of defense against
pathogens
such as
,
, or other foreign substances.
immunity
is acquired at birth before any exposure to pathogens and involves rapid,
responses.
(adaptive)
immunity
develops only after exposure to the inducing agent and involves
and
.
Innate immunity:
External defenses
The
system
provides a physical barrier.
In the trachea,
ciliated
cells sweep mucus and entrapped matter upward, away from lungs.
Internal defenses
Phagocytes are types of
blood
cells
which
ingest
invading microorganisms by
.
The
system
contains a type of phagocyte called
, as well as
, which carry out defensive actions at
nodes.
Local
response
is initiated when injured cells release
and other chemicals.
Acquired immunity involves
lymphocytes
of two types:
and
cells.
Lymphocytes circulate through the
and have antigen
receptors
cell receptors have two
of chains that bind to specific, intact
.
cell receptors have one
and one
chain, and bind to small fragments of antigens, which in turn bind to
(Major Histocompatibility
Complex)
proteins involved in nonself recognition.
(antibody-mediated) immunity:
In the
immune response, clonal selection of B
cells
produces short-lived
cells that secrete antibodies and long-lived
cells.
In the
immune response,
cells facilitate a
faster,
more efficient response.
Humoral immunity summary:
mediated immunity is similar to humoral immunity, but involves the clonal selection of
T cells.
T cells are activated upon exposure to antigens and stimulate
T
cells.
Cytotoxic T cells attack infected and
cells, and also
tissues by secreting
and other enzymes that
destroy
the target cell.
Cell-mediated immunity summary:
Exercise: Immune Responses.
The
ABO
blood group is a result of antibodies to nonself
on
blood cells.
Allergies are exaggerated (hypersensitive)
responses
to antigens called
.
Acquired Immunodeficiency Syndrome (AIDS) is caused by the Human Immunodeficiency
(
HIV
), and results in a loss of
T cells.
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