Download Biology 2

Comparative Anatomy 2
Biology 2
Thursday, April 4, 2013
Comparative Anatomy
• study of similarities and differences
between organisms
• circulatory systems - open vs closed,
single loop vs double loop
• respiratory systems - skin, gills, trachea,
lungs
Thursday, April 4, 2013
Excretory Systems
• osmoregulation - salt and water balance
• remove nitrogenous waste from protein breakdown
• Protein metabolism produces ammonia
• Fish and aquatic invertebrates excrete
ammonia directly to water across skin or gills
• Mammals, Adult amphibians and sharks convert
ammonia to urea which is less toxic and
requires less water for excretion.
• Birds, reptiles and insects convert ammonia to
uric acid which requires very little water for
excretion
Thursday, April 4, 2013
cell/organism
water
x ion or molecule
Osmoregulation
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
isotonic
no net movement
of water or salts
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H2O
x
Fresh water
body has more
solutes than
surroundings
x x
x
H
2O
x
x
x
x
x
x
x
x
x
x
x
x x
x
x
x x
x x
x
x x x
Salt water
if body has less
solutes than
surroundings
No excretory system
• many marine invertebrates
• release ammonia across surface
• body is isotonic to seawater
x x
x
x
x
x
x
x
x
x
x
x
x
x x x
x
x
x x x x
x x
x x
x
x x x
Thursday, April 4, 2013
Protonephridia
• found in flatworms
• earliest excretory system in terms of evolution
• there are numerous flame cells which are ciliated cells that
draw water into the system.
• a system of tubules carries the water to excretory pores in
skin
• mostly salt/water balance
http://www.youtube.com/watch?v=Rb_3KIB4CmE
Thursday, April 4, 2013
Malpighian Tubules
• these are tubules that empty into gut in abdominal region
•collect wastes from coelom
•found in insects
•see diagram on handout and in textbook
Thursday, April 4, 2013
Green Gland
• found in crustaceans at base of antennae
•excretes excess salt
•other waste diffuses across gills
•see diagram on handout and in text
Thursday, April 4, 2013
Metanephridia
• found in annelids, pair in each segment
•excrete excess salt
• a funnel shaped nephridiostome collects fluid from coelom.
•A convoluted tubule carries material to nepridiopore which is
an opening in the body wall. The tubules cross the septa into
the adjacent segment.
•Salt and water are adjusted as fluid flows through tubule.
•See diagram on handout and in text.
Thursday, April 4, 2013
Urinary System
• found in vertebrates
• see diagram in text and handout
• in mammals, it consists of
• 2 kidneys
• 2 ureters - carry urine from kidney
to bladder
• 1 urinary bladder - stores urine
• 1 urethra - carries urine to surface
Thursday, April 4, 2013
Kidneys
• filter blood
• composed of many nephrons and blood vessels
• see diagram on handout and in textbook
• in the nephron capsule, fluid and dissolved
molecules leave blood and enter nephron
• as fluid flows through nephron tubules, salt and
water levels are adjusted, needed materials such as
sugars are reabsorbed
• waste materials flow into collecting tubules which
merge to form ureters.
Thursday, April 4, 2013
Salt Glands
• Some marine birds and mammals have glands to
secrete excess salt.
Thursday, April 4, 2013
Cartilaginous Fish
• Retain urea in tissue
• Body is isotonic to seawater
Na+
Na+
urea
Na+ Na+
urea
urea Na+
Na+
Thursday, April 4, 2013
Na+
Na+
Na+
Na+
Na+
Na+
Marine Bony Fish
• Drink seawater to replace water lost to diffusion
• Gills actively pump out salt.
Na+
Na+
Na+ Na+
Na+
+
Na
Na+
Na+ Na+
Thursday, April 4, 2013
H2O
Na+
Na+
Na+
Na+
Freshwater Bony Fish
• Body fluids more concentrated than freshwater
• Diffusion results in water gain, salt loss
• Gills actively pump in salt.
• Produce dilute urine to rid body of water.
Na+
H2O
Na+
+
Na
+
Na
Na+
Thursday, April 4, 2013
Lymphatic System
• addition to circulatory system in vertebrates
• produces cells that defend against disease
• removes and cleanses excess tissue fluid
• mammalian system includes lymphatic
vessels, lymph nodes, thymus, spleen, tonsils
and bone marrow.
• note that it drains into vein near heart
• see diagram in textbook
• fish do not have vessel system, only birds
and mammals have lymph nodes.
Thursday, April 4, 2013
Defense Cells
• found in lymphatic organs
• also circulate in blood
Lymphocytes
“specific immunity”
Thursday, April 4, 2013
Macrophages
“engulf material”
Lymph Vessels
• lymph capillaries - pick up debris & excess fluid from tissues
• merge into progressively larger lymph vessels
• connect to vein near heart
Thursday, April 4, 2013
Lymph Nodes
• found along lymphatic vessels
• concentrated in neck, armpit and groin
• contain lymphocytes and macrophages to
cleanse fluid
• note that there are several vessels going in but
one coming out so fluid spends time in node for
cells to cleanse.
• see diagram on handout and textbook
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Antigen
• Substance that triggers defense response
Common Antigens:
• viruses
• bacteria
• parasites
• transplanted tissue
Thursday, April 4, 2013
Non-specific defenses
• Defenses that work against a wide variety of invaders
• macrophages and other phagocytic cells
• skin and mucus membranes (line gut, respiratory
system) are physical and chemical barriers
• some blood proteins attack invaders - interferon
(viruses), complement (bacteria)
Thursday, April 4, 2013
Specific Defense
• Responses specific to a particular invader
• aka Immune System
Y
Y Y
Y
Y
B Lymphocytes
•mature in bone marrow
•produce and release
antibodies against antigen
(e.g. bacteria)
•different B cells respond to
different antigens
Thursday, April 4, 2013
Y
T Lymphocytes
•mature in thymus
•lymphocyte itself kills
antigen (e.g. virus)
containing cells
•different T cells respond
to different antigens