Transcript Introduction to Animal Physiology

What type of tissue is composed of cells
embedded in a matrix?
a) nervous
b) epithelial
c) muscle
d) connective
e) None of the above are correct.
Which of the following is a main benefit of
multicellularity?
a) Each cell can perform all of the necessary
physiological processes needed by the
body.
b) Each cell can dump its waste directly into
the environment.
c) Only some body cells need to make ATP.
d) Cells can divide up the labor of
performing essential physiological
processes.
e) Each cell has direct access to nutrients in
the environment.

Different types of tissues working
together for a common function = organ

Different organs working together for a
common function = organ system
Which organ system(s) control or regulate
body activities?
a) nervous system
b) endocrine system
c) circulatory system
d) immune system
e) Both a) and b) control or regulate
body activity.
What is the function of the respiratory
system?
a) exchange gases between the internal
and external environment
b) recycling fluids that leak from the
circulatory system
c) transport gases to and from tissues in the
body
d) make ATP from glucose and other
energy-rich molecules
e) purify the blood by filtering out wastes

2 main functions:
› Maintains the proper water balance for body
› Cleans blood of waste bi-products

The diffusion of water across a semipermeable membrane

Why should we care?
› Our cells are sacs with semi-permeable
membranes
› Without the proper balance of water in cells,
life systems shut down

Water will move from a dilute solution to
a concentrated solution
Demonstrated in the last slide
 Concentration of solutions relative to
adjoining solutions (one cell to the next
cell or body relative to surroundings, etc.)
 Ex. Red Blood Cell in different solutions

A
B
C

Different environments present different
problems
› Marine – tendency to gain salt + lose water
› Freshwater – opposite – gain water, lose salt
› Terrestrial – dry – very hypertonic
 Humans drink
2300 ml/day
get
200
from metabolism
gain
2500
Urinate
1500 ml/day
Lost due to evaporation: 1000 ml/day

Physical barriers to water movement
› Scales on fish, cuticle, hair, feathers

Pump water or salt from body
› Urinate, flame cells of Planaria
› Salt glands of marine birds and reptiles

Pump water or salt into body
› Drink
› Freshwater fish have gill pumps that take in
salt and concentrates it in the blood

Waste – what is it?
› Ammonia (NH3) is the most toxic
 Biproduct of protein breakdown
 If eliminated in its pure form – needs to be with
lots of water – ex. Freshwater animals
 If terrestrial and need to conserve water –
 Ammonia is changed to a less toxic form
 Chemical change requires energy
 Urea – 2 ammonia + CO2 (fish, amphibians, mammals,
some invertebrates)
 Uric Acid – ring structure = powdery product (terrestrial
organisms in dry locations)
Excess Ions
 Toxins
 Excess vitamins
 Other unneeded breakdown products

Single celled animals – contractile
vacuoles
 Earthworms – tube with cilia filters
coelomic fluid and blood vessels
associated with tube give off waste from
blood


Body has different fluid compartments:
› Blood - 5% body wt
› Interstitial -15% body wt
 (lymph collects and returns to blood)
› Intracellular (inside cells of body) – 50% body wt
Nephron
1 million/kidney
1. Filter blood
2. Secrete
molecules/ions into
nephron
3. Reabsorb some
ions/molecules
4. Regulate amount of
water lost
5. Eliminate urine

Secretion (2)
› Selective (requires
energy) transport of
additional
molecules in blood
into proximal tubule

Reabsorption (3)
› Selective (requires
energy) transport of
needed substances
back into blood
› Most of water,
solutes such as
sodium, amino
acids and glucose

Osmoregulation (4)
› Loop of Henle
› Salt gradient in cortex
and medulla of kidney
 Medulla high conc
 Water removed from
tubes
 Bottom of loop – inside
tube = hypertonic
 Upward arm of Loop –
membrane not
permeable to water
 Salts pulled out
 More water pulled out
through wall of
collecting duct

Distal Tubule (2 +3)
› Drugs and toxins
removed from blood
› Again much by
active transport
(requires energy)

Collecting Duct
› Eliminates urine (5)
a)
b)
c)
Bowman’s capsule, proximal tubule,
loop of Henle, distal tubule, collecting
duct
Loop of Henle, Bowman’s capsule,
proximal and distal tubules, collecting
duct
Proximal tubule, loop on Henle, distal
tubule, collecting duct, Bowman’s
capsule
Drop in blood pressure detected by
heart sensors
 Sensor information stimulates
hypothalamus to secrete ADH
 ADH makes collecting ducts more
permeable to water
 More water reabsorbed and retained by
body, blood volume increases, blood
pressure increases

________________ gain most of their heat
from their environment, while
_________________ can use metabolic
heat to regulate their body temperature.
a) Endotherms; ectotherms
b) Plants; animals
c) Fungi; animals
d) Birds, lizards
e) Ectotherms; endotherms
Which is the correct order of the processes
used by the kidney in forming urine?
a) reabsorption > filtration > excretion
b) filtration > reabsorption > excretion
c) excretion > filtration > reabsorption
d) filtration > excretion > reabsorption
e) excretion > reabsorption > filtration