what type of tissue is composed of cells embedded in a matrix? a) nervous b) epithelial c) muscle d)...
TRANSCRIPT
Introduction to Animal Physiology
Chapter 20
What type of tissue is composed of cells embedded in a matrix?
a) nervousb) epithelialc) muscled) connectivee) 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.
Body Organization
Different types of tissues working together for a common function = organ
Different organs working together for a common function = organ system
Organ Systems Overview
Which organ system(s) control or regulate body activities?
a) nervous systemb) endocrine systemc) circulatory systemd) immune systeme) 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
Homeostasis – Maintaining a stable internal environment
Homeostasis varies
Excretory System
2 main functions:› Maintains the proper water balance for body› Cleans blood of waste bi-products
What is osmosis?
The diffusion of water across a semi-permeable 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
Osmosis con’t
Water will move from a dilute solution to a concentrated solution
Relative Osmotic Pressure
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 solutionsA B C
Real world problems relative to this issue:
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 2500Urinate 1500 ml/day
Lost due to evaporation: 1000 ml/day
Solutions to water balance problems:
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
2nd Function: Waste Removal
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)
Other Wastes:
Excess Ions Toxins Excess vitamins Other unneeded breakdown products
Systems vary among animals
Single celled animals – contractile vacuoles
Earthworms – tube with cilia filters coelomic fluid and blood vessels associated with tube give off waste from blood
Mammals – ex. Human
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
Parts of Excretory System
Nephron1
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)
What is the correct order of flow through the parts of a nephron?
a) Bowman’s capsule, proximal tubule, loop of Henle, distal tubule, collecting duct
b) Loop of Henle, Bowman’s capsule, proximal and distal tubules, collecting duct
c) Proximal tubule, loop on Henle, distal tubule, collecting duct, Bowman’s capsule
High blood pressure medication can be simply a diuretic. How would this work to lower blood pressure?
Antidiuretic Hormone (ADH)
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
Animation for Ch 20
________________ gain most of their heat from their environment, while _________________ can use metabolic heat to regulate their body temperature.
a) Endotherms; ectothermsb) Plants; animalsc) Fungi; animalsd) Birds, lizardse) Ectotherms; endotherms
Which is the correct order of the processes used by the kidney in forming urine?
a) reabsorption > filtration > excretionb) filtration > reabsorption > excretionc) excretion > filtration > reabsorptiond) filtration > excretion > reabsorptione) excretion > reabsorption > filtration
Read Chapter 21Circulation & Respiration