Respiratory and Excretory Systems

Respiratory and Excretory Systems

Organisms exchange:

Oxygen (O2) and Carbon Dioxide (CO2)

A. Heterotrophs: (e. Humans)

1.  Need 02 for cellular respiration

2.  Release excess CO2 from cellular respiration

Examples of exchange of gases:

Earthworms – diffusion through skin.

Fish and Mollusks – gills (O2 that is dissolved in H2O.

Insects – through spiracles (holes along abdomen) that lead to a trachea. Hemolymph allows diffusion of gas into cells.

Cellular Respiration Equation

ORGANELLE - Mitochondria

C6H12O6 + O2 pyruvate + CO2+ ATP

ENZYMES

B.  Autotrophs: (plants)

1. Need water, carbon dioxide and sunlight

Photosynthesis Equation

ORGANELLE - Chloroplast

SUNLIGHT

6CO2 + 6H2O ATP/NADPH C6H12O6 + O2

ENZYMES

Roots:

a.  O2 is in spaces in soil and dissolved in water (enters plant through successive osmosis)

b.  CO2 diffuses into soil following cellular respiration from heterotrophs

Stems:

a.  Lenticles – small holes along branches, more on growing tips, allow O2 intake and CO2 release.

Leaves - job in photosynthesis

a.  Gas exchange takes place in the spongy and palisade cells.

b.  A thin film of H2O surrounds these cells, allowing diffusion of gases.

c.  CO2 passes through stoma into cells

d.  CO2 passes out to the air

Purpose of a Respiratory System?

a.  To allow intake of O2

b.  To allow release of CO2

Parts of the Respiratory System:

Pulmonary Artery – Delivers deoxygenated blood to lungs

Pulmonary Vein – Takes oxygenated blood from lungs to heart.

Alveoli – where gases diffuse to (or from) lung spaces into (or out of) capillaries.

Oxygen – carried by hemoglobin in RBC’s

CO2 – carried dissolved in plasma, HCO3

CO – carbon monoxide has a 20X higher attraction to hemoglobin then O2. Can kill us by limiting our oxygen in blood.

External Respiration – Gas exchange in lungs.

Internal Respiration – Exchange at cells. Allows mitochondria to make ATP(Energy)

Structure / Function
Nostrils / Warm air
Nasal Passage / Warm, Filter, Moisten Air
Pharynx / Direct air to trachea
Epiglottis / Keep food out
Glottis / Opening to trachea
Larynx / Voice Box
Trachea / Protect airway (cartilage rings)
Bronchus / Split to lungs
Bronchial Tubes / Branches of Bronchus
Bronchioles / Smaller branching
Alveoli / Sacs for gas exchange, delivery to the blood
Capillaries / Gas exchange
Diaphragm / Muscle to fill/empty lungs
Esophagus / Food à stomach
Pleural Membrane / Sack around lungs, allows creation of a vacuum for “suction”

Step

/ Inspiration
Breathing In / Expiration
Breathing Out
1 / Rib Muscles Contract / Relax
2 / Diaphragm Contracts / Relax
3 / Lowers Pressure / Lung Tissue Shrinks
4 / Creating a Vacuum / Forcing Air Out

Average breaths a minute = 18

Liters / Volume Name / Explanation
0.5 / Tidal / Normal in and out breathing
1.2 / Residual / Air that cannot be expelled
1.6 / Expiratory Reserve / Air that can be forced out
1.6 / Inspiratory Reserve / Air that can be forced in
3.7 / Vital Capacity / Tidal + Expiratory + Inspiratory
4.9 / Total / “ + “ + “ + residual

Can I kill myself by holding my breath?

Nope, I would pass out and then the “automatic” portion of my brain would start my breathing again.

Problems with the Respiratory System:

Hyperventilate – Rapid Breathing, not getting rid of enough CO2

Lung Cancer – primary cause smoking.

Pneumonia – bacterial caused fluid in lungs.

Emphysema – Breaking up of alveoli, fewer areas for gas exchange, “suffocating” for years.

Bronchitis – Inflammation of the bronchi.

Asthma – immune system causes inflammation of bronchi.

Tuberculosis – Bacterial caused breakdown of lung tissue, coughing blood.

Suffocation – insufficient O2 to cells.

Smoking:

(http://www.cdc.gov/nccdphp/tobaccou.htm)

·  Increase in # females that smoke

·  Fastest growth in teenagers

·  Tobacco companies increased addictive nature of cigarettes.

·  About 430,000 deaths are attributed to cigarette smoking each year. (http://www.cdc.gov/nccdphp/tobaccou.htm)

·  Approximately one of every two lifelong smokers will eventually die of smoking.

·  If current smoking patterns continue, an estimated 25 million persons alive today, including 5 million children younger than 18 years of age, will die prematurely of smoking-attributable diseases.

Excretory System

Excretion – Removal of nitrogenous waste.

Nitrogenous waste:

1.  Waste from the breakdown of Proteins, and other cellular functions.

2.  Builds up in blood after being released from cells.

3.  Is poisonous if it builds up in the body.

3 Types:

a.  Ammonia (NH3) – highly toxic – may be excreted by Fish.

b.  Urea [(NH2)CO] and Uric acid [C5H4N4O3]– less toxic forms that enable land animals to excrete nitrogenous wasted with minimal loss of H2O.

Why?

1. If toxic – poisons tissues.

2. If left in blood poison organs.

3. Gout – uric acid crystals that settle in joints, from protein-rich diets (liver)

How removed?

1.  Aquatic organisms – live in H2O and excrete ammonia, diluted with water to decrease toxicity.

a. Fish – have kidneys to do this.

b.  Other – excrete through skin

2.  Terrestrial organisms – land organisms convert ammonia to urea or uric acid.

a. Earthworms – excrete ammonia through skin into wet soil and urea from kidneys.

b.  Insects, Reptiles, Birds – excrete uric acid as insoluble crystals that will not dissolve in water.

c. Human/Mammals – have kidneys that excrete urea, H2O, and salts in urine.

Kidneys Job is Filtration

Located – Embedded in fat along either side of the spine.

Make urine = urea + excess salts + H2O

Liver

/ Ammonia + CO2 to form less toxic urea, sent to kidney
Renal Artery / Carries blood to kidney to be filtered. (Filtered every 30 min.
Nephron / Tube in kidney that filters.
Glomerulus / Ball of capillaries in kidney
Bowman’s Capsule / Extracts water, salt, wastes from Glomerulus, takes too much H2O & salts from the blood.
Tubule / Tube in kidney that returns 99% of H2O & salts back to blood.
·  ADH – hormone that triggers body to absorb water, rather than excrete it.
Renal vein / Carries filtered blood to body.
Ureters / Carries urine to bladder (2)
Urinary Bladder / Stores urine.
Urethra / Tube through which blood leaves bladder.

Problems:

a.  Alcohol – diuretic

b.  Caffeine – diuretic

c.  Nephritis – inflammation

d.  Kidney failure – need dialysis to filter blood.

e.  Homeostasis – balance of salt & H2O

f.  Diabetes insipidus – extreme thirst due to passage of large quantities of dilute urine.

g.  Diabetes Mellitus – sugar in urine due to lack of insulin.

Plants excrete?

No wastes, sometimes they concentrate