Foundations of Biological Sciences 152 Exam 5

Oxygen

Oxygen

• is necessary for aerobic respiration

• final electron acceptor in electron transport chain

• Respiratory Gas

Carbon Dioxide

• produced as a result of the breakdown of food

• Respiratory Gas

Respiratory Gases

Collectively, oxygen and carbon dioxide are considered to be the ______ in animals

Diffusion

• Use over small distances (cell to cell)

• Governed by Fick’s Law

• VERY quick cell to cell (0.1µs)

Bulk Flow

• Necessary for large distances (organ to organ)

Fick’s Law

• the rate of diffusion of a gas across a segment of membrane depend upon the concentration of the gas on both sides of the membrane (C1 and C2), and the distance the molecule have to travel (L)

• Rate is proportional to C1-C2/L

True

True or False? all animals need to obtain oxygen from, and release carbon dioxide to, their environment.

Gas Exchange Membrane

a thin layer of epithelial tissue through which the respiration gases move between the external environment and the animals respiratory system

• How animals obtain oxygen and expel carbon dioxide

• Held in respiratory organs

True

True or False? Human lungs have a surface area of over 120m2

Lungs and Gills

The two basic types of respiratory organs found in animals are:

Gills

• are respiratory organs in which the gas exchange membrane is folded outwardly (evadignated) and is surrounded by the external environment (i.e. water)

• Can be external or internal

• Ventilation is unidirectional, water moves in one direction over the gills

External Gills

Direct contact with the environment

Internal Gills

Held in a protective cavity

Lungs

• respiratory organs in which the gas exchange membrane is folded inwardly (invaginated) and the external medium (air) is drawn into the lung via tidal ventilation

• Ventilation is tidal, air flow into the lungs, and once the oxygen has been obtained, it flows out the same way it entered

Ventilation

• the movement of the environmental medium (Water or air) into or through the gas exchange membrane

• the moving air and out

True

True or False? Water have about 1/20 of the oxygen as air (at the same temperature)

True

True or False? Respiration in water requires ten times the energy as air, water is more viscous than air

True

True or False? Solubility of oxygen in water decreases with increasing temperature and increasing salinity

Counter - Current Gas Exchange

What is the term that describes the highly efficient way that fish extract oxygen from water?

True

True or False? Respiration in most terrestrial vertebrates involves tidal ventilation into sac-like lungs.

Interior Surface of Terrestrial Vertebrates

• have a lot of surface area and are coated with surfactants to ease the diffusion of oxygen into the blood stream.

Positive Pressure

• used by amphibians

• Pushes air into the lungs, after gulping air the mouth and nostrils are sealed and the air pushed into the lungs

Suction

• In reptiles and mammals, the lungs expand, and the air rushes into the lungs

Bird respiratory organs

• highly efficient

• due to flight requiring a lot of energy avian respiratory system provides a lot of oxygen via unique adaptations

  • Arrangement of Parabronchi and air sacs

Insects

• Use a set of tubes (tracheae) that open directly to the air through their exoskeleton (spiracles) to deliver oxygen directly to their cells

Tracheae

The pipe-like organs that deliver air directly to the cells and tissues in insect are the:

Spiracles

• opening in insect exoskeleton to allow respiration

True

True or False? some animals do not have gills or lungs or any other respiratory tissues. They are able to allow respiratory gases to diffuse through their skin.

Respiration in Humans

• Like all mammals, have a high metabolism and require a lot of oxygen to meet their metabolic needs

• Can extract oxygen from air with high efficiency

  • direct result of extensive surface area provided by the branching airways and close connections with the circulatory system

• Ventilation by musculature (diaphragm and intercostal muscle)

Mechanics of Breathing

• air flows from high to low pressure

• When chest expands pressure inside is lower than pressure outside

tidal volume

The typical amount of air in the lungs, that remains between between an inhalation and an exhalation, is the:

True

True or False? Humans breathe via involuntary control

False

True or False? ALL marine species breathe via involuntary control.

Neurological Control of Breathing

• sensory receptions sense H+ (pH)

• As CO2 is generated H+ is produced

• CO2 is produced by cellular respiration

Respiratory Rate

• Increased H+ causes motor centers to in the brainstem to increase the rate and depth of breathing

• Increased respiration eliminated more CO2, which decreases H+

Three Ways of Transport of CO2 in Blood

• Dissolved in Blood: 5%

• Bound to Hemoglobin: 10%

• Bicarbonate Ions (HCO3-): 85%

Methods of Respiring

• Fish can respire briefly from atmosphere, but once gills dry the surface area reduces and make it impossible for fish to retain enough oxygen

• Humans can’t respire in oxygen at all

True

True or False? In humans, oxygen consumption increases as speed increases.

True

True or False? In fish (in water), oxygen consumption exponentially increases as speed increases.

Hydrodynamic Resistance

Why water is hard to move through

True

True or False? Torpedo shaped fish are the fastest.

Thermoregulation, River Otter

• Endoterm

• Maintains the same body temperature in increasing environmental temperature

Thermoregulation, Bass

• Ectotherm

• body temperature increases an enviornmental temperature increases

Regulation

Animals body temperature remains the same as external temperature increases (sea otter)

Conformers

Animals body temperature increases as external temperature increase (Large mouth bass)

True

True or False? Metabolic ‘investment’ and ‘running costs’ of regulation or conforming must be supported by energy/food

Homeotherms

have increased metabolic rate when external temperature is EITHER higher or lower than preferred body temperature (expensive process)

Poikilotherms

have slowly increasing metabolic rate as external temperature increase (inexpensive process)

Homeostasis

process of regulating internal environment to support physiological systems

Control Mechanism - Negative Feedback Control

• Body notices change in external temperature, control mechanisms sends message to effectors to do something to either increase or decrease internal temperature accordingly

• wait for signal to go ‘wrong’

Control Mechanisms - Positive Feedback Control

• Controlled variable → Sensors → Control mechanisms → effectors

• wait for signal to go ‘right’

Epithelium

sheet of epithelial cells that covers a body surface or organ or lines a body cavity

Simple Epithelium

single layer of cells on a nonliving basement membrane; lines all blood vessels, intestines, and other tubules

Connective Tissue

• Fibrous connective tissue

• Bone

• Cartilage

• Blood

Nervous Tissue

nerves, spinal cord, brain

Types of Muscle Tissue

• Skeletal

• Cardiac

• Smooth

Levels of Animal Cell Specialization

1) Cells

2) Tissues (epithelial, connective, muscle, nervous)

3) Organs (e.g. stomach)

4) Multi-organ systems (e.g. digestive system)

False, organs like the heart are made of two seperate tissues

True or False? Organs are only ever made of one tissue

True; sponges do

True or False? Few animals eat continuously

Maintaining Homeostasis in Digestion

• must regulate release of nutrients to maintain homeostasis

• sophisticated feedback systems involving hormones

  • e.g. glucose (insulin / glucagon)

Diabetes

consequence of not being able to produce enough insulin

Blood Glucose Rise above normal

• stimulates pancreas to secrete insulin

• increase in circulating insulin

• uptake of glucose by cells

• Glycogen (storage form of glucose) synthesis use of glucose in metabolism

• Blood Glucose concentration drops

Blood Glucose drops below normal

• stimulates pancreas to secrete glucagon

• increase circulating glucagon

• Breakdown of glycogen

• release of glucose to blood

• blood glucose level rises

Excretory Systems

• Multiple roles

• Maintenance of internal environment includes

  • Osmoregulation

  • Solute Concentration

  • Removal of nitrogenous wastes

Osmoregulation

• Excretory system

• water

Solute Concentration

• Dissolved Ions / Salts

Regulating the Composition of Body Fluids

• Three Factors

  • Water Volume

  • Solute load (ions)

  • Osmosis

• The composition of water volume and solute load determine the outcome of osmosis

Water Volume

• the correct amount of water in the body is important

True

True or False? A goldfish absorbs water constantly from its environment; the fish must void water as fast as it enters

False, Saltwater fish drink water constantly, but freshwater fish do not drink water

True or False? All fish drink water

The Principle Solutes are

Na+, K+ and Cl-, HOP43-

True

True or False? Ion concentrations determine direction of ion movement and/or osmotic gradients.

Plasma

• similar in composition to interstitial

• has protein anions

Instrastitial

• has lots of potassium, phosphates, and even more protein anions than plasma

• Needs lots of salts outside of the cell

Kidney

• key excretory organ

• functional unit is the nephron

• main function is to regulate the composition and volume of the blood plasma, by selectively removing solutes and water from the plasma

• Adjust the U/P ratio up and down to regulate fluid balance in the body

Nephron

• create urine from blood plasma

  • discharge urine in collecting ducts

• Human kidneys contain over one million _____

True

True or False? The urine/plasma (u/p) ration reflects kidney function.

U/P Ratio

• the ratio of urine and plasma osmotic pressures

• in many animals U/P cannot be higher than 1.0

When U/P is <1.0

• the kidneys are making dilute urine; the plasma is becoming more concentrated

When U/P is >1.0

• The kidneys are making concentrated urine; the plasma is becoming more dilute

True

True or False? Mammals, birds and insects are the only animals that can make urine with U/P > 1.0

True

True or False? Some desert mammals can achieve osmotic U/P ratios as high as 10 or 20

False; ability to produce concentrated urine is important to prevent dehydration

True or False? For groups that live on land, concentrated urine does not need to be produced.

Nitrogenous Waste Excretion

• Carbohydrates and fat end up as water and CO2 and are easily excreted

• Protein and nucleic acid breakdown also produce nitrogenous waste, which can be toxic

Ammonia (NH3)

• is very toxic

• Aquatic organisms can excrete this quickly so it is not a problem

  • Are Ammonotelic, eliminate nitrogenous waste as ______

• Terrestrial animals cannot eliminate _____ quick enough to prevent toxicity

Animals Convert NH3 (Ammonia)

• to urea or uric acid

  • requires ATP (disadvantage)

    • But allows enough time for renal excretion without toxicity

Iso-osmotic

Some have body fluids that are ______ to their environment - Same osmotic pressure

Hyper Osmotic

If body fluids have higher osmotic pressure than the environment

Hypo-Osmotic

is body fluids have lower osmotic pressure than the enviornment

Osmotic Conformer

Allow internal environment to change; tolerate consequences

Osmotic Regulator

maintain internal environment; accept metabolic rates

True

True or False? Water balance and dehydration are the greatest challenges for terrestrial animals

Humidic Animals

body coverings are highly permeable to water, so they lose water by evaporation (millipedes, centipedes, land snails, most amphibians)

Xeric Animals

body coverings prevent high rates of water loss (birds, lizards, mammals, insects, spiders)

Blood Filtration in Nephrons

• Bowman’s capsule containing a cluster of capillaries glomerulus

• Blood pressure forces fluid, containing small molecules and ions from glomerulus into Bowman’s capsule

• Proteins and cells remain in the glomerulus (blood)

• Very large amount of filtrate is produced

• Works like a coffee maker

Proximal Convoluted Tubule (PCT)

• In the Nephron

• active transport removes sodium and chloride

• as salt is removed, osmosis starts to remove water

• This retunes most of the filtrate to the blood / body

The role of the circulatory systems

• Once oxygen enters the body via the gas exchange membranes and respiratory organs, it must be distributed around the body

• Also distributes nutrients and helps in the removal wastes, but the distribution of oxygen seems to be its primary function

True

True or False? The circulatory system in insects delivers nutrients and hormones, which can be delivered at slower rates than oxygen.

Two types of circulatory systems in animals

open and closed circulatory systems

Closed Circulatory Systems

• the circulatory fluid (blood) is always enclosed in blood vessels as it travels throughout the body

  • Allows for more efficient and faster circulation, since the blood will be pressurized by the vessels

• Typically found in animals with high metabolic demands; Vertebrates, annelids, some mollusks

• Blood is pumped away from the heart into arteries, then arterioles, then capillaries

• Blood returns to the heart via venules and then veins