BIO202 Final - TT1 Material

Physiology

study of how structure and function of the body work together to allow behavioural responses to the environment

Integrative physiology

shaped and limited by chemical and physical properties of environment and evolutionary relationships

Anatomy

structure and function

Biogeography

spatial and temporal distribution of organism

Biomechanics

how organism moves

Conservation biology

organism's environment

Ecology

how organism relates to others in same niche

Ethology

animal's behaviour

1. understanding human health and disease

2. agricultural production of animals for food

3. understanding invasive species

Applications of animal physiology

Model organism

non-human species that are used to help us understand biological processes, very useful for genetics research, generally easy to work with/maintain/breed

Rat, mouse, fruit fly, nematode, sea urchin, frog, plant

examples of model organisms

carbon, water, light

major building blocks, solvent, life-sustaining energy

environmental, scaling, evolutionary

Limitations of physiological functions

light, temperature, water, pH, radiation

Environmental limitations

Aquatic environment

Wet all the time, less light, more dense/viscous, oxygen hard to extract, abundant suspended nutrients

Terrestrial environment

dry all the time, more light, less dense/viscous, oxygen easier to extract, no suspended nutrients

Scaling

relationships between anatomical/physiological/ecological traits relative to body size

Anatomical traits

specific structure to organism body size

Physiological traits

function and how function may change to body size (metabolic rate)

Ecological traits

how a train impacts interaction with environment (ex. How does flight performance impact predation)

SA 4x, V 8x, SA to V ratio decreases

Object 2x in size

SA of an organism

involved in exchange of material with the environment

Volume of an organism

responsible for the processing and use of materials from the environment

Large animals

SA to V ratio is small because there is less skin relative to body and it becomes more difficult to get optimal O2 (lungs help)

Small animals

SA to V ratio is large because lots of skin/SA so optimal O2 for given volume

Evolutionary limitations

ancestral characteristics of each animal group

Homology

similarity due to shared common ancestry

Ancestry

limits diversity of adaptations to the environment

Analogy

Similarity due to similar environmental pressures (independent of ancestry)

Pax like gene

homologous trait that controls the development of simple eye structures

Physiological adaptation

metabolic or physiologic adjustment within the cell, or tissues, of an organism in response to an environmental stimulus resulting in the improved ability of that organism to cope with its changing environment

Homeostasis

response to constant change needed to function at optimal rate; dynamic regulation of an animal's internal environment (temperature, pH, dissolved oxygen, glucose)

Conformers

internal environment varies with the external environment

Regulators

maintain internal stability even as external conditions change (cannot control internal conditions at environmental extremes)

Ectotherm

animals that do not have internal control of their body temperature; body temperature is generally similar to the temperature of the environment

Endotherms

an animal that maintains a constant body temperature in the face of environmental changes; able to maintain a level of activity because they generate internal heat that keeps their cellular processes operating optimally even when the environment is cold

Hypothalamus

regulates body temperature

Body temperature falls

blood vessels constrict so that heat is conserved; sweat glands do not secrete fluid; shivering generates heat

Body temperature rises

blood vessels dilate, resulting in heat loss to the environment; sweat glands secrete fluid; as the fluid evaporates heat is lost from the body

Negative feedback

stimulus, sensor, control, effector

Positive feedback

intensifies a change in the body's physiological condition rather than reversing it; deviation from normal range results in more change (production of action potential, clot production, childbirth)

Sugar + oxygen

carbon dioxide + water

Energy

obtained by the oxidation of food

Oxygen

abundant in the air and is dissolved in water

Oxygen in aquatic environment

lower diffusion rate and solubility, less available O2 in a given volume of fluid

Animals in water

need more energy to run an O2 pump or need a more efficient O2 pump in water

Oxygen diffusion

faster than CO2 diffusion because it is less bulky

Diffusion coefficient

constant for each molecule/atom; ability to diffuse in a medium expressed as a rate

Solubility

carrying capacity of a certain area expressed as a concentration; how much of a molecules can be diffused here

a solute will move from a region of high concentration to a region of low concentration across a concentration gradient (larger difference = faster diffusion)

Fick's first law

Concentration gradient

source of potential energy

the amount of substance diffuses across a surface is proportional to the area of that surface and inversely proportional to the distance across which It diffuses

Fick's Second Law

Diffusion rate

proportional to (DAPS)/(X*sqrt(MW))

Diffusion coefficient

D

Cross sectional area

A

Partial pressure gradient

P

Solubility of gas in fluid

S

Diffusion distance

X

Molecular weight of gas

MW

[O2]

proportional to pO2 at constant temperature (amount of O2 that dissolved in liquid is determined by pO2 and solubility of liquid)

Ventilation

active movement of respiratory medium; air coming in and out

Perfusion

gas uptake; oxygen entering circulatory system for gas exchange; the flow of blood in the pulmonary capillaries which ensures gas delivery within the body

External respiration

getting air into body

Internal respiration

use of O2 to make energy

Ventilatory surface

gills, lungs (outer surface layer may not be sufficient)

Marine turbellarian worms

among the largest aquatic animals that rely primarily on diffusion for gas exchange

Gills and lungs

composed of folds to increase surface area for gas exchange (big A) and very thin membrane (small X)

Gill arch

larger blood vessels

Gill filaments

Smaller blood vessels

Gill lamellae

Capillaries

Unidirectional flow

medium enters at one point and exits at another

Operculum

hard structure protecting gill system and opens to let water in

Countercurrent flow

water and blood moving in opposite directions in gill system

Concurrent flow

diffusion gradient is not as efficient or disappears

Climbing perch

has lung like structures allowing it to gather oxygen through air

Tracheal system

open to air via spiracles which lead into trachea internally to contact tissue

Unidirectional flow in insects

from spiracles to abdomen and then out through different set of spiracles

Locust

insect with hard exterior exoskeleton so gas exchange is not possible

Spiracles

holes through exoskeleton on ventral side of insect which are sealed by trachea; can open and close for unidirectional flow

1. Control air flow into trachea

2. Control water loss

3. Keep dust out

Role of spiracles

Insect trachea

branches into every cell in organism and has direct access to trachea so it does not need a circulatory system to transport oxygen

Locusts while flying

need high O2 so dilate trachea during this time to increase area and partial pressure goes down

Ventilation in birds

two complete cycles of inhalation and exhalation for each breath

Unidirectional flow in birds

medium enters at one point and exits from another

oxygenated air goes straight to posterior air sac

1st bird inhalation

air enters parabronchi where gas exchange happens

1st bird exhalation

deoxygenated air inflates anterior air sacs, 1st inhalation of next breath happens simultaneously

2nd bird inhalation

deoxygenated air leaves body

2nd bird exhalation

lungs (parabronchi)

Ventilatory surface in birds

Cross-current exchange

capillaries are perpendicular to parabronchi, airflow is perpendicular to blood flow

Mammals

do not have unidirectional flow

Tidal flow

medium enters and exits, comes out same way it came in; both inhalation and exhalation for each cycle of breath

total pressure is the sum of all the partial pressures of a gaseous mixture

Dalton's law

gases move from areas of high pressure to areas of low pressure; the pressure of gas is inversely proportional to the volume of its container

Boyle's law

the concentration of gas in a liquid is directly proportional to the solubility and partial pressure of that gas

Henry's law

1. Atmospheric pressure

2. Intra-alveolar pressure

3. Intrapleural pressure

Pulmonary ventilation dependent on

Atmospheric pressure (760mmHg)

pressure of atmospheric gases pushing against you

Intra-alveolar pressure/intrapulmonary pressure

pressure of the air within the alveoli, which changes during the different phases of breathing

Intrapleural pressure

the pressure of the air within the pleural cavity, between the visceral and parietal pleurae; always lower than intra-alveolar and atmospheric pressure; ensures that lungs stay closely connected to thoracic wall and follow its movements during a breath cycle

Inhalation

diaphragm contracts, lung volume increases causing pressure to be more negative and allowing air to flow in