CH. 40 Basic Principles of Animal Form and Function

Anatomy vs Physiology

the biological form of an organism vs the biological functions an organism performs (closely related)

Exchange

Nutrients, waste products, gas exchanged across cell prop to cell surface area

• Single Cell: in water has lots of SA

• Multi cell: only have 2 cell thick body wall

Interstital Fluid

fills the space between cells, which links exchange surfaces to body cells

• complex body plan helps animals maintain stable internal enviornment

Tissues

make up organs, which together make up organ systems

1. Epithelial

2. Connective

3. Muscle

4. Nervous

Epithelial Tissue

covers the outside of the body and lines the organs and cavities within the body

• closely joined

• cuboidal, columnar, squamous

• simple, stratified (multi tier), pseudostratified (single layer that varies lengths)

Connective Tissue

mainly binds and supports other tissues + contains sparsely packed cells scattered throughout an extracellular matrix (fibers in a liquid, jellylike, or solid foundation)

• Fibers: Collagenous (strength + flex), Reticular (joins), Elastic (stretch + snap)

Connective Tissue Cells (2)

1. Fibroblasts: secrete the protein of extracellular fibers

2. Macrophages: involved in the immune system

Types of Connective Tissue (6)

1. Loose: binds epithelia to underlying tissue + hold organs

2. Fibrous: found in tendons + ligaments

3. Bone: form skeleton

4. Adipose: store fat for insulation + fuel

5. Blood: cells + plasma

6. Cartilage: support

Muscle Tissue

For body movement, cells consist of filaments of the proteins actin and myosin, which together enable muscles to contract

1. Skeletal/Strained: voluntary move

2. Smooth: involuntary move

3. Cardiac: contraction of heart

Nervous Tissue

functions in the receipt, processing, and transmission of information

• Neurons/Nerve cells: transmit nerve impulse

• Glial/Glia cells: support

Endocrine System

releases signaling molecules called hormones (affect 1+ regions) into the bloodstream

• hormones have long-lasting effects over large area

• use for control + coordination

Nervous System

transmits information between specific locations

• use for control + coordination

Regulator

uses internal control mechanisms to control internal change in the face of external fluctuation

Conformer

allows its internal condition to vary with certain external changes

Homeostasis

maintain a “steady state” or internal balance regardless of external environment

• Humans: body temp, blood pH, glucose at constant lvl

• Stimulus cause fluctuations detected by sensor then send response

Negative vs Positive Feedback

helps return to normal range vs amplifies stimulus

How is Homeostasis altered?

1. Circadian Rhythm governs physiological changes (every 24hrs)

2. Acclimatization: temporary external environment change, lipid composition change, antifreeze

Thermoregulation

process by which animals maintain an internal temperature in a normal range

Endothermic

animals generate heat by metabolism, more energetically expensive

• Birds + mammals

Ectothermic

gain heat from external sources, greater variation in internal temp

• fish, amphibians, non-avian reptiles

Physical process to exchange heat (4)

• Pokikilotherm: body temp varies with envir

• homeotherm: constant body temp

1. Radiation

2. Evaporation

3. Convection

4. Conduction

Integumentary System (5)

Heat regulation in mammals often involves the skin, hair, and nails

1. Insulation

2. Circulatory adaptations

3. Cooling by evaporative heat loss: sweat, bath, panting

4. Behavioral responses

5. Adjusting metabolic heat production

Insulation

Skin, feathers, fur, and blubber reduce heat flow between an animal and its environment

• allows for countercurrent exchange (transfer heat btwn fluids in opp directions)

Circulatory Adaptation

Many endotherms & some ectotherms can alter the amount of blood flow between the body core and skin (shark, fish, insect- thorax)

• Vasodilation: inc blood flow in skin, facilitate heat loss

• Vasconstriction: dec blood flow in skin

Thermogenesis

adjustment of metabolic heat production to maintain body temperature, inc by muscle activity

• Non-shivering inc metabolic activity in mitochondria

• Brown fat for rapid heat production

Hypothalamus

Controls thermoregulation to trigger heat loss/generating mechanisms

• Fever

Bioenergetics

overall flow and transformation of energy in an animal

• determines nutrition needs (ATP)

• leads to biosynthesis

Biosynthesis

includes body growth and repair, synthesizing storage material such as fat, and production of gametes

Metabolic Rate

sum of all the energy an animal uses in a unit of time

• determined by heat loss, amount of O₂ or CO₂ produced, energy content of food

• Prop to body mass (m^3/4) + inverse to activity duration = higher in small aninmals

Types of Metabolic Rate (2)

1. Basal metabolic rate (BMR): endotherm at rest at comfortable temp

2. Standard metabolic rate (SMR): ectotherm at rest, lower

• both assume non-growing, fasting, non-stress animal

Torpor

state of decreased activity and metabolism

• enables animals to save energy while avoiding difficult and dangerous conditions

• Estivation: animals survive w/ scarce water for long period

Hibernation

long-term torpor that is an adaptation to winter cold and food scarcity

• 20x lower than normal rates