ANIMALS

Structure and Function

Unifying Themes in Animal Anatomy and Physiology

• There is a correlation between form and function.

• The comparative approach allows us to see how species of diverse evolutionary history and varying complexity solve problems common to all.

• Animals have the capacity to respond and adjust to to environmental change in two temporal scales.– Long term adaptation.– Short term – physiologic responses.

TisssueGroups of Cells With Common Structures

and Functions

Four types of tissue

1. Epithelial

2. Connective

3. Nerve

4. Muscle

Epithelial• Form- sheets of tightly packed cells• Function – cover the outside of body, line

organs and body cavities• Categorized by the number and shape of

the free surface cells– Simple – one layer of cells– Stratified – multiple layers of cells– Psuedostratified – one layer but appears to be

multilayer because cells are different lengths– Cell shape – cubodial, columnar or squamous

Some Tissues Are Specialized in Absorption or Secretion

• Some ciliated – lining of respiratory system

• Some are mucous membranes – line nasal and oral cavity

• Structure fits forms– Example: simple

squamous epithelium is leaky and specialized for diffusion

Connective Tissue• Form -characterized by a sparse cell

population scattered through an extensive extracellular matrix

• Function – to bind and support tissue• Three types

– Collagen – tensile strength (resists stretching)

– Elastic fibers – long thread s of protein– Reticular fibers – prolonged to form

connections to adjacent tissue

Types of Connective Tissue

• Loose connective tissue ( has all three types of fibers)

• Adipose tissue – fat storage (each cell has one large fat droplet)

• Fibrous connective tissue- tendons and ligaments

Types of Connective Tissue

• Cartilage – skeleton of all vertebrate embryos

• Bone - mineralized

• Blood – composed of plasma, leukocytes, erythrocytes and platelets ( made in the marrow)

Nerve Tissue• Form – neurons

that are specialized to conduct an impulse of bioelectric signal

• Function – senses stimuli and transmits signals from one part of the animal to another

Muscle Tissue• Form – parallel bundles of

• microfilaments made of the contractile proteins, actin and mycin

• Funtion - long excitable cells capable of contraction

• Most abundant tissue in most animals

• Three types of muscle

Types of Muscle•Striated – responsible for voluntary movements.

•Cardiac – forms the contractile wall of heart.

•Smooth – unstriated and is found in walls of organs and is responsible for involuntary movement.

Systems are interdependent: an organism is a living whole greater than the sum of its parts.

Animals are hetrotrophs that harvest chemical energy from the food they ingest.

Animals Have a Range of Metabolic Rates

• Minimum – support basic life functions• Maximal – occur during peak activity• Determined by measuring

– Oxygen used for cellular respiration– Heat loss per unit of time

• Metabolic rate per gram is INVERSELY related to body size among similar animals

• Endotherms– Generate own body heat

– Require more kilocalories than ectotherms

– Many are homeothermic

– Bird and mammals

– BMR• 1600-1800 kcal/day – men

• 1300-1500 kcal./Day-women

• Ectotherms– Acquire most of body

heat from environment

– Include fish, amphibians, reptiles and invertebrates

– SMR (standard metabolic rates) must be determined at a specific temperature

FUEL MANAGEMENT

• Monomers of any complex organic molecule can be used for fuel. CH2O and fats are used first.

• Oxidation of fat liberates 9.5 kcal/gram (twice that of CH2O or protein)

• Excess food taken in is stored as– Glycogen in the liver and muscles– Fat in adipose tissue

When the diet is deficient in calories

• Glycogen is used first• Fat• Body protein (results

in muscle atrophy and can even result in consumption of brain proteins)

Diet must supply carbon and nitrogen necessary for biosynthesis of other organic molecules.

• Essential amino acids are those that must be obtained from the diet.

• Human adults can synthesis 12 of the 20 amino acids.

• Protein deficiency results when the diet lacks one or more of the amino acids.

• Humans can not store amino acids therefore a deficiency results in the retardation of protein synthesis

Other Essential Nutrients

• Essential fatty acids – unsaturated fatty acids that can not be produced by the body – usually not a problem

• Vitamins

Feeding Adaptations• Suspension feeders – sift small particles from water

– Clams, oysters, baleen whales

• Substrate feeders-live in or on food and eat through it– Leaf miners

• Deposit feeders-ingest partially decayed organic materials with substrate– Earthworms

• Fluid feeders-suck nutrient rich fluid from a living host– Tick, aphids, leech, hummingbirds, bees

• Bulk feeders – eat relatively large pieces of food

• Intracellular – vacuoles– Sponge – only intracellular digestion

• Extracellular – occurs within compartments that are continuous with the outside of the body– Simple body plan – gastrovascular

cavity– Complete digestive track or

alimentary canal

Four Main Stages of

• Ingestion

• Digestion– Enzymatic digestion cleaves into monomers– Mechanical fragmentation

• Absorption

• elimination

Digestive EnzymesEnzyme Location Function

Salivary amylase

Gastric Juice

Pepsin

Pancreatic amylase

Pancreatic lipase

Trypsin &

chymotryosin