Chapter 40: Basic Principles of Form and Function By Tricia Thai and Vanessia Lam.

Chapter 40: Basic Principles Chapter 40: Basic Principles of Form and Functionof Form and Function

By Tricia Thai and Vanessia By Tricia Thai and Vanessia LamLam

Functional Anatomy

An animal’s anatomy and physiology reflects major themes of biology.Anatomy-study of structurePhysiology-study of function

Adaptations are made through evolution to create an animal’s form in which it can survive in it’s environment. Ex: The streamline body of dolphins to maximize speed in the water.

Physical Laws and Animal Form

Physical requirements affect an animal's ability

The ability to perform certain actions like flying depends on an animal's size and shapeEx: a huge dragon can't fly because it can't generate enough lift

Physical Laws & Animal Form cont’d

Evolutionary convergence reflects independent adaptations of different species in similar environmental challengesEx: laws of hydrodynamics constrain shapes of fast swimmers, that's why sharks, tuna, penguins, dolphins, and seals have a similar body(smooth coat, fins/flaps on each side, tail)Ex: seals and penguins live near ice thus need blubber insulation

Exchange w/ the Environment

An animal's size and shape affects how it exchanges energy and materials w/ its surroundings

All cells need to be bathed in aqueous mediumEx: Single Cell layer, in unicellular protist all cells contact the environmentEx: Double Cell Layer, hydra's body only has two layers of cells b/c water can circulate in and out of hydras mouth, every cell gets in contact with environment

Ex: Complex Animal, digestive system, respiratory, circulatory, and excretory system are used

The structure of tissue in animals connects with its function

There are four main categories of tissue within vertebrates: epithelial, connective, nervous and muscle.

Animals are multicelluar where groups of cells with the same function make up tissue. Tissues with common structure and function form an organ which in turn is a part of an organ system.

Epithelial Tissue

Epithelial tissue act like a protective barrier between the internal and external environment of the animal due to their compactness.

They also line the organs within an animal’s body. Some of them are specialized in absorption of

essential nutrients held together by tight junctions functions as barrier against mechanical injury,

microbes, and fluid loss

 Glandular epithelia

absorb or secrete chemical solutions

-Ex: glandular epithelia that line the lumen(cavity) of the digestive and respiratory tracts form a mucous membrane, they secrete mucus that lubricates the surface and keeps it moist

Membranes of Epithelial Tissue

Mucous membrane

-smooth moist epithelium that lines the digestive tract and air tubes that lead to the lungs

Basement Membrane

- a dense layer of extracellular matrix that epithelial cells are attached to

Types of Epithelia Layers

Simple Epithelium-has single layer of cells Pseudostratified Epithelium-single layered but looks

complex b/c of shapes of cells Stratified Epithelium-multiple tiers of cells

Cuboidal-like dice Columnar-a whole bunch of columns standing next to

each other Squamous-like floor tiles

Connective Tissue

Binds and supports other tissues Made of protein There are 3 types of connective tissue fibers:

collagenous fibers, elastic fibers, reticular fibers Major types of connective tissue are in

vertebrates: loose tissue, adipose tissue, fibrous connective tissue, cartilage, bone, blood

Collagenous fibers

Are made of collagen(very abundant)

Has a non-elastic structure, don't tear easily when you pull lengthwise

Ex: when you pinch skin on your hand it doesn't break b/c of collagenous fibers

Elastic fibers

Long threads made of elastin

They have a rubbery quality that complements nonelastic strength of collagenous fibers

Ex: When you pinch your skin and then release, elastic fibers quickly restore original shape

Reticular fibers

thin and branched

composed of collagen and continuous w/ collagenous fibers

form tightly woven fabric that joins connective tissue to adjacent tissue

Loose connective tissue

Binds epithelia to underlying tissue and holds organs cells are scattered There are 2 types of predominate connective tissue

cells: fibroblasts and macrophages Fibroblasts-secrete the protein ingredients of the

extracellular fibers Macrophages-are amoeboid cells, they roam the

maze of fibers engulfing foreign particles and debris of dead cells by phagocytosis

Adipose tissue

A form of loose connective tissue

Serve as fat storage or fuel reserve for energy in the body

Pads and insulates the body

Each adipose cell has a fat droplet

Fibrous connective Tissue

Organized as parallel bundles of cell

Located in tendons (muscle to bones) and in ligaments (bones to bones)

Tip: To remember ligaments think of (BOBOLI) BOne BOne LIgament

Types of Connective Tissue

Cartilage-collagen in a rubbery matrix (chondroitin)-flexible support

Bone-mineralized tissue by osteoblasts

Blood-liquid plasma matrix with erythrocytes(RBC's) that carry O2 and leukocytes(WBC's) that carry immunity

Muscle Tissue

-made of long cells called muscle fibers

-muscle fibers are capable of contracting when stimulated by nerve impulses

-muscle fibers have large numbers of contracting units called myofibrils

-myofibrils are arranged parallel in the cytoplasm of muscle fiber cells

-myofibrils are made up of actin protein and myosin protein

Muscles

Muscle is the most abundant tissue in animals

Muscle contraction uses up most of the energy-consuming cellular work in an animal

Vertebrates have three types of muscle tissue: skeletal, cardiac, and smooth

Types of Muscle Tissue

Skeletal-for voluntary movement, striated

Cardiac-makes up contractile wall of heart, branched striated

Smooth-involuntary activities, no striations

Nervous Tissue

senses stimuli and transmits signals from one area of the animal to another

Located in many animals, it is most concentrated in the brain

the brain functions as a control center that coordinates many of the animal's activities

Types of Cells in Nervous Tissue

Neuron/ Nerve Cell-functional unit of nervous tissue-specialized to transmit nerve impulses

Dendrites-transmits impulses from the tips to the rest of the nerve cell/ neuron

Axons-transmits impulses to another nerve cell/ neuron 

Organs

An organ is a specialized center of body function composed of several diff. types of tissues

in some organs, tissues are arranged in layers

Ex: vertebrate stomach and other tubular organs of the digestive system have four major tissue layers

Organs (cont’d)

Mesenteries-sheets of connective tissue that suspend organs of vertebrates in moist or fluid filled cavities

Thoracic cavity-in mammals, houses the lungs and heart

Diaphragm- separates thoracic cavity from lower abdominal cavity

Lower abdominal cavity-in mammals, houses parts of the digestive, excretory, and reproductive system

Major Tissue Layers of Organs

1. Mucosa-an epithelial layer that lines the lumen, secretes mucus and digestive juices into the lumen

2. Sub mucosa-a matrix of connective tissue that contains blood vessels and nerve cells

3. Muscularis-consists mainly of smooth muscle tissue

4. Serosa-thin layer of connective and epithelial tissue

Bioenergetics

the flow of E through an animal

limits the animal’s behavior, growth, &

reproduction

determines how much food it needs 

Energy Sources and Allocation

food is digested by enzymatic hydrolysis

E containing molecules are absorbed by our cells then used: to generate ATP by the catabolic processes of cell respiration and fermentation , E of ATP is used to power cellular work, to keep organs and organ systems functioning/ for production and use of ATP generate heat to its surroundings

After energetic needs of staying alive are met, any remaining molecules from food can be used in biosynthesis (body growth and repair), synthesis of storage material(fat), production of gametes

Biosynthesis

Biosynthesis requires both carbon skeletons for new structures and ATP to power their assembly

Biosynthetic products(like fat) can be broken down for fuel when needed

Questions to Think About When “Quantifying E(energy) Use is Brought up

How much of the total energy of an animal obtains from food does it need just to stay alive?

How much energy is needed to fly/ swim/ walk? What fraction is used for reprodustion? Answers are found by physiologists by measuring

the rates at which animals use chem.. energyand how these rates changein diff. circumstances

Metabolic rate 

amount of E an animal uses in a unit of time 

Also known as the sum of all the Energy requiring biochemical reactions occuring over a given time interval 

measured by monitoring an animal’s rate of heat loss w/ calorimeter

Metabolic Rate (cont’d)

Varies by age, sex, size, activity level, time of day, and many other variables

When an animal exercises their BMR or SMR rates can be up 5-10 times higher

BMR or Basal metabolic rate- describes the number of kilcalories needed each day when an animal is totally at rest, fasting, and not stressed

SMR or standard metabolic rate- the metabolic rate of a fasting, resting ectotherm; it is determined at a specific temperature

Calorimeters

Calorimeters are closed, insulated chamber equipped w/ a device that records an animals heat loss to measure metabolic rate for small animals

E is measured in calories or kilocalories 1 kilocalorie=1000calories 

Bioenergetic Strategies

Animal bioenergetic rate is related to its bioenergetic “strategy” Two basic energetic strategies found in animals: 

Endothermic-in mammals and birds, bodies are warmed mostly by heat generated by metabolism, body temp. maintained in narrow range -high energy strategy that permits intense, long duration activity over a wide range of temperatures

Ectothermic -gain their heat from external sources 

Body Plans

Our bodies have made adaptations to physically support ourselves on land

These adaptations are based on body proportions and posture

Our body sizes affect the way in which our cells and bodies interact with the environment

Regulation of Our Internal Environment

Our internal environments that surround our cells is called interstitial fluid

Homeostasis-moderates changes within our internal environment sue to pH, or saturation, etc.-homeostasis is based on feedback mechanisms involving a receptor molecule, a control center, and an effector

Homeostasis

Negative feedbackEx: If some variable moves above or below a set point, a control is turned on and off in order to return the environment back to normal

Positive feedback- a mechanism in which a variable is used to amplify activityEx: Uterine contractions during childbirth