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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