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How Animals work Theme is Biology: Form and function

What a structure can do is influenced by it’s form

The form of a structure is uniquely suited to what that structure does

Both the form and function evolve together Areas of Biological study:

Anatomy: the structures of an organism (form)Physiology: how the structures work (function)

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We are a tube within a tube We are a thick walled tube Running through the

center of the tube is a digestive system, another tube.

http://biology.kenyon.edu/courses/biol112/Biol112WebPage/Syllabus/Topics/Week%207/Resources/coelom.GIF

http://www.mscd.edu/~biology/231course/cavity.jpg

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Which way is which?

http://anthro.palomar.edu/animal/images/dorsal.gif

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Tissues A tissue is a group of similar cells that

usually have a similar embryological origin and are specialized for a particular function.

Tissue cells are often separated by non-living, intercellular materials that cells produce. This substance is called the matrix.

Histology – the study of tissues

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Four Principal Types of Tissues:

Epithelial –covering and lining; and glands

Connective – protects and supports, binds organs together, stores energy, and provides immunity

Muscle – movement Nervous –transmits impulses that

coordinate body activities

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Feature of Epithelial Tissue Closely packed cells with little extracellular

material Epithelial cells are arranged in continuous sheets,

in single or multiple layers Epithelial cells have two surfaces

One side is up against other tissuesThe other side faces an open space

http://www.cnas.missouristate.edu/labimages/biology/bio122/images/Week%208%20Images/trachea.jpg

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Connective Tissue Connective tissue is the most

abundant and widely distributed tissue in the body .

The functions of connective tissue:Binding, attachment and support (bones,

tendons and ligaments, organs)Protection- bones and adipose tissue Insulation - adipose tissueStorage - of energy and fat soluble

substancesTransportation - blood

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Skeletal Smooth Cardiac voluntary involuntary involuntarycells are long short, spindle-shaped branchedmany nuclei single nucleus single nucleusstriated nonstriated striated

intercalated disks

Muscle Tissue

Diagram of skeletal muscle

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Nervous tissueSends signals to other parts of body

neurons : Dendrites - (one or many) receive

incoming signalsCell bodyAxon - (one) transmits outgoing signals

neuroglia : protective and supporting cells

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dendrites

Axon

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Organs are two or more tissues which together perform a specialized function.

Epithelial membranes are thin structures that usually contain both epithelial and connective tissue.

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Integumentary system is the skin and the organs derived from it (hair, glands, nails)

One of the largest organs2 square meters; 10-11 lbs.Largest sense organ in the body

The study of the skin is Dermatology

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Three types of epithelial membranes

Serous MembranesLine cavities and cover organs

Mucous membranes Line cavities that open to the exteriorLayer of epithelium over connective tissue;

Cutaneous membrane is the skin the major organ of the integumentary system

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Functions:

1. Regulation of body temperatureCellular metabolism produces heat as a

waste product .High temperature

Dilate surface blood vessels Sweating

Low temperature Surface vessels constrict shivering

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2. Protection

physical abrasion

dehydration

ultraviolet radiation

3. Sensation

touch

vibration

pain

temperature

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4. ExcretionSweat, rid excess salt for example

5. Immunity/ ResistanceKeeps microbes out, fights infections

6. Blood Reservoir8-10 % of blood in a resting adult

7. Synthesis of vitamin DProduced by exposure to UV lightaids absorption of calcium

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Anatomy Epidermis Skin Dermis Subcutaneous layer or hypodermis

See next two slides

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The Skeletal System comprised mostly of connective tissue In the case of most vertebrates, a skeletal

system is comprised of bone Various bone types

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Functions of Bone Support

For soft tissuesFor attachment of skeletal muscles

Protection Movement Storage : minerals, fat Blood cell production – hematopoiesis

Erythrocytes, leukocytes, platelets

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Matrix As a connective tissue, bone is living cells

embedded in a matrix consisting of Secreted substances (proteins)

Proteoglycans and glycoproteinsCollagen – reinforces, gives tensile strength

Mineral salts Tricalcium phosphate (hydroxyapatite) and

calcium carbonateCalcium is thus needed for bone.

Bone is an active, living material!

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Remodeling Bone is continually being broken down and

reformed 3-5 % of bone calcium exchanged each year In response to stress on bones Balance between actions of osteoclasts and

osteoblastsOsteo means boneOsteoblasts MAKE bone, osteoclasts dismantle it.

Vitamins needed for maintenance, esp. D

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3 related organ systems Two important things that animals do: feed

and breedWe’ll skip “breed”, but explore 3 organ

systems by looking at “feed” Part of “survival of the fittest” is being able

to procure nutrients to survive and live long enough to breed.Digestive system: processes nutrientsRespiratory exchanges nutrients and wastesCardiovascular system transports these

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Needed to function (but not discussed) Urinary system: without kidneys to filter

waste products from the blood for excretion, we’d be in trouble.

Muscles: movement required for animals. Nervous system and endocrine system:

nerve cells allow communication by electrochemical signals

Coordinated with chemical signal: hormones

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Digestive system Food is needed

Organic materials to break down for energyOrganic molecules as building blocks for

cellular materialSpecific organic molecules (amino acids,

vitamins) we are unable to make ourselvesCertain minerals needed to assist enzymes

How much?We need enough energy (measured in

calories) to power our activities.Over and under nutrition can occur.

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A digestive system needed A large organism has a system for

extracting nutrients from food for distributing to the rest of the body.

Food must be physically broken down Food must be chemically broken down Nutrients must be absorbed Excess water used in digestion must be

recovered Waste must be excreted

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Parts of a digestive system Mouth

Teeth for breaking up foodSaliva for wetting, breakdown of starch

Esophagus: muscular tube for transferring food to the stomach

StomachPhysical digestion; muscular stomach churnsChemical: low pH (high stomach acid)

dissolves food; enzymes also breakdown food

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Food passes into small intestineBile salts and enzymes from liver (via

gallbladder) act as detergents, break up fats.Pancreas neutralizes stomach acid, adds

enzymes that break down food more. Small intestine: site of nutrient absorption

Possesses a high surface areaCells are arranged in villiEach cell is covered with microvilliEach villus contains lots of blood capillaries

for transporting nutrients away

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Form and function in the small intestine

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/V/villi.gifhttp://distance.stcc.edu/AandP/AP/imagesAP2/digestion/microvilli.jpg

villi

High surface area for lots of absorption.

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The end of the line Large intestine = colon

Most of the water is absorbed here In an irritated colon, material is moved

through quickly before all the water is absorbed: diarrhea

Home to billions of bacteria Most are anaerobic Responsible for bad odors, production of

gas from fermentation Feces are mostly bacterial bodies;

undigested food a smaller proportion

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Respiratory system During metabolism, cells “burn” organic

molecules.E.g. glucose ultimately gets converted to CO2,

energy is released.Process needs oxygen, releases CO2

Respiratory system must efficiently get O2 into the bodyYet protect from microbes, dirt and dust,

drying out, etc.

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Respiratory anatomy Nose, sinuses Trachea = windpipe, tube that leads from

oral cavity (mouth) to lungs Bronchi: the trachea branches Bronchioles: the bronchi branch into

smaller tubes that lead to the lobes of the lung

Alveoli = air sacs: small compartments in which gasses are transferred between air and bloodstream

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Lungs

http://www.aduk.org.uk/gfx/lungs.jpg

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Respiratory protections Ciliated epithelium

Surfaces lined with cells that secrete mucus, push mucus along with cilia

Mucus with entrapped bacteria, dust, pushed towards mouth for coughing out or swallowing

Swallowing leads to stomach, acidThings that kill epithelium interfere with these

protections Influenza virus smoking

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Single ciliated cell

Cilia

http://n2.bioeng5.bioeng.auckland.ac.nz/ontology/images/RespiratoryEpitheliumCiliatedEpithelialCell.png

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Where does Oxygen go?

http://training.seer.cancer.gov/module_anatomy/images/quiz_dd_pulmonary_circulation.jpg

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Cardiovascular terms to know Cardio means heart; vascular means tubes From big to small

Arteries, arterioles, capillaries: Take blood AWAY from the heart

Veins, venules, capillaries Bring blood TO the heart

Capillaries are where exchange of materials between blood stream and cells occurs.

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Status of blood

Pulmonary circulationBlood traveling AWAY from heart to lungs has

little O2 content (in blue): pulmonary artery

Blood traveling from lungs TO heart has lots of O2 (in red): pulmonary vein.

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The rest of the circulation Heart has 4 chambers in a mammal

2 atria and 2 ventriclesPulmonary and systemic circulation

Blood returns from body into right atrium Flows into right ventricle, pumped to lungs Returns from lungs to left atrium Flows into left ventricle, pumped to the rest

of the bodyMain artery leading to rest of body: aorta

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Heart structure

Ao = aortaLA = left atriumLV = left ventriclePA = pulmonary arteryRA = right atriumRV = right ventricle

Match up with description on previous slide.

http://www.rch.org.au/cardiology/media2/Fontan_pic1.gif