Transcript How Animals work

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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/B
iol112WebPage/Syllabus/Topics/Week%20
7/Resources/coelom.GIF
http://www.mscd.edu/~biology/231co
urse/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 nonliving, 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 tissues
 The other side faces an open space
http://www.cnas.missouristate.edu/labimages/biolog
y/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 tissue
 Storage - of energy and fat soluble
substances
 Transportation - blood
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Muscle Tissue
Skeletal
voluntary
cells are long
many nuclei
striated
Smooth
involuntary
short, spindle-shaped
single nucleus
nonstriated
Cardiac
involuntary
branched
single nucleus
striated
intercalated
disks
Diagram of skeletal
muscle
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Nervous tissue
Sends signals to other parts of body
neurons :
Dendrites - (one or many) receive
incoming signals
Cell body
Axon - (one) transmits outgoing signals
neuroglia : protective and supporting cells
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Axon
dendrites
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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 organs

2
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 Membranes
 Line

cavities and cover organs
Mucous membranes
 Line
cavities that open to the exterior
 Layer 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 temperature
 Cellular
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.
Excretion
 Sweat,
 5.
Immunity/ Resistance
 Keeps
 6.
microbes out, fights infections
Blood Reservoir
 8-10
 7.
rid excess salt for example
% of blood in a resting adult
Synthesis of vitamin D
 Produced
by exposure to UV light
 aids 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 tissues
 For 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 glycoproteins
 Collagen – reinforces, gives tensile strength
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Mineral salts
 Tricalcium
phosphate (hydroxyapatite) and
calcium carbonate
 Calcium is thus needed for bone.
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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
osteoblasts

 Osteo
means bone
 Osteoblasts MAKE bone, osteoclasts dismantle it.
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Vitamins needed for maintenance, esp. D
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3 related organ systems
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Two important things that animals do: feed
and breed
 We’ll
skip “breed”, but explore 3 organ
systems by looking at “feed”
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Part of “survival of the fittest” is being able
to procure nutrients to survive and live
long enough to breed.
 Digestive
system: processes nutrients
 Respiratory exchanges nutrients and wastes
 Cardiovascular 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
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Food is needed
 Organic
materials to break down for energy
 Organic molecules as building blocks for
cellular material
 Specific organic molecules (amino acids,
vitamins) we are unable to make ourselves
 Certain 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 food
 Saliva for wetting, breakdown of starch
Esophagus: muscular tube for transferring
food to the stomach
 Stomach

 Physical
digestion; muscular stomach churns
 Chemical: low pH (high stomach acid)
dissolves food; enzymes also breakdown food
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
Food passes into small intestine
 Bile
salts and enzymes from liver (via
gallbladder) act as detergents, break up fats.
 Pancreas neutralizes stomach acid, adds
enzymes that break down food more.
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Small intestine: site of nutrient absorption
 Possesses
a high surface area
 Cells are arranged in villi
 Each cell is covered with microvilli
 Each villus contains lots of blood capillaries
for transporting nutrients away
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Form and function in the small intestine
villi
High surface area for lots
of absorption.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/V/villi.gif
http://distance.stcc.edu/AandP/AP/imagesAP2/digestion/microvilli.jpg
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The end of the line
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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 body
 Yet
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
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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, acid
 Things 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/RespiratoryEpitheliumCiliate
dEpithelialCell.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
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 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 circulation
 Blood
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 ventricles
 Pulmonary 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 body
Main artery leading to rest of body: aorta
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Heart structure
Ao = aorta
LA = left atrium
LV = left ventricle
PA = pulmonary artery
RA = right atrium
RV = right ventricle
Match up with description
on previous slide.
http://www.rch.org.au/cardiology/media2/Fontan_pic1.gif