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Classification Overview


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									Classification Overview
A kingdom which is in flux and subject of much debate because of the great variety of organisms included.
Mostly unicellular
May be autotrophs (algae), heterotrophs (protozoa), or saprophytes (slime molds)

This is an old term and not a part of the current classification but still used in the literature.
Phyla of algae are formed by the color of the algae. Some are multicellular.
Land plants evolved from chlorophyta, green algae.

This is also from older classification systems and means “first animal”
This includes heterotrophic, single-celled organisms
Groups of protozoa are classified by their means of movement

Contains the phylum rhizopoda, amoeba.
Moves by pseudopods, false feet, which is the flowing of cytoplasm against the cell membrane to push the
cell along

The phylum ciliophora, contains the paramecia
Move by cilia
Very complex cell structure

Contains the phylum zoomastigina of trypanisomes which cause sleeping sickness, a brain inflamation
Move by means of flagella

The phylum sporozoa contains Plasmodium which causes malaria
The adult cells have no means of movement and are parasitic depending on their hosts to move them about

Slime Molds
As the name implies, these were once thought to be molds. However, they are now seem as a colony of
individual cells similar to amoeba.
They are found on land and in fresh water

Survey of the Animal Kingdom
Animals are multicellular, eukaryotic hetertrophs lacking cell walls.

Animal Characteristics
-Carbohydrates stored as glycogen
-Nervous and muscular tissue are unique to animals
-Diploid stage dominant
Specialized Systems
Internal transport
Gas exchange

Animal Types
-95% are invertebrates
-Most are aquatic
-The most familiar are the 5% which belong to the phylum Chordata, subphylum vertebrata

Used to Classify Animals
A. Symmetry
B. Number of embryonic layers
C. Coelomate vs. acoelomate
D. Protostome vs. deuterotstome embryology

A. Symmetry
-Radial--primitive animals
-Bilateral--most animals

A. Radial Symmetry
 Have oral and aboral sides
No front, back,
right or left

A. Bilateral Symmetry
Have: Dorsal--along spine
  Anterior--toward head
  Posterior--toward tail
  Medial--central line

B.Embryonic Germ Layers
Simplest, Porifera (sponges), have none
Cnidaria (jellyfish) have 2--ectoderm and endoderm
All others have 3--ectoderm, mesoderm, endoderm

C. Body Cavity--Coelom
Acoelomate--solid body, no cavity
Pseudocoelomate--body cavity which separates mesoderm and endoderm
Coelomate--cavity in mesoderm
C. Acoelomate
-In Platyhelminthes--flatworms
-not as much room for development of systems
-movement of molecules must be by diffusion through cells

C. Pseudocoelomate
-In Nematoda, round worms
-Room for organ systems
-Distribution of molecules faster
-Movement easier
-Disadvantage--digestive tract cannot be muscular

C. Coelomate
-Found in all other animals
-Advantages--all of those of a pseudocoelom PLUS
 THE DIGESTIVE SYSTEM WILL BE MUSCULAR and peristalsis becomes possible

D. Type of Embryology
 Two types of embryology are named by the development of the mouth opening from the gastrula:
-Protostome--mouth first
-Deuterostome--mouth second (anus first)

D. Protostome Characteristics
-Spiral cleavage--cleavage planes diagonal to vertical axis of embryo
-Early determination--determination occurs by 4-cell stage

Deuterostome Characteristics
-Radial cleavage--cleavage planes parallel or perpendicular to embryo axis
-Late determination--embryocnic cells totipotent through 8-cell stage

Animal Phyla
Animals are informally divided into two groups:
-invertebrates which do not have a backbone
-Vertebrates which do have a backbone (may be cartilage)

Invertebrate Animal Phyla
1. Porifer--sponges
2. Cnidaria--jellyfish
3. Platyhelminthes
4. Nematoda
5. Molluska--clams
6. Annelida--earthworms
7. Arthropoda--insects
8. Echinodermata--starfish
Vertebrate Phylum
Phylum: Chordata
Animals having a notochord at any time in their development
Subphylum: Vertebrata
Animals whose notochord develops into vertebrae

1. Porifera
-Means porebearer-incurrent and excurrent (osculum) pores for water movement & filter feeding
-Mostly marine, some freshwater
-Does not have true tissues or embryology of other animals
-Only 2 cell layers
-Sessile--attached, do not move around

1. Porifera--Specialized Cells
-Epidermis covers outer surface
-Collar cell (choanocyte)
-lines inner surface
-has flagella to move water
-traps and digests food
-Amebocytes--food distribution

1. Porifera--Skeleton
 The “skeleton” may be made of:
 -Spicules--sharp, calcium carbonate or silica pieces
 -Spongin--soft, flexible protein fibers

1. Porifera
 The main evolutionary improvement of the porifera is the interdependence of cells making it a truly
multicellular, not colonial, organism.

2. Cnidaria
-Means stinging cell
-Mostly marine, some fresh water
-Examples: jellyfish, hydra, anemones, Portuguese man-of-war, corals

2. Cnidaria
-Radial symmetry
-2 cell layers--ectoderm and endoderm with mesoglea between
-Nerve cells in mesoglea
-Gastrovascular cavity with only a single opening

2. Cnidaria
-Tentacles with stinging cells called cnidocytes containing a nematocyst with a stinger
-Body plan may be
-polyp--tree-like cylinder

2. Cnidaria
-Hydra reproduces asexually by budding but may also reproduce sexually if conditions are poor
-Hermaphroditic (form ovaries and testes on the same animal) but not self-fertilizing
2. Cnidaria
 Main evolutionary improvements are the nerve network in the mesoglea and muscle cells which allow the
animal to sense and respond to its environment

3. Platyhelminthes
-Means flatworm
-Planaria, tapeworm, flukes
-Three cell layers--has systems
-Protostome embryology

3. Platyhelminthes
-Bilaterally symmetrical
-Cephalization with eyespots located at anterior
-Digestive system with single ventral opening in free-living forms

3. Platyhelminthes--Planaria
-Free-living carnivores
-No special organs for breathing or circulation
-Move by cilia on underside
-Eyespots light sensitive
-Lateral auricles for smell
-Hermaphroditic but cross fertilize

3. Platyhelminthes--Tapeworm
-Have only scolex (head) with hooks and suckers and proglottids (reproductive segments)
-Depends on host for all other needs

3. Platyhelminthes--Flukes
-All are parasitic
-Suckers allow attachment to internal organs of the host
-Needs two hosts

3. Platyhelminthes
 The important evolutionary advancements are the development of 3 embryonic layers allowing for system of
organs and bilateral symmetry leading to cephalization.

4. Nematoda
-Three cell layers
-Protostome embryology
-Digestive system with mouth and anus

4. Nematoda
-Found in marine and fresh water, soil, as plant tissue and animal tissue parasites
-Separate make and female sexes with internal fertilization
4. Nematoda
-Free-living forms important in decomposition and nutrient recycling
-Parasitic forms do much harm to plants and animals

4. Nematoda
-Important animal parasites are:

4. Nematoda
 The main evolutionary developments are the pseudocoleom and the one-way food tube with a mouth and
anus for more efficient digestion of food (new food and waste do not mix).

5. Molluska
-Means soft body
-Snails, clams, oysters, slugs, octopuses, and squid
-Many have a hard shell
-Three cell layers
-True coelom--muscular digestive

5. Molluska
-All have a mantle
-Most have open circulatory system, cephalopods have closed
-Have specialized breathing organs
-Protostome embryology

5. Molluska
-Some hermaphroditic some have separate sexes
-One group, celphalopods (octopus and squid) have well-developed brains and eyes

5. Molluska
-Body made of
-Muscular foot
-Visceral mass of internal organs
-Mantle--a heavy fold of tissue to surround and protect organs and secrete a shell

5. Molluska--4 Classes
-Gastropod (stomach foot)--snails and slugs
-Bivalvia (2 shells)--clams
-Cephalopods (headfoot)--octopus, squid, chambered nautilus

5. Molluska
 The main evolutionary development is the presence of a true coelom which allows a muscular digestive
system, efficient transport of molecules, and internal hydrostatic pressure for movement, and independent
organ movement.
6. Annelida
-Means segmented worm
-Earthworms, leeches, marine worms
-segmentation allows specialization of body regions

6. Annelida
-Complex digestive system with mouth, pharynx, esophagus, crop, gizzard, intestine
-Closed circulatory system in all with hemoglobin

6. Annelida
-Complex nervous system with “brain” and ventral nerve cord
-Hermaphroditic but mate
-Marine, freshwater, and land forms

7. Arthropoda
-Means jointed foot
-Crayfish, lobsters, shrimp, crabs, millipedes, centipedes, spiders, insects
-Largest phylum with over 1 million described species

-Marine, freshwater, and land forms
-There may be some fusion of the segments

-Protostome embryology
-Marine, freshwater, and land forms
-Variety of mouth styles

-Exoskeleton of chitin
-Drawback to exoskeleton is that it must be shed to grow

7. Arthropoda --Chracteristics
-Jointed appendages for
-sensory receptors

-Specialized gas exchange organs
-gills in aquatic forms
-tracheal systems in insects
-book lungs in spiders
Class Crustacea (aquatic mandibulates)
-Lobster, shrimp, crayfish, crab, sow bug, pill bug, Daphnia, barnacles
-Specialized appendages
-Mouth formed from appendages

Class Crustacea (aquatic mandibulates)
-Can regenerate appendages
-Separate sexes

Class Diplopoda (terrestrial mandibulates)
-Eat decaying leaves, etc.
-Some texts say there are two pairs of legs per segment; other say two fused segments
-Like dark, moist places

Class Chilopoda (terrestrial mandibulates)
-One pair of legs per segment
-Like dark, moist places
-Poisonous bite to paralyze prey

Class Aracnida (chelicerates)
-Spiders, scorpions, mites, ticks
-Two body regions
-Eight legs

Class Aracnida (chelicerates)
-Lack antennae
-Have simple eyes
-Poisonous fangs (chelicerae)
-Book lungs
-Make silk to spin webs

Class Insecta (terrestrial mandibulates)
-Insects are the lagrest group of arthropods
-3 body regions

Class Insecta (terrestrial mandibulates)
-6 legs (3 pairs) attached to abdomen
-1 or 2 pairs of wings which have led to their success
-Compound eyes
-Pair of antennae
Class Insecta (terrestrial mandibulates)
-Open circulatory system
-Breathe with trachea and spicules
-Reproduce sexually with internal fertilization

Importance of Insects
-Compete with other animals for food
-Vectors of disease

 Metamorphosis is the process of developing from a fertilized egg to an adult. The two types are
-Complete metamorphosis
-Incomplete metamorphosis

Complete Metamorphosis
 The phases of complete metamorphosis are

Incomplete Metamorphosis
 The stages are

Comparing Metamorphosis
-young does not compete with adults for food
-young do not move as fast

Comparing Metamorphosis
-young does compete with adults for food
-young move fast even though they usually lack wings

8. Echinodermata
-Means spiney skin
-Starfish, brittle stars, sand dollars, sea cucumbers, sea urchin

8. Echinodermata
-Immature are bilaterally symmetrical
-Mature are radially symmetrical
-Move with water vascular system
Phylum Chordata

Characteristics of Chordata
-Deuterstome embryology
-Have a notochord --a tough, flexible rod between the gut and nerve cord-- and pharyngeal slits during their
-Dorsal, hollow nerve cord
-Muscular tail

Subphylum Vertebrata
-Notochord becomes vertebrae
-High degree of cephalization
-Skeleton of cartilage and/or bone
-Respiratory and circulatory systems have evolved to support more active life styles
-Advanced forms move to land

Classes of Vertebraates
1. Agnatha
2. Chondrichthyes
3. Osteichthyes
4. Amphibia
5. Reptlia
6. Aves
7. Mammalia

Class: Agnatha
-Means “without jaws”
-Lampreys and hagfish
-Oldest fossilized vertebrates
-Cartilage only
-Slimey skin with no plates or scales

-External parasites
-No teeth, use rasping tongue to grind onto prey
-Moved successfully from salt to freshwater of the Great Lakes

Class: Chondridthyes
-Means “cartilaginous fish”
-Sharks, skates, rays
-Have true jaws
-Marine forms only
-Most swim continuously to keep water moving over gills

Class: Chondridthyes
-Two-chambered heart
-Gills with gill slits only
-Excellent smell, site, and hearing
-Teeth are modified scales
-Internal fertilization
-Oviparous or ovoviviparous
Class: Osteichthyes
-Means “bony fish”
-Marine and freshwater forms
-Perch, tuna, sea horses, eels--more than 30,000 species
-Skin of bony scales
-Skeleton of bone

Class: Osteichthyes
-Gills with operculum
-2-chambered heart
-Mostly oviparous with external fertilization
-Well developed optical lobe
-Lateral line for hearing

Class: Amphibia
-Means “double life”
-May move to land as an adult
-Must always return to water to lay eggs
-Frog, toad, salamander, caecilian
-External fertilization, oviparous

Class: Amphibia
-Larval form has gills and 2-chambered heart
-Adult has lungs and 3-chambered heart
-About 70% of adults oxygen absorbed through moist skin

Benefits of Life on Land
-At first, fewer predators
-Easier to move through air
-Easier to move air over ventilating surfaces
-More niches to fill to lessen competition for survival

Class: Reptilia
-Means “to crawl” because these are the first vertebrates to have evolved so that they do not have to spend
any part of their lives in water
-Alligators, crocodiles, snakes, lizards, turtles

Class: Reptilia
Characteristics making life on land possible:
-Waterproof skin with keratin
-Efficient lungs and almost 4-chambered heart
-Internal fertilization
-Amniote egg

Amniote Egg (amniotic egg)
-Has a leather-like shell which prevents dehydration
-Has extraembryonic membranes which
-protect the developing embryo
-function in gas exchange
-provide of efficient nourishment
-store waste products
Amniote Egg
-Amnion: protects the embryo by enclosing it in a fluid-filled sac
-Yolk sac: Connects to the gut and delivers nutrition from the yolk
-Allantois: Stores waste away from the developing embryo
-Chorion: surrounds all others and controls gas exchange

Class: Aves
-Means “birds”
-Possess many reptilian characteristics such as amniotic egg and scales on their legs which seem to indicate
that they evolved from reptiles

Class: Aves
-Modifications for flight:
-“hollow” bones
-no teeth
-lungs and air sacs
-4-chambered heart

Benefits of Flight
-Can avoid land-based predators
-Can exploit flying prey such as insects
-Allows migration to best use foods and nesting sites

-Body temperature is internally controlled and remains relatively constant
-Advantage: can remain active all the time
-Disadvantage: Requires food

Class: Mammalia
-Means “breast”
-mammary glands for milk
-relatively large brains

Three groups of Mammalis
-Monotremes--duckbilled platypus--which are egg-layers
-Marsupials--kangaroo, opossum, koala--with pouches
-Placentals--all others--which carry young internally full term

Review of Improvements
Body covering
-Slimey skin to protective scales
-Moist skin to waterproof
-Hair covering for insulation
Review of Improvements
Breathing mechanisms
-Gills with slits only so that animal had to keep moving
-Gills with operculum to move water
-Lungs needing body to move
-Lungs with diaphragm

Review of Improvements
-2-chambered heart which sent blood through gills with no need to keep high oxygen blood and low separate
-3-chambered heart which began to separate high and low oxygen blood
-4-chambered heart separated blood completely

Review of Improvements
-Ammonia needed much water but little energy to form
-Urea needed less water but more energy to form
-Uric acid needed little water but much energy to form

Review of Improvements
-Internal fertilization
-Water egg tied organisms to the water even if they could live the rest of their life on land
-Amniote egg allowed animals to live completely on land

Review of Imorovements
-Ectothermy (cold blooded)
-made organisms rely of environmental temperature for their level of activity
-but required less food to fuel the control of temperature

Review of Imorovements
-Endothermy (warm blooded)
-made organisms independent of the environmental temperature for their level of activty
-required more food to fuel the control of body temperature

Review of Improvements
-No fins made balance hard
-Fins helped in movement and balance in water
-Limbs made movement on land possible
-Limbs under body most efficient
Overview of Animal Systems
-Makes blood cells (in vertebrates)

-Hydrostatic (in cnidarians, platyhelminthes, nematodes, and annelids)
-Fluid-filled coelom provides for movement only and does not protect or support

-Exoskeleton Z (arthropods)
-Hard external covering of chitin
-Provides for support, protection and movement
-must be shed to grow

-Endo skeleton (echinoderms and vertebrates
 -Support, protection, movement, makes blood cells
-Bone and cartilage in vertebrates

Muscle Types
There are 3 types of vertebrate muscle:

-In digestive system and blood vessels
-No striations
-Relatively weak
-Does not tire easily

Striated Characteristics
-Skeletal muscle--attaches to bone
-Voluntary-- conscious control
-Has stripes when viewed under the microscope
-Very strong
-Tires easily
-Found in the heart only
-Has the best characteristics of each of the other two
 -Does not tire

Muscle Action
-Muscles move bones by attaching to bones across a joint
-Muscles work in pairs to move bones
 while one relaxes, the other contracts

Muscle Structure
I. Muscle--bundle of long fibers
  A. Fiber--single cell w/ many nuclei--consists of many myofibrils
   1. Myofibril--composed of 2 kinds of filaments
    a. Thin filament--actin
    b. Thick filament-- myosin

Muscle Structure Thin Filament
The thin filament is composed of:
-two strands of actin
-one strand of tropomyosin
-many individual troponin molecules

Muscle Structure Thick Filament
Myosin strands of the thick filament end in expansions called heads or cross bridges

Muscle Structure Sarcomere
 -The arrangement of the thin and thick filaments establishes the UNIT OF MUSCLE CONTRACTION
called a sarcomere
 -A sarcomere is defined by a series of bands:
  Z, I, A, and H

Muscle Structure Sarcomere Bands
-Z band: Borders of the sarcomere--defines sarcomere
-I bands: Adjacent to Z bands and contain only actin filaments
-A bands: Areas containing both thick and thin filaments
-H bands: Area in center of sarcomere containing only thick filaments

Muscle Contraction--Sliding Filament Model
 When stimulated by a nerve impulse, the thin filaments of a muscle slide over the thick filaments and
shorten the distance between the Z lines of each sarcomere

Muscle Contraction--Sliding Filament Model
-Contraction is an all-or-nothing reaction at the level of the sarcomere
-Increased strength of the muscle contraction is achieved by the number of units which contract.
Muscle Contraction
L. An action potential in a motorneuronn arrives at the neuromuscular junction
M. Acetylcholine is released from the motor neuron
O. Acetylcholine is received by the sarcolemma (fiber membrane)

Muscle Contraction
N. Electrical excitation (depolarization) begins to spread through the sarcolemma
K. Electrical excitation spreads to the T-system tubules
H. Excitation of the T-tubules causes lateral sacs of the sarcoplasmic reticulum to release calcium ions

Muscle Contraction
B. Calcium ions bind with troponin in the thin filament
J. Tropomyosin molecules move into the groove of the thin filaments exposing the binding sites of the actin

Muscle Contraction
I. Myosin-ATP complex forms cross bridges to the thin (actin) filaments
D. Hydrolysis of ATP causes the myosin heads to swivel
E. Thick and thin filaments slide, shortening the distance between Z lines

Muscle Contraction
A. Myosin heads detach from the thin filament as ATP attaches to the myosin
F. The calcium pump actively transports calcium ions into lateral sacs of the sarcoplasmic reticulum

Muscle Contraction
G. Tropomyosin molecules come out and cover the actin binding sites
C. Thick and thin filaments slide, lengthening the distance between Z lines

Muscle Contraction
There are two types of muscle fibers:
 Slow (twitch) fibers
 Fast (twtich) fibers

Muscle Contraction
Slow (twitch) fibers
-have less sacroplasmic reticulum
-therefore, calcium ions remain in cytoplasm longer
-for endurance activities such as marathons

Muscle Contraction
Fast (twitch) fibers:
-Calcium ions are actively transported into sarcoplasmic reticulum more rapidly
-can fire more often
-for power such as weight lifting and sprinting
The Human Body
 As organisms evolved, there had to be changes in the digestive system which allowed for more efficient
extraction of energy from the food eaten.

Digestion is the process of changing complex food molecules which a cell cannot use into simple molecules
which individual cells can use.

Digestion Types
-In food vacuoles of protists
-In coanocytes of sponges
-In the gastrovascular cavity of cnidarians
-In a digestive system beginning with Planaria

Digestive System Types
-Mouth only
-Not much room for system development

Digestive System Types
-More room for a longer digestive system
-Both mouth and anus
-System not muscular

Digestive System Types
-Mollusks, annelids and above
-All other characteristics
-PLUS a muscular digestive system

 Glands external to the alimentary canal itself were added.
-Salivary glands

Digestion in Humans
Consists of 4 phases
-Elimination of indigestibles
Taking in of food
-Eating as we know it

-enzymatic hydrolysis of molecules
-occurs in a series of specialized compartments of alimentary canal

 The taking up of the monomers by the circulatory system so that they can be distributed to all cells of the

Elimination of Waste
 Some materials such as fiber (roughage, bulk) cannot be digested because we do not have enzymes which
recognize the shape of the particular molecule.

-Mastication (chewing) breaks large pieces into small and mixes with saliva to make a bolus (a ball of
chewed food)
-Taste buds
-sweet, sour, salt, bitter

-Salivary Glands
-parotid, sublingual, submaxillary
-Produce amylase
-Digests starch to the disaccharide maltose

Tongue pushes food to pharyx which is the back of the mouth shared by the respiratory and digestive system.
Presence of the bolus here triggers swallowing

This is the connection between the mouth and stomach. No digestion occurs here.

-Churning--mixes food with the digestive juices to form a liquid called chyme
-Produces pepsinogen which is an inactive enzyme
-Produces mucus to protect the stomach muscle itself
-Produces HCl which
-Kills bacteria
-Denatures protein--amylase deactivated
-Converts pepsinogen to the active form PEPSIN which breaks protein into polypeptide

-Endocrine control
 Stomach produces GASTRIN which is released into the bloodstream to have a positive feedback effect of
increasing levels of HCl and pepsin.

Digestion--Small Intestine
-Three sections

Digestion--Small Intestine
-All chemical digestion is completed in the small intestine
-Completed digestion depends on the products of the liver and pancreas

-Liver produces bile
-Bile stored in gallbladder
-Bile passes through common bile duct to duodenum when fat is present
-Bile emulsifies (breaks into pieces) fat

-Bicarbonate buffer to neutralize the high acid content of chyme entering duodenum
-Pancreatic amylase (starch to maltose)
-Pancreatic trypsin and chymotrypsin which digest polypeptides to amino acids
-Pancreatic lipase hydrolyzes fat to fatty acid and glycerol

Digestion--Small Intestine
 Gland cells in the wall of the small intestine also produce enzymes
-maltase--maltose to glucose
-lactase--lactose to glucose and galactose
-sucrase--sucrose to glucose and fructose

Digestion--Small Intestine
 Gland cells in the wall of the small intestine also produce enzymes
-dipeptidases--splits polypeptides

Digestion of Nucleotides
-Nucleases hydrolyze DNA and RNA into nucleotides
-Nucleotidases and nucleosidases hydrolyze nucleotides into nitrogen bases, sugar and phosphate
End Products of Digestion
-monosaccharides--glucose, fructose and galactose
-Fats--fatty acids and glycerol
-Protein--amino acids
-Nucleotides--sugar, bases, phosphate

Endocrine Control in Small Intestine
-released from duodenum when chyme enters
-signals pancreas to release bicarbonate

Endocrine Control in Small Intestine
-released from duodenum when chyme enters and signals
-liver to release bile if fat is present in chyme
- pancreas to release enzymes

Endocrine Control in Small Intestine
-released from duodenum in response to fat in chyme
-inhibits peristalsis to slow digestion

-Villi are small, finger-like projections in the wall fo the small intestine which increase surface area and
contain capillaries and lacteals

In villi
-capillaries absorb sugars, amino acids, bases, etc.
-lacteals absorb fatty acid and glycerol
-Most nutrients go to liver for processing

Large Intestine or Colon
-Reabsorbs water
-E. coli processes waste and makes vitamin K which is absorbed into the body
-Feces consisting of indigestibles are stored and released

 The respiratory system works with the circulatory system to transport oxygen and carbon dioxide between
the respiratory organs and the cells of the body.

-Sponges through nematodes and annelida had no respiratory structures and exchanged directly with the
-Mollusks had gills and an open circulatory system
-Arthrodops had
-gills in crustaceans
-spiricles and trachea in insects
-book lungs in arachnids

-gills and a 2-chambered heart in agnatha through osteicthyes
-gills and a 2-chambered heart in immature amphibians and lungs and a 3-chambered heart in adults
-lungs and a 4-chambered heart in reptiles, aves, and mammals

Respiration in Humans
1. Nasal passages warm, moisten, and filter air
2. Pharynx is shared with digestive system
3. Epiglottis closes over opening to trachea when swallowing

Respiration in Humans
4. Glottis is the opening to the trachea
5. Larynx is the voice box and contains vocal cords
6. Trachea is the windpipe and has cartilaginous rings to prevent collapsing

Respiration in Humans
7. Broncus (bronchi) branch from the trachea to left and right lungs
8. Bronchioles branch off bronchi to better penetrate lungs
9. Lungs -- gas exchange occurs
10. Diaphragm is a muscle which aids in breathing by altering the size of the chest cavity
11. Alveolus (alveoli) are membranous sacs surrounded by capillaries where the actual gas exchange occurs

Respiration in Humans
Negative Pressure Breathing
-Diaphragm contracts and lowers
-Intercostal muscles contract raising the ribs and pushing them out

Negative Pressure Breathing
-Size of the thoracic cavity increases
-Air pressure in the thoracic cavity decreases
-Air pressure in environment pushes air in

Negative Pressure Breathing
-Diaphragm relaxes and pushes up
-Intercostal muscles relax and move ribs in and down

Negative Pressure Breathing
-The size of the thoracic cavity decreases
-Air pressure in the chest increases
-Air rushes out of lungs
Control of Breathing
 The medulla oblongata of the brain monitors the pH of the cerebrospinal fluid which is affected by the level
of carbon dioxide. Therefore, the rate is controlled by carbon dioxide.

Transport of Oxygen
-Hemoglobin made of 4 proteins each with a single iron atom
-Oxygen transported by the iron in hemoglobin
-Iron’s affinity for oxygen changes with the shape of hemoglobin changes

Transport of Oxygen
-The Bohr Effect
-Higher pH causes a change in shape of hemoglobin and it holds on to oxygen more tightly
-Lower pH causes a change in the shape of hemoglobin and it holds less tightly to oxygen

 A circulatory system allows an animal to grow larger and be more complex because needed molecules no
longer have to diffuse from cell to cell to be moved around the body.

Types of circulation:
-gastrovascular cavity--cnidaria
-open system has a heart and circulates fluid which is NOT always contained
-closed system has a heart and blood vessels to direct flow

Gill breathers
-2-chamber heart
-atrium collects blood
-ventricle pumps blood
-oxygenation part of systemic flow through gills

Amphibians--skin breathers
-gills and 2-chamber in larva
-rudimentary lungs and 3-chamber in adults
-right atrium receives blood from body
-left atrium gets blood from lungs
-ventricle pumps--mixes blood

-thick skin requires most oxygen to come from improved lungs
-3-chambered heart with ventricles almost separated into two but does allow some mixing of blood

 Circulation helps to maintain homeostasis (all levels remain the same) in the vertebrate body by transporting
oxygen, carbon dioxide, food, waste, hormones, etc.
Birds and mammals
-warm blooded and need much energy requiring oxygen
-complete 4-chamber heart where blood low in oxygen an blood high in oxygen never mix

Circulation--The Heart
-2 thin-walled atria receive blood
-right atrium gets blood low in oxygen returned from the body by the anterior and posterior vena cavas
-left atrium gets blood high in oxygen from the lungs through the pulmonary veins

Circulation--The Heart
-2 thick-walled ventricles pump blood to the body
-right ventricle pumps blood low in oxygen to the lungs through the pulmonary artery
-left ventricle pumps blood high in oxygen to the body through the aorta

Circulation--Heart Beat
-Controlled by the SA node (sinoatrial) in the right atrium
-both atria pump together
-0.1 sec after, both ventricles contract
-sound is from valves

Circulation--Blood Vessels
Arteries--carry blood away from the heart
- muscular, very thick-walled because of blood pressure from force of left ventricle
-carry blood high in oxygen except for pulmonary artery

Circulation--Blood Vessels
-made of lining cells only so molecules can leave easily
-carry materials to every cell of the body
-connect arteries and veins

Circulation--Blood Vessels
Veins--carry blood toward the heart
-muscular, thin-walled with valves because blood is under such low pressure
-carry blood low in oxygen except for pulmonary veins

1. Rt atrium 8. aorta
2. rt ventricle     9. arteries
3. pulmonary art. 10. arterioles
4. Lungs       11. Capillaries
5. pulmonary veins 12.venules
6. left atrium 13. veins
7. left ventricle 14.vena cavas
Circulation--Blood Pressure
 Blood is pumped from the left ventricle into the aorta and then to other arteries with great force and pushes
on the walls of the arteries to create a pressure.

Circulation--Blood Pressure
 2 pressure measurements
-systolic pressure
       When the heart is pumping, the pressure in arteries is great
       When the heart is filling and the pressure in arteries is lower

Circulation--Blood Pressure
 Blood pressure is stated as
 systolic / diastolic
and normal is
130 / 80

Circulation--Blood Pressure
 Very low blood pressure is not good because cells may not get enough oxygen and nutrients to function

Circulation--Blood Pressure
 High blood pressure is not good because the extra force on the arteries may cause them to burst and result in
internal bleeding such as a stroke.

Circulation--Blood Pressure
Factors causing high pressure
-lack of exercise
-smoking which constricts arteries
-high fat and salt diet

Circulation--Heart Attack
-Death of the cardiac muscle from oxygen deprivation
-Caused by
-diet with too much fat
-lack of exercise

-Blood clot
-May block flow of blood to the brain causing stroke or to the heart causing heart attack

-Vascular disease caused by plaque build up in vessels
-Caused by
-high fat diet which increases LDL (low density lipoprotein) which clogs arteries
-Smoking which increases LDL
-Caused by
Lack of exercise because exercise increases the HDL (high density lipoprotein) which is the good kind that
actually reduces cholesterol, LDL

-Hardening of the plaque in the arteries wit calcium deposits which narrows arteries and makes them less

Nervous System
Performs 3 functions
-Sensory input collected from sensory organs
-Integration analyzes input
-Motor output uses muscles or glands to respond to input

Nervous System
Composed of
1. Neurons: transmit electrical and chemical signals
2. Supporting cells: protect, support, and insulate neurons

Neuron structure consists of:
-Cell body with nucleus
-Dendrites leading to cell body
-Axon leading away from cell body

Supporting Cells
-Do not carry nerve impulses
-Outnumber neurons
-They are
-Schwann cells which insulate neurons
-Glia cells which protect and insulate

Myelin Insulation
 Schwann and glial cells produce myelin which:
-speeds up impulse
-deteriorates in multiple sclerosis

Nerve Impulse
 The nerve impulse is an electrical current carried along the neuron because of:
1. Polarization
2. Rapid depolarization
3. Refractory period of repolarization

Nerve Impulse--Polarization
 The sodium/potassium pump actively transports 3 Na ions out of the cell and 2 K ions into the cell creating
an electrical imbalance with more positive charges outside than inside the cell.
Nerve Impulse--Polarization
 This is a resting potential will be maintained because charged particles do not pass through the lipid bilayer
and the protein active transport channels are closed after the gradient is established

Nerve Impulse--Depolarization
 When stimulated, the neuron will VERY BRIEFLY become more permeable to the ions, and they will
rapidly diffuse across the membrane causing a depolarization or electrical impulse.

The Nervous System
1. Central
     A. Brain
   B. Spinal cord

2. Peripheral
   A. Somatic
   B. Autonomic
       1. Sympathetic
       2. Parasympathetic

The Nervous System
The nervous system is divided into the central nervous system and the peripheral nervous system.

The Nervous System
 The central nervous system is made up of the:
     -medulla oblongata--automatic reg.
-Spinal cord

The Nervous System
The peripheral nervous system contains nerves that branch off of the central system and consists of the:
    -somatic nervous system
    -autonomic nervous system

The Somatic Nervous System
The somatic system controls voluntary activities.

The Autonomic Nervous System
-The autonomic nervous system controls involuntary activities.
-Consists of sympathetic and parasympathetic

The Autonomic Nervous System--Sympathetic
The sympathetic creates the conditions for “fight or flight” which allows response to threatening conditions.
The Autonomic Nervous System--Sympathetic
Under the sympathetic:
  -pupils dilate
  -heart and breathing rates increase
  -digestion and excretion slow

The Autonomic Nervous System--Parasympathetic
The parasympathetic is active for maintenance of the body’s activities under normal conditions.

The Autonomic Nervous System--Parasympathetic
Under the parasympathetic:
    -pupils constrict
    -heart and breathing slow
    -digestions and excretion increase

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