Protection, support and movement in animals
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Transcript of Protection, support and movement in animals
PROTECTION, SUPPORT AND MOVEMENT IN
ANIMALS
PROTECTION: INTEGUMENTARY SYSTEM
The Integumentary system’s primary function is to maintain homeostasis. It also protects the body, and its other organs and tissues, from infection, dehydration, sunburn and sudden changes in temperature.
The Integumentary System of animals includes an outer protective body covering called the integument and associated structures and secretions.
• the external covering of an animal• it may refer to the skin, cuticle or
membrane of an organism• protects the animal from
mechanical and chemical injury and invasion by other microorganisms
What is an Integument?
Integumentary Systemof
Invertebrates
Snails, slugs, oysters, and clams are protected by a hard shell made of calcium carbonate secreted by the mantle, a heavy fold of tissue that surrounds the mollusc's internal organs.
Spiders, insects, lobsters and shrimp have bodies covered by an external skeleton, the exoskeleton, which is strong, impermeable, and allows some arthropods to live on land.
The exoskeleton is composed of layers of protein and a tough polysaccharide called chitin, and can be a thick hard armor or a flexible paper-thin covering.
Plasma Membrane• structurally and chemically identical to
the plasma membrane of multicellular organisms
• used as protective covering of some single-celled protozoa
Pellicleoffers further environmental protection and
is a semi rigid structure that transmits the force of cilia or flagella to the entire body of the protozoan as it moves
protective covering of some protozoa
Cuticles• It is the noncellular, hardened or
membranous protective covering of many invertebrates
• consists of chitin and proteins in rigid plates that a flexible membrane links together
Structure of a Paramecium
rests on a basement membraneoutermost layer of epithelial tissue and is
one to several cell thickan integument or outer layer of various
invertebrates
• outer covering of parasitic flukes and tapeworms
Epidermis
Tegument of a tapeworm
Tegument
Integumentary System of Vertebrates
Integumentary System of Vertebrates
Skinvertebrate integument largest organ of the vertebrate body and
grows with the animal Its layers:
1) EpidermisThe outer, protective, nonvascular layer of
the skinIt covers the dermisIt consists of a basal layer of actively
dividing cellsThe epidermis may bear a variety of
specialized structures (Example: feathers, hairs)
Made up of connective tissues, cells and elastic fibers beneath the epidermis
It is thicker than the epidermisDense and fibrous
3) Hypodermis• “below the skin”• Consists of loose connective tissue, adipose
tissue, and nerve endings, separates the skin from deeper tissues
2) Dermis
Skin of Jawless Fishes• Have relatively thick skin• Slime protects the animals from external
parasites• Multicellular slime glands in their skin
secretes large amount of mucous to cover the body surface for protection
Examples: Lampreys and Hagfishes
Lamprey
Hagfish
Skin of Cartilaginous
Fishes• Multi layered and contains mucous and
sensory cells
Denticles– Are bones in the form of placoid scales
found in the dermis– Contains blood vessels and nerves and are
similar to vertebrate teeth• As cartilaginous fishes grow throughout
life, the skin area also increases.
• Once denticles reach maturity, they do not grow; thus, continually wear down and are lost
• Denticles give cartilaginous fishes a sandpaper textureExamples: Sharks, skates and rays
Denticles seen through an electron microscope
Skin of Bony Fishes
• Contains scales- Small flat bony overlapping plates that cover the bodies of fish and composed of dermal bone
Examples: Tuna and Seahorses
Skin of Amphibians• Consists of a stratified epidermis and a
dermis containing mucous and serous gland plus pigmentation cells
• Their skin is highly permeable and they us it to obtain both oxygen and water from their environment
• Earliest amphibians were covered by dermal bone scale like their fish ancestors
• Often times their skin is moist
Skin of Reptiles• is comprised of two main layers, the
epidermis and the dermis• Epidermis: Outer layer of the epidermis is
thick, lack glands, and is modified into keratinized scales, scutes (thick scales), beaks, claws, plaques, and spiny crests.
It is completely covered in keratin. The keratin is composed of many layers of very thin, flat cells
• Dermis: consists of connective tissue. In some reptiles, there may be small
bones called osteoderms. These are what form the distinctive specialized scales on savannah monitors and crocodilians, for example.
• Reptile skin heals much more slowly than mammalian skin, often taking about 6 weeks for the defect to be fully restored.
• The thick keratinized layer resists abrasion, inhibits dehydration and protects like a suit of armor.
Skin of Birds• The epidermis is usually thin and only
two or three cell layers thick.• “Thin Skinned”• Outer keratinized layer is often quite soft• The most prominent parts of the
epidermis are the feathers (collectively known as plumage)
• Feathers, provides the strong yet lightweight surface area needed for powered, aerodynamic flight.
• They also serve as insulation, trapping pockets of air to help birds conserve their body heat.
• The varied patterns, colors, textures, and shapes of feathers help birds to signal their age, sex, social status, and species identity to one another.
Skin of Mammals• Notable features of mammalian skin :
HairA greater variety of epidermal glands
than in any other vertebrate classA highly stratified, cornified epidermisA dermis many times thicker than the
epidermis
• The skin of mammals is constructed of two layers, a superficial nonvascular epidermis and an inner layer, the dermis or corium. Epidermis
o is composed of stratified squamous epithelium and consists of several layers of a variety of cells.
othe cells pushed toward the surface ,from the deepest layer of the epidermis, dies and becomes keratinized.
oKeratinized cells make up the outer skin layer called stratum corneum.
Dermis The thickest portion of mammalian skin is
composed of dermis which contains blood vessels, lymphatic vessels, nerve endings, hair follicles, small muscles and glands.
• HypodermisIn mammals, it consists of loose connective
tissue, adipose tissue and skeletal muscles. Adipose tissue stores energy in the form of fat and provides insulation in cold environment.
The Structure of the Mammal’s Skin
Skin of Mammals: Glands• Sudoriferous glands (Sweat
Glands)
They are distributed over most of the human body surface. These glands secrete sweat by a process called perspiration which helps regulate the body tempera-ture and maintain homeostasis. In some mammals ,sweat glands also produce pheromones.
• Sebaceous glands
are simple glands connected to hair (oil) follicles in the dermis.
They lubricate and protect by secreting sebum. Sebum is permeability
barrier, an emollient and a protective agent against microorganisms.
Sebum also acts as a pheromone.
AppendagesHair is composed of keratin filled cells that
develop from the epidermis. The portion of hair that protrudes from the
skin is the hair shaft and the portion embedded beneath the skin is the root.
The arrector pilli muscle(smooth involuntary muscles) attaches to the connective tissue sheath of hair follicle surrounding the bulb of the hair root.
Arrector Pilli MuscleWhen this muscle contracts, it pulls the follicle
and its hair to an upright/erect position. In human, this is referred to as a ‘goose
bump.’This action helps to warm an animal by
producing an insulating layer of warm air between the erect hair and skin.
If hair is erect because the animal is frightened instead of cold, the erect hair also makes the animal look larger and less vulnerable to attack.
Nails
¨ Like hair, they are modification of the epidermis.
¨ They are flat, horny plates on the dorsal surface of the distal segments of the digits (e.g. finger and toes of primates).
¨ Other mammals have claws and hooves. ¨ Other keratinized derivatives of mammalian
skin are horns and the baleen plates of the tooth less whales.
SUPPORT: SKELETAL SYSTEM
There are 3 kinds of Skeletons:
A. Fluid Hydrostatic Skeletons / Hydroskeleton
(Gr. Hydro, water + statikos, to stand)A core of fluid (such as blood) surrounded
by a tension-resistant sheath of longitudinal and/or circular muscles
B. Rigid Exoskeletonsª (Gr. Exo , outside + skeleton)ª Have loco motor functions because they
provide sites for muscle attachment and counter forces for muscle movements
ª Support and protect the body, but these are secondary functions
C. Rigid Endoskeletons (Gr. Endo, within + skeleton) A skeleton that lies beneath the surface of
the body
The Skeletal System
of Vertebrates* An endoskeleton enclosed by other body
tissues* Consists of 2 main types of supportive
tissues :1. Cartilage
A specialized type of connective tissue that: provides a site for muscle attachmentaids in movement at jointsprovides supporttransmits the force of muscular contraction
from one part of the body to another during movement
2. Bone or Osseous TissueA specialized connective tissue that:
◊ provides a point of attachment for muscles ◊ transmits the force of muscular contraction
form one part of the body to another during movement
Skeleton of Fishes
Most jawed fishes have an axial skeleton that includes a notochord, ribs, and cartilaginous or bony vertebrae.
Skeleton of Tetrapods• Tetrapod endoskeleton become
modified for support on land.
Human EndoskeletonHas two major parts :• Axial Skeleton
– Made up of the skull, vertebral column, sternum, and ribs
• Appendicular Skeleton
- Composed of the appendages, pectoral girdle, and pelvic girdles
MOVEMENT: MUSCULAR SYSTEMMOVEMENT: MUSCULAR SYSTEM
Nonmuscular Movement and Muscular Movement
Movement is a characteristic of certain cells, protists, and animals
4 cell types that contribute movement:• Amoeboid cells• Flagellated cells• Ciliated cells• Muscle cells
Muscle Cells
– Smooth Muscles / involuntary muscles• Higher brains do not control its
contractions– Cardiac Muscles
• Involuntary• have a single nucleus and are striated
– Skeletal Muscles/ Striated Muscle• A voluntary muscle• The nervous system consciously controls
its contractions
Nonmuscular Movement• It is from the basic framework of the
cell that specialized contractile mechanisms emerged
The Muscular System of Invertebrates
Locomotion of Soft-Bodied Invertebrates
• Pedal locomotion– Can mover a firm substratum
Examples: flatworms, cnidarians, gastropod molluscs
• Looping MovementLeeches : have interior and posterior
sucker that provide alternating temporary point of attachment
Lepidoteran Caterpillars: arching movements are equivalent to the contraction of longitudinal muscles
• Water-Vascular SystemStar Fish: along each canal are
reservoir ampullae and tube feet. The tube feet extend by hydraulic pressure and can perform simple step-like motions
Terrestrial Locomotion in Invertebrates: Walking
• Has flexible joints, tendons, and muscles that attach rigid skeletal cuticle and form limbs
• Examples: arthropods –Crabs : sideward–Lobsters, spider : forwards
Terrestrial Locomotion in Invertebrates: Flight• Muscles changing the shape of the thorax
cause wings to move up and down
• An insect must exert a force against the ground sufficient to impart a take-off velocity greater than its weight
• Examples: Fleas, Grasshoppers, Leafhoppers
Terrestrial Locomotion in Invertebrates: Jumping
The Muscular System of Vertebrates• Provides sites for skeletal
muscles to attach• Tendons : tough, fibrous
bands or cords, attach skeletal muscles to the skeletons
Structure of Skeletal Muscle Tissuea. A skeletal muscle in the forearm consists of
many muscle fibers (cells)b. Bundled inside a connective tissue sheathc. A skeletal muscle fiber contains many
myofibrilsd. Myofibrils consists of functional units called
sarcomerese. The characteristics striations of a
sarcomeres are due to the arrangement of actin and myosin filaments
References
Book: Miller, S. and Harley, J. (2005). Zoology. Avenue of
the Americas, New York. McGraw-Hill Companies, Inc.
Websites:• http://www.crystalgraphics.com/• http://www.ehow.com/
about_6308504_integumentary-system-animals.html
• http://www.merriam-webster.com/dictionary/integument
• http://science.jrank.org/pages/3626/Integumentary-System-Invertebrate-integuments.html
• http://www.thefreedictionary.com/cuticle• http://www.thefreedictionary.com/epidermis• https://www.google.com/url?
sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CDEQFjAA&url=http%3A%2F%2Fimages.imthegeek.multiply.multiplycontent.com%2Fattachment%2F0%2FSyC4uwooCI8AABIfx4o1%2FIntegumentary%2520System-Vertebrates.ppt%3Fnmid%3D303183592&ei=3o32ULOGIaiuiQfr1oDADg&usg=AFQjCNGVD6vzA9WwQU7Zum5WDH_4eb00MA&bvm=bv.41018144,d.aGc
• http://www.encyclopedia.com/topic/epidermis.aspx
• http://www.mesa.edu.au/fish/fish03.asp• http://marinelife.about.com/od/marinelife101/f/
What-Is-A-Bony-Fish.htm• http://sleep1937.tripod.com/id1.html• http://www.anapsid.org/basicdermatology.html• http://www.britannica.com/EBchecked/topic/
360838/mammal/235401/Form-and-function• http://sparknotes4pak.blogspot.com/2012/05/
skin-of-mammals-is-complex-than-other.html