Support, protection, and movement Flashcards
Integument (4)
An outer covering.
Includes:
SKIN
Derivatives: hair, setae, scales, feathers, horns
Functions of Integument (9)
Protects against abrasion,
protects against water loss,
barrier against invasion by pathogens,
protects from UV light damage,
thermoregulation,
sensory receptors within,
excretory,
respiratory,
pigmentation,
secretes molecules
Two layers of skin
Epidermis/
Dermis
What specific type of tissue constitutes the epidermis?
Stratified squamous epithelium
The germinal layer is…
A layer of the stratified squamous epithelium
What’s true about glands with respect to tissue?
They are lined by a simple epithelium
Germinal layer
produces other layers by mitosis
Cornified layer (2)
Keratinized cells fill with keratin and lose nucleus and organelles.
Layer is resistant to abrasion and water loss
Integumentary derivatives arise from epidermis (3)
Hair,
Feathers,
Scales
Structure of Dermis (9)
Composed primarily of connective tissue.
Fibroblasts +
collagenous fibers.
Macrophages.
Lymphocytes.
Chromatophores.
Fat cells.
Blood vessels.
Nerves
Compact dermis tissue type?
Dense CT
Scales can be different. Explain
Some scales are dermal origin.
Some scales are epidermal origin.
Integumentary derivatives contain….
combinations of Epidermal and Dermal Components
Skeletal Systems do what? (3)
Provide rigidity to body,
provide surfaces for muscle attachment,
provide protection for internal organs
Two basic types of skeletal system (2)
Rigid and
Hydrostatic
Rigid Skeletons provide…
rigid elements to which muscles can attach
Two types of rigid skeletons
endoskeleton and exoskeleton
Exoskeleton
Protective outer skeleton that often must be molted to allow growth.
Arthropods
Endoskeleton (2)
Found in echinoderms and vertebrates.
Vertebrate endoskeleton is composed of bone and cartilage
Rigid skeletons can be composed of what tissue? (think surprising)
Cartilage. They can be Cartilaginous. This is a derived trait since their ancestors had bony skeletons.
In bony/terrestrial vertebrates, where do you find cartilage? (4)
Articulating surfaces of bone joints in adults,
Elements of the larynx,
trachea,
and bronchi
Bone functions (3)
Protection, support,
reservoir for calcium and phosphorus,
blood cell production
Most bone develops from… but also…
Cartilage (this is called endochondral bone) e.g., long bones. …
and embryonic cells (this is called dermal bone. e.g., bones of face, cranium, clavicle - think crocodile scales, turtle shell, fish scales, bony plates of sturgeon
Hydrostatic Skeleton Movement
Muscles in the body wall contract against incompressible fluids in the coelom. This causes expansion and lengthening in one direction then deflation and shortening on the polar opposite of the system to produce locomotion.
A whole skeletal muscle is considered what?
An organ
Average length of skeletal muscle
3 cm but can as long as 30 cm in the sartorius
Skeletal muscle hierarchy (4)
organ (of muscular system tissue) –>
fasciculus (bundle of skeletal muscle cells called fascicles in connective tissue) –>
muscle fiber (aka muscle cell in a nucleated sarcolemma) –>
myofibrils in sarcomeres (actin and myosin)
How are actin and myosin composed relative to each other?
At the myofibril level, the myosin is composed of two bundles of myosin molecules, oriented so the heads face outward from the center of the actin filament. The thin filaments are composed of a double strand of actin protein, twisted into a helix.
How does the muscle contract?
During contraction, myosin heads form molecular cross bridges that act as levers to pull the thick and thin filaments past each other. This causes sarcomeres to shorten. All sarcomeres contract simultaneously, causing the entire muscle fiber to contract.
What happens to the A bands and I bands during contraction?
the I bands (the light actin filaments) shorten because the myosin is shortening them inward by pulling them and shortening the muscle.
Contraction is a ____ process
Active
Relaxation is a ____ process
Passive
