Biology 1120 Exam Three

Front 1

Hydrostatic Skeleton

Back 1

A hydrostatic skeleton or hydroskeleton is a structure found in many cold-blooded organisms and soft-bodied animals consisting of a fluid-filled cavity, the coelom, surrounded by muscles. The pressure of the fluid and action of the surrounding muscles are used to change an organism's shape and produce movement, such as burrowing or swimming. Hydrostatic skeletons have a role in the locomotion of echinoderms (starfish, sea urchins), cnidarians (jellyfish), annelids (earthworms), nematodes, and other invertebrates.
Penis is a hydrostatic skeleton.

Front 2

Exoskeleton

Back 2

In arthropods it is composed of chitin which limits the size of the organism, has to be shed regularly. Provides a place for muscle to attach (absent in the hydrostatic skeleton). Echinoderms have skeletons that are made of calcium carbonate.

Front 3

Endoskeleton

Back 3

All vertebrates possess an endoskeleton. Contained within the body, layer of soft tissue outside and are generally protecting soft tissue underneath.

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Axial Skeleton

Back 4

Skull, Spinal Column, Ribs. All vital tissues protected by it. Cartilaginous and Bony.

Front 5

Appendicular Skeleton

Back 5

Pectoral Girdle and all it's attachments as well as the Pelvic Girdle and all its attachments. Includes arms, legs, fingers, toes. Cartilaginous and Bony.

Front 6

Intramembranous Ossification.

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"Inside the Membrane" ex. Bones of Skull.

Front 7

Endochondral Ossification

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"Within Cartilage" tiny little cartilaginous models of the bones form early in development. Osteoblasts come in and lay down bone tissue.

Front 8

Undifferentiated Mesenchymal Cells

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form the osteoblasts, chondroblasts, and fibroblasts.

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Fibroblasts

Back 9

produce collagen

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Chondroblasts

Back 10

produce chondrocytes

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Osteoblasts

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produce osteocytes and osteoclasts. Osteoclasts are present because our bones are constantly remodeling themselves, have to be able to break down.

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Bone Structure

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medullary bone lies deep within, forms the center of the bone. compact bone forms the next layer. spongy bone, toward the ends, less compact than compact bone. The area that is the spongy bone was the cartilage that formed the bone early in development.

Front 13

Epiphyses

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shock absorber for bones, small amount of cartilaginous tissue on each end of a bone.

Front 14

Periosteum

Back 14

fibrous sheath that forms around the outside of a bone

Front 15

Vascular Bones

Back 15

have osteocytes, are a system of Haversian canals (filled with blood vessels and nerves) that supply innervation and perfusion to osteocytes. Each osteocyte resides within a lacuna and communicate via canaliculi.

Front 16

Avascular Bones

Back 16

birds and fish have avascular bones.

Front 17

Slightly Movable Joints

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fibrous and cartilaginous, in the pelvis and spine respectively. don't want much movement here, but we need some gove

Front 18

Intervertebral Disk

Back 18

serves as a pad between the vertebrae.

Front 19

Synovial Joints

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containing a lubricating fluid contained within a fibrous capsule. the epiphyses of each bone are capped with articular cartilage.

Front 20

Avascular Bones

Back 20

birds and fish have avascular bones.

Front 21

Slightly Movable Joints

Back 21

fibrous and cartilaginous, in the pelvis and spine respectively. don't want much movement here, but we need some gove

Front 22

Intervertebral Disk

Back 22

serves as a pad between the vertebrae.

Front 23

Synovial Joints

Back 23

containing a lubricating fluid contained within a fibrous capsule. the epiphyses of each bone are capped with articular cartilage.

Front 24

Ball and Socket Joint

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one at pelvic girdle, one at shoulder. permits movement in all directions.

Front 25

Hinge Joint

Back 25

allow movement in a single plane. elbow, knee, finger, etc.

Front 26

Gliding Joint

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permit sliding of one surface over another. i.e. the spinal column.

Front 27

Combination Joint

Back 27

allow rotation and side to side sliding. temporo-mandibular joint

Front 28

Muscle Origin

Back 28

immovable

Front 29

Muscle Insertion

Back 29

movable

Front 30

Muscles in Animals with Exoskeleton

Back 30

muscles occur in opposing groups in the animals, the flexor and the extensor.

Front 31

Muscles in Animals with Endoskeleton

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also have opposing actions, have agonists/antagonists and synergists (act to stabilize the joint).

Front 32

Skeletal Muscle Organization

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entire muscle is covered by the epimysium (all mysium come together into tendons [bulk] or aponeuosis [sheet] that attach to periosteum of bone. the fascicles are covered by perimysium (fascicles are bundles of muscle fibers. muscle fibers are covered by endomysium.

Front 33

Muscle Fibers

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Huge cells, multinucleated, develop through the fusion of embryonic cells called myoblasts. made up of myofibrils (contractile organelles) that are made up of myofilaments. Muscle fibers also contain Transverse-tubules which are filled with ECF in order to distribute charge throughout the muscle. the t-tubules are continuous with (adjacent to) the sarcolemma and extend into the sarcoplasm.

Front 34

Sarcoplasmic Reticulum

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like the ER in other cells

Front 35

Sarcolemma

Back 35

an extensible membrane enclosing the contractile substance of a muscle fiber

Front 36

Myofibrils

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made up of protein myofilaments, Actin (thin filament) and Myosin (thick filament). Are responsible for the striations present in skeletal muscle, due to their arrangement.

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Sarcomere

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repeating end-to-end functional units within cells. a group of actin and myosin filaments, they repeat like a train to make up the myofibrils.

Front 38

Z-Line

Back 38

each end of the "coach" on the train. stabilizing proteins. the peripheries of the sarcomere. actin attaches to the z-lines, extends across it.

Front 39

Muscle at Rest/Contraction

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only a small portion of overlap between the actin and myosin (which is in the center) is

Front 40

H-Band

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occur in the center of the sarcomere, where only myosin is present.

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I-Band

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occur at the periphery, actin only

Front 42

A-Band

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occur where the actin and myosin overlap

Front 43

Thin Muscle Filament

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made up of 3 proteins - Actin - twisted strand with myosin binding sites (beads) Tropomyosin - covers the myosin binding sites along the actin (ribbon) Troponin - calcium receptors (when calcium attaches, troponin moves tropomyosin out of the way allowing actin and myosin to bind)

Front 44

Calcium's Role in Contraction

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calcium is released by the sarcoplasmic reticulum after it is stimulated by the change in charge in the fluid that is traveling through the transverse tubules.

Front 45

Thick Muscle Filament

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composed of several myosin subunits packed together. Myosin consists of two polypeptide chains wrapped around each other, each chain ends with a globular head. Myosin heads can "cock".

Front 46

Sliding Filament Theory

Back 46

explanation of muscle contraction - neither filament shortens, the entire unit shortens (sarcomere). actin and myosin slide past one another. when the actin heads are allowed to bind (due to troponin activation and movement of tropomyosin) to the actin filament.

Front 47

Contraction Cycle

Back 47

(1)ACh (always the neurotransmitter released at the NMJ) triggers increase in Ca++ with pulls troponin shifting tropomyosin away from the myosin binding sites. (2) Myosin heads form cross bridges to the actin binding sites. (3) ATP is released to pivot myosin heads toward the H-Line (4) ATP binds to the myosin, used after the head "fires" to bring it back to the "cocked" position.

Front 48

Rigor Mortis

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Lack of ATP prevents myosin from breaking away from actin after the final contractions

Front 49

Perikaryon

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the bulbous end of a neuron containing the cell nucleus, also known as the soma or cell body.

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Dendrites

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are the branched projections of a neuron that act to conduct the electrochemical stimulation received from other neural cells to the perikaryon, or cell body.

Front 51

Axons

Back 51

a long, slender projection from a neuron that conducts electrical impulses away from the perikaryon