Cells, tissues, organs, systems Flashcards
what are cells
-smallest structural and functional unit of an organism
-cytoplasm enclosed by a membrane
-makes extracellular matrix
what is a tissue
-collection of cells with similar structures that function together as a unit
-extracellular matrix fills any spaces between the cells
what is a organ
-a collection of tissues organized into a structural unit that performs one or more functions
-typically self-contained
what is a system
-a collection of organs that work together to perform one or more functions
what are the different kinds of tissues
-connective tissue
-epithelial tissue
-muscle tissue
-nervous tissue
what is connective tissue
-supports and connects other tissues
-cells and extracellular matrix
-ECM: fibres and ground substance
-fibres: collagen, elastic, reticular
-GS: usually fluid (but can be solid in bones)
what is the order of strongest to weakest connective tissue fibers
collagen, elastic, reticular
connective tissue proper
-loose, dense, reticular, elastic, adipose
-superficial fascia is loose connective tissue (less colog)
-Deep fascia is dense irregular connective tissue (more colog)
-tendons, aponeuroses, and regular connective tissue which is dense regular connective tissue
what is the difference between a tendon and ligament
tendon is muscle to bone, ligament is bone to bone
what is special connective tissue
-blood
-cartilage
-bone
-bone marrow
what are the three types of muscle tissue
-smooth
-skeletal
-cardiac
defining characteristics of smooth muscle cells
-nonstriated
-spindle-shaped
-one central nucleus per cell
defining characteristics of skeletal muscle cells
-striated
-extremely long, cylinder-shaped
-multinucleated, peripheral nuclei
defining characteristics of cardiac muscle cells
-striated
-elongated, branching
-one central nucleus (occasionally two) per cell
even though muscle cells are so long how do they communicate with one and other
because they have multiple nuclei per cell so signals get around fast
how are skeletal muscle tissues made up
-muscle fiber=multinucleated muscle cell
-surrounded by endomysium (reticular connective tissue)
-fascicle=group of fibers surrounded by perimysium (dense irregular connective tissue)
-epimysium merges with the deep fascia
what are tendons
-dense oregular connective tissue
-dont contract like muscles
-attach muscle to bone
-muscle turns into tendon
-viscoelastic
-aponeurosis=broad, flat tendon
what do tendons sometimes need
protection:
-seamoid cartlage or bone
-bursa (fluid-filled cushion)
-synovial sheath (like bursa, but wraps around tendon)
skeletal muscle tissue functions
-mainly forms muscles that attach to and move the skeleton
-under voluntary control
-some skeletal muscles prevent movement to maintain body position and achieve desired motion
-others stabilize joints
-other:
-move eyeball
-facial expression
-respiration
-straining (urination, defecation, parturition)
-urinary bladder and bowel continence
-twitch or wrinkle skin
what is the weakest muscle with the greatest displacement and the strongest muscle with the least displacement
parallel non-fusiform, non-parallel fusiform
muscle terminology: attachment (bony and non-bony)
-origin= least movable attachment (proximal)
-insertion= most movable attachment (distal)
muscle terminology: agonists and synergists vs. antagonists
-an agonist muscle provides most of the forces to cause a movement = prime mover
-a synergist muscle causes the same movement as an agonist muscle
-an antagonist muscle resists thar movement (causes opposite movement)
muscle terminology: neutralizers and fixators
-neutralizer muscle cancels out extra motion produced by an agonistic muscle so that the movement occurs in the desired plane
-a fixator muscle stabilizes the origin of an agonist muscle to help agonist muscle function effectively
muscle terminology: entric vs intrinsic muscles of the thoracic appendage
