Introdction To Basic Tissue Types Muscle And Nervous Flashcards Preview
Muscle tissue
functions
includes
- generating movement of animal body and its parts
- musculoskeletal system, visceral organs, heart
muscle cells
made from
- myocytes
- large amounts of contractile proteins actin and myosin
Myofibril
made from
Structural and functional subunits of muscle cells-
- actin and myosin myofilaments
types of muscle
differences
- smooth and striated
- size and shape of cell, number, and location of nuclei
- both surrounded by external lamina (basement membrane of epithelial tissue)
Striated muscle cells
- cross striations at light microscopic level by myofilaments
- parallel arrays
- Skeletal and cardiac based on function and location
Smooth muscle
not organized in parallel arrays
-does not have striated appearance
Comparison of three muscle types
- Skeletal -Cylindrical Multiple, flat, peripheral
- Cardiac -Branched. Single, block like, central -Smooth- Fusiform. Single, spindle-or corkscrew-shaped, central
Organization skeletal muscle
characteristics
looks like
types
held together by connective tissue,
- multinuclearted from individual myoblasts during development
- polygonal shape, long axes are in the direction in which the contract
- Endomysium, perimysium, epimysim
Endomysium
Thin delicate layer of reticular fibers that immediately surrounds individual muscle fibers
Perimysium
Thicker layer that surrounds group of fibers forming bundle (fascicle)
Epimysium
Forms dense sheath surrounding collection of fascicles which forms a muscle
Organization of Cardiac muscle
characterization
- myocardium.
- striated bc myofilaments organized like skeletal muscle
- fibers are not multinucleated like skeletal muscle
- multiple cells end to end
- cells attach to each other via intercalated discs
- can form branched fiber by joining of two or more cells
Smooth muscle
- sheets or bundles of elongated fusiform cells - tapered ends
- cytoplasm will stain envelope with eosin
Sensory component of nervous system
Collects info from external environment and from within body
Motor component of nervous tissue
Controls activity of muscles, organs, and even individual cells
division of nervous system
CNS- brain and spinal chord PNS- nerves that conduct impulses to and from brain and spinal chord
Cell types of nervous tissue
Neurons and neuroglia ( supporting cells) Neuron- functional unit of nervous system, receive stimuli from other cells and conduct electrical impulses accordingly
Neuroglia- non conducting cells,
- near neurons,
functions: physical support, electrical insulation, facilitation of repair, regulation internal fluid environment in CNS, clearance neurotransmitters metabolic exchange between vascular system and neurons