Lab 7 Flashcards
Muscle tissues
- function
- muscle cells called what?
- highly cellular tissues that use ATP to generate force to produce contractions.
- produces most kinds of body movements, maintains posture and generates heat.
- Muscle cells are called muscle fibers, as these cells have an elongated shape
The cytoplasm of the muscle cell is the ____
Cell membrane is referred to as the ______
Cytoplasm = sarcoplasm
Cell membrane = sarcolemma.
3 types of muscle tissue found in the human body
skeletal muscle tissue
smooth muscle tissue
cardiac muscle tissue
Skeletal Muscle Tissue
- long, thick, cylindrical cell
- ends of fibers are blunt
- multiple, nuclei, peripherally located
- contains striations
- sarcomeres are the functional units
- attached to bones and when these muscles contract, movement of the skeleton occurs
LOCATION: skeleton (skeletal muscles
FUNCTION: moves bones of skeleton
CONTROL: voluntary
Unique: number and position of nuc
Smooth Muscle Tissue
- shorter spindle-shaped cells, with tapered ends
- cells are tightly packed in a sheet-like arrangement
- single oval nucleus, centrally located
- no striations
LOCATION: GI tract, uterus, eye, blood vessels (within the walls of hollow organs, such as blood vessels and organs of the digestive, urinary, respiratory and reproductive tracts)
FUNCTION: peristalsis, blood pressure, pupil size, erect hair. (contraction moves materials along internal passageways and regulates the diameter of blood vessels and respiratory tracts)
CONTROL: involuntary
Unique: No striations, spindle with tappered ends
Cardiac Muscle Tissue
- cells that branch in an irregular pattern
- striations.
- one nucleus, oval and centrally located
- intercalated discs where cells join end-to-end
LOCATION: wall of the heart
FUNCTION: pump blood continuously
CONTROL: involuntary
Unique: fibers branch, intercalated disc
striations
- transverse bands or striations, that are visible as light and dark bands within each fiber
- result of the arrangement of parallel structures called myofibrils within the sarcoplasm.
sarcomeres
Structural unit of myofibril
-parallel structures make up myofibril, these are in turn made up of the orderly arrangement of even smaller structures called myofilaments, which are arranged in compartments called sarcomeres
intercalated discs
- regions where the cell membranes of adjacent cells contact each other and contain desmosomes and gap junctions
- allow for cohesion and rapid electrical conduction
- vital roles in bonding cardiac muscle cells together and in transmitting signals between cells
two major divisions of the nervous system
The central nervous system
- the brain
- spinal cord
The peripheral nervous system
-all nervous tissue outside the brain / spinal cord
Neurons
• structural and functional units of nervous tissue
• largest and most prominent Ner.Sys cell
• convert stimuli into electrical signals (action potentials)
• Contain
- cell body (soma): nuc, mito, nissil body, ribos, neurofibrils
- dendrites: tapering, branched processes, receive stimuli or information from other neurons
- axon: cytoplasmic process, conduct information to other cells and is often referred to as a nerve fiber
Nissl bodies
aggregations of rough endoplasmic reticulum. important elements of the cytoskeleton
the manufacture and release of proteins and amino acids.
neurofibrils
found in soma. bundles of protein filaments which are important elements of the cytoskeleton.
play a role in the transport of proteins and other substances within the cytoplasm.
myelin
• a fatty sheath, protects and insulates the axon and also increases the speed of conduction of nerve impulses
• PNS: myelin sheath formed by Schwann cells
• CNS: myelin sheath formed by oligodendrocytes
• Schwann cells and oligodendrocytes are types of neuroglia cells.
•
nodes of Ranvier
- small gaps in the myelin sheath where the plasma membrane of the axon is exposed
- enable the nerve impulse to jump from node to node, hence increasing the speed at which an impulse travels.
telodendrites (axon terminals)
fine branched endings of the axon