Shared Flashcard Set

Details

Exam 3 (continued)
Exam 3 (cont.)
110
Anatomy
Undergraduate 1
11/21/2011

Additional Anatomy Flashcards

 


 

Cards

Term
What is the source of the muscular system?
Definition
the anatomical system of a species that allows it to move. Energy for this comes from ATP, the energy source of the cell.
Term
Nervous system
Definition
an [biological system|organ system] containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body
Term
List at least five functions for the muscular system.
Definition
Contraction(never push/pull away), cause movement(usually), resist motion(hold posture)movement of body fluids(blood/urine), produce heat
Term
List the three types of muscles, sketch them, and give their names according to anatomy, location, and function.
Definition
Cardiac muscle tissue forms the bulk of the wall of the heart. Smooth muscle tissue is located in the walls of hollow internal structures such as blood vessels, the stomach, intestines, and urinary bladder. Skeletal muscle tissue is named for its location - attached to bones.
Term
Describe the anatomy of an individual muscle fiber.
Definition
individual muscle fibers are called myocytes. Each myocyte contains many myofibrils, which are strands of proteins (actin and myosin) that can grab on to each other and pull. This shortens the muscle and causes muscle contraction.
Term
Why are there so many coverings on the muscle?
Definition
To cover and protect bones and other muscles
Term
Fascia
Definition
layer of fibrous tissue that permeates the human body. A fascia is a connective tissue that surrounds muscles, groups of muscles, blood vessels, and nerves, binding those structures together in much the same manner as plastic wrap can be used to hold the contents of sandwiches together
Term
Epimysium
Definition
layer of connective tissue, which ensheaths the entire muscle. It is composed of dense irregular connective tissue. It is continuous with fascia and other connective tissue wrappings of muscle including the endomysium, and perimysium
Term
Fasciulus
Definition
A bundle of anatomical fibers, as of muscle or nerve. Also called fascicle
Term
Muscle Fiber
Definition
A cylindrical, multinucleate cell composed of numerous myofibrils that contracts when stimulated
Term
Perimysium
Definition
a sheath of connective tissue that groups muscle fibers into bundles (anywhere between 10 to 100 or more) or fascicles
Term
Endomysium
Definition
meaning within the muscle, is a layer of connective tissue that ensheaths a muscle fiber and is composed mostly from reticular fibers.
Term
Sarcolemma
Definition
the cell membrane of a muscle cell (skeletal, cardiac, and smooth muscle) It consists of a true cell membrane, called the plasma membrane, and an outer coat made up of a thin layer of polysaccharide material that contains numerous thin collagen fibrils.
Term
Sarcoplasm
Definition
cytoplasm of the muscle fiber
Term
Myofibrils
Definition
basic unit of a muscle myosin(thick) actin(thin)
Term
Explain the sliding theory. How is it related to all animals? What is the spring theory?
Definition
The sliding filament theory is the explanation for how muscles produce force (or, usually, shorten). It explains that the thick and thin filaments within the sarcomere slide past one another, shortening the entire length of the sarcomere. It replaced the spring theory
Term
Draw and label an actin filament and a myosin filament.
Definition
Myosin(thick) Actin(thin)
Term
Explain the mechanism of muscle contraction beginning with an impulse from the brain.
Definition
The brain sends signals, in the form of action potentials, through the nervous system to the motor neuron that innervates several muscle fibers.
Term
What is the role of calcium in muscle contraction? How is calcium removed?
Definition
The calcium ions result in movement of troponin and tropomyosin on their thin filaments, and this enables the myosin molecule heads to "grab and swivel" their way along the thin filament.
Term
What is a muscle unit?
Definition
A motor unit plus all muscle fibers that it controls
Term
Draw and label a reflex arc.
Definition
receptor, sensory neuron, Interneuron, grey matter, white matter, transverse section through spinal cord, motor nerve fiber, effector
Term
What is the significance of the numbers of nerve fibers which go to a muscle?
Definition
The more force required, more nerves fire and activate more muscle fibers.
Term
Describe the physiology of the synaptic cleft.
Definition
When an action potential reaches the presynaptic terminal of the motor neuron acetylcholine is released into the synaptic cleft. small space between neuron and muscle
Term
What is a neuromuscular junction?
Definition
the site where a motor nerve fiber and a skeletal muscle fiber meet; (also called a synapse or synaptic cleft)
Term
Define: motor neuron, motor unit, motor end plate, acetylcholine, and acetylcholinesterase.
Definition
Motor cell, neuron and muscle fiber, end of axon, neuromuscular transmitter, enzyme
Term
Curare
Definition
blocks acetylcholine from receptor sites. No contraction due to no membrance change, death by asphyxiation
Term
Organophosphate
Definition
inhibit acetylcholinesterase, found in pesticides, death by asphyxiation
Term
Botulin
Definition
bacteria block release of acetylcholine
Term
Myasthenia gravis
Definition
muscle weakness (skeletal muscle)
Term
What is a satellite cell?
Definition
Undifferentiated cell in muscle which replaces injured muscle cells
Term
Define Ratchet Theory? What are the two types of muscle contraction?
Definition
Theory of muscle contraction which indicates “ratcheting” of myosin filament. Isometric and isotonic
Term
Threshold Stimulus
Definition
The minimum stimulus needed to elicit a response
Term
Refractory Period time
Definition
needed for electrolyte balance again before next response
Term
All or None Law
Definition
no partial contraction either a response or not
Term
Rheobase
Definition
intensity of stimulus sufficient to elicit a response
Term
Chronaxie
Definition
two times rheobase
Term
Muscle Tone
Definition
continuous contraction
Term
Muscle Hypertrophy
Definition
enlagement due to exercise
Term
What is a pith? Double pith?
Definition
deals with the medulla, is a tissue in the stems of vascular plants. Double pith is brain and spinal cord
Term
What is a muscle twitch?
Definition
A single contraction (isometric or isotonic)
Term
Label: latent, contraction, and relaxation time.
Definition
10ms, 40ms, 5ms
Term
Define: Summation, Tetanus, Treppe, and Fatigue
Definition
An increase in response to stimuli in rapid succession, maximal summation, “staircase” of summation, drop in tension after prolonged stimulation
Term
Muscle fatigue
Definition
due to no blood, acetylcholine exhausted, lactic acid build up
Term
Muscle cramp
Definition
due to lack of ATP needed to remove calcium
Term
Rigor mortis
Definition
lack of ATP, may last for 72hrs
Term
What is creatine phosphate? What is its significance?
Definition
High energy phosphate bond 4-6 times more abundant than ATP in muscle cell
Term
What types of skeletal fibers are there? Why are there different types of fibers?
Definition
slow twitch or slow oxidative fibers, contain large amounts of Myoglobin, many mitochondria and many blood capillaries. fast twitch or fast oxidative fibers, contain very large amounts of Myoglobin, very many mitochondria and very many blood capillaries. fast twitch or fast glycolytic fibers, contain a low content of Myoglobin, relatively few mitochondria, relatively few blood capillaries and large amounts glycogen.
Term
visceral and cardiac muscle physiology and anatomy.
Definition
Viscereal contracts slower than skeletal muscle no striation, Cardiac muscle is a type of involuntary striated muscle found in the walls and histologic foundation of the heart, specifically the myocardium
Term
What is calmodulin?
Definition
Protein which binds calcium
Term
What is the function of the nervous system?
Definition
Homeostatic control. Nervous system ->brain->fast. Endocrine system ->pituitary->slow
Term
Compare the nervous system to the endocrine system
Definition
Nervous system ->brain->fast. Endocrine system ->pituitary->slow
Term
What are the differences between the two systems?
Definition
The nervous system has excitability/conductivity characteristics and control central/peripheral systems
Term
Discuss feedback.
Definition
Homeostatic control The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.
Term
What is negative feedback?
Definition
After increase from normal the artery is sensitive to pressure, After the heart there is a decrease from A B normal
Term
Positive feedback?
Definition
Increase from normal goes straight to brain then heart then there is an increase in blood pressure
Term
What is the origin of the nervous system?
Definition
A few hundred nerve cells are all a lowly nematode needs to find food and a mate.
Term
What are the characteristics of the nervous system?
Definition
Excitability capable of reacting to stimuli. Conductivity capable of transmitting impulses
Term
What are the two major parts of the nervous system?
Definition
Central and peripheral nervous system
Term
What is a Schwann cell?
Definition
Peripheral nerves. Forms a jelly roll covering around nerve fiber
Term
Who was Schwann?
Definition
a German physiologist. Who discoverd of Schwann cells in the peripheral nervous system, the study of pepsin, the discovery of the organic nature of yeast, and the invention of the term metabolism.
Term
Where are Schwann cells found?
Definition
any of the large nucleated cells whose cell membrane spirally enwraps the axons of myelinated peripheral neurons supplying the myelin sheath between two nodes of Ranvier (in the PNS)
Term
Describe the role of the Schwann cell.
Definition
supporting nerve regeneration
Term
Why is a Schwann cell compared to a "jelly roll?"
Definition
It forms a protective myelin sheath
Term
What is the significance of the Schwann cell?
Definition
neurolemmocytes are the principal glia of the peripheral nervous system (PNS).
Term
Define: neurolemma, myelin, lipoprotein, myelination, CNS, white matter, gray matter.
Definition
Outer covering  w/o myelin contains nucleus, medullated fiber, myelin, w/ myelin, brain & spinal chord, groups of myelinated fibers, unmyelinnated nerve fibers & cell bodies
Term
What is a Node of Ranvier?
Definition
Gap between schwann cells
Term
What is salutatory conduction?
Definition
Electrical arcing or jumping from node to node
Term
Describe the anatomy of a neuron.
Definition
Nerve cell.structurak and functional unit of nervous system
Term
What is unusual about the cell body of the neuron?
Definition
Most cell bodies are within the CNS
Term
What is the function of a nissl body?
Definition
Membranous sacs similar to rough ER
Term
Where are nissl bodies found?
Definition
In the nucleus
Term
Define: melanin, lipofuscin
Definition
Melanin, skin pigment (substance that gives the skin its color). Lipofuscin given to finely granular yellow-brown pigment granules composed of lipid-containing residues of lysosomal digestion.
Term
Define: ganglia, nuclei, center.
Definition
Group of cell bodies in a cluster covered with connective tissue. Group of cell bodies in the brain and spinal chord. Group of nuclei associated with a particular function
Term
What are the two processes from a neuron?
Definition
Dendrite and axon
Term
How are they similar? different?
Definition
Dendrite is the main receptive surface of a neuron, short, highlybranched. Axon is a single fiber from nerve body, may have many branches at terminals
Term
What is axoplasmic flow? What is its significance?
Definition
Cytoplasm down the axon thought to supply needed materials
Term
Include the following labels: axon hillock, axon collateral, telodendria, neurolemma, myelin, and Schwann cell.
Definition
Conical elevation where axon leaves the cell body. Side branches from axon. Fine filaments at terminal and of axon. Outside layer of axon. Layer under neurolemma, in the nucleus.
Term
Discuss regeneration of a nerve fiber. of a nerve cell body?
Definition
the damage must be far from the cell body
Term
How much regeneration might be expected per day?
Definition
1mm per day. 1in per month
Term
Why is it thought that brain and spinal cord regeneration is impossible?
Definition
Scar tissue is formed so fast that axon doesn’t have time for regeneration
Term
Describe neuroglial cells
Definition
Also called glial cells. Capable of reproduction, found only in brain & spinal chord, more numerous than neurons in CNS, tumors of CNS develop from glial cells not from neurons
Term
What is the function of glial cells?
Definition
Fill spaces, support neurons, hold (connect) organs together, protection and cleaning (phagocytic)
Term
List the four types of neuroglial cells.
Definition
Astrocytes (star cells), oligodendrocytes (few tree), microglia (small glia), ependymal
Term
What is the newest information on the function of the glial cells?
Definition
to supply nutrients to neurons; to insulate neurons electrically; to destroy pathogens and remove dead neurons; and to provide guidance cues directing the axons of neurons to their target
Term
Make a list of the types of nerve endings. Describe each.
Definition
Free nerve endings (touch, pressure, vibration, itch/tickle, thermal,pain, proprioceptors
Term
Draw and label a nerve impulse.
Definition
Looks like a long tube in resting nerve fiber it is negative on inside and positive outside. Moving impulse have positive and negative inside and outside
Term
Include: position of Na ions, polarized, mV, depolarized, resting potential, action potential
Definition
Outside in resting, inside/outside in moving impulse,.electrically charged due to distribution of ions. +30 mV. is a change in a cell's membrane potential, making it more positive, or less negative -70mV resting potential. Na+ moves in rapidly k+ moves out rapidly
Term
Describe a nerve impulse.
Definition
a difference in charge supplied by ion position
Term
How is it compared with a fuse and not with a copper wire?
Definition
the nerve impulse is now known to be a wave of activity quite similar to the flame of a candle or the burning of a dynamite fuse
Term
What are sodium channels?
Definition
integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's plasma membrane
Term
Define: Refractory Period, Absolute, Relative.
Definition
Delay before another impulse. (1/2500 sec) no impulse (reestablishing resting potential). With high intensity stimulus impulse triggered (polarization not complete)
Term
Discuss saltatory, diameter of fiber, and all or none with respect to the nerve fiber.
Definition
the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials without needing to increase the diameter of an axon. Larger diameter = faster impulse. is the principle that the strength by which a nerve or muscle fiber responds to a stimulus is not dependent on the strength of the stimulus.
Term
Discuss some factors which influence a nerve impulse
Definition
Calcium ions and drugs
Term
Draw, label, and discuss the four types of circuits discussed in class.
Definition
Diverging circuit – one impulse  several responses, converging circuit- more stimulus from one source or from different sources, reverberating circuit - continuous impulse, parallel circuit - stream of impulses
Term
An action potential
Definition
is initiated and propagates in the axon of a motor neuron.
Term
The action potential causes
Definition
the release of acetylcholine from the axon terminals at the neuromuscular junction.
Term
Acetylcholine
Definition
diffuses from axon terminals to motor-end-plate membrane
Term
Acetylcholine binds to
Definition
receptor sites on the motor-end-plate membrane.
Term
Bound acetylcholine increases
Definition
the permeability of the motor end plate to sodium and potassium ions, producing an end-plate potential (EPP).
Term
By local current flow the EPP depolarizes
Definition
the muscle membrane to its threshold potential and thus generates an action potential that then propagates over the surface of the muscle membrane
Term
The action potential propagates
Definition
from the surface into the muscle fiber along the transverse tubules.
Term
Depolarization of transverse tubules
Definition
leads to the release of calcium ions from the lateral sacs of the sarcoplasmic reticulum that surrounds the myofibrils.
Term
These calcium ions
Definition
bind to troponin on the thin filaments, causing tropomysin to move away from its blocking position covering the cross-bridge binding sites on actin.
Term
The energized myosin
Definition
cross bridges on the thick filaments bind to actin: ACTIN + MYOSIN*-ADP-P ----> ACTIN-MYOSIN*-ADP-P
Term
This binding triggers
Definition
the release of energy stored in myosin, producing an angular movement of the cross bridge. ACTIN-MYOSIN*-ADP + P ----> ACTIN-MYOSIN + ADP – P
Term
ATP binds to myosin
Definition
breaking the linkage between actin and myosin, thereby allowing the cross bridge to dissociate from actin. ACTIN-MYOSIN + ATP ----> ACTIN + MYOSIN-ATP
Term
The ATP bound to myosin is
Definition
split, transferring energy to the myosin cross bridge and readying it for another cycle: MYOSIN-ATP ----> MYOSIN* - ADP – P
Term
The cross bridges repeat
Definition
the cycle (10 to 13), leading to the movement of the thin filaments past the thick filaments.These cycles of cross-bridge movement continue as long as calcium remains bound to troponin.
Term
The concentration of calcium ions around the myofibrils
Definition
decreases as calcium is actively transported into the sarcoplasmic reticulum by a membrane pump that uses energy derived from the splitting of ATP.
Term
Removal of calcium ions from troponin
Definition
restores the blocking action of tropomyosin, the cross-bridge cycle ceases, and the fiber relaxes.
Supporting users have an ad free experience!