Exam 1
muscle spindles
sensory structures in skeletal muscles
Extrafusal muscle fibers
skeletal muscle fibers
Visceral (autonomic) response
smooth muscle (organs and glands) and cardiac muscle (heart)
What does the autonomic nervous system control?
smooth muscle, cardiac muscle, glands, and adipose tissue
intramural muscle fibers
specialized muscle fibers of the spindle
where are motor neuron cell bodies located
spinal cord
where are motor neuron dendrites located
spinal cord
Stretch reflex mechanism
stretch extrafusal fibers of skeletal muscles-> stretch intrafusal fibers of spindle-> stimulate sensory neurons-> synapse with motor neurons in spinal cord-> muscle contraction (and or increase tone)
Monosynaptic reflex
stretch reflex
crossed extensor reflex
supports the body during a withdrawal reflex
What is the range of the action potential?
+50 mV to +70 mV (positive inside cell)
What is acetylcholine (ACh)?
A neurotransmitter.
What is Tetanus? (NOT the disease?
A rapid succession of nerve impulses produces sustained muscle contraction. But individual motor units contract and relax (what occurs in normal contraction)
What are the direct effects of neurotransmitters?
ACh and Glycine.
What does the head of myosin do?
ATPase activity.
What are the types of refractory periods?
Absolute refractory period and relative refractory period.
Melanin
Absorbs UV radiation. Too much UV radiation will lead to DNA damage which can lead to skin cancer
What are the types of neurotransmitters?
Acetylcholine, biogenic amines, amino acid neurotransmitters, anandamide, neuropeptides, nitric oxide and carbon monoxide,
What is involved in relaxation?
Acetylcholinesterase and Calcium ATPase
What are thin filaments made up of?
Actin, tropomyosin, and troponin.
What does stimulus intensity depend on?
Action potential frequency and recruitment
How do chemical synapses transmit?
Action potential reaches synaptic terminal of presynaptic cell-> Calcium influx-> exocytosis of neurotransmitter vesicles-> neurotransmitters diffuse between cells-> neurotransmitter binds to receptor on surface of postsynaptic cell-> graded potential reduced.
Neuronal Stimulation
Action potential reaches synaptic terminal-> ACh released from synaptic terminal-> ACh binds to receptors at motor end plate-> action potential generated in sarcolemma-> action potential spreads into T-tubules.
Excitation-contraction coupling
Action potential through t-tubules-> Calcium released from sarcoplasmic reticulum-> Calcium binds to troponin subunit-> tropomysin is shifted-> active sites on G-actins are uncovered-> contraction cycle
Contraction Cycle
Action sites are uncovered on actin during excitation-contraction coupling-> cross bridge formation (myosin binds to actin)-> power stroke (myosin moves actin towards the center of the sarcomere using stored enerfy-> cross bridge detachment (ATP binds to myosin head and breaks bond between thick and thin filaments)-> cycle repeats at a rate of 5x per second. Thin filaments are moved towards the center of the sarcomere
Negative Feedback loop
Activate control center-> Inhibit (or activate) effector-> Factor decreases-> receptor detects decrease in factor-> Activate control center-> Activate (or inhibit) effector-> increase in factor-> receptor detects increase in factor-> goes back to "activate control center", completing loop. Factor is maintained in normal range.
Positive Feedback Loop
Activate control center-> control center activates effector-> Factor increases even more-> receptor detects further increase in factor-> Increased activation of control center-> Increased activation of effector-> Factor Increase-> Receptor detects increase in factor-> Go back to beginning. Factor is amplified with each cycle.
What are the divisions of the nervous system?
Afferent Division and Efferent Division
What do gap junctions do in intercalated discs?
Allow action potential to spread rapidly.
What does the nervous system do for the cardiac muscles?
Alter heart rate and alter contraction strength.
What is the postsynaptic effect?
Alters the postsynaptic cells response to the neurotransmitter. May have long term effects.
What is the presynaptic effect?
Alters the rate of neurotransmitter release
How do leak (passive) channels work?
Always open. Involved with resting potential.
What is involved in propagation?
Amplitude, continuous propagation, saltatory propagation, axon diameter.
What is the neurotransmitter receptor?
An ion channel
What are the functions of opioids?
Analgesia and euphoria
What is the function of norepinephrine?
Appetite, body temperature, attention, and regulate pituitary gland.
What is wave summation?
Applying a second stimulus during the first contraction increases the strength of the second contraction.
Cells in the bone structure
Are scattered throughout the matrix.
What does the neuroglia contain in the central nervous system?
Astrocytes, oligodedrocytes, microglia, ependymal cells.
Hierarchy of the Bodies organization
Atoms-> Molecules-> Organelles-> Cells-> Tissues-> Organs-> Organ Systems-> Organism
Movement by the skeletal system
Attached to the muscles. Helps lungs, muscles, etc contract.
What does the tail of myosin do?
Attaches to other myosin molecules.
What are the functions of dopamine?
Attention, muscle tone, and movement.
Reflex definition
Automatic response to as sensory stimulus
What are pacemaker cells used for?
Automaticity, pacemaker cells initiate contractions.
Intrinsic Regulation
Autoregulation. Cell, tissue, and/ or organ adjusts to environmental change.
What are the neuron processes?
Axons and dendrites.
Tight Junctions
Between epidermal cells
What are opioids?
Bind to same receptors as opium and morphine
How are gated (active) ion channels chemically regulated?
Bind to specific chemicals (ACh for example)
What is in sensory neurons?
Cell body, dendrites, and axons
Specialties of Physiology
Cell physiology, Organ physiology, Systemic physiology, Pathological physiology
Internal Environment
Cells require a fairly constant internal environment in order to function. Organ systems act to maintain the proper environment for the cells.
What is the M line?
Center of sarcomere. Has proteins that connect thick filaments.
What do neuron axons do?
Change in the resting potential during nerve impulse transmission.
What are transmembrane potentials?
Charge gradient across the cell membrane, measured in mV.
What is another name for Vitamin D3?
Cholecalciferol
What do desmosomes do in intercalated discs?
Connect cells to each other.
What do the myofibrils do in the muscle fibers?
Contain contractile proteins.
What does the sarcoplasmic reticulum in the muscle fiber do?
Contains the endoplasmic reticulum and stores calcium.
Insensible Perspiration
Continuous evaporation of water from the surface of the skin (about 500 ml a day), not done by the sweat glands
What are fast fibers?
Contract quickly, fatigue quickly
What are slow fibers?
Contract slowly, fatigue slowly.
Temperature example of negative feedback
Control Center- Thermoregulatory center of brain Receptors- detect changes in body temperature Effector- Sweat glands of skin
What is the ventricular system?
Fluid-filled cavities in the brain and spinal cord.
Sources of Vitamin D3
Food and synthesis in skin.
Osteoblasts
Form new bone tissue
What is the function of oligodendrocytes?
Forming myelin sheaths
Support by the skeletal system
Framework of the body. Spinal cord.
What kind of cells are neurons?
Functional cells- they transmit nerve impulses.
Hypodermis (Subcutaneous Layer)
Functions with the skin
What is actin made up of?
G- actin (globular protein) and F-actin (two strands of G-actins).
What is an electrical synapse?
It is the least common. Contains gap junctions.
What does the visceral smooth muscle do?
It is the most common(coming in sheets or layers), contain many gap junctions, a functional syncytium so that it contracts as a unit,
How is the hypodermis involved in temperature regulation?
It provides insulation.
What makes up skin color?
Melanin, Carotene, and Hemoglobin
Protection
Melanin, Keratin, Sebum, and Tight Junctions.
What is the absolute refractory period?
Membrane cannot respond with an action potential. Occurs during the depolarization phase.
What is the Z line?
Middle of the I bands. Mark the boundaries of the sarcomere. They interconnect the thin filaments.
Where are interneurons located?
Most are in the CNS between sensory and motor neurons.
What is the motor unit?
Motor neuron plus the muscles cells it innervates.
What is the neuromuscular junction made up of?
Motor unit, acetylcholine, synaptic terminal, and motor end plate.
What are the functions of muscles?
Movement, heat production, posture, and support organs.
What is spatial summation?
Multiple synapses at the same point in time. Simultaneous graded potentials at the synapses.
What is weak stimulus?
Neurons with low thresholds are activated.
What is the mechanism of the indirect effects via G proteins?
Neurotransmitters bind to receptors-> G proteins activated-> second messengers activated-> ion channels open-> graded potential produced-> IF threshold is reached-> action potential produced.
What is the mechanism of indirect neurotransmitters via enzymes?
Neurotransmitters diffuse into cell-> enzymes activates-> second messengers activated-> ion channels open-> graded potential produced-> IF threshold is reached-> action potential produced
What is the effect of indirect neurotransmitters via enzymes?
Nitric oxide and carbon monoxide
What is complete tetanus?
No relaxation phases.
Normal Range
Normal values between the upper and lower limits. Examples include temperature, pH, glucose, etc. Body functions are maintained within the normal range.
What is a dendrite?
Numerous short processes. Receive stimuli or nerve impulses.
What is involved in bone health?
Nutrition and hormones.
Sebum
Oily Secretion
What is the structure of ion channels?
Protein pores through the membrane.
What is incomplete tetanus?
Short relaxation phases.
Known as "negative" feedback because?
The effector reverses in direction of the factor. It opposes or negates the stimulus.
Known as Positive Feedback because?
The effectors move the factor in the same direction.
Cell
The functional unit of life
How are the filaments arranged?
The heads point away from the M line.
What is the use of glucose?
With oxygen, energy+CO2 are the products. Without oxygen-> energy and lactic acid.
Marrow Cavity
Yellow marrow is for lipid storage. Red marrow (ends of marrow) is for blood cell formation. Yellow bone marrow can be changed back to red.
What does the I (light) band contain?
Z lines
gamma motor fibers
contract intramural fibers when the skeletal muscle contracts
reflex mechanism
contract muscle-> stretch tendon-> stimulate sensory neurons-> spinal cord interneurons-> inhibit motor neurons-> relax muscles
Osteoclasts
degrades bone tissue. Helps keeps bones refreshed.
Brain
nerve impulses are sent to the brain to let you know whats happening
What is the mechanism of neurotransmitters?
neurotransmitters bind to receptors-> ion channels open->graded potential produced-> IF threshold is released-> action potential produced.
Divergence
one neurons synapse with several neurons
Monosynaptic complexity
one synapse between sensory neuron and motor neuron Fastest type
where are motor neuron axons located
periphery
Spinal cord
preexisting basic motor patterns
what is the function of the tendon reflex
prevent injury to tendons
Monosynaptic reflex functions
prevent overstretch of muscle and adjust muscle tone
Cranial reflex
processed within brain
Spinal reflex
processed within spinal cord
Sensory dendrites
respond to stretch of intrafusal fibers
Flexor reflex (ipsilateral)
right side of body
How is a neuron structured?
Cell body and processes.
Polysynaptic complexity
Two or more synapses. Interneurons connect sensory and motor neurons Produce more complex response
What is continuous propagation?
Unmyelinated axons. Myelin sheath- insulating layer of lipids around the axon. Nodes- myelin is absent, Na+ and K+ channels are concentrated here. Action potentials- generated one at the nodes -> very rapid conduction of nerve impulse.
What is creatine phosphate?
Used as a phosphate for rapid ATP synthesis.
What is the function of Vitamin D3?
Used by the kidneys to make calcitriol.
What is the multiunit smooth muscle?
Very few gaps junctions, inititation in the nervous system.
Functional categories of smooth muscle?
Visceral smooth muscle and multiunit smooth muscle.
Effects of nutrition on Bone Health?
Vitamins necessary to bone health- Vitamin D3- needed for synthesis of calcitrol. Vitamins A, B12, C and K-stimulate collagen synthesis in osteoblasts. Must have adequate protein. Adequate Calcium and other minerals.
What kind of repair do Schwann cells do?
Wallerian degeneration. Axon is cut-> end degenerates-> Schwann cells form a car along original location of axon-> axon grows a long cord-> Schwann cells demyelinate axon.
What are the functions of Sebum?
Waterproofs the skin and retards growth of microorganisms (low pH).
What is Recruitment of stimulus intensity?
Weak stimulus and Strong stimulus.
How is Vitamin D3 synthesized in skin?
7 dehydrocholesterol is made by cells then UV light converts 7- dehydrocholesterol into Vitamin D3.
What is the relative refractory period?
A higher than threshold stimulus may generate an action potential. Occurs during the repolarization phase.
What kind of fibers do muscles contain?
A mixture of types. Relative proportions depending upon functions of muscles.
All or None Law
A neuron generates a maximum action potential or no action potential. Once threshold is reached, the neuron fires with the same strength every time.
Examples of Positive Feedback
Blood clotting, Menstrual cycle, Child Birth
What in contracting muscle is an energy source?
Blood glucose and muscle glycogen.
Cell
Body functions depend upon the cell function
How does the skeletal system work in blood cell formation?
Bone marrow - yellow- makes blood cells and stores lipids and fats.
What is strong stimulus?
Both low and high threshold neurons are activated. Number of neurons responding is increased.
Example Loop for Negative Feedback using Temperature
Brain sends output to sweat glands-> sweat glands secrete-> temperature decreases-> receptor detects decrease in temperature-> Send input to brain-> brain sends output to sweat glands-> sweat glands stop secreting-> temperature increases-> receptors detect increase in temperature-> sends input to brain-> Go back to beginning and start loop over
What is acetylcholinesterase?
Breaks down ACh in synapse.
What is acetylcholinterae?
Breaks down ACh. Removes it from the synapse and prevents constant stimulation.
Melanin
Brown pigment in the skin. Located in the epidermis. Synthesized by melanocytes in response to UV light. Transferred to epidermal cells to protect DNA.
Effects of hormones on Bone Health.
Calcitrol in the kidneys increases Calcium and phosphate absorption in small intestine. Growth Hormone (pituitary gland) increases protein synthesis. Thyroid Hormones increases osteoblast activity. Gonadal steroids- increase osteoblast activity- end of bone growth at puberty and maintenance of bones post-puberty.
What happens in the latent phase of a simple twitch?
Calcium is released but contraction cycle not yet started.
What happens in the relaxation phase of a simple twitch?
Calcium levels decrease
Matrix
Callagen- protein. Minerals- mainly calcium.
What is afferent division?
Carried sensory input to CNS
What is the function of efferent division?
Carries motor output to muscles, glands, and adipose tissue.
What areas of the body are affected by graded (local) potentials?
Cell body and dendrites
Outermost Strata
Dead cells which are shed from surface
What does calcitonin do?
Decreases blood calcium
What does the parathyroid hormone do in the kidneys?
Decreases calcium excretion. Less calcium is able to leave blood.
How are neurotransmitters inactivated?
Degraded by enzymes.
How does nitrous oxide inactivate?
Degraded in cell very quickly because they are toxic to cells.
What is the neurotransmitter effects on the postsynaptic membrane in the excitatory category?
Deplarization. Promotes generation of an action potential IF threshold is reached.
What is the action potential (nerve impulse)?
Depolarization
What are the 2 graded (local) potentials?
Depolarization OR hyperpolarization
What are the 3 things associated with ion flow?
Depolarization, repolarization, and hyperpolarization
What are the disorders caused by serotonin issues?
Depression, OCD, hallucinations, and suicide.
What disorders are caused by norepinephrine issues?
Depression.
What do intercalated discs contain?
Desmosomes, gap junctions, myofibrils, and functional syncytium
Bone strength
Determined by osteoblast and osteoclast activity.
Example of Intrinsic Regulation
Distension of Intestine-- Smooth muscle contraction.
What are the 3 types of neural circuits?
Divergence, convergence, and serial processing
Innermost strata
Dividing cells
Where is the sensory neuron cell body located?
Dorsal root ganglion
What can happen when there are issues with opioids?
Drug addiction.
What are the two types of postsynaptic potentials?
EPSPs and IPSPs.
What is titin?
Elastic protein that extends to the z line.
What are the types of synapses?
Electrical and chemical.
What is the synaptic terminal?
End branch of the motor neuron. Contains ACh.
What is anandamide?
Endogenous marijuana. Canabanoid receptor. Same as marijuana.
What areas are affected by the action potential (nerve impulse)?
Entire axon
Interneuron (association)
Entirely within the CNS
Structure of the Skin
Epidermis, Dermis, Hypodermis, Skin color
What are EPSPs?
Excitatory graded potentials. Depolarize membrane. Must be added together to produce an action potential.
What is glutamate?
Excitatory.
How does oxygen debt happen?
Exercise strenuously-> continue breathing hard after exercise-> use O2 to oxidize lactic acid to regenerate ATP and phospocreatine
What is the muscle fiber transverse tubules?
Extensions of the Sarcolemma which carry the action potential into the cell.
Disease
Failure of homeostasis
What are the fiber types?
Fast fibers(majority), slow fibers, and intermediate fibers.
How is amplitude involved in propagation?
First action potential has the same amplitude as the last. Propagation occurs without loss in amplitude.
What are the types of ion channels?
Gated (active) channels and leak (passive) channels
What is glycine?
General inhibition. (prevents convulsions)
What does calcium ATPase do?
Gets pumped into the sarcoplasmic reticulum for storage and pumped out of cells.
What are the amino acid neurotransmitters?
Glutamate, glycine, and GABA.
What is liver glycogen?
Glycogen->glucose->blood-> muscle cell
Keratin
Hard protein produced by epidermal cells.
How do muscles help with heat production?
Heat is a product of metabolism and muscles generate 85% of body heat.
What are hormone groups?
Hormones that also function as neurotransmitters in the brain.
What is the neurotransmitter effects in the postsynaptic membrane in the inhibitory category?
Hyperpolarization. Inhibits generation of an action potential.
Where is lipid storage?
Hypodermis
What is involved in temperature regulation?
Hypodermis and Perspiration.
What is resting potential?
In all resting cells. Range from -10mV to -100mV(negative inside the cell). Maintained by Na+(moved out) and K+(moved in)
Where are satellite cells located?
In the ganglia
How are organic wastes excreted?
In the sweat.
How does muscle fatigue happen?
Increase lactic acid-> decrease pH-> decrease ATP synthesis-> decrease contractions
Increase the factor, then
Increase the factor more
What does the Parathyroid Hormone do?
Increases blood calcium
What does calcitonin target in the kidneys?
Increases calcium excretion. More calcium leaves blood.
What is neuropeptide Y?
Increases food intake.
What is Calcitriol?
Increases the calcium and phosphorous absorption from the small intestine.
What does increasing the stimulus do to graded potentials?
Increases the effects, increases the area affected.
What does the parathyroid hormone target in the bones?
Increases the osteoclast activity. More calcium is able to enter the blood.
What are the functions of tight junctions?
Inhibit entry of microorganisms and involved in waterproofing.
What is an IPSPs?
Inhibitory graded potentials. Hyperpolarize membrane. Subtract from EPSPs -> more difficult to generate an action potential.
Effects of inactivity on bone strength
Inhibits osteoblasts. (osteoclasts are able to degrade more than the osteoblasts build.
Dermis
Inner layer of skin, dense connective tissue, nerves, and blood vessels.
What do interneurons do?
Integrate sensory input and motor output. Control higher functions of the brain, such as learning, memory, and thinking.
What is a neuronal pool?
Interconnected neurons (interneurons). Act together to perform a specific function
How is the nervous system organized?
Into the central nervous system(CNS) and the peripheral nervous system (PNS)
Types of Regulation
Intrinsic (auto regulation) and Extrinsic Regulation
How are the communication junctions involve in synapses?
Involved in transmission of the nerve impulse.
Positive Feedback
Is NOT involved in homeostasis
What is the microglia?
It does phagocytosis
What is the hinge area of myosin?
It is located between the head and tail. It allows molecules to bend.
Why are twitches the only contractions in the heart?
It wouldn't be able to pump blood otherwise. Summation and tetanus would be too strong.
How are SSRIs (selective serotonin reuptake inhibitors) used to treat serotonin issues?
Keep serotonin in the synapse longer. -> prolongs the effect.
What is the Cori cycle?
Lactic acid from skeletal muscle-> realeased into blood-> liver converts it to glucose-> released into blood-> skeletal muscle uses glucose to make glycogen
What is axon diameter?
Larger diameter axons have a faster rate of propagation.
Simple twitch (contraction and relaxation) phases
Latent, contraction, and relaxtion
What are the functions of glutamate?
Learning and memory. Pain transmission.
What are the functions of nitric oxide (NO) and carbon monoxide (CO)?
Learning and memory. Smooth muscle relaxation.
What is the function of ependymal cells?
Line the ventricular system
What are myelin sheaths?
Lipid-rich cell membrane that forms a layer of insulation
What is the graded potential?
Localized change in the membrane potential.
Components of the Hypodermis
Loose connective tissue and adipose tissue
What does the A band (dark) contain?
M line and H zone
Homeostatis
Maintenance of a stable internal environment.
How many mitochondria are present in the muscle fibers?
Many
Bone structure
Marrow cavity, matrix, and cells.
Osteocytes
Mature osteoblasts. Maintains bone tissue.
What happens in the contraction phase of a simple twitch?
Maximum tension is produced
What absorbs UV radiation to help protect the skin?
Melanin
What is contained in the action potential?
Muscle cells and neuron axons.
What is muscle tone?
Muscles always have some degree of contraction. Stabilizes body. Facilitates initiation of contraction.
What do Schwann cells do?
Myelination and repair.
What are thick filaments made up of?
Myosin
How does depolarization work?
Na+ ions enter cell. Inside of the cell becomes more positive
Feedback Loops
Negative Feedback and Positive feedback.
If normal body range is increased
Negative feedback will decrease it
What is a chemical synapse?
Nerve impulse is transmitted by chemicals called neurotransmitters.
What does the peripheral nervous system include?
Nerves-axons, and the ganglia- neuron cell bodies.
What is the initiation of contraction in the visceral muscle?
Nervous system, stretch, chemicals in local environment, intrinsic (pacesetter cells initiate rhythmic cycles of contractions)
Where is acetylcholine located?
Nervous systems and neuromuscular junctions (motor end plate)
What type of communication junctions are involved in synapses?
Neuronal, neuromuscular, and neuroglandular.
What are the types of nervous system cells?
Neurons and neuroglia
What is tropomyosin made up of?
One tropomyosin per 7 G-actins. In the resting state it covers the active sites on G-actins.
How are gated (active) ion channels voltage regulated?
Open or close in response to transmembrane potential. Only on axons, skeletal muscles, and cardiac muscles. Involved with action potentials.
How do opioids and Substance P interact?
Opioids block the release of substance P
What is included in the neuropeptides group?
Opioids, substance P, and neuropeptide Y.
Carotene
Orange Pigment. Located in the epidermal and adipose cells. Converted to Vitamin A.
What are smooth muscles?
Organs and blood vessels
What does the skeletal system protect?
Organs. IE abdominal cage, rib cage.
Epidermis
Outer layer of skin, Epithelial tissue, Strata
What regulates the heart?
Pacemaker cells and the nervous system.
What is the function of Substance P?
Pain transmission
What are the disorders caused by dopamine issues?
Parkinson's disease, schizophrenia, and drug addiction.
Where are the sensory neuron dendrites located?
Periphery
What is reverberation?
Positive feedback loop. Collateral axon stimulates presynaptic neuron.
How does hyperpolarization work?
Positive ions leave (primarily K+). inside of the cell becomes more negative.
What are the types of neuromodulator effects?
Presynaptic effect and postsynaptic effects.
What are the types of neuromodulators?
Primarily neuropeptides and opioids. Same as neurotransmitters.
Control Center (Nervous system) (Integration Center)
Processes information from receptors. Integrates input from different receptors.
What are the functions of Keratin?
Protects against skin abrasions and waterproofs the skin.
What do gated (active) ion channels do?
Protein changes conformation to open and close channel.
What are the gap junctions contained in an electrical synapse?
Protein channels that link two cells. Transmit the nerve impulse electrically between cells-> as though the 2 cells share a common membrane.
Regulatory Components
Receptor, Control Center(Nervous system- integration center), Effector (Cell or Organ)
Hemoglobin
Red pigment. Located in the Red Blood Cells in the dermis. Red with Oxygen Attached.
What is GABA?
Reduces anxiety.
What is the function of satellite cells?
Regulate external chemical environment of neurons.
Calcium
Regulates many cell processes Blood calcium level must be kept within a normal range.
Extrinsic Regulation
Regulatory organ systems, Nervous system- immediate effects, Endocrine System- long term effects
How do neuromodulators release?
Released along with the neurotransmitter.
What is calcium ATPase's function?
Removes calcium from the cytoplasm
Effector (cell or organ)
Respond to output from control center. Produce an effect on homeostasis (effectors are usually muscles or glands)
Receptor (Sensor)
Responds to environmental changes. Sends information to control center.
Negative Feedback
Responsible for maintaining homeostasis.
What are energy sources?
Resting muscle (fatty acids) and contracting muscle.
How does repolarization work?
Return to resting potential after depolarization.
Skeletal Muscle Cell (Muscle Fiber)
Sarcolemma, Transverse tubules, glycogen granules, nuclei, sarcoplastic reticulum, Mitochondria, Myfibrils.
How does the heart contract?
Sarcomeres and twitches.
Tension
Sarcomeres shorten during contraction-> muscle fibers shorten-> muscle shortens and pulls on tendon-> tension exerted on tendon-> tendon exerts tension on bone-> muscle pulls bone-> movement (muscles only pull)
What does the neuroglia contain in the peripheral nervous system?
Satellite cells and Schwann cells
What do the motor neurons do?
Send motor output to muscles, glands, and adipose tissue
What do sensory neurons do?
Send sensory input to the CNS
Types of perspiration
Sensible and Insensible perpiration
Reflex arc
Sensory stimulus in periphery-> sensory neuron-> interneuron (information processing)-> motor neuron-> effector response in periphery
What are the types of neurons?
Sensory, motor, and interneurons
What are the biogenic amines?
Serotonin, norepinephrine, and dopamine.
What is parallel processing?
Several neurons process the same information at the same time.Allows different responses to the same information to occur at the same time.
Convergence
Several neurons synapse with one neuron
How do the sarcomeres work in the heart?
Similar to that of the skeletal muscles
What are the types of contractions?
Simple twitch, Treppe, Wave Summation, and Tetanus (not the disease)
What is temporal summation?
Single synapse over time. New graded potentials develop before the old ones die out.
What is an axon?
Single, long process that branches at the end and transmits nerve impulses.
What else does graded local polarization affect?
Site of stimulation(local).
Somatic response
Skeletal muscle and protective functions
What does the somatic nervous system control?
Skeletal muscles
Integumentary System
Skin and its accessory structures. (Accessory structures include hair, nails, and glands.)
What is the function of serotonin?
Sleep, appetite, sexual behavior, and body temperature.
What are the functions of anandamide?
Sleep, tranquilization, analgesia, increase apetite, extinguish traumatic memories. -> people self medicate with marijuana when they have issues with anandamide.
What are the components in efferent division?
Somatic nervous system (SNS) and autonomic nervous system (ANS)
Where are the sensory neuron axons located?
Spinal cord
Osteoprogenitor Cells
Stem cells that form new osteoblasts.
How does the action potential (nerve impulse) generate?
Step 1) Initiation- occurs when depolarization reaches the threshold level (-65 to -55 mV). 2) done via graded potentials which reach axon Step 2) Wave of depolarization. Depolarization opens voltage gated Na+ channels. 2) membrane is depolarized even further. Step 3) Wave of repolarization- Voltage gated K+ channels open. 2) Voltage gated Na+ channels begin to close. 3) Inside of cell becomes more negative. (loses positive charge) (repolarization wave- follows depolarization wave down to the axon). Step 4) Return to resting potential. 1) Voltage gated K+ channels close. 2) transient hyperpolarization (loss of K+) 3) Na/ K+ ATPase- restores the resting potential
What is treppe stimulation?
Stimulation that occurs right after the relaxtion phase. Next contraction is stronger until maximum is reached.
Effects of exercise on bone strength
Stress on bones generates an electrical field in bone minerals. Osteoblasts are attracted to electrical field and form new bone tissue.
Sensory
Structures that send information to the brain about touch, pressure, pain, and temperature.
What is the neuroglia or glial cells?
Support cells
Functions of the Skeletal System
Support, movement, protection, storage, and blood cell formation
Sensible Perspiration
Sweat glands secrete a watery substance to cool the body
What is the structure of myosin?
Tail, head, and hinge area.
What are the 2 types of summations?
Temporal summation and spatial summation.
What are thin filaments attached to?
The Z line.
How does the skeletal system work as a storage unit?
The bone marrow stores lipids, fats, and minerals.
What does the central nervous system include?
The brain and spinal cord.
What does the funtional syncytium of intercalated discs mean?
The cardiac muscle functions as a single unit
What are intermediate fibers?
The intermediate of fast and slow fibers.
Glycogen metabolism happens where in the body?
The liver and in muscles
What must be known to understand disease?
The normal physiology
What is the muscle fiber sarcolemma?
The plasma membrane.
What is the Motor End Plate?
The region of the sarcolemma next to the motor neuron. Has receptors for ACh
What are sarcomeres?
The smallest functional unit of the muscle fibers.
What do muscle cells do?
Trigger contractions.
What is the action potential frequency?
The stronger the stimulus, the more frequent the action potentials are. -Action potential strength cannot be increased.
Physiology
The study of how living organisms perform their functions.
Physiology
The study of the functions of the cell or organism.
What is the H zone?
There is one on each side of the M line. They contain only thick filaments.
What do glycogen granules do in muscle fiber?
They are in the cytoplasm for energy.
What is important about the nuclei in muscle fibers?
They are multinucleated.
What are astrocytes?
They are the blood brain barrier and form the framework of the CNS- many cell processes. They adjust interstitial fluid composition. It does very limited repair in the CNS and forms scar tissue.
How are effects of graded potential affected by distance?
They decrease.
How are gated (active) ion channels mechanically regulated?
They respond to physical distortion of membrane and some sensory receptors in skin
What are myofibrils made up of?
Thick (myosin) filaments and Thin (actin) filaments
What is the zone of overlap?
Thick filaments plus thin filaments.
What is the arrangement of a contractile protein (or sarcomere)?
Thick filaments, thin filaments, stabilize proteins, regulate proteins.
What is the structure of smooth muscles?
Thin and thick filaments in sarcoplasm, NOT arranged in sarcomeres, NOT tubules, dense bodies,
What are the dense bodies in smooth muscles?
Thin filaments and other smooth muscle cells.
What kind of filaments are presents in the I band?
Thin filaments only.
What is the sliding filament theory?
Thin filaments slide toward center of sarcomere. The length of the thin and thick filaments remains constant, but the length of the sarcomere is shortened.
What is troponin made up of?
Three subunits, affinities for G-actin, tropomyosin, and calcium.
Where is Calcitonin located?
Thyroid gland
What is a neurotransmitter?
Transmits the nerve impulses.
What are the indirect effects via G proteins on neurotransmitters?
biogenic amines, GABA, glutamate, neuropeptides, hormone groups, anandamide
flexors
bring a body part in
What are the parts of the motor neurons
cell body, dendrites and axons
What are the types of neurotransmitters on the postsynaptic membrane?
excitatory and inhibitory.
extensors
extend a body part out
Muscle fibers
extrafusal and intafusal
Types of muscles
flexors and extensors
Innate reflex
forms during brain development (blinking and sucking)
Where is the (light) band?
from one A band to the next A band.
What is muscle glycogen?
glycogen-> glucose
What is the mechanism of contraction of smooth muscles?
increase in intracellular calcium-> calcium binds to calmodulin-> activate myosin light chain kinase-> ATP hydrolysis-> phosphorylate myosin-> cross bridge formation-> contraction (tetanic contractions)
What does parathyroid hormone do in the small intestine?
increases the action of calcitriol. More calcium enters the blood.
Serial processing
information is relayed from one neuron to another neuron
What does calcitonin target in the bones?
inhibits osteoclasts. This means less calcium will enter the blood.
Acquired reflex
learned motor pattern
Crossed extensors reflex (contralateral)
left side of body
higher centers of brain
modify basic patterns to reduce complex movements.
Polysynaptic reflexes
much more complex
What do myofibrils do in intercalated discs?
myoofibrils of 2 cells anchored together at discs-> pull together
