A&P Lecture exam #3
Pyramidal cell found where?
(Cerebral cortex
relaxation....Ca2+ -ATPase pump continuously, moves Ca2+ into?
+ into sarcoplasmic reticulum (SR)
Motor function do what?
- Activates effectors (muscles and glands) through cranial and spinal nerves • Helps maintain homeostasis (with the endocrine system) • Responsible for perception, behavior, learning, memory
Peripheral Nervous System (PNS)....Cranial nerves
- Emerge from the brain; 12 pairs
in deep wound healing what happens in the migratory phase?
- blood clot becomes a scab -epithelial cell bridge wound beneath scab -fibroblasts synthesize scar tissue .... collagen fibers and glycoproteins -damaged blood vessels begin to grow -granulation tissue fills the wound
in fibrosis what is a hypertrophic scar?
- elevated above the epidermal surface - within the original wound boundaries
In deep wound healing what happens in the proliferative phase?
- growth of epithelial cells beneath scab -collagen fibers secreted by fibroblasts deposited randomly -growth of blood vessels continues
what makes up and defines osteoprogenitor cells?
- only bone cell that divides - differentiate into osteoblasts -found in inner osteogenic layer of periosteum, in endosteum, & in canals within bone that have blood vessels.
Bone Growth in Thickness:Appositional growth, bone forms where?
1. Bone forms at surface in ridges on either side of periosteal blood vessels • Osteoblasts secrete ECM, become surrounded osteocytes
Muscle Metabolism....3 ways to produce ATP in muscle fibers:
1. Creatine phosphate (unique to muscle fibers) 2. Anaerobic glycolysis 3. Aerobic respiration
Sources of oxygen in muscular tissue:
1. Diffusion from the blood 2. From myoglobin within muscle fibers
contraction cycle....Attachment of Myosin to Action
1. Energized myosin head attaches to myosin‐binding site on actin 2. Phosphate group released from myosin head • Myosin head at this stage = cross-bridge • Only one head binds to actin at a time
what does the periosteum do?
1. Isolates bone from surrounding tissue 2. Provides a route for circulatory and nervous supply 3. Participates in bone growth and repair
what are the four cell types of bone?
1. Osteoprogenitor cells 2. osteoblasts 3.. osteocyte 4. osteoclast
NMJ includes what
1. Synaptic end bulbs 2. Synaptic cleft 3. Motor end plate
3 examples of the epidermal growth factor...
1. abrasions 2. minor burns 3. edges of deeper wounds
Ossification (osteogenesis) what are the 4 main situations?
1. initial forming of bones in embryo and fetus 2. growth of bones during infancy, childhood, and adolescences 3. remodeling of bones 4. repair of fractures
what are the two points of the articular cartilage
1. lacks perichondrium and blood vessels 2.reduces friction and absorbs shock
Microscopic Anatomy of Skeletal Muscle Fiber, diameter?
10 to 100 μm
Histology of Bone (osseous) Tissue: extracellular matrix is made up of?
15% water, 30% collagen, 55% mineral salts ---Calcium phosphate + calculate hydroxide = hydroxyapatite crystals ▪Also calcium carbonate, magnesium, fluoride, potassium, sodium
Bone Growth in Thickness:Appositional growth, what forms tunnels? and what happens with the periosteum?
2. Ridges around blood vessels form tunnels • Periosteum is now endosteum inside bone
Contraction Cycle 3: Power Stroke, 3rd part?at the end??
3. At end, ADP is released from myosin head
Bone Growth in Thickness:Appositional growth,,, osteoblasts do what to form concentric lamellae?
3. Osteoblasts in endosteum secrete ECM, form new rings of concentric lamellae
what are xBone's Role in Calcium Homeostasis
99% of body calcium is stored in bone • Blood level calcium ions (Ca2+) are very closely regulated • Nerve & muscle cells depend on stable Ca2+ level in extracellular fluid • Blood clotting and many enzyme activities require Ca2+ • Osteoblasts and osteoclasts help "buffer" the blood Ca2+ level by bone remodeling
Phosphate group from creatine phosphate to ADP =
= creatine + ATP
Phosphate group from ATP to creatine =
= creatine phosphate + ADP
what is the a band? what does it extend?
A band: Darker middle part of sarcomere ▪ Extends entire length of thick filaments
in sliding filaments the a band does what?
A band: no change in width
A motor unit contains the same type of what?
A motor unit contains the same type of skeletal muscle fiber
Nerve Impulse Generates Muscle Action Potential...4. act binds to what? opens what to flow into cell? cell gains what?
ACh binds to ACh receptors • Opens ion channel in ACh receptor, Na+ and other cations flow into cell ▪ Cell gains positive charge, changes membrane potential
Nerve Impulse Generates Muscle Action Potential...6. what is broken down and by what to be activity terminated.
ACh broken down by acetylcholinesterase (AChE), activity terminated
Nerve Impulse Generates Muscle Action Potential....3 what diffuses across synaptic cleft?
ACh diffuses across synaptic cleft
Acetylcholine (ACh): is what and is found where?
Acetylcholine (ACh): neurotransmitter ▪ Found in synaptic vesicles in cytosol of synaptic end bulbs
Action potentials travel down what?
Action potentials travel down axon toward axon terminals
Active muscle fibers require what?
Active muscle fibers require oxygen, glucose, fatty acids
Fast Oxidative-Glycolytic Fibers....Activities like what???
Activities like walking and sprinting
Unfused (Incomplete) Tetanus.... additional what?? sustained but what???
Additional stimuli while muscle fibers are partially relaxing • Sustained but wavering contraction
Aerobic respiration is slower than anaerobic glycolysis, but produces what? ▪1 glucose →
Aerobic respiration is slower than anaerobic glycolysis, but produces much more ATP ▪1 glucose → 30 or 32 ATPs
Gap Junctions... what are they?
Allow diffusion of ions & small molecules between cells • Fast spread of nerve and muscle impulses
Motor Unit Recruitment....Allows contraction for what?
Allows contraction for longer periods
Transverse tubules (T tubules): allow for what?
Allows fast spread of action potential along sarcolemma
bone remodeling allows for what?
Allows for extraction of bone minerals to maintain calcium levels in blood
Appositional growth: what is it?
Appositional growth: growth at outer surface of tissue
Endochondral Ossification,Development of secondary ossification centers, what stimulates formation?
Arteries entering the epiphyses stimulate formation
Endochondral Ossification:Development of primary ossification center artery penetrates what?
Artery penetrates the perichondrium and cartilage model ▪ Stimulates osteoprogenitor cells in perichondrium to osteoblasts ▪ Perichondrium to periosteum
nerogolia in Central nervous system
Astrocytes • Oligodendrocytes • Microglia • Ependymal cells
Athletes have what?
Athletes have thicker and stronger bones
Autorhythmicity: is what?
Autorhythmicity: involuntary alternating contraction and relaxation
Axon terminal: found where? divides into what?
Axon terminal: end of motor neuron, divides into synaptic end bulbs
Initiation of Contraction Cycle fourth?Binding sites are free and???
Binding sites are free and contraction cycle begins
What is bone remodeling?
Bone continuously renews itself throughout life
what is bone deposition?
Bone deposition: Osteoblasts add minerals & collagen fibers
what can bone mass do in response to strain
Bone mass can be increased in response to heavy loads or strain
what is bone resorption?
Bone resorption: Osteoclasts remove bone minerals & collagen fibers
what happens in Enlargement of the Medullary Cavity?
Bone tissue lining medullary cavity is destroyed by osteoclasts in the endosteum
Central Nervous System (CNS)
Brain and Spinal cord
cardiac muscle only has one what and what doe sit look like?
Branched, striated fibers • Usually only one nucleus in center of cell
muscle fatigue Contributing factors:Buildup of what?
Buildup of lactic acid and ADP
Bundles of Axons CNS --- ??? PNS --- ???
Bundles of Axons CNS --- Tract PNS --- Nerve
Clusters of Neuronal Cell Bodies CNS --- what??? PNS --- Ganglion (pl. Ganglia)
CNS --- Nucleus (pl. Nuclei) PNS --- Ganglion (pl. Ganglia)
Nerve Impulse Generates Muscle Action Potential...2. what flows through open channels and what is stimulated to release each into synaptic cleft
Ca2+ flows through open channels • Stimulates synaptic vesicles to release acetylcholine (ACh) into synaptic cleft
contraction...Voltage-gated Ca2+ channels move, then what?
Ca2+ release channels open
Calcitonin (CT): does what?
Calcitonin (CT): decreases blood Ca2+ level
Endochondral Ossification, what part of the cartilage begins to calcify
Cartilage in middle begins to calcify
Anaerobic Glycolysis.... catabolism of glucose to...? produces enough tap for how long of exercise?
Catabolism of glucose to generate ATP when creatine phosphate depleted ▪ Produces enough ATP for about 2 minutes' exercise
factors of appositional growth
Cells in inner cellular layer of the perichondrium differentiate into chondroblasts, chondroblasts surrounded with extracellular matrix & become chondrocytes • Matrix accumulates beneath the perichondrium on outer surface of cartilage • Continues through adolescence
Nerve Impulse Generates Muscle Action Potential..5. what triggers muscle action potential? what propagates?
Change in membrane potential triggers muscle action potential • Action potential propagates along sarcolemma (membrane) to T tubules ▪ Causes Ca2+ release from SR into sarcoplasm and CONTRACTION
Interstitial growth: happens when?
Childhood and adolescence
Endochondral Ossification: Chondroblasts to what
Chondroblasts chondrocytes
Endochondral Ossification: what happens during the growth of the cartilage model? what type of growth?
Chondrocytes divide and secrete cartilage ECM ▪ Interstitial growth (growth in length)
Endochondral Ossification, growth of cartilage model what begins dying?
Chondrocytes within calcified ECM begin dying
Closed (Simple) fracture: does what?
Closed (Simple) fracture: does not break the skin
Ganglia (sg. Ganglion) clusters of what?
Clusters of neuronal cell bodies in the PNS
what is a colles?
Colles: fracture of radius where the distal fragment is displaced posteriorly
Comminuted fracture: does what?
Comminuted fracture: bone is splintered, crushed, or broken in pieces at the site of impact
Myofibrils do and are what?
Contractile organelles in skeletal muscle fibers • Appear as thread-like structures within sarcoplasm ▪ Diameter: about 2 µm • Extend the entire length of a muscle fiber • Striation in myofibrils is source of muscle fiber striation
what is contractibility
Contractility: ability to contract when stimulated by nerve impulse
Muscle fiber also varies in: 3 things....?
Contraction and relaxation speed • Metabolic reactions to generate ATP • Speed of fatigue
twitch contraction
Contraction of muscle fibers in motor unit in response to a single nerve action potential
Contraction: is what???
Contraction: sliding of filaments
Creatine is synthesized where? & transported to what?
Creatine is synthesized in liver, kidneys, and pancreas & transported to muscles
Contraction Cycle, Cycle repeats as long as???
Cycle repeats as long as ATP and Ca2+ is available
what happens in the Bone remodeling phase
Dead portions of fracture resorbed by osteoclasts • Compact bone replaces spongy bone where needed • Osteoclasts remodel bone to original shape
Motor Unit Recruitment....Delays what?
Delays fatigue
unipolar neuron
Dendrites and one axon are fused together to form a continuous process that emerges from the cell body
muscle fatigue Contributing factors:Depletion of what?
Depletion of glycogen and other nutrients
Sensory function do what?
Detects internal and external stimuli and carries them into the central nervous system through cranial and spinal nerves
the Endochondral Ossification is the development of what?
Development of cartilage model
Each muscle fiber is close to what?
Each muscle fiber is close to 1+ blood capillaries
Each skeletal muscle penetrated by what?
Each skeletal muscle penetrated by a nerve, an artery, & 1 - 2 veins
Elasticity: what is it?
Elasticity: ability to return to original length and shape after contraction or extension
what is electrical excitability?
Electrical excitability: ability to produce muscle action potentials (impulses) in response to specific stimuli: • Chemical stimuli (neurotransmitters, hormones, pH) • Autorhythmic response to electrical signals
Peripheral Nervous System (PNS)....• Spinal nerves
Emerge from the spinal cord; 31 pairs
the epimysium encircles what? and is what type of connective tissue?
Encircles entire muscle • Dense irregular connective tissue
what is the endomysium
Endomysium: inner layer •
Where is spongy bone located?
Ends of long bone such as thighs & upper arm, with an outer layer of compact bone.
Aerobic Respiration.....Enough ATP for what?
Enough ATP for rest or light exercise
where is the epimysium
Epimysium: outer layer
Endochondral Ossification,,Formation of articular cartilage and epiphyseal growth plate,,,, what happens in the epiphyseal growth plate?
Epiphyseal (growth) plate: Hyaline cartilage remaining between diaphysis and epiphysis until maturity
what happens in Bone Growth in Length?
Epiphyseal chondrocytes stop dividing • Growth plate cartilage is completely replaced by bone • Bone growth ends
Excitation: is what???
Excitation: muscle action potential
Extensibility: what is it?
Extensibility: ability to stretch, within limits, without being damaged
muscle fatigue Contributing factors:Failure of motor neuron to release enough what?
Failure of motor neuron to release enough acetylcholine
what is the fascia
Fascia: dense sheet of irregular connective tissue
Fast Glycolytic Fibers...Fatigue
Fatigue quickly
Transverse tubules (T tubules): are filled with what?
Filled with interstitial fluid
What is the sarcoplasmic reticulum?
Fluid-filled membranous sacs surrounding each myofibril
Oligodendrocytes (CNS) form what?
Form the myelin sheath around CNS axons - Myelinated axons
what happens in the Reactive phase
Formation of fracture hematoma • Swelling and inflammation • Blood supply is cut off, nearby bone cells die • Phagocytes and osteoclasts remove the dead bone tissue
Frequency of stimulation: depends on what?
Frequency of stimulation: # of impulses per second
Microglia (CNS) function as what?
Function as phagocytes
what is the sarcomere?
Functional unit of a myofibril
Nodes of Ranvier - are what?
Gaps in the myelin sheath
Fast Oxidative-Glycolytic Fibers...Generate ATP by???
Generate ATP by aerobic respiration & anaerobic glycolysis, high glycogen levels
Slow Oxidative Fibers.... generate app by what?? has many what?
Generate ATP by aerobic respiration, many mitochondria
Fast Glycolytic Fibers...Generate ATP by anaerobic glycolysis,
Generate ATP by anaerobic glycolysis, high glycogen level
Glycolysis forms pyruvic acid from
Glycolysis forms pyruvic acid from glucose (like anaerobic respiration)
What is a greenstick fracture?
Greenstick fracture: one side of bone is fractured, other side bends ▪ Generally only occurs in children
Endochondral Ossification: Growth of what model?
Growth of cartilage model
what is the h band?
H band: area within A band with only thick filaments
Neurons (Nerve cells).. Have what??? • Convert stimuli into what??? and conduct them to other what???
Have electrical excitability • Convert stimuli into electrical signals (nerve action potentials or nerve impulses) and conduct them to other neurons, muscles, or glands
what does skeletal muscle do?
Heat production • Protection
High blood Ca2+ levels do what?
High blood Ca2+ levels trigger CT secretion ▪ Inhibits activity of osteoclasts ▪ Speeds uptake and deposition into bone
Endochondral Ossification,,Formation of articular cartilage and epiphyseal growth plate,,,, hyaline cartilages role with articular cartilage?
Hyaline cartilage covering epiphyses becomes articular cartilage
Fast Glycolytic Fibers...Hydrolyze ATP quickly,
Hydrolyze ATP quickly, strong and quick contractions
in sliding filaments what happens in the I band and h zone?
I band and H zone: narrow and eventually disappear during contraction
what is the I band?
I band: remaining thin filaments, no thick filaments
what is an impacted fracture
Impacted fracture: one end of bone firmly driven into interior of other end
what is contact inhibition?
In normal tissues cells stop dividing when they came into contact with the other cell
Muscle fatigue is caused by
Inability of a muscle to maintain force of contraction after prolonged activity
Factors Affecting Bone Growth and Remodeling, in hormones, include what?
Include Insulin-like growth factor (IGF), Thyroid hormones (T3, T4), insulin
Factors Affecting Bone Growth and Remodeling in hormones increase what?
Increase of sex hormones (estrogen, androgens) at puberty trigger growth and skeletal changes
due to Low blood Ca2+ triggers PTH secretion what happens and what increases etc...
Increases the number and activity of osteoclasts ▪ Increases Ca2+ reabsorption in the kidney ▪ Stimulates formation of calcitriol (active form of Vitamin D), promoting Ca2+ absorption from gastrointestinal tract
what happens in the peristeal capillaries in the development of the primary ossification center
Induces growth of primary ossification center in center of bone ▪ Trabeculae form in the calcified cartilage
Initial segment - the first part of what?
Initial segment - the first part of axon
muscle fatigue Contributing factors:Insufficient what?
Insufficient O2
intercalated discs attach what together and what do they contain
Intercalated discs (thick areas of membrane) attach cells together ▪ contain gap junctions and desmosomes
Interstitial growth what is it
Interstitial growth: growth within the tissue
Endochondral Ossification: Development of primary ossification center, happens where from the surface?
Inward from surface
Smooth Muscle found where?
Iris • Walls of internal hollow structures (blood vessels, airways to lungs, stomach, intestines, gallbladder, urinary bladder, uterus) • Attached to hair follicles in skin
Isometric contraction: • Used for what?
Isometric contraction: muscular contraction in which the length of the muscle does not change • Used for maintaining posture and holding objects in a fixed position
Junctional folds: is what?
Junctional folds: deep groves in motor end plate provide surface area
Krebs cycle and electron transport chain ???? ▪ Yields what? in aerobic respiration
Krebs cycle and electron transport chain reactions ▪ Yields ATP, CO2 , H2O and heat
Slow Oxidative Fibers...Large amount of what?
Large amount of myoglobin and many capillaries
Fast Oxidative-Glycolytic Fibers....Large amounts ???
Large amounts of myoglobin and many blood capillaries
Fast Oxidative-Glycolytic Fibers....Largest what
Largest fibers
What is the epiphyseal plate?
Layer of hyaline cartilage that allow the bone to grow lengthwise in the diaphysis.
in sliding filaments Lengths of individual thick and thin filaments does what?
Lengths of individual thick and thin filaments does NOT change
Ligand: is what?
Ligand: molecule that binds to receptor
what does the fascia do?
Lines body wall and limbs • Supports and surrounds muscles and organs • Holds muscles with similar functions together • Carries nerves, blood vessels, and lymphatic vessels
what does skeletal muscle look like?
Long, cylindrical fibers with striation (stripes) • Multinucleated with nuclei at periphery of cell
demineralization causes what?
Loss of bone mass from demineralization Especially significant to aging in women
what triggers PTH to secrete
Low blood Ca2+ triggers PTH secretion
white muscle fibers..?
Low myoglobin content
Fast Glycolytic Fibers...Low what???, fewer ????, few???
Low myoglobin, fewer blood capillaries, few mitochondria
what is the m line?
M line: Supporting proteins hold thick filaments together at the center of the H band
myosin does what and is what?
Main component of thick filaments • Motor protein in all three types of muscle tissue • Converts ATP chemical energy into mechanical energy
what is the main stain on bone?
Main strain on bone is pull of skeletal muscles and gravity
Astrocytes (CNS) maintain what?
Maintain chemical environment around neurons • Maintain blood brain barrier
Slow Oxidative Fibers....Maintaining what???, what type of activities?
Maintaining posture and aerobic, endurance activities
Dendrites -
Major input portion - May be highly branched - Usually short
Microscopic Anatomy of Skeletal Muscle Fiber, Mature muscle fibers (myocytes) do not undergo what?
Mature muscle fibers (myocytes) do not undergo cell division Number of muscle fibers is set before birth!
3 layers are continuous with the connective tissue that attaches skeletal muscle to other structures, the may do what?
May extend to form tendons to attach muscle to bone • May extend as flat sheets (aponeuroses)
Mechanical strain causes what?
Mechanical strain causes increase deposition of minerals and collagen fibers
Smooth Muscle, what does it look like?
Non-striated spindle-shaped cells with single, central nucleus ▪ Gap junctions common
Nuclei are located next to what?
Nuclei are located next to sarcolemma
Anaerobic Glycolysis.... occurs where? in heavy exercise what happens?
Occurs in cytoplasm (sarcoplasm of muscle) ▪ Anaerobic: does not require oxygen In heavy exercise, not enough oxygen reaches muscle fibers
bipolar neurons have what?
One main dendrite and one axon, in retina
Open (Compound) fracture: does what?
Open (Compound) fracture: broken ends of the bone protrude through skin
Endochondral Ossification:Development of medullary cavity, what do the osteoclasts do?
Osteoclasts break down some trabeculae, creating medullary cavity
what happens in the Reparative phase: bony callus formation
Osteoprogenitor cells develop into osteoblasts. • Osteoblasts produce trabeculae • Fibrous cartilage callus is converted into spongy bone bony callus
Endochondral Ossification,Development of secondary ossification centers, outward from where?
Outward from center to surface
what happens during the aging and bone tissue?
Over time, resorption by osteoclasts outpaces deposition by osteoblasts
Parathyroid hormone (PTH): does what?
Parathyroid hormone (PTH): increases blood Ca2+ level
in Endochondral Ossification what surrounds the cartilage model
Perichondrium surrounds the cartilage model
Endochondral Ossification:Development of primary ossification center what grows into calcified cartilage?
Periosteal capillaries grow into the calcified cartilage
Muscular Tissue Function, posture???
Posture: stabilize body positions
what is a Pott?
Pott: fracture of distal end of fibula
Endochondral Ossification; Development of medullary cavity, what grow towards the ends?
Primary ossification center grows toward the ends
Integrative function.. do what?
Processes sensory information by analyzing it and making decisions for appropriate responses (Integration)
Ependymal cells (CNS) produce what?
Produce and assist in the circulation of the cerebrospinal fluid
Motor Unit Recruitment....Produces
Produces smooth movements
Purkinje cell in the where?
Purkinje cell in the cerebellum
Rapid reaction: is what? ▪ Enough ATP for about how many seconds
Rapid reaction: first energy source for contraction ▪ Enough ATP for about 15 seconds
Myoglobin content... what type of muscle fiber? with what characteristics?
Red muscle fibers: • High myoglobin content • More mitochondria • More blood capillaries
Initiation of Contraction Cycle...second?Released Ca2+ bind
Released Ca2+ bind to troponin
Slow Oxidative Fibers...Resistant to what???, sustained contractions for how long???
Resistant to fatigue, sustained contractions for many hours
Smaller compartments of myofilaments is what?
Smaller compartments of myofilaments: sarcomeres
Motor (efferent) division what are the tw types?
Somatic nervous system and Autonomic nervous system
Muscular Tissue Function, storage and movement???
Sphincters: rings of smooth muscles at exit of hollow organs • Cardiac muscle contractions • Smooth muscles contract & relax in walls of blood vessels, gastrointestinal tract, gall bladder, reproductive system, & urinary system
Endochondral Ossification,Development of secondary ossification centers, what's in the center of the epiphyses and what isn't?
Spongy bone in center of epiphyses ▪ No medullary cavity in epiphyses
Desmosomes... what are they?
Stability for cells and tissues • Prevents separation under tension • Common in epidermis and cardiac muscle cells
Synapse - Site of communication between neurons or between what?
Synapse - Site of communication between neurons or between a neuron and an effector cell
Synapse: is what?
Synapse: region of communication between two neurons or a neuron and target cell
Synaptic cleft: is what?
Synaptic cleft: gap between cells in synapse
what is fibrosis?
tissue repairing which involves repair by dense connective tissue by the formation of scar tissue
Dystrophin: links thin filaments to
to integral membrane proteins of sarcolemma
Anaerobic Glycolysis...If no oxygen, pyruvic acid converts to
to lactic acid
intramembranous ossification and the formation of what?
trabeculae, connective tissue differentiates into red bone marrow
Ca2+ is released to bind with what in the contraction cycle
troponin in the contraction cycle
All of the muscle fibers in one motor unit contract in
unison
in deep wound healing in the inflammatory phase, what is the inflammation due from?
vascular and cellular response
Anaerobic Glycolysis..Glucose enters muscle fibers via what?
via facilitated diffusion or breakdown of glycogen
Periosteal arteries and veins
with nerves enter diaphysis through perforating cannals
Motor Unit Recruitment...The weakest motor units are recruited first, with progressively what?
with progressively stronger motor units added if needed
Unmyelinated axons -- without what
without myelin sheath
Myelin sheath • A greatly extended and modified WHAT wrapped around the WHAT - Multilayered what??? Acts as an electrical insulator - Increases the what?
• A greatly extended and modified plasma membrane wrapped around the axon - Multilayered lipid and protein covering Increases the speed of nerve impulse conduction
brittleness is caused by what from age?
• Brittleness from decreased protein synthesis with age
in Endochondral Ossification chondroblasts do what?
• Chondroblasts secrete hyaline cartilage
Schwann cells (PNS), form what and participate in what?
• Form the myelin sheath around PNS axons • Participate in axon regeneration
bone remodeling what percent of bone mass at a time?
• Includes about 5% of the total bone mass at a time
Fast Glycolytic Fibers...• Intense anaerobic movements of what?
• Intense anaerobic movements of short duration
• Motor end plate: is what?
• Motor end plate: part of muscle opposite synaptic end bulbs
Excitation-Contraction Coupling, occurs where?
• Occurs at triads triad = T tubule of sarcolemma + 2 terminal cisterns of sarcoplasmic reticulum
Factors Affecting Bone Growth and Remodeling, in hormones promote what?
• Promote cell division, stimulate osteoblasts, enhances bone protein synthesis
what is contained in the sarcoplasmic reticulum?
Terminal cisterns: Dilated end sacs found on both sides of a T tubule
Frequency of Stimulation
The total force (tension) a single muscle fiber can produce depends on frequency of stimulation
Muscular Tissue Function Thermogenesis:is what?
Thermogenesis: generation of heat
What are thick filaments called?
Thick filaments: myosin protein ▪ 16 nm in diameter, 1-2 µm long
thin axon étend from where to get to a group of muscle fibers
Thin axon extends from brain or spinal cord to group of muscle fibers
Contraction Cycle 3: Power Stroke, 2nd part, thin filaments?
Thin filament is pulled along thick filament toward center of sarcomere • Generates muscle tension (force) • Energy required for action is from the energy stored in myosin head from ATP hydrolysis
What are thin filaments called?
Thin filaments: actin protein ▪ 8 nm in diameter, 1-2 µm long
titan and dystrophin link to what?
Those proteins link to extracellular connective tissue matrix proteins
Titan: is what?
Titan: huge, elastic protein stabilizes thick filament from Z disc to M line
What is the periosteum?
a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints. -connective tissue sheath & associated blood supply
Action potentials always have the same size in a ???
a given neuron or muscle fiber
in the development of the periosteum in intramembranous ossification what replaces the spongy bone at the surface
a thin layer of compact bone
Excitation of muscle fiber causes what?
action potential to travel along T tubule
Wave Summation....Second stimulus triggers release of more Ca2+, activating additional what?
activating additional sarcomeres while muscle is still contracting
Most of ATP the body uses comes from
aerobic respiration
Pyruvic acid enters the mitochondria and undergoes what?
aerobic respiration
Refractory period:
after a muscle fiber has been stimulated and a contraction has occurred, the muscle fiber loses excitability and cannot respond to additional stimulation
Most skeletal muscles are a mixture of all what?
all three types of skeletal muscle fibers
Microscopic Anatomy of Skeletal Muscle Fiber, length?
average 10 cm (4 inches)
what happens in epidermal wound healing?
basal cells divide and migrate to fill spaces created by the wound....
Muscle Tone....When motor neurons are damaged, muscle becomes what??
becomes flaccid (loss of tone)
Where is the metaphysis?
between diaphysis and epiphysis
myoglobin does what? found where? and releases what?
binds O2 that diffuses into muscle fiber ▪ Found only in muscle ▪ Releases O2 when needed
relaxation....Voltage-gated Ca2+ channels blocking...?
blocking Ca2+ release channels
what do osteoclasts do?
break down bone
Anaerobic Glycolysis...Glycolysis: series of chemical reactions that break down what?
break down glucose into pyruvic acid
Latent period: Muscle action potential passes over sarcolemma, and what happens?
brief delay between stimulus and beginning of contraction Ca2+ released from sarcoplasmic reticulum (SR)
what do osteoblasts do?
build bone
Axon hillock (part what?
cell body
What is the inner osteogenic layer of the periosteum do?
cell layer enables bone growth
compact bone: concentric lamellae
concentric rings in the osteon
Compact bone: interosteonic canals
connect blood vessels/ nerves in medullary cavity, periosteum, & osteonic canals
compact bone: bone lacunae
contain osteocytes
Excess ATP is used to synthesize
creatine phosphate
muscle fatigue Contributing factors:Depletion of what?
creatine phosphate
Histology of Bone (osseous) Tissue: calcification
crystallization of mineral salts hardens bone ▪Initiated by osteoblasts
Sarcoplasm: is what?
cytoplasm of muscle fibers
muscle fatigue Contributing factors: Inadequate Ca2+ released from sarcoplasmic reticulum and decline of what
decline of Ca2+ in sarcoplasm
What is the outer fibrous layer of the periosteum?
dense irregular connective tissue
in Endochondral Ossification mesenchymal cells gather and do what?
differentiate into chondroblasts
Muscle Tone....Degree of muscle tension/tautness/resistance during what? ▪ Due to weak, involuntary contractions of what???
during rest or in response to stretching ▪ Due to weak, involuntary contractions of motor units
Where is the epiphysis?
ends of bone
Nutrient artery and vein
enter diaphysis of long bones through nutrient foramen ---supply inner compact bone, spongy bone, and bone marrow
skin- wound healing, what are the 2 types?
epidermal and deep wound healing
in fibrosis what is a keloid scar?
extends beyond wound boundaries.
osteoblasts secrete what?
extracellular matrix...which is the ossification center
Fast Oxidative-Glycolytic Fibers....Moderately high resistance to ???
fatigue
Histology of Bone (osseous) Tissue: connective tissue?
few cells, much extracellular matrix
Compact Bone: Interstitial Lamellae
fills spaces between osteons
what happens in deep wound healing?
force of fluids and specialized cells into damaged area and fibroblasts suture the edges together with collagen fibers
Axon of a somatic motor neuron branches out, forms what? ▪ Each skeletal muscle fiber has only one what?
forms NMJ with many separate muscle fibers ▪ one NMJ
Acetylcholine receptors: ligand-gated ion channels found where
found in motor end plate
spongy bone contains
have lamellae, bone lacunae, osteocytes, bone canaliculi, spaces filled with red and yellow marrow, blood vessels
Actin molecules twist together to form
helix-shaped filament
endochondral ossification
hyaline cartilage is produced from mesenchyme and then replaced by bone
Fast Glycolytic Fibers....Strength training can increase size of fibers:
hypertrophy
Ligand-gated channel opens/closed in response to what?
in response to ligand binding
cardiac muscle is only found where
in the heart
in deep wound healing other than vasodilation what happens?
increased permeability of blood vessels
Motor Unit Recruitment...Process in which the number of active motor units
increases
What are trabeculae?
interconnecting rods or plates of bone, lined with endosteum
Anaerobic Glycolysis...Most lactic acid diffuses where
into blood
Wave Summation....If muscle fibers are stimulated while previous twitch is still occurring, second contraction is
is stronger
Anaerobic Glycolysis....Liver cells take up lactic acid and convert it to what
it back to glucose
relaxation...High Ca2+ in SR, low..?
low Ca2+ in sarcoplasm
lots of glycogen....means what?
macromolecule made of glucose....Glucose is used in ATP synthesis
Relaxed muscle fibers produce more what?
more ATP than needed
Shoulders and arms:
more fast glycolytic fibers
Postural muscles of the neck, back, and legs:
more slow oxidative fibers
contraction....Ca2+ -ATPase pump continuously, moves what?
moves Ca2+ into sarcoplasmic reticulum (SR)
In contraction, Ca2+ binding to troponin changes its shape, moving... what?
moving tropomyosin out of the way
Eccentric isotonic contraction:
muscle lengthens during contraction
Concentric isotonic contraction:
muscle shortens during contraction
myelin sheath,,,Axons surrounded by myelin sheath are called what?
myelinated axons
muscle fiers =
myocyte cells
what are Even smaller filaments within myofibrils?
myofilaments
Myosin binding sites to bind
myosin heads
relaxation...Ca2+ released from troponin, myosin-binding do what?
myosin-binding sites on actin blocked
Force or tension that a single muscle fiber produces depends on rate of impulses arriving at
neuromuscular junction (NMJ)
Cells communicate across synapse with chemical ???
neurotransmitters
Total tension that a whole muscle can produce depends on number of what?
number of muscle fibers that are contracting together
Creatine kinase (CK) catalyzes transfer of what?
of high‐energy phosphate groups:
myelin sheath,,, Formed by oligodendrocytes (in the CNS) or what?
or Schwann cells (in the PNS)
What is the medullary cavity? and what does it contain?
or marrow cavity is the hollow space within diaphysis. ---- contains fatty yellow bone marrow and blood vessels
each skeletal muscle is a separate what?
organ
what is the classification of intramembranous ossification?
osteoblasts to osteocytes -osteocytes deposit calcium and other minerals into ECM
spongy bone does not have what?
osteons
Somatic nervous system output to what?
output to skeletal muscles (voluntary)
Autonomic nervous system...output to what?
output to smooth and cardiac muscles and glands (involuntary)
Contraction period: Ca2+ binds to troponin, myosin-binding sites on actin are exposed, and ???
peak tension in muscle fiber cross-bridges form
intramembranous ossification and the development of what?
periosteum, mesenchyme at edge of bone develops into periosteum
epidermal wound healing pictures...
pictures...
Muscle Tone....Important for maintaining what?
posture and balance, functioning of the digestive organs, maintaining blood pressure
intramembranous ossification
process by which bone forms directly from mesenchymal tissue ---flat bones of skull, facial bones, mandible, medial part of clavicle mesenchymal cells to osteoprogenitor cells to osteoblasts
Mitochondria: does what?
produce ATP to provide energy for muscle fibers
Action potential: electrical signal that propagates ???
propagates along membrane of neuron or muscle fiber
In sliding filaments,,, Myosin heads attach to and "walk" along thin filaments, pulling...?
pulling thin filaments toward M line
contraction....Ca2+ flows into sarcoplasm faster than what?
pumped into SR
What is the epiphyseal line?
remnant of the epiphyseal plate, seen in adult bones, no more growth in the bone
Compact Bone: Osteon
repeating unit within bone
compact bone: osteonic canal
runs through the center of osteon ---contians blood vessels, lymphatic vessels, and nerves
Voltage-gated Ca2+ channels in T tubule membrane... do what?
sense voltage
Aerobic Respiration....Duration of energy:
several minutes to hours
Where is the diaphysis?
shaft of bone (middle)
in sliding filaments, Total length of sarcomere
shortens
contraction....Ca2+ binds troponin, myosin-binding sites are what?
sites on actin freed
Triggers opening of Ca2+ release channels in terminal cisternal membranes when what?
skeletal muscle fiber is excited
Muscle contraction occurs as filaments do what?
slide past each other
speciaal senses what are they?
smell, tastes, vision, hearing, equilibrium
Sensory (afferent) division... what are the the two senses?
somatic senses and special senses
Increased Ca2+ concentration in sarcoplasm does what?
start muscle contraction
what does the epidermal growth factor do?
stimulates division and replacement of basal stem cells
Decreased Ca2+ concentration in sarcoplasm: does what?
stops muscle contraction
mineral homeostasis?
store and release minerals
metaphyseal arteries and veins/ epiphyseal arteries and veins
supply metaphyses and epiphyses.
Functions of bones
support, protection, movement, mineral storage, blood cell formation....
Somatic senses.. what are they?
tactile, thermal, pain, and proprioceptive sensations
Relaxation period: Ca2+ transported back into SR, myosin-binding sites are covered by tropomyosin,
tension in muscle fiber decreases myosin heads detach from actin
Isotonic contraction: • Used for what?
tension remains constant while muscle changes length • Used for body movements and moving objects
Creatine phosphate is 3 - 6 x more plentiful than what?
than ATP in sarcoplasm of resting muscle fibers
Hemopoiesis
the production of blood cells and platelets, which occurs in the red bone marrow.
in the periosteum what do the perforating fibers do?
thick bundles of collagen extend from periosteum into bone extracellular matrix. - attach collagen to bone
Actin is a _____ filament
thin
Compact Bone: bone canaliculi
thin channels connect bone lacunae ▪ allow nutrients to diffuse to osteocytes ▪ osteocytes extend processes through canaliculi & communicate with each other via gap junctions
Regulatory Muscle Proteins are part of what?
thin filaments
What is articular cartilage in a bone?
thin layer of hyaline cartilage covering the articulation part of epiphysis.
What is edosteum?
thin membrane lining medullary cavity ---contains bone-forming osteoprogenitor cells and connective tissue.
in deep wound healing what happens in the maturation phase?
-epidermis restored to normal thickness - scab sloughs off - collagen fibers organized - fibroblasts presence decreases -blood vessels reverse to normal
what is the perimysium?
. Perimysium: middle layer •
Anaerobic Glycolysis.... 1 glucose molecule → blank??? ▪ Not much ATP but fast and without??? ▪ Anaerobic glycolysis produces fewer ATPs than what but faster?
1 glucose molecule → 2 ATP and 2 lactic acid ▪ Not much ATP but fast and without oxygen ▪ Anaerobic glycolysis produces fewer ATPs than aerobic respiration, but faster
Recruitment order:
1) Slow oxidative 2) Fast oxidative-glycolytic 3) Fast glycolytic
Anaerobic Glycolysis....Muscle soreness from accumulation of lactic acid in what?
Muscle soreness from accumulation of lactic acid in muscle fibers and blood stream
Fast Oxidative-Glycolytic Fibers....Myosin head ??? what type of contraction cycle
Myosin head ATPase hydrolyzes ATP quickly, faster contraction cycle
Slow Oxidative Fibers... what happens with myosin heads??? what type of contraction cycle?
Myosin head ATPase hydrolyzes ATP slowly, slow contraction cycle
contraction cycle...ATP Hydrolysis... what happens?
Myosin head binds ATP 2. ATP hydrolyzed into ADP, energy to myosin 3. Energized myosin head moves perpendicular to filaments ADP and phosphate group still attached to myosin head
Contraction Cycle 4: Detachment of Myosin from Actin
Myosin head detaches from actin when ATP binds to myosin
Contraction Cycle 3: Power Stroke, first part?
Myosin head pivots
myosin heads do what? and hydrolyzes what?
Myosin head: binds ATP and actin ▪ ATP binding site hydrolyzes ATP to generate energy
myosin tails do what?
Myosin tail: Points toward the M line in center of sarcomere
Muscle action potentials arise where?
NMJ
NMJ: does what?
NMJ: synapse between somatic motor neuron and skeletal muscle fiber
what happens in the negative feedback system....
Negative feedback system with parathyroid cells acting as receptors
Nerve Impulse Generates Muscle Action Potential...1. nerve impulses arrive where? stimulates what?
Nerve impulse arrives at synaptic end bulbs • Stimulates voltage-gated channels to open
Nerves are what motor neuron?
Nerves are somatic motor neurons
Gray matter - are what?
Neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia
Neurons show great diversity in what?
Neurons show great diversity in size and shape
new bone is what?
New bone is more fracture resistant than old bone
Cell body (Perikaryon, Soma)
Nissl body - rough endoplasmic reticulum (rER) and free ribosomes
Fused (Complete) Tetanus... no muscle what? sustained what??
No muscle relaxation between stimuli • Sustained contraction
Transverse tubules (T tubules): are what?
Tunnels of sarcolemma toward center of muscle fibers
Endochondral Ossification, Development of secondary ossification centers, happens around what time?
Usually around time of birth
where is skeletal muscle located?
Usually attached to bones with tendons, some attached to skin
what is a vertebral compression fracture?
Vertebral compression fracture: vertebral body compressed into wedge shape
Muscle Metabolism... very high amounts od what are needed?
Very high amounts of ATP needed during muscle contraction
Is skeletal muscle voluntary or involuntary?
Voluntary movement controlled by neurons of somatic nervous system • Some unconscious control (diaphragm in breathing, posture)
Endochondral Ossification:Development of medullary cavity, compact bone has what part?
Wall of cavity eventually replaced by compact bone
White matter - Primarily what?
White matter - Primarily myelinated axons -- Tracts (White color due to whitish color of myelin)
Triglyceride storage
Yellow bone marrow Triglycerides stored in adipose cells Serves as a potential chemical energy reserve
Z disc passes through what?
Z disc passes through center of I band
Z discs: are what?
Z discs: dense protein separating sarcomeres
in sliding filaments distance between 2 discs what?
Z discs: distance between Z discs shortens
Interstitial growth, Zone of calcified cartilage
Zone of calcified cartilage: replacement by bone in progress • Osteoclasts dissolve cartilage, osteoblasts build bone
Interstitial growth, what happens in the Zone of hypertrophic cartilage:
Zone of hypertrophic cartilage: large maturing chondrocytes
what is the zone of overlap?
Zone of overlap: thick and thin filaments next to each other
Interstitial growth what is the Zone of proliferating cartilage
Zone of proliferating cartilage: chondrocytes divide and secrete ECM
Interstitial growth, what is the Zone of resting cartilage?
Zone of resting cartilage: anchors epiphyseal plate to epiphysis
Blood removes what?
Blood removes heat and metabolic waste products
what happens in the Reparative phase: fibrous cartilage callus formation
Blood vessels grow into fracture hematoma • Fibroblasts from periosteum enter the fracture site, produce collagen fibers • Cells from periosteum develop into chondroblasts and produce fibrous cartilage • Formation of fibrous cartilage (collagen fibers & cartilage)
deep wound healing: inflammatory phase?
Blood clot forms in wound, seals the edges, White blood cells (neutrophils, macrophages) and mesenchymal cells (become fibroblasts) arrive
cardiac muscle is blood pumping to....
Blood pumping to body adjusted by hormones & autonomic (involuntary) nervous system
Interstitial growth: does what?
Division of existing chondrocytes & deposition of increasing amounts of extracellular matrix
myofilaments do not do what?
Do not extend length of myofibril
Factors Affecting Bone Growth and Remodeling.. what are they?
Minerals: large amounts needed, especially calcium and phosphorus • Vitamin A: stimulates osteoblasts • Vitamin C: collagen synthesis • Vitamin D: calcium absorption in the intestines • Vitamins K, B12: synthesis of bone proteins as well as hormones
Leg muscles:
More slow oxidative and fast oxidative-glycolytic fibers
Smooth Muscle, motion?
Motion (usually involuntary), some autorhythmicity to cells of digestive tract
Motor unit: is what?
Motor unit: A somatic motor neuron and all skeletal muscle fibers it stimulates
Muscular Tissue Function, movement???
Movement: through interaction of skeletal muscles, bones, & joints
Microscopic Anatomy of Skeletal Muscle Fiber,,,Multinucleated due to what?
Multinucleated due to fusion of myoblasts during development
Sarcolemma: is what?
Sarcolemma: plasma membrane of muscle fibers (cells)
Initiation of Contraction Cycle... first? Sarcoplasmic reticulum releases....
Sarcoplasmic reticulum releases calcium ions (Ca2+) into sarcoplasm
Neroglia in Peripheral nervous system
Schwann cells • Satellite cells
the endomysium separates what and is mostly what?
Separates individual muscle fibers • Mostly reticular fibers
multipolar neurons... have what?
Several dendrites and one axon • Most abundant type in the central nervous system
Axon -
Single output process
What does the sarcoplasmic reticulum do?
Stores Ca2+ in a resting muscle fiber • Release of Ca2+ triggers muscle contraction
Neuroglia (Glia)... Supportive what? • Do not generate or conduct what???
Supportive functions • Do not generate or conduct nerve impulses
Satellite cells (PNS) surround hat and regulate what?
Surround the cell bodies of neurons in ganglia • Regulate the exchanges of materials between neuronal cell bodies and interstitial fluid
the perimysium is surrounded by what? and is what type of connective tissue?
Surrounds muscle fascicles (bundles of 10 - 100+ muscle fibers) • Dense irregular connective tissue
what is the triad?
Triad: formation of T tubules on either side of terminal cistern
Tropomyosin....does what?
Tropomyosin: in relaxed muscle, blocks myosin from binding to actin
Initiation of Contraction Cycle...third?Troponin moves tropomyosi.....
Troponin moves tropomyosin away from myosin‐binding sites on actin
Troponin: does what
Troponin: holds tropomyosin in place