Bones provide a _____ that supports the body and cradles its soft organs.
The vertebrae surround the spinal cord, and the rib cage helps protect the ____ of the thorax.
Skeletal muscles, which attach to bones by ____, use bones as ____ to move the body and its parts.
Bone is a reservoir for ____, most important ____ and ____. The stored ____ are released into the bloodstream in their ionic form as needed for distribution to all parts of the body,
Mineralized bone matrix stores important ____ factors.
What is hematopoiesis?
Blood cell formation
Where does red cell formation occur within certain bones?
What is stored in bones' cavitvies as a source of energy for the body?
Bones produce ____, hormone that helps to regulate insulin secretions, glucose homeostasis, and energy expenditure.
Osteocalcin is a hormone produced by bones. It helps to regulate ___ secretions, ____ homeostasis, and ____ expenditure.
What are the two types of substances found in bones' matrix?
Minerals and growth factors
Describe the functions of a bone's marrow cavities.
Sites for red cell formation and fat storage
There are ____ named bones in the human skeleton. They are divided into the two groups: ___ and ____.
The axial or appendicular skeleton form the long axis of the body and included the skull, vertebral column, and rib cage.
The ____ skeleton consists of the bones of the upper and lower limbs and the girdles (shoulder and hip bones) that attach the limbs to the ___ skeleton.
Does the axial or the appendicular skeleton help us move from place to place (locomotion) and manipulate our environment?
Bones are classified by their shape as ___, short, ___, or ____.
Long bones are ___-er than they are ___.
They are named for their ____ shape, not their overall size.
A long bone has a ____ plus two ends.
Short bones are roughly ___ shaped.
Examples are ___ and ___.
____ bones are a special type of short bones that form in a tendon.
___ bones are thin, flattened, and usually a bit curved.
____ bones have complicated shapes that fit none of the other classes of bones' profiles.
Ex. ___ and ___
Every bone has a dense outer layer that looks smooth and solid to the naked eye. The external layer is ___ bone and the inner layer is ___ bone.
Other name for spongy bone.
Spongy bone, a honeycomb or small needle-like or flat pieces called ____. In living bones, the open spaces between the ____ are filled with red or yellow bone marrow.
Short, Flat, and irregular bones share a simple design: They all consist of thin plates of __ bone (____) covered by ___ bone.
The compact bone is covered outside and inside by connective tissue membranes, respectively the ___ and ___.
Short, irregular, and flat bones contain bone marrow (between the ____), but no well-defined marrow cavity. Where they form movable joints with their neighbors, ____ cartilage covers their surfaces.
The shaft, or ____, forms the long axis of the bone. It is constructed of a relatively thick ___ of compact bone that surrounded a central ___ cavity. The medullary cavity in adults contain fat called _____.
Yellow bone marrow
The ____ are the bone ends. In many cases, they are broader than the diaphysis.
The epiphyses: the outside consists of compact bone, inside is spongy. A thin layer of articular (____)cartilage covers the joint surface of each epiphysis, cushioning the opposing bone ends during movement and asorbing stress.
Between the diaphysis and each epiphysis of an adult long bone is and ____ Line, a remnant of the ____ plate, a disc of hyaline cartilage.
The epiphyseal line or plate is also called ____.
A glistening white, double-layered membrane called the ____ covers the external surface of the entire bone except the joint surfaces.
The external fibrous layer of the periosteum is ___ connective tissue. The internal ____ layer, next to the bone surface , consists primarily of primitive stem cells, ____, that give rise to all bone cells except bone-destroying cells.
The periosteum is richly supplied with nerve and blood vessels, which pass through the shaft to enter the marrow cavity via a ____.
_____ fibers are tufts of collagen fibers that extend from its fibrous layer into the bone matrix and secure the periosteum to the underlying bone.
The ____ also provides anchoring points for tendons ad ligaments.
A delicate, connective tissue membrane called the ____ covers internal bone surfaces. It covers the trabeculae of spongy bone and lines the canals that pass through the compact bones.
Like the periosteum, the ____ contains ____ cells that can differentiate into other bone cells.
Red marrow, _____ tissue, is typically found within the trabecular cavities of spongy bone and long bones and in the dipole of flat bones.
In newborn infants, the medullary cavity of the diaphysis and all areas of spongy bone contain ___ bone marrow.
The red marrow found in the dipole of flat bones (such as the sternum) and in some irregular bones (hip bones) is more or lessactive in hemopoiesis.
Bone ____ serve as sites of muscle, ligament, and tendon attachment, as joint surfaces, or as conduits for blood vessels and nerves.
Bone markings serve as sites of muscle, ligament, and tendon attachment, as ____ surfaces, or as ____ for blood vessels and nerves.
____-bone markings that bulge outward from the surface.
Bone marking; projections, include ____, ____, ____, and others.
Bone markings; projections, indicate (in most cases) the ___ created by muscles attached to and pulling on them or are modified surfaces where bones meet and form joints.
Bone markings; projections, allow ___ and ___ vessels to pass.
What are the 5 major cells in the bone?
Bone Lining Cells
Osteogenic cells are ____ active stem cells found in the ___ and ____.
In growing bones, they ae flattened or squamous cells.
____ are bone forming cells that secrete the bone matrix.
Unmineralized bone matrix secreted include ____ and calcium-binding proteins that make up the initial unmineralized bone, or ____.
When osteoblasts become completely surrounded by the matrix being secreted, they become ____.
The spidery ____ are mature bone cells that occupy spaces (_____) that conform to their shape.
What bone cell monitors and maintains the bone matrix?
If they die, they are reabsorbed into the matrix.
What bone cell acts as stress or strain sensors and respond to mechanical stimuli. They communicate with osteoblast and osteoclasts(responsible for bone remodeling).
Bone lining cells are ___ cells found on the bone surfaces where bone remodeling is not going on.
Bone lining cells on the external surface are also called ____ cells, and those lining internal surfaces are called ____ cells.
What cells are giant multinucleate cells located at sites of reabsorption?
Osteoclasts, when actively reabsorbing, rest in a shallow depression called a ____ bay and exhibits a distinctive ____ border that directly contacts the bone.
The structural unit of compact bone is called either the ____ or the ____ system.
Each osteon is an elongated cylinder oriented ___ to the long axis of the bone.
Tiny weight-bearing pillars
What are considered tiny weight-bearing pillars in the bone?
Each matrix tube of the osteon is a ____ and for that reason compact bone is often called ____ bone.
Although, all of the collagen fibers in a particular lamella run in a ___ direction, the collagen fibers in adjacent lamella run in ____ directions.
This alternating pattern is beautifully designed to . . .
Withstand torsion stresses- the adjacent lamellae reinforce one another to resist twisting.
Running through the core of each osteon is the ____ canal, Haversian ____, containing small blood vessels and nerve fibers that serve the osteon's cells.
Canals of a second type called ____ canals, lie at right angles to the long axis of the bone and connect the blood and nerve supply of the medullary cavity to the central canals.
Perforating (Volkmann's) canals
Spidery-shaped ____ occupy lacunae at the junctions of the lamellae.
Hairlike canals called ____ connect the lacunae to each other and the central canal.
____ tie all the osteocytes in a mature osteon together, allowing them to communicate and permitting nutrients and wastes to be relayed from one osteon to the next throughout the osteon.
Lying between intact osteons are incomplete lamellae called ____ lamellae.
What lamellae is located just deep to the periosteum and just superficial to the endosteum, extending around the entire circumference of the diaphysis?
The trabeculae in spongy bone align precisely along lines of ___ and help the bone resist ___.
Only a few cells thick, trabeculae contains irregularly arranged ____ and ____ interconnected by canaliculi.
Nutrients reach the osteocytes of spongy bone by diffusing through the ____ from capillaries in the ____ surrounding the trabeculae.
Bone contains organic and inorganic substances.
Organic include ____ and ___.
Inorganic include ___.
Osteoid makes up 1/3 of the bone matrix, includes ground substance (____, ____) and collagen fibers, both of which are secreted by osteoblasts.
Bone's resilience is thought to come from ___ bonds on or between collagen molecules. These bonds stretch and break easily on impact, dissipating energy to prevent the force from rising to a fracture.
The balance of bone tissue (65%) consists of inorganic ____ or mineral salts, largely ____.
The crystals account for the most notable characteristics of bone- its exceptional hardness, which allows it to resist ____.
The hormonal controls of the bone primarily involve ____ (PTH), produced by the ___ gland. To a much lesser extend ___, produced by parafolicular cells (C cells) of the tyroid gland may be involved.
When blood levels of ionic calcium decline, PTH is released. The increased PTH level stimulated ____ to resorb bone, releasing ___ into blood.
When blood levels of ionic calcium rise, PTH is release is stopped. The decrease of PTH levels stimulated ____ to stop resorb bone, causing ___ blood levels to drop.
In humans, calcitonin appears to be a hormone in search of a function because its effects on calcium homeostasis are negligible. When administered at pharmacological (high doses) doses, it ____ lower blood calcium levels temporarily.
___- a hormone released by adipose tissue, plays a role in regulating bone density.
____ is better known as a neurotransmitter that regulates mood and sleep, but most of the body's is made in the gut (intestine).
____ Law holds that a bone grows or remodels in response to the demand placed on it.
A bone is loaded(stressed)whenever weight bears down on it or muscles pull on it. This loading is usually off center and tends to ____ the bone.
As a result of mechanicl stessors, long bones are thickest ___ along the ___, exactly where bending stresses are greater.
Hollow in the middle for ____.
Wolff's law explains handness(being left or right handed) results in the bones of one upper limb being ___ than those of the less-used limb.
What type of activy leads to large increases in bone strength?
Curved bones are thickest where ?
They are most likely to buckle
The trabeculae of spongy bone form ___, or struts, along lines of compression.
Large, bony projects occur where heavy, active ____ attach.
Because compressed and stretched regions are oppositely charged, it has been suggested that electrical signals direct ___.
Fluid flows within the canaliculi also appeat to appear to provide stimuli that directs the ____ process.
Joints are classified by ___ and ____.
Concerning joints, structurally, there are ____, ____, and ____.
The functional classification of joints is based on the amount of ____ allowed by the joint.
Joints, functionally classifying them there is ____, ___, and ____.
In fibrous joints, the bones are joined by ____ of connective tissue. No joint cavity is present. The amount of movement depends on . . .
The length of the connective tissue fibers.
Most fibrous joint are ___ moveable.
Is there a joint cavity present in fibrous joints?
What are the 3 types of fibrous joints?
What fibrous joint occurs between bones of the skull?
It's wavy, articulating bone edges interlock, and the junctions is completely filled by ____ amounts of very short connective tissue fibers that are continuous with the periosteum.
Sutures allow the skull to expand as . . .
The brain grows during birth.
Sutures mature and become Gomphoses?
T or F
False, they become syndesmoses.
Because movement of the cranial bones would damage the brain, the movable nature of ___ is a protective adaptation.
In syndesmoses, the bones are connected only by ___.
The amount of movement depends on the ___ of the connecting fibers.
Where are two places you can find syndesmoses fibrous joints?
Distal ends of the tibia and fibula
Radius and Ulna/ hand area
Where can you find gomphosis fibrous joints?
Teeth, with their bony alveolar sockets
The fibrous connection in gomphoses is the short ____ ligament.
What fibrous joint is described as a peg-like socket?
In cartilaginous joints, there are united by ____.
Cartilaginous joints lack a ____ are ___ moveable.
Name the two types of cartilaginous joints.
A bar or plate of hyaline cartilage unites the bones at a _____, junction of cartilage.
Virtually, all synchondroses are _____ (immovable).
The epiphyseal plate is a common example of what joint?
Epiphyseal plates are temporary joints and eventually become ____.
Another example is the costal cartilage of the first rib and the ____ of the sternum.
Symphysis are joints where ____ united the bones.
Symphysis act as ___ absorber joints and permit a limited amount of movement.
What cartilaginous joint is functional classified as amphiarthrotic?
Intervertebral joints and pubic symphysis of the pelvis are examples of what type of joints?
Synovial joints are those separated by a . . .
Fluid-containing joint cavity
All synovial joints are ____ (freely moveable).
What are 6 features of synovial joints?
Nerves and blood vessels
Synovial joints have articulating cartilage covering the joints. What is it?
In synovial joint, what plays a part in absorbing compression?
Spongy cushions known as articulating cartilage
What occupies free space in the synovial joints?
The joint cavity of synovial joints is enclosed by twolayered articular capsule.
Name them and describe them.
Fibrous layer: Dense irregular connective tissue, continuous with the periostea of the articulating bones. strengthens against pulling apart.
Synovial membrane: Loose connective tissue, covers all internal joint surfaces not hyaline cartilage.
What is the function of the synovial joint's articulating capsule's synovial membrane?
Make synovial fluid and line the inside not hyaline cartilage
Synovial fluid is derived largely by _____ from ___ flowing through the ____in the synovial membrane.
Synovial fluid, found in articular cartilage, provides a slippery, weight-bearing film that reduces friction between cartilage.
Without this, what would happen to the joint?
The synovial fluid is forced from the cartilages when a joint is compressed; then as pressure on the joint is relieved, the fluid seeps back into the articular cartilages like water into a sponge, ready to be squeezed out again the next time the joint is loaded (pressure).
Name the process.
What process lubricates the free surfaces of the cartilages and nourishes their cells?
Synovial called contain ___- cells that rid the cavity of microbes and cellular debris.
Synovial joints are reinforced and strengthen by a number of band-like _____. Most often, these are ____, which are thickened parts of the ____ layer.
In other cases, they remain distinct and are deep outside the capsule (_____)or deep to it(____).
Since intracapsular ligaments are covered with the synovial membrane, they do not lie within the joint cavity.
Synovial are not very innervated and blood rich.
T or F
False, they are heavily innervated and supplied with blood
Concerning synovial joints, some, such as the hip and knee, have cushioning ___ pads between the fibrous layer and the synovial membrane or bone.
Where present, these ____ discs, or ___, extend inward from the articular capsule and partially or completely divide the synovial cavity into two.
Articulating discs occur in the knee, ___, and a few other joints.
Bursae and tendon sheaths are part of the synovial joint.
T or F
False, they are just associated
What is the purpose of bursae and tendon sheaths?
Reduce friction between adjacent structures during joint activity.
Basically lube bags
What are described as flattened fibrous sacs lined with synovial membrane and containing a thin film of synovial fluid?
What is described as an elongated bursa that wraps around a tendon subject to friction?
Common where several tendons are crowded within a narrow canals
Concerning synovial movement,
Attached to immovable
Attached to the movable bone
Range of motion allowed by synovial joints varies from . . .
Name and describe them.
Nonaxial Movement: slipping movement
Uniaxial: Movement in one plane
Multiaxial: Movement in 3 more more planes
What are the 3 general types of movements for synovial joints?
Describe Gliding movements
When a flat and flat bones' surface glide or slip over another.
Examples of gliding movement joints.
Intercarpal and intertarsal
Flat articular processes of the vertebrae
What are the 6 angular movements?
What movement is described a bending movement, usually along the sagittal plane, the decreases the angle of the joint bringing articulating bones closer?
What two movements move along the sagittal place?
The arm flexed at the shoulder when the arm is lifted in an anterior direction is what type of movement?
What movements move only the frontal plane?
What movement is described as the turning of a bone around its own axis?
What is the only movement allowed between the first two cervical vertebrae
Also, common at the hip and shoulder joints.
Rotation mat be directed toward or away from the ___.
Describe the following movements:
Nonangular anterior and posterior movement along the transverse plane. ie. jaw forward or back
Lifting or dropping ie. should shrugging or drop jaw
Saddle joint between metacarpal 1 and the trapezium ie. touch finger tips
What are the types of synovial structural types?
Ball and socket
Plane joints are ___-axial movement
Ball and Socket . . .
Plane joints allow ___ movement
Hinge joints allow ___ movement
Pivot joints allow ___ movement
Condylar and Saddle joints allow ___, ____, ____, and ____movements
Ball and socket is FREE!!!
Intercarpal, intertarsal joints and joints between vertebral articular surfaces are examples of ___ joints. (structural)
Elbow and interphalangeal joints are ___ joint (structurally)
Proximal radioulnar joints and atlantoaxial joint are examples of ___ joints. (structurally)
Metacarpophalangeal (knuckle) joints and wrist joints are examples of ___ joints (structurally).
Carpometacarpal joints of the thumbs are examples of ____ joints. (structurally)
Muscle type: Elongated, striations, voluntary
Muscle type: Elongated , striated, unvoluntary
Muscle type: Walls of hollow visceral organs, nonstriated, unvoluntary
The region of a myofibril between two successive Z discs is a ____.
What is known as the smallest contractile unit of a muscle fiber- the functional unit of skeletal muscle?
Sarcomeres contain an __ band flanked by half an __ band at each end.
Shortening occurs if and when the ___ generate enough tension on the thin filament to exceed the forces that oppose shortening.
Contraction ends when the cross bridges become ___.
The ____ states that during contraction, the thin filaments slide past thick ones so that the actin and myosin filaments overlap to a greater degree.
Neither the thick nor the thin filaments change ____ during contraction.
Sliding Filament model of Contraction
The Sliding Model of Contraction:
1. Nervous system stimulates muscle fibers, the ___ heads on the thick filaments latch onto the ___-binding sites on ___ in the thin filaments, and the sliding begins.
The Sliding Model of Contraction:
2: These cross-bridge attachments form and break several times during contraction, acting like tiny ratchets to generate ____ and propel the thin filaments toward the ___ of the ___.
The Sliding Model of Contraction:
3: Thin filaments slide ____, the z discs to which they attach are pulled towards the __ line.
The Sliding Model of Contraction:
Overall, as the muscle shortens . . .
The I band shortens
Distance between Zs shorten
H zones disappear
Contiguous A bands move close together, length does not change
Skeletal Muscle fiber to contract:
1: Fiber stimulated
2: Generation of ____ in its sarcolemma
3: ____ automatically propagated along the sarcolemma
4: Intracellular ___ ions levels must rise briefly, providing the final trigger for contraction.
Nervous system stimulation of muscle fiber and generation of action potential occur at the _____ junction and set events in motion.
Nerve cells that activate skeletal muscle fibers are called _____.
Somatic motor neurons
Each axon gives off several short, curling branches that collectively form an elliptical _____ junction, or motor end plate, with a single muscle fiber.
Each muscle fiber has only one neuromuscular junction, located approx. ___ along its length.
The end of the axon, the axon terminal, and the muscle fiber are exceedingly close, but remain separated by a space, the ____.
The synaptic cleft is filled with a gel-like extracellular substance rich with ____ and ___ fibers.
Within the moundlike axon terminal are ____, small membranous sacs containing the neurotransmitter ____(ACH)
The trough-like part o the muscle fiber's sarcolemma that helps form the neuromuscular junction is highly folded (____ folds); provide large surface area for millions of ACH receptors.
ACH diffuses into the ACH receptors causes the ____.
After ACH binds to its receptors, its effect is quickly terminated by _____, located in the synaptic cleft.
What enzyme in the synaptic cleft prevents continued muscle fiber contraction in the absence of additional nervous system stimulation?
Resting membrane of sarcolemma is ___.
3 steps for action potential in sarcolemma.
Generation of an end plate potential
1: Binding of ACH to receptors.
2: Opens ______ gated ion channels allowing Na+ and K+ to pass.
3: Inner becomes negative because Na+ has a higher driving force.
4: Start of ______.
5: Prior ignited an action potential, spreads around, opens ___-gated Na+ channels. Needs to reach ____ to start action potential
6: AP propagates in ___ directions from the neuromuscular junction.
7: Reaches peak of neg. charge, ____ starts.
8: Na+ channels ___, voltage-gated ___ channels open.
Depolarization/ end plate potenial
During repolarization, potassium ions concentration is substantially higher inside the cell than in the extracellular fluid, K+ diffuses rapidly out of the muscle, restoring ____ charge conditions.
During repolarization, a muscle fiber is said to be in ____ period, cannot be stimulated.
The ___________ pump restores thr ionic conditions of the resting membrane.
Initiating Muscle Contraction:
1: Impulse via axon opens ___-gated calcium channels in the axonal membrane. Calcium triggers release of ____ into synaptic cleft.
2: ACH bind with reprtors opening chemically gated ______ channels. Greater influx of ____ causes a local voltage change (endplate potential)
3: Generation and propagating an AP.
4: AP along the _ tubules changes the shape of voltage sensitive proteins in the tubules, which in turn stimulate ___ calcium release channels to release calcium into the ____.
When intercellular calcium levels are ___, the muscle cell is relaxed, and ____ molecules physically block the active (myoin0binding)sites on troponin.
When nerve impulses arrive in quick seccussion, intracellular ___ levels soar due to successive puffs of rounds of Ca+ released from the SA.
As the Ca+ pumps of the SA reclaims calcium ions from the ___ and ___ again changes shape, tropomyosin again blocks actin's myosin-binding sites. The contraction ends.
Cross bridge formation requires ___.
The force of muscle contraction depends on the number of ___ cross bridges that are attached to ___.
More motor units,
More or less force?
The bulkier the muscle and the greater the cross-sectional area, the more ___ it can develop.
The large fibers of large motor units produce the most ____ movements.
__________ excercise increases muscle force by causing muscles to hypertrophy.(incease)
More frequency of contraction, more ____
Describe the ideal length-tension relationship.
When the muscle is slightly stretched and permits sliding along nearly the entire length of the thin filaments. If the muscle is stretched so much that the filaments do not overlap, the myosin heads have nothing to attach to and cannot generate tension
On muscle velocity, there are slow and fast fibers
Reflects how fast their myosin ____ split ___, and the pattern of electrical activity of thier motor neurons.
Contraction duraction also varies with fiver types and depends on how quickly ___ moves from the cytosol into the SR.
Oxidative fibers use aerobic pathways for ATP generation
Glycolytic fibers more ____ pathways and _____.
Factors that affect force of muscle
Number of muscle fibers recruited
Size of muscle fibers
Frequency of stimulation
Degree of muscle stretch
Fast and slow fibers are _____ fibers
Slow oxidative fibers resist ___, high endurance, little power, many ____, rich ___ supply, and abundant supply of myoglobin
Fast glycolytic fiber: contracts ____. little use of ___, glycogen reserves, tire quick, contract ____, few ____, little myoglobin,
The morse stress on a muscle to the longer ___ period.