Anatomy and Physiology Exam 3

Bone

a type of connective tissue

Bone cell type 1: Osteoblasts

bone building cells - has an abundance of endoplasmic reticulum and ribosomes - function is to produce collagen and proteoglycans . secrete matrix vesicles which contain high concentration of calcium ions and phosphates that can be used to form hydroxyapatite - ossification (formation of new bone by osteoblasts) occurs by appositional growth on the surface of previously existing material, either bone or cartilage

Synaptic vesicles

are small, spherical sacs that carry neurotransmitters

Fibrous Joint

are the connections between 2 bones that are held together by fibrous connective tissue - have no joint cavity and exhibit little or no movement (amphiarthroses and synarthroses) - can be divided into 3 subdivisions: sutures exhibit little or no movement, syndesmoses exhibit little movement, and gomphoses exhibit little movement

Circumferential lamellae

are thin plates that extend around the bone and form the outer surfaces of compact bones - bone of the face is composed of compact bone so thin that no osteons exist with the compact being composed of only circumferential lamellae - interstitial lamellae are between the osteons and are remnants of concentric or circumferential lamellae that were partially removed during bone remodeling

T tubules

are tubelike folds of the sarcolemma that extend into the inside of the muscle fiber - carries electrical impulses into the center of the muscle fiber so that the muscle fiber contracts together

Synaptic cleft

is the space between the presynaptic terminal and the muscle fiber

Rotation (circular movement)

is the turning of a structure around its long axis

Bone remodeling

is when old bone is replaced with new bone - process: osteoclasts removes old bone and osteblasts aids in the replacing of old by deposit of new bone - converts woven bone into lamellar bone and is involved in several important function: bone growth, changes in bone shape, adjustment of the bone to stress, bone repair, and calcium ion regulation in the body

Synarthroses

non-movable joints (some fibrous and cartilaginous joints have no movement)

Skeletal system function 4: mineral storage

some minerals in the blood are stored in bone. minerals are released from the bones into the blood if blood levels of these minerals decrease. - 2 main minerals stored in bones are calcium and phosphorous. - adipose tissue is stored within bone cavities

Motor Neuron

specialized nerve cells responsible for stimulating skeletal muscle contraction - Originate in the brain and spinal cord and extend to skeletal musclefibers through the nerves

Sarcoplasmic reticulum

specialized variant of smooth endoplasmic reticulum found in the skeletal muscle fibers that stores high levels of calcium ions - its function is to release calcium ions to induce a muscle contraction

Red marrow

is the site of blood cell formation

structure of synovial joint

- articular disk helps adjust the connection between articulating bones, which helps with joint stability and reduces wear on the articular cartilage - joint cavity is the space around the articular surface of the bones in a synovial joint - joint capsule surrounds a joint cavity and is filled with synovial fluid. helps hold the bones together while still allowing for movement

Bone fracture and repair steps

1. hematoma formation 2. callus formation 3. callus ossification 4. bone remodeling

7 types of muscular functions

1. movement of body 2. maintenance of posture 3. respiration 4. production of body heat 5. communication 6. constriction of organs and vessels 7. contraction of the heart

Steps of the Neuromuscular junction

1. send an action potential to open voltage-gated Ca ion channel 2. Ca ions cause vesicles to migrate & fuse to the plasma membrane of the presynaptic terminal 3. release the acteylcholine from the synaptic vesicles 4. acetylcholine diffuse to & bind ligand-gated Na channels to open them 5. Na enters the muscle fiber causing them to depolarize & produce an action potential 6. close ligand-gated Na channels by removing acetylcholine from the channel 7. break down acetylcholine for future us-

Endomysium

A delicate layer of connective tissue that separates the muscle fibers within each fascicle - function: serves as a passageway for the blood vessels and nerves thatsupply each muscle fiber

Skeletal muscle component 4

Adipose

Production of ATP in skeletal muscle fibers 4

Aerobic production of ATP during more exercise and normal conditions

Production of ATP in skeletal muscle fibers 3

Anaerobic production of ATP during intensive short-term exercise

Skeletal muscle component 3

Connective tissue; has 3 layers

Production of ATP in skeletal muscle fibers 1

Conversion of 2 ADP to 1 APT then covering1ATP to 1AMP by the enzyme adenylate kinase

Muscle contraction for muscle fiber aspect 1

Electrical component; there are 3 muscle fiber components that respond to and transmit electrical signals

Epimysium

Forms a sheath made of dense irregular connective tissue around the skeletal muscle - merge with muscular fascia - function: outer layer of that separates the muscle from the surroundingtissue and organs

Lag

Is the gap between the time of stimulus application to the motor neurons and the beginning of a contraction - Is the time during which the action potential is traveling along the axon to the sarcolemma

Muscle contraction for muscle fiber aspect 2

Mechanical component; there are 2 muscle fiber components that contribute to contractility

Rapidly growing bones width

Osteoblasts from the periosteum lay down bone under the periosteum, which gradually increases the amount of bone surrounding the medullary cavity and the overall thickness of the bone - the layers increase in width as the osteoblast continue to produce bone

2 types of flexion: Plantar flexion and dorsiflexion

Plantar flexion- movement of the foot toward the plantar surface Dorsiflexion- movement of the foot toward the shin

Various results for multiple-motor unit recruitment depending on the strength of the stimulus; either be subthreshold or threshold stimulus

Subthreshold stimulus- is not strong enough to cause an action potential in any of the axons in a nerve and does not cause a contraction Threshold stimulus- is strong enough to produce an action potential in a single motor unit axon contributing to all the muscle fibers of the motor unit to contract

Production of ATP in skeletal muscle fibers 2

Transfer of a phosphate from a molecule of creatine phosphate by the enzyme creatine kinase from ADP to ATP

2 types of extension: abduction and adduction

abduction- is movement away from the midline adduction- is movement toward the midline

Neurotransmitter of interest in the neuromuscular junction

acetylcholine

Myofilaments

actin and myosin provide the mechanical aspect of the muscle contraction

Acidosis and ATP depletion

anaerobic respiration results in the breakdown of glucose to lactate and protein accounting for lowered pH

Bone cell type 3: osteoclast

bone destroying cells - breakdown of bone is called bone reabsorption and this breakdown of bone is important for mobilizing crucial calcium ions and phosphates for use in many metabolic processes. broken down bone liberates calcium which goes back into the blood - are massive multiple nuclei cells whose differentiation follows a complex pathway - are derived from the red bone marrow cells that also differentiate into monocytes

Skeletal system function 2: organ protection

bones are hard and surrounds the organs to protect them

Skeletal system has 4 components

bones, cartilage, tendons, and ligaments

Cardiac muscle tissue

branched, cylindrical cells connected via intercalated discs - single centrally located nucleus - has striations - involuntary control and can contract spontaneously - moves blood throughout vessels - located in the heart

Calcium homeostasis

calcium is an important physiological regulator of many processes required to achieve and maintain homeostasis: stimulation of skeletal muscle contraction, stimulation and regulation of cardiac muscle contraction, exocytosis of cellular molecules, and important for neural signaling

Articular cartilage

can be found within joints and covers the end of long bones with hyaline cartilage

Muscle contractions

causes an increased pressure inside of vessels and hollow organs - contributes to the shortening of muscles to generate force and lengthening of the muscle to cause passive 'activity'

Cartilage growth type 1: Appositional Growth

chondroblast in the perichondrium add new cartilage to the outside edge of the existing cartilage

Cartilage growth type 2: Interstitial growth

chondrocytes in the center of the tissue divide and add more matrix in between the existing cells

Joints

commonly named according to the bones or portions of bones that join - classified structurally which is based on the major connective tissue type that bind the bones together and whether a fluid-filled joint capsule is present.

Ball-and-socket joint

consist of a ball at the end of one bone and a socket in an adjacent bone in which a portion of the ball fits - multiaxial and free rotation

Hinge joint

consist of a convex cylinder in one bone is applied to a corresponding concavity in the other bone - uniaxial

Pivot joint

consist of a relatively cylindrical bony process that rotates within a ring composed partly of bone and partly of ligament - uniaxial and restricted rotation

Motor unit

consist of a single motor neuron and all the muscle fibers it innervates - an action potential in the neuron of a motor unit causes a contraction of all the muscle fibers in that motor unit

Symphyses

consist of fibrocartilage and exhibit little or no movement

Synchondroses

consist of hyaline cartilage and exhibit little or no movement

Connective tissue

consist of matrix (which has spread out cells separated by a nonliving material) - bone cells produce the bone matrix and become entrapped within it - these cells break down old matrix so the new matrix can replace it - bone marrow composition is responsible for the characteristic of bone

Mature bone matrix material 1: 35% organic

consist primarily of collagen and proteoglycans - collagen and mineral components are responsible for the major functional characteristics of bone - collagen fibers lend flexible strength to the matrix. becomes the primary constituent, and the bone becomes overly flexible if mineral in a long bone is reduced. - mineral components give the matrix weight-bearing strength. become primary constituent and the bone is very brittle if the amount of collagen is reduced in the bone

Mature bone material 2: 65% inorganic

consist primarily of hydroxyapatite (consists primarily of calcium and phosphate)

Plane joint

consists of 2 flat bone surfaces of about equal size between which a slight gliding motion can occur - uniaxial as some rotation is possible but is limited by the presence of ligaments and adjacent bones

Saddle joint

consists of 2 saddle shaped articulating surfaces oriented at right angles to each other so that their complementary surface articulate - biaxial

Spongy bone

consists of trabeculae (interconnecting rods or plates of bone) - the space between the trabeculae is filled with bone marrow and blood vessels - are thin and consist of several lamellae with osteocytes located in lacunae between the lamellae - the surface is covered with a single layer of cells consisting mostly of osteoblasts with a few osteoclasts - function: are oriented along the lines of mechanical stress within a bone with the patterns realigning with the new lines of stress if the force on a bone is changed slightly

Flat bones

contain an interior framework of spongy bone sandwiched between two layers of compact bone

Synovial Joint

contain synovial fluid and allow considerable movement between articulating bones

Perichondrium

covers most cartilage - is a protective connective tissue sheath - consist of a double-layered outer layer of dense irregular connective tissue containing fibroblasts - outer layer is penetrated by blood vessels and nerves - nutrients must diffuse through the cartilage matrix to reach chondrocytes because blood vessels and nerves do not enter the cartilage matrix - consist of an inner, more delicate layer which has fewer fibers and contains chondroblasts

Lowered pH due to anaerobic respiration 2

decrease in calcium ion release from the sarcoplasmic reticulum

Perforating canals

delivers blood to the central canals of the osteons - run perpendicular to the central canals of the osteons - they contain blood vessels from the periosteum or medullary cavity that delivers nutrients in the blood vessels to the osteocytes

Long bones consist of

diaphysis, epiphyses, articular cartilage, and epiphyseal plate

Elevation and depression (special movement)

elevation- moves a structure superiorly depression- moves a structure inferiorly

joints

formed when two or more bones come together

Ossification

forms two types of bone (formation of new bone by osteoblasts) - woven and lamellar

Diarthroses

freely movable joints (synovial joints have considerable movement)

Hormones

growth hormone (GH) from the anterior pituitary increases general tissue and bone growth by stimulating interstitial cartilage and appositional bone growth - disruptions in normal growth hormones can cause dramatic changes in an individual's height

Hyaline cartilage

has the strongest association with bones - most bones start out as a hyaline cartilage - growth in one length and bone repair often involve making hyaline cartilage before being replaced with bone - matrix firm and flexible. made of cartilage and chondrocytes functions as - growth in long bones. rigid and flexibility support in trachea, bronchi, ribs, and nose. strong, smooth, and flexible articulations in embryonic skeleton. - located in long bones, respiratory, cartilage rings, etc...

Short and irregular bones

have a composition like the epiphyses of long bones which consist of compact bone surfaces surrounding a spongy bone center with small spaces that are usually filled with marrow

Cartilaginous Joint

hold 2 bones together by a pad of cartilage - they have no joint cavity and exhibit little or no movement (amphiarthroses and synarthroses) - can be divided into synchondroses and symphyses

Inversion and eversion (special movement)

inversion- turns the ankle so that the plantar surface of the foot faces medially; toward the opposite foot, with the weight on the outside edge of the foot (rolling out) eversion- turns the ankle so that the plantar surface faces laterally, with the weight on the inside edge of the foot (rolling in )

Cardiac muscle tissue

involuntary muscular movement - found only in the heart - contributions: delivers blood to the rest of the body via the circulatory system

Smooth muscle tissue

involuntary muscular movement - location: walls of hollow organs, blood vessels, and ducts of glands

Circumduction (circular movement)

is a combination of flexion, extension, abduction, and adduction that occurs at freely movable joints

pituitary gigantism

is a condition that manifests due to excessive growth hormone secretions

Pituitary dwarfism

is a condition that manifests due to insufficient growth hormone secretions

Periosteum

is a connective tissue membrane covering the outer surface of a bone - outer fibrous layer consists of dense irregular collagenous tissue that contains blood vessels and nerves

Hematoma formation

is a localized mass of blood released from blood vessels but confined within an organ or space - forms when the blood vessels in the bone and surrounding periosteum are damaged with the hematoma forms a clot

Callus formation

is a mass of bone tissue that forms at a fracture site and there are 2 types: - external callus encircles the break and connects the broken ends of the bone - internal callus forms between the ends of the broken bones and fractures that occurs in the diaphysis of a long bone

Muscular contraction

is a mechanical event and is measured in force/tension; unlike action potential which is an electrochemical event measured in mV

Ellipsoid joint

is a modified ball-and-socket joint, consisting of an articular surface that is ellipsoid (oval) in shape - biaxial and restricted movement

Endosteum

is a single later of connective tissue that lines the internal surface of all cavities within bone and consist of osteoblasts, osteoclasts, and osteochondral progenitor cells

Calcium homeostasis regulator 2: calcitriol

is a steroid hormone derived from Vitamin D3 - increases blood calcium ion levels. is stimulated by PTH in the kidney and contributes to PTH-induced increases in blood calcium ion levels - stimulate RANKL produced by osteoblasts - works with PTH to increase osteoclast activity for bone reabsorption and assist the kidney tubules by preventing calcium ion removal through urine

Flexion (angular movement)

is an opposing movement that consist of a bending movement that decreases the angle of the joint to bring the articulating bones closer together

Extension (angular movement)

is an opposing movement that consist of a straightening movement that increases the angle of the joint to straighten the articulating bones

Epiphyseal plate

is located between the epiphysis and diaphysis - ossifies and becomes the epiphyseal lines when the bone stops growing -- the site of lone bone growth

Yellow marrow

is mostly adipose tissue

Calcium homeostasis regulator 1: parathyroid hormone

is secreted by cells in the parathyroid gland and is essential for the maintenance of blood calcium ion levels within the homeostatic limits - production and secretion are controlled by calcium ion sensing receptors in the parathyroid gland - is triggered by the reduction in blood calcium levels and increases blood calcium ion levels by exerting direct regulatory control of osteoblasts and osteocytes to increase formation and activation of osteoclasts

Calcium homeostasis regulator 3: calcitonin

is secreted from C cells in the thyroid gland when blood calcium level is too high. - lowers blood calcium ion levels by inhibiting osteoclast activity

Presynaptic terminal

is the axon terminal or where the nervous cell ends

Diaphysis

is the center portion of the bone that is composed primarily of compact bone and surrounds a hollow center called the medullary cavity - some spongy bone cane be found lining the medullary cavity

Resting membrane potential

is the charge difference across the plasma membrane of a cell - can be measured in units called millivolts (mV) - the resting membrane potential across a neuron and muscle fiber is between -70mV to -90mV

Epiphyses

is the end of along bone and consisting mostly of spongy bone with its outer layer consisting of compact bone

Lamellar bone

is the mature bone - organized into lamellae (thin, concentric sheets or layers approximately 3-7 micrometers thick) - the collagen fibers of one lamellae lie parallel to one another, but at an angle to the collagen fibers in the adjacent lamellae - osteocytes found within their lacunar are arranged in layers sandwiched between lamellae

Motor endplate

is the muscle plasma membrane in the junction

Neuromuscular junction

is the point of contact where the motor neuron axon branches with the muscle fiber

Myogram

is the recording of a single isolated muscle twitch - there are 3 phases of a myogram

Contraction

is the release of calcium ion from sarcoplasmic reticulum and initiating a cross-bridge cycle

Muscle twitch

is the response of a muscle fiber to a single action potential along its motor neuron

Skeletal muscle fibers produce ATP through 4 processes

listed below...

Perimysium

loose connective tissue that subdivides the fascicles - function: serves as a passageway for the blood vessels and nerves thatsupply each fascicle

Skeletal system function 5: blood cell production

many bones contain cavities filled with red bone marrow, which gives rise to blood cells and platelets

Skeletal muscle tissue

most abundant type of muscle tissue - voluntary muscle movement (nervous system contributes to the voluntary movement of the skeletal muscle) - makes up 40% of body's weight - contributions: locomotion, facial expression, posture, respiratory functions, speech, etc...

Motor unit number

motor units in different muscles contain a different number of muscle fibers - delicate and precise movement performed by muscles have many, small motor units and a small number of muscle fibers (eye movement) - powerful and less precise movement performed by muscles have fewer, large motor units and many muscle fibers (thigh muscles)

Vitamin C

necessary for osteoblasts to synthesize collagen - deficiencies results in bones and cartilage with fewer collagen fibers because collagen synthesis is impaired and can contribute to shunted growth in children - scurvy is a disease caused by vitamin c deficiency resulting in ulceration and hemorrhaging

Vitamin D

necessary for the normal absorption of calcium from the intestine - can be synthesized and ingested by the body (synthesis increases when the skin is exposed to sunlight) - rickets is a disease that occurs in childhood when Vitamin D is insufficient resulting in reduced mineralization of the bone matrix contributing to bowed bones and inflamed joints

Skeletal muscle component 2

nervous tissue

Bone development

no matter the type of bone formation, bone is first formed into woven bone and then is remodeled into lamellar bone

Gliding movements

occurs in plane joints between 2 flat or nearly surfaces that slide or glide over each other - allows slight movement

Action membrane potential

occurs when an excitable cell is stimulated (by an electrical charge) - action potentials have 2 phases: depolarization and repolarization

Voltage-gated ion channels

open and close in response to a specific membrane potential (this door is regulated by an electrical charge) (opening voltage-gated Na channel using an action potential (electrical stimulus) allows Na to cross the plasma membrane)

Ligand-gated ion channels

open when a specific ligand (key) binds to a receptor (door) of the ion channel (Acetylcholine binds to ligand-gated Na channel so Na can enter the motor-end plate)

Bone cell type 2: Osteocytes

osteoblast become osteocytes once the osteoblasts have secreted sufficient bone matrix - osteoblast account for 90-95% of bone cells and are very long-lived, with a life span of up to 25yrs. - osteocytes are connected to neighboring osteocytes through their cell extensions - osteocytes become relatively inactive, compared with most osteoblasts, but it is possible for them to produce the components needed to maintain the bone matrix

cont...

osteoclast ad osteoblast activity determine calcium ion levels available in the blood for these physiology activities - cells can either: release calcium ions from bone to increase blood calcium ion levels. significant increase in blood calcium ion levels can stop the activity of osteoclast - or add calcium ions to the bone to decrease blood calcium ion levels. significant decreases in blood calcium ion levels can stimulate the activity of osteoclast

Synovial joint classified according to shape of adjoining articular surfaces

plane, saddle, hinge, pivot, ball-and-socket, and ellipsoid joint

Compact bone

solid, outer layer surrounding each bone - consisting of more matrix and is denser with fewer pore than spongy bone - blood vessels enter the substance of the bone with the lamellae of compact bone being primarily oriented around those blood vessels - consist of the following terms:

Pronation and supination (circular movement, unique rotation of forearm)

pronation- is rotation of the forearm so that the palm faces posteriorly in relation to the anatomical position supination- is rotation of the forearm so that the palm faces anteriorly in relation to the anatomical position

Cavities of spongy bone and the medullary are filled with two types of marrow

red and yellow marrow

Repolarization

reversing the positive membrane potential by making the charge of the cell more negative until the cell's resting membrane potential is reached

Skeletal system function 1: body support

rigid strong bones are well suited for bearing weight and is the major supporting tissue of the body - cartilage provides a firm and flexible support within certain structures - ligaments holds bones together

Myofibrils

shorten the muscle fiber to induce a contraction

Myoblast

skeletal muscle fibers are developed by the fusion of myoblasts

Skeletal muscle component 1

skeletal muscle tissue

Skeletal system function 3: body movement

skeletal muscles attach to bones by tendons. The muscles contract to move the bones and produce bodily movement. - joints allow movement between bones. some joints are covered at the ends of bones with smooth cartilage allowing the bones to move freely - ligaments allow some movement between bones but prevent excessive movements

Amphiarthroses

slightly movable joints (some fibrous and cartilaginous joints have little movement)

Smooth muscle tissue

spindle cells consisting of gap junctions - single centrally located nucleus - no striations - involuntary control and can contract spontaneously - regulates the size of organs, force fluid through tubes, dilute and constrict the pupil, and regulates the rise and fall of the hair follicle - located in hollow organs, skin, and eyes

Bone formation in fetus 2: Endochondral ossification

starts with a cartilage model - located in skull bones, mandible, the epiphysis of the clavicles, and most of the skeletal system - start is in the 8th week of development and ends in adulthood (18-20yrs of age) -there are 3 steps: cartilage model formation, bone collar formation, primary ossification center formation (forms as osteoblasts produce bone on the surface of the calcified cartilage with the osteoblasts transforming the calcified cartilage of the diaphysis into spongy bone), and secondary ossification center formation (creates in the epiphyses by osteoblasts that migrate into the epiphyses)

Bone formation in fetus 1: Intramembranous ossification

starts with embryonic connective tissue membranes. - centers of ossification is the location of the membrane where intramembranous ossification begins, and it expands to form a bone by gradually ossifying the membrane - fontanels is a soft spot and is larger membrane-covered spaces between the developing skull bones that have not yet been ossified. will eventually grow together by 2 years of age. - located in skull bones, mandible, and the diaphysis of the clavicles duration: start is in week 5 of embryonic development and ends at 2 years of age. - there are 3 steps: osteoblast formatino, spongy bone formation, and compact bone formation

tendons

strong bands of connective tissue

ligaments

strong bands of fibrous connective tissue

Contractility

the ability of the muscle to shorten forcefully or conract

Relaxation

the decrease in calcium ion concentration in the sarcoplasm due to the active transport of calcium ion into the sarcoplasmic reticulum

Growth in bone width

the epiphyseal plate's is organized into 5 zones during long bone growth. - long bones increase in width and other bones increase in size or thickness because of appositional bone growth beneath the periosteum with simultaneous bone reabsorption occurring underneath the endosteum

Woven bone

the first type of bone that osteoblasts form during ossification - weak bone consisting of the collagen fibers randomly oriented in many directions - osteoclasts breakdown the woven bone and osteoblast build the stronger, more permanent lamellar bone after woven bone formation

Fast-twitch muscle fibers (type 2)

the form of myosin in fast-twitch muscle fibers causes the muscle fibers to contract more quickly and to fatigue quickly - muscle fibers will appear a dark red color - muscle fibers have a well-developed blood supply and a large amount of myoglobin

Slow-twitch muscle fibers (type 1)

the form of myosin in slow-twitch fibers causes the muscle fibers to contract more slowly and to be more resistant to fatigue - muscle fibers will appear white in color - muscle fibers have a poor blood supply and very little myoglobin

Osteon

the functional unit of compact bone and is composed of concentric rings of matrix which surrounds a central tunnel, with the osteocytes sandwiched between the rings of the matrix - osteocytes are in the lucunae between the lamellar rings - canaliculi radiate between lucunae across the lamellae and looks like minute cracks across the rings of the target - resembles a circular target with the bull's eye of the target being the the central canal - concentric lamellae are rings that surrounds the central canal - endosteum lines central canal and contain blood vessels, nerves, and loose connective tissue. vessels run parallel to the long axis of the bone are contained within the central canals

Recruitment

the nervous system regulates muscle force by increasing the number of contraction motor units - an increase in the number of motor units contracting means many muscle fibers are contracting

Sarcolemma

the plasma membrane of the muscle fiber - transmits an electrical impulse to the inside of the muscle fiber

Slowly growing bones width

the surface of the bone become smooth as osteoblast from the periosteum lay down even layers of bone to form circumferential lamellae

Lowered pH due to anaerobic respiration 1

weakening cross-bridge formation by interfering with calcium ion binding to troponin

Depolarization

when cell stimulation causes the inside of the plasma membrane to become more positive - triggering an action potential is an all-or-nothing phenomenon