A&P Exam 3

What are the components of long bones? (10)

proximal epiphysis, diaphysis, distal epiphysis, articular cartilage, epiphyseal line, spongy bone, medullary cavity, compact bone, yellow marrow, periosteum

What are the components of bone structure? (11)

perforating canal, periosteum, osteon, central canal, lamellae, osteocyte, canaliculus, lacuna, trabecula, spongy bone, compact bone

What are the components of the skeletal system?

bones, cartilage, tendons, ligaments

what are the functions of the skeletal system?

support, protection, movement, storage, blood cell production

What are the types of cartilage?

hyaline, fibro-, elastic

Chondroblasts produce _______ around them.

cartilage matrices

What are chondrocytes?

mature chondroblasts that are surrounded by matrices and stuck

What is the perichondrium?

the double-layered connective tissue sheath that covers most cartilage

Articular cartilage _________ where they ________.

ends of bones; come together to form joints

What is bone?

dense, hard connective tissue made of cells, collagen and hydroxyapatite

What is ossification?

the formation of bone by osteoblasts

What are osteoblasts?

bone forming cells that have extensive endoplasmic reticulum and numerous ribosomes to produce and secrete bone matrix

What are osteocytes?

mature osteoblasts that become surrounded by bone matrix and stuck

What are osteoclasts responsible for?

reabsorption, or breakdown of bone

What is the structure of spongy bone and what does it make up?

porous, less dense, consists of interconnecting rods or plates called trabeculae; forms the epiphyses

What is the structure of compact bone and what does it make up?

hard, denser with fewer spaces; forms diaphysis

Long bones are _____________________ and are located in __________________.

longer than they are wide; upper and lower limbs

Short bones are ________________________ and are located in _______________.

round or nearly cube-shaped; wrists and ankles

Flat bones are ____________________________ and make up ______________________________________.

relatively thin, usually curved; skull components, ribs, and shoulder blades

Irregular bones are __________________________________________________; for example, _________.

in shapes that do not fit readily into the other 3 categories; vertebrae

What is red marrow?

the site of blood formation

What is hematopoiesis?

the differentiation of stem cells into mature blood cells

Yellow marrow contains ___________________.

mostly adipose tissue

What is the periosteum?

the connective tissue membrane that covers the outer surface of bones

What is the endosteum?

a single layer of cells that line the internal surfaces of all cavities within bones

What are sinuses?

air-filled spaces in some of the flat and irregular bones of the skull

Intramembranous ossification takes places in _________________________ and produces _______________.

connective tissue membranes; woven, flat bones

What is the primary ossification center?

the middle location in cartilaginous fetal long bones where ossification begins

What is the secondary ossification center?

the epiphyseal location in cartilaginous fetal bones where ossification continues until young adulthood

The zone of resting cartilage is _____________________ and contains ____________________________ that __________________.

nearest to the epiphyses; randomly arranged chondrocytes; do not divide rapidly

The zone of proliferating cartilage is where __________________________ arranged like _____________ undergo __________________ as they divide and secrete ____________________.

slightly larger chondrocytes; stacks of coins; interstitial growth; extracellular matrix

The zone of hypertrophic cartilage is where _________________________, begin to ______________, and ______________.

chondrocytes cease, dividing; increase in size; resorb matrices

The zone of calcified cartilage is where _______________ because ______________________________________ and osteoclasts _____________________________ while the osteoblasts ______________________________ (endochondral ossification).

chondrocytes die, extracellular matrix around them calcifies; dissolve the calcified cartilage; lay down bone extracellular matrix

What is bone remodeling?

continuous turnover of bone matrix and minerals that involve resorption by osteoclasts and bone formation by osteoblasts

What are the bone repair steps?

hematoma forms, callus forms, callus ossifies, bone is remodeled

What is a hematoma?

a localized mass of blood released from blood vessels but confined within an organ or space

What is a callus?

a mass of tissue that forms at a fracture site and connects broken ends of bone

How many of each vertebrae/parts are there?

7 cervical, 12 thoracic, 5 lumbar, 1 sacrum, 1 coccyx

What are the first and second vertebrae called?

atlas and axis

What are the similarities of adult/child and fetal bones?

zones of ossification, chondrocytes, and osteoblasts/cytes

What is unique to fetal bones?

epiphyseal plates are located in the center and ends, and grow the entire bone; the osteoclasts carve out the medullary cavity

What is unique to child/adult bones?

The epiphyseal plates are located on the ends, and they elongate bones; osteoclasts are used to remodel bones

What is an osteon?

a cylindrical unit of bone that is a function and structural component of compact bone

What is the osteon composed of?

central canal, lamellae, lacuna, perforating canal

The ______________ of osteons increase with age, while __________ decreases.

number and shape; osteon size

What does an osteon do?

serve as the functional unit of the bone, providing support and strength

What is the order in “bundle within bundles” from largest to smallest?

skeletal muscle, fasciculi, muscle fibers, myofibrils, myofilaments

What is the first step of muscle contraction?

resting membrane potential” more potassium inside with a negative charge, more sodium outside with a positive charge

What is the second step of muscle contraction?

brain signal travels along an axon to muscle cell

What is the third step of muscle contraction?

calcium channels open and calcium diffuses into neuron

What is the fourth step of muscle contraction?

synaptic vesicles fuse with membrane and release acetylcholine into synapse

What is the fifth step of muscle contraction?

acetylcholine opens sodium channel and sodium diffuses into muscle cell (depolarization-positive charge inside)

What is the sixth step of muscle contraction?

potassium channels open and potassium diffuses out of muscle cell (repolarization-negative charge inside)

What is the seventh step of muscle contraction?

action potential travels along sarcolemma and t-tubules

What is the eighth step of muscle contraction?

calcium channels open on sarcoplasmic reticulum and calcium diffuses into cytoplasm of muscle cell

What is the ninth step of muscle contraction?

calcium binds to troponin which pulls tropomyosin binding sites on actin

What is the tenth step of muscle contraction?

myosin binds and pulls on actin forming a cross-bridge

What is the eleventh step of muscle contraction?

atp binds to myosin releasing it from actin

What is the twelfth step of muscle contraction?

atp is hydrolyzed to adp+p energizing myosin for next pull on actin

What are the generic parts of bones? (5)

spongy bone, epiphyses, diaphysis, compact bone, medullary cavity

What are the types of bones? (4)

long, short, flat, irregular

What are the types of bones cells and what are there specifics? (3)

osteoblasts (bone forming), osteoclasts (breaking down), osteocytes (mature cells)

What is unique to skeletal muscle?

it is voluntary and has multiple nuclei

What is unique to cardiac muscle?

it is branched

What is unique to smooth muscle?

it is not striated

what are the components of a sarcomere?

thin filaments (actin), thick filaments (myosin), i-band (only actin), h-band (only myosin), a-band (myosin and actin), m-line, z-line

What is a muscle twitch?

the contraction of an entire muscle in response to a stimulus in one or more muscle fibers

What is recruitment?

additional motor units are stimulated after initial contraction occurs

What is the “type I” muscle fiber?

slow twitch muscle fiber-contracts and fatigues slowly

What is the “type II” muscle fiber?

fast twitch muscle fiber-contracts and fatigues quickly

What are IIa and IIx muscle types?

IIa is intermediate, IIx is the fastest