anatomy test 2

examples of long bones

femur, humerus, ulna, radius, clavicle, metacarpals, phalanges

examples of short bones

carpals, tarsals

examples of flat bones

scapula, ribs, sternum

example of a pneumatized bone

ethmoid bone

example of a sesamoid bone

patella

sutural (wormian) bone

projection growing into the suture- found within the sutures of the skull

examples of irregular bones

vertebrae, temporal bone

canaliculi

“little canals” that connect lacunae and osteocytes to each other

osteoclast

cells that act to reabsorb or breakdown bone tissue

lamellae

concentric rings or tubes of bone matrix

chondrocyte

mature cartilage cell (usually trapped in lacunae); can divide

lacunae

a small cavity that often houses cartilage or bone cells

endosteum

a cellular membrane lining the spicule, trabeculae, canals, and medullary cavity of bone

chondroblast

immature cartilage cell that is responsible for matrix production; is close to O2 and nutrients

haversian (central) canal

canal lined with endosteum to supply blood vessels, lymphatics and nerve to bone; vertical canal that runs down the middle of an osteon

ossification

process of bone formation

mesenchymal cell

embryonic connective tissue cell that gives rise to all other connective tissue (common embryonic origin of all CT)

interstitial growth

cartilage growth due to mitosis of chondrocytes- may occur along epiphyseal plate of long bone to increase bone in length

appositional growth

growth of bone or cartilage due to the addition of bony matrix or cartilage to the outer surface (just under periosteum)

osteoblast

immature, matrix producing bone cell

periosteum

a thick, fibrous connective tissue layer surrounding the entire external surface of bone, with the exception of the articular surface

osteon

the functional and structural unit of compact bone- consist of tiny structural “pillars” made of concentric rings or tubes of bone

osteocyte

mature bone cell, usually trapped in lacunae, not active but provide structure

spicules of bone

tiny, needle-like bits of bone that connect to form trabeculae

hypertrophy

enlargement of cells

osteoid

organic components of the matrix (proteic fibers and ground substance) prior to mineralization

volkmann’s canal

contain blood vessels and nerves and run perpendicular to Haversian canals

what are the three types of connective tissue

connective tissue proper, supporting connective tissue, fluid connective tissue

functions of the skeleton

1. support of soft tissues of body

2. mineral reservoir- 98% of body’s calcium in bones

3. energy storage (yellow marrow)- fat stored in medullary cavity of long bones

4. blood cell production (red bone marrow)- in cavities of spongy bone

5. protection of vital organs

6. leverage and movement

connective tissue proper

-dense regular CT: aligned in a regular fashion; in ligaments, bone sheaths, tendons; have fibroblasts/cytes

-adipose: stored in bone; have adipocytes

supporting connective tissue

-cartilage: in joint discs, intervertebral discs, symphysis pubis; have chondroblasts/cytes

-osseous tissue: bone; have osteoblasts/cytes

fluid connective tissue

blood- formed in red bone marrow

cartilage characteristics

1. no blood vessels/nerves

2. consists primarily of water (60-80%)

3. surrounded by perichondrium

4. growth ends at 18-20 years

5. little healing in adulthood

6. collagen resists tension

7. poor at resisting “shearing forces” (tearing)

8. cartilage cells: chondroblasts and chondrocytes

perichondrium

-dense CT that surrounds cartilage

-like a girdle

-blood vessels here- help with growth/repair

-provides gas and nutrients to cartilage cells

hyaline cartilage

-most abundant

-has fibers (too small to see)

-located on end of bone, growth plate, costal cartilage

elastic cartilage

-many elastic fibers

-tolerates repeated bending, recoil

-located within ears/epiglottis (bendy areas)

fibrocartilage

-abundant collagen fibers

-retwisting and compression

-no perichondrium

-located in intervertebral disc, menisci

two types of osseous tissue

spongy bone and compact bone

every bone has:

blood vessels, nerves, and lymphatic vessels

spongy (cancellous) bone

-honeycomb-like network of bone

-form trabeculae (beams) to resist directional stresses; trabeculae surrounded by endosteum

-cavities filled with red bone marrow

-found in epiphysis and center of bone organ

-replaced every 4 years

compact bone

-beams of bone help to transmit weight within the bone

-allows compression down the medial diaphysis and tension along lateral diaphysis

-bone forms concentric rings of matrix (osteon)

-bone cells are trapped within cavities (lacunae)

-organized “nested rings” in periphery of bone

-replaced every 10 years

steps to change from spongy to compact bone

1. bone formation at the surface of the bone produces ridges that parallel a blood vessel

2. the ridges enlarge and create a deep pocket

3. the ridges meet and fuse, trapping the blood vessel inside the bone

organic compounds of the non-cellular matrix (osteoid)

-provide flexibility

-primarily: collagen fibers

-resists: twisting and tension

inorganic compounds of the non-cellular matrix (osteoid)

-provide durability and hardness

-calcium and phosphate

-98% of calcium held in bone

osteoclasts

-derived from WBCs

-breaks down old matrix (osteoid)

-releases calcium and phosphate

osteoprogenitor cells

-will form all new bone cells

-can divide

canaliculi transfer

-mineralized matrix so no diffusion through the matrix

-protoplasmic extension of adjacent cells can connect with canaliculi

-waste, nutrients, gas, etc. diffuse from cell to cell

intramembranous ossification

-bone develops between layers of fibrous membrane

-embryonic CT cells change into osteoblasts and form bone

what bones are formed by intramembranous ossification

flat bones (mainly in skull)- can be seen in fontanels (baby’s soft spots)

endochondral ossification

-cartilage model formed first

-bone replaces cartilage over time

-some cartilage remains at epiphyseal (growth) plate until growth ends

what bones are formed by endochondral ossification

mainly long bones of the body

bone grows in length until age ______

15-20

bone grows in width mainly until age ______

15-20 but will continue to form new bone for life

appositional growth

bone cell lays down new bone tissue along outside of bone (deep to periosteum)

in appositional growth, bone grows in _____

width

intersitial growth

-bone replaces cartilage, where cartilage cells have died

-occurs along epiphyseal (growth) plates

in interstitial growth, bone grows in _____

length

how much of your total body weight does muscle account for

40-50%

muscle characteristics

1. excitability

2. contractibility

3. extensibility

4. elasticity

muscle excitability

responds to external stimuli (hormones/nervous stimulus)

muscle contractibility

actively shortens along longitudinal axis

muscle extensibility

can stretch beyond original length, without tearing (contrast with brain, bone, spleen, or kidney)

elasticity

recoils to its original length

the muscle organ consists of

muscle fibers (cells) + connective tissue + nervous tissue + epithelial tissue

muscle function

change chemical energy into mechanical energywhat

mechanical energy in muscles is used to…

1. produce skeletal/skin movement

2. maintain posture/body position/joints

3. support soft tissue

4. regulate incoming and outgoing material- move material along tract

5. skmaintain body temperature (goosebumps, muscle contractions produce heat)

skeletal (somatic) muscle characteristics

1. striations

2. cylindrical fibers

3. multiple, peripheral nuclei

4. voluntary control

5. cannot divide

6. will fatigue over time

7. attached to skeleton and skin

every muscle organ has…

1. at least one artery, one vein, and one nerve

2. muscle cells/fibers

3. bundles of muscle cells = fascicles

4. connective tissue wraps the muscle organ into multiple tubes within a tube

arteries, veins, and nerves in muscle cells

-travel within CT to get to cells

-activate for contraction

-provide blood for cells

aponeuroses

a flattened, tendinous sheet derived from interwoven fibers of the endomysium, perimysium, and epimysium of skeletal muscle

endomysium

connective tissue covering surrounding a skeletal muscle cell (fiber)

epimysium

connective tissue (deep fascia) encircling many skeletal muscle fascicles

perimysium

connective tissue encircling a single skeletal muscle fascicle

fascicle

a bundle of many skeletal muscle cells (fibers)

myofilaments

contractile protein filaments consisting of mainly actin and myosin

thin myofilament

actin (contractile protein)

thick microfilament

myosin (contractile protein)

myofibril

bundles of myofilaments found in a single muscle cell

neuromuscular junction

junction of a motor neuron and a skeletal muscle fiber

sarcolemma

plasma membrane of a skeletal muscle cell (fiber)

sarcoplasmic reticulum

skeletal muscle cell endoplasmic reticulum; regulates calcium ion (Ca2+) storage and release to control muscle contraction

sliding filament theory

explains muscle contraction as the result of actin and myosin filaments sliding past each other within a sarcomere to shorten it and generate force

how is a tendon formed

blending and intertwining of the collagen fibers from the epimysium, perimysium, and endomysium