BIO 230 Exam #3 - Bradley University

appendicular skeleton

consists of more long bones

- "appendages"

- scapulae and upper extremities

axial skeleton

consists of load-bearing bones

- such as skull, spine, ribs, and sternum

short bones

tarsals and carpals

flat bones

scapulae, sternum, cranial bones, ribs

irregular bones

sacrum, vertebrae

long bones

humerus, radius, phalanges, ulna

3 parts of a long bone

epiphysis, metaphysis, and diaphysis

epiphysis

end of bone

- thicker

- contracts to joints

- coating of cartilage at joint surface

metaphysis

growth plate

- cartilage is replaced by bone (as ossified until growth plate closes)

diaphysis

shaft of long bone

- thinner cortical bone

- thicker trebeculae (spongy)

periosteum

outer connective tissue covering of bone

- highly vascularized

- supplies sensation

- acts as anchoring system for ligaments and tendons

cortical bone

compact, strong, structurally supportive

trabecular bone

spongy, loose w/ holes, allows flexibility

- stores bone marrow

what is the principle cell of cortical bone?

osteocyte, lays down a lacunae

lacunae

small cavities in bone that contain osteocytes

- ring-like structures

trabecular bone structure

no circular pattern, less densely packed (allows for bone marrow)

ossification

process of bone growth

- divided into zone 1 and 2

ossification zone 1

resting

ossification zone 2

proliferation

osteoblasts

build back bone

osteoblasts build bone by laying down _______ ________ to replace the cartilage

calcium phosphate

ossification zone 3

hypertrophy

ossification zone 4

calcification

ossification zone 5

ossification

osteoclasts

break down old bone

- re-absorb and turn into calcium phosphate

process of bone reformation

1. activate osteoclasts

2. osteoclasts eat the bone, CaP+

3. pre-osteoblasts come in and invite osteoblasts in

4. osteoblasts build new bone

5. osteoblasts get trapped in bone, become osteocytes

how does bone remodeling get regulated?

parathyroid hormone

what does PTH work with?

vitamin D

- to restore Ca+ levels in the blood

when PTH is suppressed

- bone re-absorption is down

- blood calcium increases

when PTH is stimulated

- bone re-absorption is up

- blood calcium decreases

why does bone re-absorption occur?

to maintain normal homeostasis for blood Ca+ levels

vitamin D promotes

bone turnover, and will indirectly cause increased osteoclast activity

with low Vitamin D and more osteoclasts:

excessive bone breakdown can occur

- ex: osteoporosis and osteopenia

wolff's law

adaptation, bone changes when stress is applied

minimal essential strain

threshold where enough stress has been put on bones to change and not cause damage

yellow bone marrow

functionally less effective

hematopoietic cells

differentiate into different cells eventually

granulocytes

neutrophils, eosinophils, basophils

agranulocytes

monocyte

what does bone marrow produce?

hematopoietic stem cells

- leukocytes

- megakaryocytes

- erythrocytes (membrane that house hemoglobin)

ligaments

connects bone to bone, promotes stability of joints

fibrous joints

no movements

- ex: cranium

cartilaginous joints

some movement

- ex: spine

synovial joints

full movement

- ex: fingers, shoulder, knee

diarthrosis

full movement

- ex: full movement

amphiarthrosis

little movement

- ex: pelvis

synarthrosis

immovable

- ex: teeth

cardiac muscle cells

single nucleus

skeletal muscle cell

single line, multiple nuclei

smooth muscle cell

no branching, diamond shaped

what kind of fibers make up fascia

collagen fibers

the cytoskeleton provides

cell shape, organization, and movement

the cytoskeleton includes

microtubules, intermediate filaments, and actin filaments

motor proteins

use ATP as an energy source to promote movement

- catabolic reaction

motor proteins consist of 3 parts

- head

- hinge

- tail

hinge of motor protein

allows it to make up a microtubule or around actin to grab it

how does movement occur?

ADP is released, causing the motor protein to detach

- the head cocks forward, re-attaches

- pulls the actin filament past it

epimysium

surrounds entire muscle

perimysium

becomes a part of the tendon

endymysium

inner most layer

satellite cell

stem cells, become new cells

sarcolemma

cell membrane

muscle fiber

single muscle cell

myofibril

functional unit of the cell

- creates the muscle contraction

I band

disappears at contraction

where does myosin live?

A band

Z disc

connects actin to structural support

H zone

stability

- connect to microtubules and intermediate filaments

sarcomere

multiple makes up a myofibril

actin filament

moved over myosin filaments

sarcoplasmic reticulum

sends signals to contract

- through calcium

a thick filament contains

several motor proteins wound together

troponin binds to

tropomyosin

how is there stability in thin filaments where myosin binds?

tropomyosin locks in both myosin and troponin (orange line)

where does troponin bind to tropomyosin?

in a thin filament

muscles contract because of an

action potential in the axon terminal causes gated calcium ion channels to open

after the calcium gated ion channels open, calcium unlocks

acetylcholine

after calcium unlocks acetylcholine

calcium ions facilitate the fusion of the (ach) vesicle with the cell membrane

- exocytosis (throws out ACh into the synaptic cleft)

when ACh is released into the synaptic cleft

they bind to cholinergic receptors (on the muscle)

- these are ligand gated sodium channels

what does the binding of ACh to ligand gated sodium channels cause

a stimulus spike

- the action potential moves across the sarcolemma

t-tubule

wraps around myofibril into the sarcoplasmic reticulum

- extension of the sarcolemma into the muscle

when a muscle contracts, it gets

shorter

where is calcium stored

sarcoplasmic reticulum

during muscle relaxation

- calcium is pumped back into the sarcoplasmic reticulum

- moves calcium against the concentration gradient

- calcium is re-absorbed, ATP is required

- myosin heads release ADP and a phosphate group

myofibril contraction

- I band shortens as actin is pulled

- A band stays the same

- Z line moved H zone

- H zone shortens

if we have a medication that blocks ACh release, how can this affect muscle contraction?

prohibit action potential, prevent muscle from contraction

energy

ability to promote change or do work

potential energy

energy that an object possessed due to its structure or location

exergonic

moves energy out, releases it

- catabolic

endergonic

moves energy in, stores it

- anabolic

cells use ATP to drive what kind of reactions

endergonic

cellular respiration

a process by which living cells obtain energy from organic molecules and release waste products

the inner membrane space has folds to

increase surface area for reactions to happen

is ATP synthesizes during aerobic respiration

no

anaerobic

glycolysis

metabolism has an

absence of oxygen

what does glycolysis create?

lactic acid / more acidity

if O2 is present,

aerobic respiration occurs

- glycolysis

- pyruvate oxidation

- citric acid cycle

- electron transport chain

makes many ATP

if O2 is absent

fermentation occurs

- glycolysis

- fermentation

makes few ATP, mostly lactate or alcohol

enzymes are

catalysts