Download MOVEMENT Anatomy Unit

Movement
(Chapters 31 & 39)
Kaitlyn Devine, Amia Davis, Nicole Fleury, and
Alex Cisneros
Introduction
http://ed.ted.com/lessons/why-sitting-is-bad-for-you-murat-dalkilinc
What is movement?
What allows for movement within the human body?
What are the layers of organization? Start with tissues.
How do bones grow?
Form (typically) Follows Function
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Natural selection chooses for appendages that better suit an animal to its
surroundings.
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Apes have nails rather than claws because they are better for climbing.
Depending on their diet, different galapagos finches had different shaped beaks.
Anatomy studies structure, while physiology studies functions of a
structure.
The environment limits the possibilities of form
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Physical laws
Nutrient availability
■ This is why dragons aren’t real, and why fish are nice and smooth.
Convergence shows how a certain form is favorable by having multiple organisms with
the same adaption.
Types of Tissues: Epithelial
Epithelial tissue
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Armor for organisms
Tightly packed at junctions, may employ several layers.
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Functions as barrier from physical forces, water loss, and foreign bodies.
Glandular epithelia excrete/absorb chemicals.
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Epi- means “above”
Think: mucous membranes.
Can be
Simple (one layer of cells, pseudostratified is also “simple”), stratified
(Multiple cell layers), cuboidal (CUBEoidal), columnar, or squamous.
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Who names these things?
Types of Tissues: Connective
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Think cartilage, bones,
and even blood.
Connective
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SURPRISE! Connective tissues connect and support other tissues!
Quite sparse in comparison to epithelial tissue. Inside of the extracellular
MATRIX.
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That matrix is the foundation for the cells. It can be a jelly, a liquid, or even solid.
Three kinds of connective tissue: collagenous, reticular and elastic.
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I’m starting
to feel that
we are
connecting.
Collagenous Connective Tissue
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SURPRISE! Collagenous tissues are made out of collagen. That’s
CH5NOC5H9NOC5H10NO2. Collagen is not stretchy, and it’s really tough,
doesn’t tear easy.
Collagen is part of the reason why you can’t tear your face off!
Found in ligaments, tendons, skin…
Most abundant protein in mammals.
Should’ve had
collagen.
Elastic Fibers
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Made of, you guessed it, elastin! Long and thready.
When grandma pinches your cheek, you don’t suffer facial deformities
because elastin snaps your face back into place.
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How cool is that?
Shows an example of emergent properties.
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Collagen or elastin alone would not allow skin to behave as it does, but when together,
cheek pinching becomes a safe practice!
Reticular Fibers
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Works together with collagenous tissue to actually connect the
collagenous tissue with a neighboring tissue, like say, BONES!
Reticular fibers are also composed of CH5NOC5H9NOC5H10NO2 (collagen)
but they differ structurally.
○ Considering that reticular fibers connect two tissues, and are continuous w
from) collagenous fibers, what would you expect that the structure is?
○ The structure is thin and branched so that it can weave tightly with other, a
tissues.
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Check out that
TRIPLE HELIX :OO
Collage
n
Types of Tissues: Muscular
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Muscle tissue is long and fibrous, and is capable of contracting.
Contraction is triggered by the release of acetylcholine.
Muscles themselves are composed mainly of Actin and Myosin
Most abundant tissue in animals.
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Wow, I guess muscles are kind of useful then eh?
There are skeletal, cardiac, and smooth muscles.
Types of Tissues: Nervous
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Nerve tissue is composed of Neurons (no, Ron -_-)
The neuron (nerve cells) specializes in sending out those electrochemical
signals that *trigger* according responses.
You might find nerve tissue in brains (or not joke) where they are most
concentrated.
We’ll leave the rest for the nervous system group, when their time comes.
Organs: Skin
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Protection
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Thermoregulation
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Protects underlying parts of the
body from physical trauma
Pathogen invasion
Water loss
Role in regulating body
temperature
Sensory structures monitor
touch, pressure,
temperature, and pain
Regions of the Skin
Epidermis
● Thickness determines thin or thick skin
● Stem cells become flattened and hardened as they
push to the surface
● Cells undergo keratinization
○ Hardening because the cells produce keratin
● Melanocytes
○ Specialized cells that produce melanin
Dermis
● Region of dense fibrous connective tissue beneath the
epidermis
● Collagen fibers: flexible; offer resistance to
overstretching
● Elastic fibers: maintain normal skin tension; stretch to
allow movement of muscles and joints
Subcutaneous layer (hypodermis)
● Composed of loose connective tissue and adipose
tissue (stores fat)
Organ Systems
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Next level up from organs...
Defined as interacting groups of
different organs.
The organ systems of vertebrates
carry out life processes that are
common to all organisms
Include digestive, respiratory,
excretory, circulatory…
Life Processes
Human Systems
Coordinate body activities
Nervous; endocrine
Acquire material and
energy
Skeletal; muscular;
digestive
Maintain body shape
Skeletal; muscular
Exchange gases
Respiratory
Transport materials
Cardiovascular
Excrete wastes
Urinary
Protect the body from
disease
Lymphatic; immune
Produce offspring
Reproductive
Homeostasis
The process of maintaining regularity within the body.
Negative Feedback
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A primary mechanism in homeostasis that keeps a variable close to a
particular value or set point
Homeostatic mechanisms have 2 components:
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Sensor - detects change in the internal environment
Control Center - brings the conditions back to normal
NOTE: there is no change in the same direction instead there are
fluctuations above or below the set point
Negative Feedback
(cont’d)
Example: the regulation of body
temperature
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Hypothalamus harbors
mechanisms for this process
Above Normal: control center
directs blood vessels of skin to
dilate, which allows more
blood to flow to the surface to
help transfer heat to the
environment
Below Normal: control center
directs blood vessels to
construct conserving heat
Homeostasis
Positive Feedback
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A mechanism that brings greater change in the same direction
Examples:
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Childbirth: Nerve impulses cause the excretion of hormones which cause
the uterus to contract. These get worse and worse until the child is born.
Blood Clotting: Specific blood cells are directed to an open wound to
induce clotting a prevent excessive bleeding.
This mechanism has specific cutoff points.
Skeletons
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Functions:
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Support systems
Rigidity
Protection
Surfaces for muscle attachment
Types:
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Hydrostatic: Cnidarians, flatworms, roundworms, and annelids
Exoskeleton: molluscs and arthropods
■ Made of calcium carbonate or chitin (respectively)
Endoskeleton: sponges, echinoderms, and vertebrates
■ Sponges: mineralized spicules and spongin
■ Echinoderms: calcareous plates
■ Vertebrates: cartilage, bone, or both
Diversity of Skeletons: Hydrostatic
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Hydrostatic skeletons are typically found in primitive animals, like
earthworms or sea stars.
As the name suggests, hydrostatic skeletons are “water filled.” They allow
for elongation and
Consists of fluid held under pressure by a closed body compartment.
Diversity of Skeletons: Exoskeletons
Exoskeleton: a protective external skeleton as in
molluscs and arthropods
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Gets stronger by getting thicker and gaining
weight
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Less room for internal organs
Molluscs
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Calcium carbonate shell
■ Used for protection against environment and
predators
■ Grows with the animal
Exoskeletons cont’d
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Arthropods
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Chitin → a strong, flexible nitrogenous polysaccharide
■ Protects from predators, “wear and tear,” and drying
out
■ Terrestrial life
● Appendages allow for flexible movements
Molting
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How arthropods get rid of an exoskeleton that has
become too small for them
Animals are vulnerable until new exoskeleton hardens
■ Muscle contractions may not become body
movements
Diversity of Skeletons: Endoskeletons
Endoskeleton (internal skeleton)
Sponges, echinoderms, and vertebrates
Advantages of jointed vertebrate endoskeleton:
● Can grow with the animal (molting is not required)
● Supports the weight of large animal (without limiting the space for
internal organs)
● Protects vital internal organs
● Is protected by outer soft tissues (soft tissues are usually easier to repair)
● Joints allow flexible and complex movements
The Human Skeletal System
Functions that contribute to homeostasis:
● Support the body
● Protects vital internal organs
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Provides sites for muscle attachment
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Makes movement possible
Important storage reservoir for ions
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The skull, the brain; the rib cage, the heart and lungs
Calcium and phosphorus
Produces blood cells
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Within the red bone marrow
The Human Skeletal System
Bone Growth and Renewal
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Osteoblasts assist in calcification, and once mature, become osteocytes.
Osteocytes maintain the structure of a bone.
Osteoclasts reabsorb old bone material.
Bones lengthen (longitudinal growth) at the epiphyseal plate, a place
where hyaline cartilage is present. The bone grows (length-wise) by
ossification (bone-ifying) of the hyaline cartilage, adding another layer to
the bone.
Horizontal growth, called, appositional growth occurs in the midsection of
a long bone, called the diaphysis.
Bone Growth (a continuation)
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Horizontal growth occurs when osteoblasts
calcify beneath the periosteum (the dense
outside parts of bones that do not include joints).
The osteoblasts grow outwards whilst the
osteoclasts reabsorb the inner, older section of
bone. Once maturity is reached, resorption and
regeneration of bone tissue establish an
equilibrium, so that no net bone growth takes
place.
Bone Repair
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Can be divided into arbitrary steps, in this case, three
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Reactive
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Hematoma (blood clot) forms and osteoclasts absorb bone fragments around wound.
Fibroblasts move into wound site (fibroblasts will excrete the collagen necessary for the
later steps of the process).
Repairing
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Reactive, repairing, remodeling phases.
A fracture callus forms after hyaline cartilage growing from each side of the breakpoint
meet and osteoblast begin to form woven bone in the area. This callus is then replaced
by lamellar bone (dense cartilage) and then even later with trabecular bone (bone, but
not dense bone).
Remodeling
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A long process which can take 5 years. Calcifies the callused area and packs in bone tissue
in an attempt to return to original bone strength.
Anatomy of A Long Bone
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Built for strength and support
Not solid: has a medullary cavity bounded by
compact and spongy bone
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Adult long bones generally contain yellow bone marrow
which is a fat-storage tissue
Compact bone: bounds cavity on sides
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Contains osteons which are the main structural units of the
bone
Osteocytes (bone cells) lie in lacunae (cavities within the
bone)
■ Lacunae are arranged around central canals
● Central canals contain blood vessels and nerves
■ Lacunae separated by a matrix of collagen fibers and
mineral deposits (calcium and phosphorus salts)
Anatomy of a Long Bone cont’d
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Spongy bone: bounds cavity on ends
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Has bony bars and plates separated by random spacing →
lighter than compact but built for strength
■ Bars and plates follow lines of stress to give most
support
■ Spaces: filled with red bone marrow
● Produces blood cells → assists in homeostasis
The Axial Skeleton
Skull
● Bone parts share names with brain parts.
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Remember when you had soft
spots? Those things were called
Fontanels, but by now they have
been replaced by sutures, and
connect your skull bones.
That mean that the bone in front of the frontal lobe is called the frontal bone, etc.
Sinuses allow for voice resonation, and reduce skull weight.
Mandible= lower jaw. It is the only movable part of the skull.
There’s a big hole at base of skull
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It allows for spinal cord to pass through
Literally called big hole in Latin.
Foramen Magnum (big hole).
Axial Skeleton (cont.)
Vertebral column
● The backbone. Directly or indirectly supports all other bones.
● Four parts:
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cervical : 7 vertebrae
Thoracic : 12 vertebrae
Lumbar : 5 vertebrae
Sacrum and coccyx(tailbone): made of several fused vertebrae. Tailbone is vestigial.
Between each vertebrae there are disks made out of fibrocartilage, which
are shock absorbers. Without them, vertebrae would grind together to
make a melodic sound.
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Alas, the disks degrade over time, and without them, thoracic flexibility is impaired :(.
Axial Skeleton (cont.)
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The backbone has four curves that maintain its structural integrity. Here’s
what it looks like when that structure becomes dishonest:
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Cause back pain
Reduce mobility
Make you look uneven
(in the case of lordosis)
laying down does not allow
lower back to touch surface
:(.
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Might be
on quiz ;)
Axial Skeleton (cont.)
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Ribcage contains ribs, costal cartilage (which connects the end bits of ribs
to the sternum), and the sternum.
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12 pairs total: 7 “true ribs” that are directly attached to the sternum by means of costal
cartilage, 5 false ribs, 3 that do not exist are not directly connected to sternum but rather
with a common cartilage, and 2 pairs that are not even connected to the sternum, called,
floating ribs.
Ribcage is protective as well as flexible. Stretches when you breathe in, comes back
when you exhale.
Appendicular Skeleton
AKA, everything that isn’t the Axial skeleton.
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Shoulder and hip bones (pectoral and pelvic) and the limbs attached to
them are the appendicular skeleton.
Pecs
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Humerus attaches to scapula(which is held in place only by muscle and hence allows for
its free movement) and clavicle in a ball-and-socket joint.
■ Head of humerus is much larger than the available socket, which is why most
people dislocate it.
Having two bones (radius and ulna) in forearm allow for twisty motion. Try it!
Appendicular Skeleton (cont.)
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Pelvic
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The two hipbones (coxal bones) are anchored to the sacrum. They are heavy and form a
cavity. In females the cavity is larger because they’re made to squeeze a baby through
there.
Feet phalanges are much sturdier than hand phalanges. Go figure. (Not really all that
remarkable, form does correlate with function after all ;))
Your shins are part of the tibia, and the part of your ankle that faces outward is the fibula.
The foot has an arch so that it can be springy!
Femur is the largest long bone in the body.
Joints
Joints are the point at which
bones are connected. (Fibrous,
cartilaginous, and synovial)
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Fibrous - immovable (like
skull sutures)
Cartilaginous - slightly
movable
Synovial - freely moveable
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Two bones are separated by a
cavity
Ligaments (fibrous connective
tissue) bind them together
The Human Muscular System
There are 3 types of muscle tissue: smooth, cardiac, and skeletal
Smooth Muscle: Found in the digestive tract (stomach, intestines, etc.)
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pushes food through the system
Cardiac Muscle: present in the heart
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helps pump blood
Skeletal (striated voluntary) Muscle
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Maintains posture, provides support, and allows movement
Macroscopic Anatomy and Physiology
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Nearly 700 skeletal muscles and associated tissues
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Skeletal muscles: attached to skeleton by tendons
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40% of weight of a human
Muscles shorten when they contract so they work in antagonistic pairs
■ One muscle flexes joint and bends limb; the other extends joint and straightens
limb
Muscles can contract without fully relaxing
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Continues until tetanus is reached
Even if muscles are at rest, they have tone
■ Helps to maintain posture
*IB Application: Antagonistic pairs of muscles in an insect leg
Antagonistic muscles:
● Muscles can exert force only by shortening
● So...they often work in antagonistic pairs
● If one muscle of an antagonistic pair flexes the joint and bends the limb, the other muscle
extends the joint and straightens the limb
Legs of crickets:
● 2 large muscles inside the femur
○ Flexor
○ Extensor
● Tendons at the ends of these muscles are attached to opposite sides of the exoskeleton of the
tibia
*IB skill: Annotated diagram of the human elbow
Antagonistic
muscle pair:
triceps and
biceps
Microscopic Anatomy and Physiology
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Special components within each muscle fiber
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Sarcolemma (plasma membrane): T shaped: dip down to
touch modified ER
■ Sarcoplasmic reticulum: storage sites for calcium
ions
● Calcium is essential for muscle contraction
● Myofibrils and sarcomeres: what causes
contractions of muscle fiber
○ Sarcomeres: 2 types of protein filaments
○ Myosin (thick); actin (thin)
■ Sliding filament model
IB skill: Drawing labelled diagrams of the structure of a sarcomere
❏
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Z lines
Actin filaments
Myosin filaments with heads
Resultant light and dark bands
A sarcomere extends
between two dark lines (z
lines)
I band: light colored b/c it
contains only actin filaments
attached to z line
A band: The dark regions of
contain overlapping actin and
myosin filaments
H zone: only myosin
filaments
*IB skill: Analysis of electron micrographs to find the state of contraction of
muscle fibers
Electron micrograph muscle fibers:
Relaxed muscle
Contracted muscle (narrower light bands; shorter sarcomeres)
ATP
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In muscle fibers, an analogy might assist in understanding how they work.
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Imagine your name is May O. Sin, and you’re pulling on a rope made by a company called
Actintm . Your hands, Ms. May O. Sin, are like the myosin heads grasping and pulling the
Actintm rope.
Energy consumption
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Adenosine Triphosphate powers muscle contraction. Respiration however, does not
provide enough atp immediately. For this reason muscle cells employ phosphocreatine,
to anaerobically phosphorylate adp to atp.
By the time all of the phosphocreatine is consumed, the mitochondria typically are
pumping out sufficient ATP to keep contraction going.
If oxidative phosphorylation is not enough, fermentation occurs.
Fermentation implies an oxygen debt, or a necessity to metabolise leftover lactate to
glucose. Approximately % of lactate is completely decomposed into water and carbon
dioxide, and the ATP gained from that is used to convert the remaining 80% of lactate
back into glucose.
Muscle Innervation
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Muscles are stimulated to contract by motor nerve fibers
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Neuromuscular junction: region of an axon terminal and the
sarcolemma of a muscle fiber
○ The branch of a motor nerve fiber ends in an axon
terminal
○ Synaptic cleft separates the axon terminal from the
sarcolemma (plasma membrane)
Nerve impulses traveling down a motor fiber cause synaptic
vesicles to release acetylcholine into the synaptic cleft
ACh diffuses across the cleft and binds to receptors in the
sarcolemma
Sarcolemma generates impulses that spread to the
sarcoplasmic reticulum
Release of calcium from the sarcoplasmic reticulum causes
actin and myosin filaments w/in sarcomeres to slide past one
another
Sarcomere contraction results in myofibril contraction resulting
in muscle fiber and muscle contraction
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Muscle Innervation
Role of calcium in muscle contraction
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The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments
ATP hydrolysis and cross bridge formation are necessary for the filaments to slide
Calcium ions and the proteins tropomyosin and troponin control muscle contractions
○ Calcium released from the sarcoplasmic reticulum combine with troponin
○ After binding, tropomyosin threads (which are winded around an actin filament) shift
their position, and myosin binding sites are exposed
Review Questions
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In what ways does form correlate with function?
What is collagen good for? Elsatin?
Give an example of emergent properties in anatomy.
What are the parts of homeostasis and how do they work?
Why is phosphocreatine,C4H10N3O5P, used in muscle Contraction?????
Why aren’t backbones perfectly straight? How many curves are in the
backbone??????
GiVE an ExaMPle oF a VesTiGiaL StRuctURe ON thE HuMaN BodY?!?!?!
Vocabulary
tissue
epithelial tissue
squamous epithelium
cuboidal epithelium
columnar epithelium
connective tissue
collagen fibers
reticular fibers
elastic fibers
muscular (contractile) tissue
skeletal muscle
smooth (visceral) muscle
cardiac muscle
nervous tissue
organ
skin
epidermis
dermis
subcutaneous layer
organ system
homeostasis
negative feedback
positive feedback
exoskeleton
endoskeleton
hydrostatic skeleton
Osteoblasts
osteocytes
compact bone
spongy bone
red bone marrow
axial skeleton
vertebral column
appendicular skeleton
pectoral girdle
pelvic girdle
joints
synovial
ligaments
tendons
tetanus
tone
sarcolemma
sarcoplasmic reticulum
myofibrils
sarcomeres
myosin
actin
sliding filament model
neuromuscular junction