Anatomy Unit 2: Support and Motion

Osteocytes release chemical signals to send osteoclasts to the damage.

1st step of bone remodeling process

Osteoclasts return calcium and phosphate to the blood through resorption.

2nd step of bone remodeling process

Macrophages promote bone tissue remodeling.

3rd step of bone remodeling process

Osteoblasts come in and build new bone.

4th and final step of bone remodeling process

flat bone

A bone that has a large surface area, specifically for muscle attachment

irregular bone

A bone with a highly specialized shape and structure, like the coxal bones

twitch

A contraction caused by a single brief stimulus is known as a:

Bone remodeling is stimulated when the osteocytes receive signals to rebuild the bone. If those signals aren't sent, the bone will not be regenerated and strengthened.

Explain why people who experience paralysis in their lower limbs have thinner, weaker bones in their legs and thighs.

Cellular respiration happens in the mitochondria and muscle contractions need lots of energy, so our muscle cells must be able to constantly break down sugars for ATP when necessary.

Explain why there is an abundance of mitochondria in our muscle cells.

The pubic arch is wider. The wider space around the sacrum provides for a birth canal. These allow females to grow and birth a baby.

How is the female pelvis different than the male pelvis?

immovable, slightly movable, freely movable

Joints can be:

fibrous

Joints in the cranial bones of the skull are which type of joint?

support for the body, protection of organs, aid in movement, storage of minerals and energy, blood cell formation, hormone production

List the 6 overall functions of the skeletal system we discussed in class.

increasing the frequency of motor neuron stimulation, increasing the number of motor units stimulated, increasing the size of muscle fibers

List three ways muscles can increase the force of their contraction.

In order to maintain homeostasis through regulation of body temperature, muscle contractions must happen, which require energy from ATP.

One function of the muscular system is to help regulate constant body temperature. Explain how this system contributes to maintain homeostasis in this way.

third class lever

Our muscles can act with our bones to form lever systems. The lever system that allows a bicep curl would be considered a:

cervical, thoracic, lumbar, sacral, coccyx

Place the regions of the vertebral column in the correct order, starting in the neck.

synvoial

Shoulder, hip, jaw, and elbow joints are all which type of joint?

Muscles contract because sarcomeres contract. Sarcomeres contract when the heads of myosin filaments can grab the thinner actin filaments and pull them to slide past each other. This causes the filaments to overlap more and the sarcomere to shorten.

Summarize the sliding filament model.

pectoral; pelvic; pelic

The _____ girdle provides more flexibility and mobility than the _____ girdle. The _______ girdle is the sturdiest of the two.

muscle fibers; myofibrils

The ______ are the muscle cells, containing specialized organelles called _________.

short bone

The bones in your wrist

hinge

The elbow joint is classified as which type of joint?

muscle fiber

The endomysium is the connective tissue that surrounds each _________.

first class lever

The lever system that allows you to lift your head from your chest would be considered a:

diaphragm

The prime mover in inspiration (inhalation)

hamstrings

The quadriceps are the prime movers in extension and are antagonized by:

buccinator

What is the main muscle of the cheek?

energy from ATP, access to the actin (so myosin can bind)

What two things must be obtained in order for a muscle contraction to occur?

fibrous

What type of joint connects bones with collagen fibers?

synovial

What type of joint has a fluid-filled cavity?

pivot

Which joint allows for supination and pronation?

ball and socket

Which joint allows for the most maneuverability of all the joints?

saddle

Which joint makes your thumb opposable?

fibula

Which leg bone doesn't actually bear any weight but instead aids in stabilizing the ankle joint?

fibrocartilage

Which of the following anatomical characteristics is not shared by all synovial joints? (articular cartilage, sensory nerve fibers, fibrocartilage, or reinforcing ligaments)

coxal bones

Which of the following is not considered to be part of the axial skeleton? (coxal bones, ribcage, vertebral column, or skull)

synovial

Which type of joints are all functionally classified as diarthrotic?

fibrous

Which type of joints are all nearly functionally classified as synarthrotic?

The last 2 ribs aren't attached to the sternum in the front; just to the vertebrae in the back.

Why are some ribs classified as "floating"?

Skeletal muscles only contract voluntarily and excitable cells, so they must be stimulated by signals from the nervous system.

Why is the nervous system critical for muscle contractions?

short bone

a bone that has approximately the same width, length, and height

offer the most flexibility and maneuverability

benefit of freely movable joints

offer the most stability

benefit of immovable joints

offer some flexibility while still being very stable

benefit of slightly movable joints

tendons

cords of dense connective tissue that connect muscles to bones

Joints in knees and elbows that provide lots of movement in our limbs

example of freely movable joints

sutures in the cranial bones that protect the skull

example of immovable joint

vertebrae of the spine

example of slightly movable joints

tarsals

the bones that make up the ankle

irregular bone

the type of bone pictured to the right

long bone

the type of bone that most of the limb bones can be classified as