1. Movement 2. Maintain posture 3. Respiration 4. Production of body heat 5. Communication 6. Heart beat 7. Contraction of organs and vessels

Chapter 7: Muscular System Flashcards by kevin galindo

Cardiac muscle

Heart- involuntary
Has 1 centrally located nuclei
Rich in mitochondria
Contract heart to propel blood through the body

How well did you know this?

Not at all

Perfectly

Functions of muscles

Movement
Maintain posture
Respiration
Production of body heat
Communication
Heart beat
Contraction of organs and vessels

How well did you know this?

Not at all

Perfectly

Smooth muscle

Located in walls or hollow organs, blood vessels, and glands
Function: to compress organs, ducts, tubes, and so on.
Has less actin and myosin
1 centrally located nucleus
Involuntary

How well did you know this?

Not at all

Perfectly

Skeletal muscle

Voluntary
Attached to the bone
Many nuclei per cell 
Longest type of muscle 
40% of body weight

How well did you know this?

Not at all

Perfectly

Abilities of the skeletal muscles

Contractibility: shorten
Excitability: respond to stimuli
Extensibility: stretch
Elasticity: recoil

How well did you know this?

Not at all

Perfectly

Coverings of the skeletal muscle

Endomysium
Perimysium
Epimysium

How well did you know this?

Not at all

Perfectly

Endomysium

Fine connective tissue sheath that surrounds each muscle fiber.
Many nuclei

How well did you know this?

Not at all

Perfectly

Muscle fiber

Skeletal muscle cells

How well did you know this?

Not at all

Perfectly

Perimysium

Connective tissue that surrounds each muscle fasciculus

How well did you know this?

Not at all

Perfectly

Muscle fasciculus

Bundle of muscle fibers

How well did you know this?

Not at all

Perfectly

Epimysium (fascia)

Connective tissue that surround entire skeletal muscle (outside)

How well did you know this?

Not at all

Perfectly

Myofibril

Thread like proteins that make up muscle fibers

How well did you know this?

Not at all

Perfectly

Myofilament

Proteins that make up myofibrils

Ex. Actin and myosin

How well did you know this?

Not at all

Perfectly

Sarcoplasm

Cytoplasm of muscle fiber

How well did you know this?

Not at all

Perfectly

Sarcolemma

Cell membrane

-contains T-tubules

How well did you know this?

Not at all

Perfectly

T-tubules (transverse)

Wrap around sarcomeres at A band

Associated with sarcoplasmic reticulum

How well did you know this?

Not at all

Perfectly

Sarcoplasmic reticulum

Type of smooth ER (SER)
Surrounds myosin
Stores and releases Ca2+

How well did you know this?

Not at all

Perfectly

Motor neuron

Nerve cells that carry action potentials to muscle fibers

How well did you know this?

Not at all

Perfectly

Neuromuscular junction
(Synapse)

Stupid hoe couldn’t just say that. Shiet.

Where nerve cell and fiber meet.

I’m gonna leave random shit places now to bug you while you study. Holla.

How well did you know this?

Not at all

Perfectly

Presynaptic terminal

End of nerve cell.

The axon bitch.

How well did you know this?

Not at all

Perfectly

Postsynaptic membrane

Muscle fiber membrane

How well did you know this?

Not at all

Perfectly

Synaptic cleft

Space between presynaptic terminal and postsynaptic membrane.

How well did you know this?

Not at all

Perfectly

Synaptic vesicle

In presynaptic terminal (nerve side)
Store and release neurotransmitters
Ex. ACh

How well did you know this?

Not at all

Perfectly

Resting membrane potential

Charge difference across the membrane of a resting cell.

Outside cell Inside cell
Na+ K+
+ charge - charge
No channels closed. Some K+ open

The inside of the cell is negative even though K+ is positive because it is able to diffuse out the cell freely but other larger negative molecules can’t.

How well did you know this?

Not at all

Perfectly

Action potential

"Electricity" Causes muscles to contract Stimulus that causes rapid depolarization and repolarization

Depolarization

Change in charges Inside becomes more positive and outside more negative Na+ channel is open

Repolarization

Na+ channels close | Change back to resting potential

Hyperpolarization

To increase polarization of membranes of muscle cells

Neurotransmitter

Chemical that stimulates or inhibit a muscle fiber

ACh

Acetylcholine

Motor unit

Group of muscle fibers that motor neuron stimulates

Actin

Thin myofilament | Contain myosin binding sites

Troponin

Attachment site on actin for Ca2+

Tropomyosin

Filament on grooves of actin | Attachment site on actin for myosin (head)

Myosin

``` Thick filament Resemble golf clubs Have 3 properties: 1. Bind to attachment sites 2. Bend and straighten during contraction 3. Break down ATP ```

Sarcomeres

1 contractile unit | Contains actin and myosin

Z disk

Protein fibers that form attachment site for actin

H zone

Center of sarcomere | Contains only myosin

I band

Contains only actin

A band

Where actin and myosin overlap

M line

Where myosin are anchored

Isometric contraction

The length of the muscle doesn't change but the amount of tension increases. (Weight)

Orgin

The non movable end of the muscle

Insertion

The movable end of the muscle

Synergist

Muscles that work together to produce a movement.

Antagonist

Muscles that oppose each other

Occipitofrontalis

Move scalp and forehead

Orbicularis oculi

Close eyes

Orbicularis oris

Close lips

Zygomaticus major/minor (lips)

Elevate and abduct

Masseter

Elevate and protracted mandible

7th step of sliding filament model

Myosin heads bind to actin (cross-bridge)

8th step of sliding filament model

P is released from myosin heads and heads bend toward center of sarcomere

9th step of sliding filament model

Bending forces actin to slide over myosin (powerstroke)

10th step of sliding filament model

Acetylocholinesterase (Ach-E: enzyme breaks down ACh) is released, Na+ channels close, muscle contraction stops

All or None Law

Either muscle contacts or it doesn't no inbetween.

Threshold

weakest stimulus needed to produce a response

Twitch

Rapid contraction and relaxation of a muscle

Tetanus

Muscle remains contracted

Isometric

Amount of tension increases (weight)

Isotonic

Amount of repetitions increases (shorten)

Tone

Constant tension over a long period of time

Orgin

non moveable end of muscle

Insertion

movable end of muscle

Belly

Middle of muscle

Synergist

muscles that work together

Antagonist

muscles that oppose each other

Skeletal muscles are named according to:

1. Location ex. tibialis anterior 2. Orgin/Insertion ex. Sternocleidomastoid 3. Size ex. Gluteus maximus 4. Shape ex. deltoid 5. Function ex. masseter

Occipitofrontalis

move scalp and forehead

Orbicularis oculi

Close eyes

Orbicularis oris

Close lips

Zygomaticus major/ minor (lips)

Elevate and abduct

Masseter

elevate and protracts mandible

External intercostals

elevate ribs for inspiration (inhale)

Internal intercostals

depress ribs during forced expiration (exhale)

Diaphragm

moves during quiet breathing

Rectus abdominis

center of abdomen | compress abdomen

External abdomen oblique

side of abdomen | compresses abdomen

Internal abdominal oblique

compresses abdomen | runs perpendicular to external abdominal oblique

Transverse abdominis

compresses abdomen

Trapezius

very superficial shoulders and upper back extends neck and head

Pectoralis major

Chest | flex shoulder,

Serratus anterior

Between ribs | elevates ribs

Deltoid

Shoulder | abductor of upper limbs

Rectus abdominis

Center of abdomen | Compress abdomen

External abdominal oblique

Sides of abdomen | Compress abdomen

Internal abdominal oblique

Compresses abdomen | Runs perpendicular to external abdominal oblique

Transverse abdominis

Compresses abdomen

Quadriceps femoris

4 thigh muscles. Primary extensors of the knee. 1. Rectus femoris 2. Vastus medialis 3. Vastus lateralis- used as a muscular injector site 4. Vastus intermedius

Hamstring

Posterior of thigh | Flexes knee rotates leg, extends hip

3 hamstring muscles

Biceps femoris Semimembranosus Semitendinosus