(PAPHY LEC) SKELETAL MUSCLE PHYSIO Calcium homeostasis - Sarcoplasmic reticulum

______________: critical physiological regulator of many processes required to achieve and maintain homeostasis

Calcium

What are the 3 functions of Calcium?

1. -

2. -

3. -

1. Stimulation of skeletal muscle contraction

2. Stimulation and regulation of cardiac muscle contraction

3. Exocytosis of cellular molecules including those important in neural signaling

When the osteoblasts and osteoclasts activities are balanced, movement of Ca ion in and out of the bone are __________

equal

Calcium homeostasis is regulated by 3 hormones:

1. -

2. -

3. -

Parathyroid hormone
Calcitriol
Calcitonin

__________________ is the term used for increased calcium in the blood

Hypercalcemia

_______________ is the term used for decreased calcium in blood

Hypocalcemia

____________________ is secreted by cells in the parathyroid gland

parathyroid hormone

________________ is essential for the maintenance of blood Ca levels within homeostatic limits

Parathyroid hormone

The key signal for secretion of PTH: _______________________

reduction of blood Ca levels

The parathyroid hormone works by two mechanisms:

1. -

2. -

Direct effects on bone cells and in the kidney
Indirect effects on the small intestine

PTH stimulates _____________ activation in the KIDNEY —> PTH-induced ______________ in blood Ca levels

Calcitriol
increases

______________ and ________: INCREASE osteoclast activity for bone reabsorption

Calcitriol
PTH

__________________ is secreted from C cells in the _____________ when blood Ca levels are TOO HIGH

Calcitonin
thyroid gland

__________________ LOWERS blood Ca levels by inhibiting __________ activity

Calcitonin
osteoclast

________________ is a partial or complete break in the bone

Fracture

Fracture can be classified into 2:

1. -

2. -

Open fracture
Closed fracture

___________________: COMPOUND fracture; bone pokes through the skin and can be seen, or a deep wound exposes the bone through the skin

Open fracture

___________________: SIMPLE fracture; bone is broken but the skin is intact

Closed fracture

What are the 4 common causes of fractures?

1. -

2. -

3. -

4. -

When force is applied to the bone than the bone can take
Caused by falls, trauma, or as a result of a direct blow or kick
Overuse or repetitive motions
Diseases that can weaken the bone

What are the 5 signs of fracture?

1. -

2. -

3. -

4. -

5. -

Swelling
Pain
Redness
Bruises
Exhibits heat

What are the 7 types of fractures?

1. -

2. -

3. -

4. -

5. -

6. -

7. -

Greenstick
Transverse
Spiral
Oblique
Compression
Comminuted
Segmental

What are the 3 stages involved in the healing process of fractures?

1. -

2. -

3. -

Inflammatory stage
Reparative stage
Remodeling stage

_______________________: formation of hematoma at the fracture site and a small amount of bone in the distal fracture fragments is resorbed

Inflammatory stage

_____________________: formation of callus; new blood vessels develop enabling cartilage to form across the fracture line

Reparative stage

__________________: the callus that is originally cartilaginous becomes ossified and the bone is broken down and rebuilt

Remodeling stage

What are the 5 signs of inflammation?

1. -

2. -

3. -

4. -

5. -

Pain
Swelling
Redness
Exhibits heat
Loss of function/disruption of function

What are the 4 general properties of muscle tissue?

1. -

2. -

3. -

4. -

Contractility
Excitability
Extensibility
Elasticity

___________________ is the ability of the muscle to SHORTEN FORCEFULLY, or CONTRACT

Contractility

_____________________ is the capacity of the muscle to RESPOND TO A STIMULUS

Excitability

________________: muscle can be STRETCHED BEYOND ITS NORMAL RESTING LENGTH and still be able to contract

Extensibility

___________________ is the ability of the muscle to RECOIL TO ITS ORIGINAL RESTING LENGTH after it has been stretched

Elasticity

__________________ is the storage for calcium in muscles

Sarcoplasmic reticulum

________________ is the cell membrane of a muscle fiber. It is the OUTERMOST COVERING of a muscle

Sarcolemma

“___________” is the term for muscle-related
“___________” is the term for bone-related

sarco
osteo

What are the 3 types of muscles?

1. -

2. -

3. -

Skeletal muscle
Cardiac muscle
Smooth muscle

Skeletal muscle is for:
- _______________

- _______________

movement
skeletal structure

Cardiac muscle increases pressure in the ___________

heart

Smooth muscle increases pressure in the _________________

hollow organs

_________________ = irregular heartbeat

arrhythmia

_____________ = high blood pressure

hypertension

__________________ = heart CONTRACTILITY

Inotropic

________________ = heart RATE

Chronotropic

Skeletal muscle with its associated connective tissue —> ______% of body weight

40

Skeletal muscle is also called _________________

striated muscle

What are the 3 connective tissue layers that support muscle contraction?

1. -

2. -

3. -

Epimysium
Perimysium
Endomysium

___________________ forms a connective tissue SHEATH that SURROUNDS each skeletal muscle

Epimysium

___________________ is the loose connective tissue serving as PASSAGEWAY FOR BLOOD VESSELS AND NERVES that supply each FASCICLE (visible bundles of muscle fibers)

Perimysium

_________________ SEPARATES the individual muscle fibers within each fascicle; serves as PASSAGEWAY for nerve fibers and blood vessels that supply each separate MUSCLE FIBER

Endomysium

The __________ will direct the muscles to CONTRACT or RELAX

brain

The two main aspects to muscle contraction:

1. -

2. -

electrical component
mechanical component

___________________: respond to and transmit ELECTRICAL SIGNALS

Electrical component structures

What are the 3 electrical component structures?

1. -

2. -

3. -

Sarcolemma
Transverse tubules
Sarcoplasmic reticulum

________________ is the cell membrane of muscle fibers

Sarcolemma

________________ CARRY IMPULSES into the center of the muscle fiber so that the muscle fiber contracts as a whole

Transverse tubules

______________________: the release of Ca is a “SWITCH” for muscle contraction

sarcoplasmic reticulum