Chapter 10 Muscle Tissue

Identify the 3 types of muscle tissue

Skeletal; attached to bone and allows movement

Cardiac; Only in the heart, makes the heart pump

Smooth; Found in the walls of hollow organs

Is Skeletal muscle voluntary or involuntary and is it smooth or striated?

Voluntary and Striated

Is Cardiac muscle Voluntary or involuntary and is it smooth or striated?

Involuntary and striated

Is Smooth Muscle Voluntary or Involuntary

Involuntary

What are the 6 primary functions of skeletal muscle tissue?

Produce movement, maintain posture and balance, support soft tissue, guard body entrances and exits, maintain body temperature, and provide nutrient reserves

What are the 3 primary connective tissue coverings surrounding a muscle and what is their location?

Epimysium; surround the entire muscle

Perimysium; Divides the muscle into bundles called fascicles

Endomysium; surrounds each individual muscle fiber

Define fascicle?

Is a bundle of muscle fibers(cell) surrounded by connective tissue

What is Sarcolemma

Plasma membrane of a muscle fiber

What is Sarcoplasm

Is the cytoplasm of a muscle fiber, filled with myofibrils

What is Myofibrils

Special organelles within a skeletal muscle fiber, it is responsible for making the muscle striated

What are the 2 most common Myofilaments

Thin filaments; made of actin

Thick filaments; made of myosin

What is Sarcomere?

The “contractile unit” of the skeletal system, approximately 10,000 in each myofibril

What are additional things about Sarcolemma

Seperates the inside of muscle fiber from outside; electrical charges are unevenly distributed across the membrane

Positive charges are on the external surface

Negative charges are on the internal surface

Called the membrane potential

But this distribution can be changed

Describe the location of Transverse Tubules ( holes in the cell membrane)

They connect the Sarcolemma to the inside of the muscle fiber

Found between terminal cisternae

What is the location of The Sarcoplasmic location (only in muscle cell)

is a specialized form of the Endoplasmic reticulum found within muscle cells

Describe a triad

2 terminal cisternae and 1 T tubule

What are Terminal Cisternae

They are special parts inside your muscles

They are also like little “storage” areas within these muscle fibers

What is the function of The Terminal Cisternae

Is to release calcium when the muscle need to contract or move

Describe the structure of Thin Filaments

The main part of a ———— filaments is a protein called Actin

What does Actin look like?

It looks like a string of beads, these beads are arranged in a long twisted line, like a twisted chain of beads

What is Troponin?

A protein that holds tropomyosin in place, it acts like a lock on the tropomyosin rope, it has 3 parts and it’s in charge of moving the tropomyosin when your muscle needs to contract

It has a receptor for calcium

What are Active Sites?

Are where myosin will bind; it is usually covered by tropomyosin

What is the process that helps your muscles move?

Actin is the main part of the thin filament. Tropomyosin covers the active sites on action; Troponin controls the Tropomyosin and moves it when calcium is released, exposing the active sites so your muscles can contract, The whole process helps your muscles move when you need them to.

What is Tropomyosin?

It is a double stranded protein molecule that prevents actin-myosin interaction

What are Thick Filaments made of?

They are made of a protein called myosin

They are the muscle pullers that helps you move!

What are the Head and Tail of myosin and how are they connected to the M line?

The “tails are connected to the M line

The “head” will interact with actin

Can change position to produce contraction

The M line is the anchor in the center, and the Thick Filaments are tied to it so they can do their job of pulling and making your muscles move.

Describe the location of Titan?

It is stretching protein inside your muscle, it’s actually the biggest protein in your whole body

It is located inside your muscle fibers stretching from the thick filaments to the Z line, like a stretchy spring that keeps everything in place

What are the 4 statements of the sliding filament theory (The sliding filament theory is a fancy way of saying how your muscles move)

H band and I bands get smaller

Zones of overlap get larger

Z-lines get closer together

Width of A band stays constant

What is resting membrane potential?

It is the tiny electric charge across a cell membrane when it is not doing anything.

What are the main contributors to the positive and negative charges on either side of the membrane

Positive charge ( outside the cell) mostly Sodium (Na+) an excess outside of the cell

Potassium (K)- an excess inside the cell

Negative Charges (inside the cell); Chloride (Cl) mostly outside the cell, but little movement occurs.

Proteins- almost entirely inside the cell, and too big to cross the membrane