Unit 5 Learning Objectives

Belzer A&P

Muscles always have a _______ __ _______ and _________.

point of origin; insertion

ID the structure indicated by B.

Epimysium. Connective tissue that surrounds the entire muscle.

Excitability

Feature of muscle tissue; muscle generates electrical signals called action potentials

Contractility

General feature of muscle; Muscles are capable of shortening to generate movement

Extensibility

General muscle feature; muscles can stretch without being damaged (most of the time).

Elasticity

General muscle feature; muscles can return to it’s original length after contraction.

ID the structure identified 2

Sarcolemma; Plasma membrane of the skeletal muscle fiber; contains voltage gated ion channels. 

ID the structure indicated by 3

Myofibril; Contractile organelles of skeletal muscle surrounded by T-Tubules, made up of repeating units of sarcomeres.

ID the structure indicated by 4

T-tubule; Invaginations of the sarcolemma that allow an action potential to move into the myofibril.

ID the structure identified by 7

Sarcomere; Basic functional unit of skeletal muscle; organization of filament proteins.

ID the spring-like structure passing through the thin and thick filament on the diagram

Titan; Component of muscle that allows elasticity and extensibility

ID the structure identified by 10

Actin - Protein that comprises thin filament; have myosin binding sites.

Sarcoplasm

Cytoplasm of muscle cells rich in glycogen and myoblobin.

ID the structure identified by 6

Sarcoplasmic reticulum (SR); Organelle in skeletal muscle tissue cells - Fluid filled calcium storage sacks that surround each myofibril.

ID the structure identified by 1

Triad; Structure that forms between two terminal cisternae and a T-tubules.

ID the structure identified by 14

Myosin: Structural proteins that form thick filaments.

ID the specific tissue type

Skeletal muscle tissue; striated and multinucleated muscle fibers.

ID the structure indicated by 1

Muscle fiber/cell

Id the structure indicated by 2

Nucleus of muscle fiber/cell

ID the structure indicated by 3

Striation/Sarcolemma

ID the specific tissue type w/ anatomical justifications.

Cardiac muscle tissue. Branched, cell’s are uninucleated, and presence of intercalated discs.

ID specific tissue type w/ anatomical justifications.

Smooth muscle tissue; Branched, no striations, multinucleated.

ID the structure indicated by A

Tendon. Structure that attaches a bone to a muscle.

ID the structure identified by C

Skeletal muscle

ID the structure identified by D

Fascicle. Bundle of muscle fibers/cells that make up the muscle unique to skeletal muscle.

ID the structure indicated by E

Muscle fiber/cell.

ID the structure identified by F

Sarcomere; basic functional unit of skeletal muscle tissue.

ID the structure indicated by 5

Terminal cisternae. The end of the sarcoplasmic reticulum (SR). Interacts with T-tubules to trigger calcium release for muscle contraction.

ID the structure indicated by 12

Troponin: Regulatory protein that regulates the activity of tropomyosin. Binds calcium and shifts tropomyosin.

ID the structure indicated by 11

Tropomyosin: Regulatory protein that covers myosin binding sites on actin.

ID the structure indicated by 13

Myosin head: Myosin that binds to actin to pull it.

ID the structure

Sarcomere. Basic unit of skeletal muscle tissue.

ID the region indicated by 4

I Band: Comprised of the Z disc and thin filaments, which are made of actin, troponin, and tropomyosin.

ID the region indicated by 5.

A Band: Comprised of thick and thin filaments, but mostly thick filaments.

ID the region indicated by 3

H Zone: Comprised solely of thick filaments.

ID the structure indicated by 2

M Line

ID the specific tissue type

Skeletal muscle tissue (cross-section)

ID the structure identified by 3

Fascicle: Bundle of muscle fibers

ID the structure identified by 2

Skeletal muscle fiber/cell.

ID the structure identified by 4

Perimysium: Connective tissue surrounding the fascicle.

ID the structure indicated by 1

Endomysium: Connective tissue membrane surrounding the skeletal muscle fiber/cell.