4.1 Joints and Muscles. What would life be like without Joints Move a joint that you use often How do different joints move. Essential Question. 1. What role do joints play in the human body?
4.1 Joints and Muscles
1. What role do joints play in the human body?
Joints are the places where two bones meet and allow movement & flexibility and provides support to the human skeleton.
2. How are joints classified by both structure and function?
Functionally, joints are classified by how much motion they allow. Structurally, joints are classified as fibrous, cartilaginous, or synovial.
3. What are the different types of synovial joints?
fibers in a rubbery gelatinous substance
What makes our bodies flexible?
of resistance, two levels of range of motion
results are recorded in most cases.
Lesson 4.2 Muscles
With a partner research the following 3 muscle tissues
Create this table in your Journal
View prepared slides
Complete Part 1 only
Cardiac- They are striated muscle fibers form the wall of the heart & function involuntarily.
Skeletal -They are attached to bone, mostly in the legs, arms, abdomen, chest, neck and face. They are striated muscle fibers (lined under microscope) & attach to bone by a tendon. They hold the skeleton together and give the body shape. They are voluntary (we control them) and contract quickly and powerfully), but they tire easily.
Smooth -They are smooth (not striated) & are controlled automatically by our nervous system. They are also called ―involuntary‖ muscles. They make up the walls of the stomach and intestine to help break down and move food. They also line the walls of blood vessels. They take longer to contract than skeletal muscles, but also don’t tire as easily.
controlled by our CNS
w/lots of mitochondria
Activity 4.2.1 Muscle Rules Part 2
represents a fascicle.
3. How are muscle fibers and membranes organized to form a whole skeletal muscle?
The epimysium(“upon muscle”) is the outermost layer of connective tissue.
The perimysium (“around muscle”) is made of connective tissue and forms casings for bundles of muscle fibers.
The endomysium (“within muscle‖) is connective tissue surrounding each individual muscle fiber.
Each fascicle is a small cluster of muscle fibers, with endomysium between the individual fibers. Blood vessels run between the fascicles, bringing the tissue nutrients & removing waste. Nerves also run throughout, controlling the movement of the muscles. Together, the network of nerves and blood vessels are referred to as the plexus
Muscles must have at least two attachments and must cross at least one joint.
Muscles always “pull” and get shorter.
The attachment that moves is known as the insertion and the attachment that remains stationary is known as the origin.
Muscles that decrease the angle between ventral surfaces of the body are known as flexors. Muscles that increase the angle between ventral surfaces of the body are known as extensors
makes its way to the
Muscles work in opposing pairs.
Muscle striations point to the attachments and show the direction of pull.
Each muscle is given a Latin name based on one or more of its features
Take a look at the following muscle names and brainstorm what you can tell about these muscles simply by their names
Muscles each have an insertion, where they attach to the moveable bone and an origin, where they attach to the stationary bone.
HBS - A.4.2.2
How to Build a Better Body
Please grab your maniken and a tool kit and sit with your partner!
Use the wrench to take the arm off your Maniken.
DO NOT LOSE THE SCREWS!
chest. These muscles are found in between
the ribs and extend from the front of the ribs,
around back and past the bend in the bones.
movements such as a bench press, a
baseball pitch, or a swimming stroke.
they unthreaded on removal.
muscle is built in a manner similar to the serratus
from the origin to the insertion.
shoulderand the wide end should run down towards
the 5th through 7th rib. The muscle will have a teardrop shape. Keep
the insertion very narrow and the origin much wider. Do not worry
about perfect shape at this point. You will trim the muscle to fit the
Flatten the carrot slightly to make a shape
similar to an isosceles triangle. Do not worry
about perfect shape at this point. You will trim the muscle to fit the Maniken®.
7. What role do calcium and ATP play in muscle contraction?
8. What is a sarcomere?
9. How does a sarcomere contract and lengthen to cause muscle contraction?
Actin and myosin are layered. Myosin filaments have hooked parts that will stretch and pull themselves along the actin filaments when ATP attaches to them.
Calcium (Ca2+)must be removed for the muscle fibers to relax
Moving (Ca2+) back into the sarcoplasmic reticulum is ACTIVE TRANSPORT (requires ATP)
If the muscle cannot remove the (Ca2+) the muscle cannot relax and will stay contracted.
11. How do nerves interact with muscles?
Efferent neurons- Nerve cells that conduct impulses away from the central nervous system
Endomysium- The delicate connective tissue surrounding the individual muscular fibers within the smallest bundles
Epimysium- The external connective-tissue sheath of a muscle
Fascicle - A small bundle or cluster, especially of nerve or muscle fibers
Insertion - The attachment of a muscle tendon to a moveable bone or the end opposite the origin
Muscle - An organ composed of one of the three types of muscular tissue (skeletal, cardiac, and smooth), specialized for contraction to produce voluntary and involuntary movements of parts of the body
Myofibril - A threadlike structure, extending longitudinally through a muscle fiber (cell) consisting mainly of think filaments (myosin) and thin filaments (actin, troponin, and tropomyosin)
Myosin- The contractile protein that makes up the thick filaments of muscle fibers
Nerve- A cordlike bundle of neuronal axons and/or dendrites and associated connective tissue coursing together outside the central nervous system
Origin - The attachment of a muscle tendon to a stationary bone or the end opposite the insertion
Perimysium-The connective-tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers
Plexus- Network of interlacing blood vessels or nerves
Rigor mortis-Temporary rigidity of muscles occurring after death
Sarcomere- Any of the repeating structural units of striated muscle fibrils
Skeletal muscle- An organ specialized for contraction, composed of striated muscle fibers (cells), supported by connective tissue, attached to bone by a tendon or aponeurosis, and stimulated by somatic motor neurons
Sliding filament mechanism-The explanation of how thick and thin filaments slide relative to one another during striated muscle contraction to decrease sarcomere length
Smooth muscle- A tissue specialized for contraction, composed of smooth muscle fibers (cells), located in the walls of hollow internal organs, and innervated by the autonomic motor neurons
Striation- Any of the alternate dark and light cross bands of a myofibril of striated muscle
Tropomyosin- A protein of muscle that forms a complex with troponin regulating the interaction of actin and myosin in muscular contraction
Troponin- A protein of muscle that together with tropomyosin forms a regulatory protein complex controlling the interaction of actin and myosin and that when combined with calcium ions permits muscular contraction