Musculoskeletal System, the Kidney and Osmoregulation Flashcards
Difference between endo and exoskeleton
Exo - hard protective skeleton on the outside of the body
Endo - Skeleton on the inside of the body made of two types of tissue bones and cartilage.
What is a first-class lever
Have the fulcrum placed between the resultant and effective force, ex. contractions in the neck
What is a second-class lever
the resultant force between the effort force and the fulcrum, ex. calf muscle contracting
What is a third-class lever
effort force is between the resultant force and te fulcrum, ex. elbow
How do levers work in the skeleton?
Bone is a lever. A joint is a fulcrum. A muscle contraction is the effective force, the body part moved is the resultant force.
What is a flexor muscle?
A muscle that decreases the angle between the 2 sides of the joint. Ex, flexing the bicep.
What is an extensor muscle?
A muscle that increases the angle between the 2 sides of the joint. Ex, flexing the tricep.
Explain the movement of grasshoppers through levers and muscles.
When the tibia moves out it is an extensor muscle, fist class lever. When the tibia moves in the flexor muscle contracts, class three lever.
What is a synovial joint?
Most common type of joint. Features a fluid-filled space between smooth cartilage parts at the ends of articulating bones such as those in the spine.
What are the two types of joints?
Ball and Socket: Move bones along several axes. Shoulder and hip.
Hinge: Move along one axis. Elbow and knee.
What is smooth muscle fibre?
Located in the walls of blood vessels, stomach and intestines. Moves internal organs. Contractile, uninuclear cells.
What is cardiac muscle?
Located on the heart. Pumps blood. Cylindrical and striated cells.
What is skeletal muscle?
Attached to the bones. Used for locomotion. Long cylindrical, striated, multinuclear cell bundles.
Skeletal muscle structure
- Each bundle runs the length of the muscle and is attached to at least one motor neuron.
- Each bundle contains multiple myofibrils.
- Myofibrils are made up of chains of sarcomeres.
Structure of myofibrils
- Actin is at the ends between Z-lines, myosin is in-between actin
- Light bands are just actin
- Dark bands are actin and myosin overlap
- H zone is just myosin