Chapter 10(muscular And Skeletal Systems) Flashcards
What is the basic unit of muscles?
Myofibril
Each thick myofilament contains
several hundred molecules of the protein myosin
Thin filaments contain
two strands of the protein actin
The myofibrils are composed of
regularly arranged myofilaments of two types, thick and thin.
The energy for muscular motion is generated by
densely packed mitochondria that surround the myofibrils.
Muscles can be divided into three main groups according to their structure, namely:
Smooth muscle tissue.
Skeletal muscle tissue.
Cardiac (heart) muscle tissue.
The smooth muscle tissues are made up
Thin, elongated, and spindle-shaped with pointed ends cells
The nucleus of the smooth muscle tissue is:
Single, large, and oval-shaped nucleus per cell
Smooth muscular tissue posses specialized cytoplasm called
sarcoplasm
Smooth muscular tissue are surrounded by a thin cell membrane called the
sarcolemma.
Why are the called smooth muscle
They are not arranged in a definite striped (striated) pattern, as in skeletal
muscles
____ muscle is not controlled by the brain
Smooth muscles
Where are smooth muscles located?
They layers in the walls of various hollow organs and blood vessels.
Functions of Smooth Muscle Tissue
- peristalsis is used for slow, involuntary movement to aid digestion
- controls blood pressure and flow by adjusting the diameter of the vessels.
What is the most abundant tissue in the vertebrate body?
Skeletal muscle
Why is it called skeletal muscles?
These muscles are attached to and bring about the movement of the various bones of the skeleton
Skeletal muscles are enclosed in a connective tissue sheath called
epimysium.
Smaller bundles of muscle fibers within the muscle are called?
Fasciculi
What is are muscle fibers
These are elongated , cylindrical cells with multiple nuclei (syncytium).
muscle fibre is made up of many smaller units, called?
the myofibrils
What are Actin filaments:
These filaments are Thinner, make up the light bands (I-bands)
What are Myosin filaments?
These filament are Thicker, make up the dark band (A-band).
What is a Sarcomere?
This is the Basic unit of contraction, composed of actin and myosin filaments arranged in a specific pattern.
Each myofibril consists of small protein filaments, known as
actin and myosin filaments.
What happens during cell contraction?
Sliding of actin filaments into the spaces between myosin filaments within sarcomeres.
Functions of Skeletal Muscle Tissue
- bring about the co-ordinated movements
- breathing process.
_____ is a unique tissue found only in the walls of the heart.
Cardiac muscle
What are the characteristics of a cardiac muscle ?
Shorter fibers, less distinct striations, thinner sarcolemma, single central nucleus per fiber, interconnected by “muscle bridges”.
Characteristics of Skeletal muscle:
Longer fibers, prominent striations, thicker sarcolemma, multiple nuclei distributed throughout the fiber.
What are the characteristics of a Smooth muscle?
No striations, single nucleus, elongated spindle-shaped cells.
_____ muscle have numerous nucleus per cell
Cardiac and skeletal muscles
What are the Functions of Cardiac (Heart) Muscle
Tissue
- Responsible for the heartbeat
- Propels blood
Which type of muscle posses muscle bridge
Cardiac muscle
What is an hydrostatic skeleton?
Fluid-filled cavities, providing internal pressure for movement and shape support (e.g., sea anemone, worms).
movement is a result of
contraction of muscles.
The sea anemone has one set of longitudinal muscles in the ____of the body, and a layer of circular muscles in ____ of the body.
- The outer layer
- The inner layer
What are Exoskeletons?
These are hard segments that cover the muscles and visceral organs.
Muscles for movement are attach to what part of the exoskeleton?
inner surface of the exoskeleton.
What skeleton restrict the growth of the animal?
Exoskeletons
cartilage and bone are types of what tissues?
Connective tissues
Function of the musculoskeletal system
- allowing the animal to move to more favourable external conditions.
- helps regulate blood calcium levels, serve as a calcium sink.
- Generating internal heat
bones fused together with some “soft spots” in infants that close by.
14-20 months
The Vertebral Column is Made up of
33 vertebrae separated by flexible cartilage disks that can deteriorate with age and cause back pain.
sternum and ribs (except the lowest pair) with cartilage for?
flexibility during breathing.
What are Immovable Joints?
Bones are tightly interlocked with no movement possible
Function of immovable joints
Provides strong structural support and protects vital organs.
What are Partly Movable Joints?
Allow some limited movement due to cartilage between bones.
Function of partly moveable joints
for spinal movement
Synovial Joints:
Most common type, offer the greatest degree of flexibility with smooth, lubricated surfaces
Function of Cartilage caps:
Protect bone ends at the joint.
Function of Synovial fluid:
Lubricates the joint, reducing friction and wear.
Function of Ligaments:
Strengthen and stabilize the joint.
Function of Tendons:
Connect muscles to bones for movement.
Function of Bursae:
Fluid-filled sacs reducing friction between bones and surrounding tissues.
Function of synovial joint
Enables wide range of motion for various activities like walking, running, and manipulating objects.
The knee joint contains how many joints)
13 bursae
