Bones
Where in the body does blood cell production primarily occur?
In red bone marrow found in flat bones and ends of long bones
Osteoblasts are bone cells that:
Build new bone by secreting bone matrix
Bone remodeling is the process of:
Constantly breaking down and rebuilding bone throughout life
Approximately what percentage of your body weight is made up of muscle?
40%
The attachment point of a muscle that typically moves during contraction is called the:
Insertion
Long bones like the femur are best suited for:
Acting as levers for movement
What is the role of osteoclasts in bone tissue?
They break down old or damaged bone tissue
When blood calcium levels are too low, what happens to bone tissue?
Bone resorption increases to release calcium into the blood
Which type of muscle tissue is involuntary and found in the walls of hollow organs?
Smooth muscle
The basic contractile unit of a muscle fiber is the:
Sarcomere
Which type of bone tissue forms the dense, outer layer of bones?
Compact bone
Which type of bone formation occurs when bone develops directly from connective tissue without a cartilage model?
Intramembranous ossification
Osteoporosis is a condition in which:
Bones become weak and brittle due to excessive bone loss
The visible striations (stripes) in skeletal muscle are caused by:
The organized arrangement of contractile proteins
Which protein forms the "thick filaments" in a sarcomere?
Myosin
The basic structural unit of compact bone is called:
An osteon (Haversian system)
The growth plate (epiphyseal plate) in a long bone is responsible for:
Increasing bone length
What vitamin is essential for calcium absorption and bone health?
Vitamin D
Cardiac muscle cells are connected by special structures called:
Intercalated discs
According to the sliding filament theory, muscle contraction occurs when:
The thick and thin filaments slide past each other
What gives bone both strength and flexibility?
The combination of collagen fibers and calcium phosphate crystals
According to Wolff's Law, bones adapt by:
Becoming stronger in response to mechanical stress
Peak bone mass is typically reached around:
Age 30
What makes cardiac muscle "autorhythmic"?
It can generate its own electrical signals without nervous system input
Type I (slow-twitch) muscle fibers are best suited for:
Long-duration, endurance activities