Anatomy & Physiology
Read the body as nested living structure: cells form tissues, tissues form organs, organs cooperate in systems, and those systems overlap in regions while regulating one another to keep the organism functioning.
The body is nested, but function runs across the nesting.
An organ belongs to a region, participates in one or more systems, contains several tissues, and depends on circulation, innervation, and regulation beyond its local boundaries. Anatomy locates the parts; physiology explains the changing relationships among them.
Study anatomical structure across organisms there. This medical branch centers the human body and clinically useful structure-function relationships.
open biology anatomyEnter the body through a functional system, while keeping the shared foundations visible.
Only the Skeletal System has a live child route right now. Planned systems remain visible because they clarify the intended anatomy curriculum, but they are deliberately non-clickable.
Cells & tissues
How do specialized cells assemble into tissues with distinct mechanical and physiological roles?
Homeostasis
How does the body keep internal variables within useful ranges while conditions change?
Skeletal system
How do bones, cartilage, joints, and living bone tissue support the body while still permitting movement and adaptation?
open systemMuscular system
How does contractile tissue turn chemical energy into force across joints and organs?
Cardiovascular system
How does a closed circulation distribute gases, nutrients, signals, heat, and waste across tissues?
Nervous system
How do excitable cells detect change, communicate, and coordinate behavior across the body?
A body region is a place where several systems meet.
Thorax
Heart · lungs · great vessels · trachea · thoracic cage
The rib cage is skeletal, breathing uses muscles, gas exchange is respiratory, and transport is cardiovascular. One region hosts several coordinated systems.
Shape, material, geometry, and organization make some physiological actions possible and others difficult or impossible.
A named system is an analytical grouping. Real tissues and organs are physically interwoven and physiologically interdependent.
Development, activity, injury, disease, adaptation, repair, and aging continually modify both anatomy and physiology.