Crash Course Anatomy & Physiology Notes, Tissues, Part 1
every cell in the body has its own specific job related to maintaining homeostasis
cells are the most basic building blocks in the hierarchy of complex structures
tissues are the fabric of the body
when 2 or more tissues combine, they form organs
type of tissue defines its function
there are 4 primary tissues
nervous tissue provides control and communication
muscle tissue gives movement
epithelial tissue lines the body cavities and organs and cover and protect the body
connective tissue provides support
histology - the study of tissues
carmine - a red dye derived from the scales of crushed-up cochineal insects, used to highlight different cell structures
nervous tissue forms the nervous system which regulates and controls the body's functions
nervous tissue senses stimuli and sends electrical impulses through the body in response to those stimuli
nervous tissue is made up of two types of neurons and glial cells
neurons sense stimuli and send messages to your brain
neurons are made up of the cell body (soma), dendrites, and the axon
cell body (soma) is the cell's life support, it has all the necessary parts like a nucleus, mitochondria, and DNA
dendrites are bushy and look like the trees that they're named after, they collect signals from other cells to send back to the soma
axon is long and rope-like, it's the transmission cable and it carries messages to other neurons and muscles and glands
glial cells provide support, insulation, protection and tether to blood vessels
muscle tissues can contract and move
the three types of muscle tissue are skeletal, cardiac, and smooth
skeletal muscle tissue attaches to all the bones in your skeleton, it pulls on the bones or skin when they contact to make your body move
skeletal tissue is made up of multinucleate and striations
cardiac muscle tissue cells are generally uninucleate meaning one nucleus, have striations
smooth muscle tissue lines the walls of the blood vessels and hollow organs, don't have striations
















