Biology 28.1
Epitelial tissues
Consists of protective sheets of tightly packed cells connected by special junctions. The skin and the membranes that line the stomach, the lungs, and other organs are epithelial tissues.
Apoptosis
A type of cell death in which the cell uses specialized cellular machinery to kill itself. Like when your hand is first formed, it resembles a mitten, then turns into a hand. The cells between the fingers dies, allowing the individual fingers to develop.
Skeletal muscle
Align in bands of orderly rows and contain many nuclei. They are responsible for nearly all voluntary muscle movements, such as lifting your foot to kick a ball.
Muscle tissue
Capable of contracting to produce movement. The human body contains skeletal, cardiac, and smooth muscle tissues.
Embryonic stem cells
Cells produced during the first few divisions of the zygote. Have the potential to become any type of specialized cell in the body.
Humans
Collections of specialized cells that work together.
Sperm cells
Develop whiplike tails that enable them to swim.
Organs
Different types of tissue that function together form an organ.
Specialized cells
Each type of specialized cell has a particular structure and a chemical make up that enable it to perform a specific task.
Cells lining the gut
Elongated and tightly packed to provide more surface area for the absorption of nutrients.
Four general types of tissues
Epithelial, connective, muscle, nervous
Zygote
Formed by the union of an egg and sperm. All cells come from the zygote. Zygote divides and differentiates into more than 200 types of different human cells.
Organ
Group of different types of tissues that work together to perform a specific function or related functions.
Tissue
Groups of similar cells that work together to perform a specialized function.
Tissues
Groups of similar cells that work together to perform a specialized function.
Mucus cells
Helps to trap foreign particles and protect the lungs from pathogens such as bacteria and viruses.
Cell specializiation
Involves two main steps: determination and differentiation.
Multicellular organisms
Made up of different cells that all have different functions.
Determination
Most stem cells become committed to develop into only one type of cell.
Cells after determination
Once a cell is committed to becoming a specialized cell, it will develop into only that type of cell. A cell committed to becoming a neuron can only become a neuron, even if transplanted into another part of the body. During normal development, determination cannot be reversed.
Lungs
Organs comprised of all four types of tissues. Muscle and connective tissue expand and contract the lungs. Nervous tissue sends and receives messages that help regulate gas exchange in the lungs and the rate at which a person breathes. Epithelial tissue forms the inner lining of the lungs.
Organ systems
Perform the most complex activities in the body.
Determination
Process by which stem cells become committed to develop into only one type of cell.
Cells in the lungs
Responsible for the exchange of gases.
Connective tissues
Serves to support, bind together, and protect other tissues and organs. Tendons, ligaments, bone, and cartilage are all connective tissues.
Smooth muscle cells
Shorter than skeletal cells and have only one nucleus. They perform involuntary movements, such as raising the hair on your arms and legs.
Differentiation
The process by which committed cells acquire the structures and functions of highly specialized cells.
Differentiation
The process by which committed cells acquire the structures and functions of highly specialized cells. It occurs because specific genes in each cell are turned on and off in a complex, regulated pattern. The different structures of these specialized cells allow them to perform specific functions within the body.
The function of muscle cells
To produce movement by contracting and relaxing.
Nervous tissue
Transmits and receives impulses in response to stimuli, processes information, and regulates the bodies response to its environment.
Organ system
Two or more organs that work in a coordinated way to carry out similar functions.
Organ systems
Two or more organs working in a coordinated way. The organ system that allows you to breathe-not only the lungs, but the sinuses, the nasal passages, the pharynx, and the larynx.
