Levels of Organization and Cell Specialization

Flashcards covering human body levels of organization, cell specialization steps, tissue types, and major organ systems.

What is a zygote?

A single fertilized cell formed by the union of an egg and sperm that divides and differentiates into more than 200 different types of human cells.

What are the two main steps involved in cell specialization?

Determination and differentiation.

What are embryonic stem cells?

Cells produced during the first few divisions of the zygote that retain the potential to become any type of specialized cell in the body.

What happens during cell determination?

Stem cells become committed to develop into only one type of cell, losing their ability to express some genetic information in a process that cannot be reversed during normal development.

What is cell differentiation?

The process by which committed cells acquire the structures and functions of highly specialized cells as specific genes are turned on and off in a complex, regulated pattern.

How do skeletal muscle cells and smooth muscle cells differ in structure and function?

Skeletal muscle cells align in bands of orderly rows, contain many nuclei, and control voluntary movements; smooth muscle cells are shorter, contain only one nucleus, and perform involuntary movements.

What is apoptosis and what is an example of its role in human development?

Apoptosis is programmed cell death; an example is the death of cells between fingers that allows individual fingers to develop from mitten-like hand structures.

What are the five levels of organization in the human body in order of increasing complexity?

Cells, tissues, organs, organ systems, and the organism.

What are the four general types of tissues in the human body?

Epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

What is the primary function of epithelial tissue?

It consists of protective sheets of tightly packed cells connected by special junctions that line organs and cover body surfaces.

What are four examples of connective tissue?

Tendons, ligaments, bone, and cartilage.

How do tendons and ligaments differ in what they connect?

Tendons connect muscle to bone, whereas ligaments connect bone to bone.

What is the function of cartilage in the skeletal system?

Cartilage covers the ends of bones to reduce friction and absorb shock.

Which minerals are stored in bones according to the lecture notes?

Calcium and Phosphorus.

What is an organ?

A group of tissues that carry out a specialized function of the body.

What organs and structures compose the human respiratory system?

Nose, sinuses, pharynx, larynx, trachea, and lungs.

What is the primary function of the endocrine system?

It influences growth, development, and metabolism, and helps maintain homeostasis.

What are the primary functions of the skeletal system?

It supports and protects vital organs, allows movement, stores minerals, and serves as the site for red blood cell production.