What is the relationship and definition of cells, tissue and organs?
Cells make up tissues that make up organs which make up organ systems. Cells are the basic unit that makes up life, tissues are groups of cells that perform common functions, and organs are structures composed of two or more tissue types joined together that perform specific function/s.
How how are tissues defined?
Groups of specialized cells that are similar in structure and that perform common functions.
What kinds of tissues are there? What makes each special (different from the others)? What functions do they perform? What elements of their structure allow them to perform those functions?
Epithelial, Connective, Muscle, and Nervous. Epithelial are sheets of closely packed cells that function in protection, exchange, and secreation. Connective are sparse cells in extracellular matrix that function in binding support of other tissues. Muscle are long cells (fibers) with contractile protein that function the movements of body parts. Nervous are neurons with branching extensions that function as transmission of nerve signals.
In what organ/parts of the body can you find examples of each type of tissue?
Epithelial tissue can be found to line or cover sufaces or body cavities. Examples: outer layer of skin, lines kidneys, and most digestive organs. Connective tissue are diverse in classification. Examples are bones, blood, tendons, cartiledge, and can surround internal organs. Muscle tissue can be found connected to bones, surrounding hollow organs and tuves including blood vessels and bladder, and the heart. Nervous tissue is located in brain and spinal cord.
What is the difference between an endocrine gland and and exocrine gland?
An endocrine gland secrete substances called hormones into the bloodstream. Secrete into the blood to carry chemical messages throughout the body
Ex: thyroid gland. Exocrine glanes secrete their products into a hollow organ or duct. Secrete into ducts to exterior of body. Ex: glands in mouth that secrete salivia.
What is the difference between the three types of cell-junctions we discussed?
Junction hold epithelial tissue together. There are tight juctions where nothing passes, adhesion junctions where it allows some movement between cells, and gap juctions that consist of protein channels that permit movement of ions or water
What are the kinds of muscle tissues? How are they the same? How are they different? Where are they found?
Skeletal is responsible for voluntary body movement. Can be found connected to tendons that are connected to bones. Cardiac muscle form contractile tissue of the heart. Smooth muscle moves the wall of internal organs such as the stomach, bladder, and arteries.
Why are tissues arranged in organs?
An organ performs functions that none of its component tissue could carry out alone. Different tissues function together to serve different function in the organ.
Can you define positive feedback and negative feedback? How do they help maintain homeostasis?
Negative feedback is a change in a variable or condition that triggers mechanisms that reverse change. Mechanisms keep internal variables fairly constant with small flunctuations around set point. Positive feedback amplifies original change. In animals most control centers that maintain homeostasis are located in the brain. Not a mechanism for maintaing homeostasis.
What is the function Integumentary system?
Protects from injury, infection and dehydration, particpates in temperature control, and receives sensory input from the internal environment.
What is the function of the Skeletal System?
Protects, supports, and anchors body parts, provides the structural framework for movement, produces blood cells, stores minerals.
What is the function of the circulatory system?
Transports materials to and from all cells, participates in the maintenance of body temperature, participates in mechanisms of defense against disease and injury
What is the function of the lymphatic system?
Returns excess tissue fluid to the circulatory system. Participates in both general and specific (immune) defense responses.
What is the function of the respiratory system?
Exchange gases (oxygen and carbon dioxide) between air and blood and participates in the production of sound (vocalization)
What is the function of the nervous system?
Detects both external and internal stimuli, controls and coordinates rapid responses to these stimuli, and integrates the activities of other organ systems.
What is the function of the endocrine system?
Produces hormones that regulate many body functions, participates with the nervous system in integrative functions.
What is the function of the digestive system?
Provides the body with water and nutrients. The liver synthesizes certain proteins and lipids for the body. The liver inactivates many chemicals including hormones, drugs, and poisons.
What is the function of the urinary system?
Maintains the volume and composition of body fluids. Excretes some wastes products
What is the function of the reproductive system?
Females produce eggs and nurtures the fertilized egg, developing embryo and fetus until birth. Male produce sperm and participate in the delivery of sperm to female.
What are the types of epithelial tissue and what shapes do they come in?
Simple which is a single layer of cells and stratified which is multiple layers of cells. Tissue can either be squamous, cubodial or columnar.
What are squamous epithelium tissue?
Consist of one or more layer of flattened cells. Forms outer surfaces of skin and lines inner surface of blood vessels, lungs, mouth, throat, and vagina.
What are cuboidal epithelium tissue?
Composed of cube shaped cells. Forms the kidheys tubules and also covers the surfaces of the ovaries.
What is columnar epithelium tissue?
Composed of tall, rectangular cells. Lines parts of the digestive tract, certain reproductive organs, and the larnyx.
What are Glandular Epithelia?
Epithelial cells adapted to make glands. Endocrine and exocrine glands.
What is a basement membrane?
Beneath the cell of an epithelial tissue and a supporting noncellular layer. Anchors the cell to the stronger connective tissue underneath. Composed primarily of protein secreted by epithelial cells
What are the different types of connective tissue?
Loose connective tissue which an example would be connects skin to muscle. Fibrous connective tissue. Examples include tendons and ligaments. Adipose tissue help to store fat. Cartilage that helps with structure and cushions bones. Bone which is Ca + collagen. And Blood, plasma.