Chapter 7: Animals:From Cells to Systems - Biology Flashcards
(14 cards)
Types of Tissues
A tissue is a cluster of cells that share the same specialized structure, and function.
1. Epithelial Tissue
2. Muscle Tissue
3. Nervous Tissue
4. Connective Tissue
Epithelial Tissue
- Line the surfaces of the body as a body covering, and between internal organs
- Made of cells with strong connections between adjoining cell membranes so they form a barrier
Types of Epithelial Tissue
Skin Epithelia
- Made of thin flat cells that form sheets, and act as semi-permeable between the inside and outside of a body
Columnar Epithelia
- Made of columns of cells that line the small intestine, the stomach, and the glands
- May secrete mucus, have finger like projections called clila, and or absorb materials
Muscle Tissue
- Designed to change their shape
- Act by lengthening or shortening
Types of Muscle Tissues
Skeletal muscle
- Made of cells that line up in the same direction making the tissue look striped, or strlated
- Attaches to the bone making it possible for the body to move
- Found in places where the body needs support like arms, legs, limbs, lower abdomen, and back
Smooth muscle
- Made of cells that are tapered at both ends, and do not have a strlated appearance
- Found in blood vessles and the wall of internal organs such as the esophagus, and stomach
- Contracts more slowly than skeletal muscle, but its action can be sustained for a long time
Cardiac muscle
- Made of cells whose nuclei appears to be between cells
- Are branched and unevenly strlated
- Contracts as a unit
Found only in the heart
Nervous Tissue
- Made of cells called neurons which have finger-like projections to receive and transfer signals
- Coordinates body action
Nervous Tissue Types
Varied in their actions:
- Some relay signals from brain or spinal cords to muscles and glands
- Others detect information from their environment (like the heat from a hot stove) and trigger the body’s response
Connective Tissue
- Strengthens, supports, protects, binds, and connects cells, and tissues
- Consists of cells in an extracellular matrix that can range from a liquid (in blood), to elastic materials that can stretch (in ligaments) to mineral deposists (in bone).
Types of Connective Tissue
Bone
- Made of cells surrounded by calcium hardened tissue through which blood run
- Needed for movement, support, protection
Fat (Adipose Tissue)
- Made of large tightly packed cells
- Found under the skin, and around organs
- Neede for energy storage, padding, and insulation
Blood
- Include red blood cells, white blood cells, and platelets within a straw colored liquid matrix called plasma
- Transports nutrients and oxygen
- Clots when the skin is cut
- Attacks invaders such as bacteria, and viruses
3 factors influencing the differentiation in cells
- the contents of the cell’s cytoplasm
- environmental conditions such as temperature
- The influence of neighbouring cells
Cell specialization (cytoplasm content)
- Mitosis makes sure that each set of daughter cells have identical sets of chromosomes, but the contents of cytoplasm differ in each daughter cell
- Human embryos even when hours old, the future of its cell, and how they will specialize is predetermined
Eg differences between the cells in an amoeba, and the cells in a blue whale is related to differences in cytoplasm
Cell Specialization
(Environmental Conditions)
- Conditions such as temperature, and absense or presense of nutrients
- Differences in environmental conditions could also explain why cells with identical genes develop differently
- Production of abnormal cells iss often linked to environmental conditions, such as presence of chemical contaminants, temperature changes, diseases, and parasites present during cell development
Stem Cells
An unspecialized cell that can produce arious specialized cells
Embryonic stem cells (uses of stem cells)
Unspecialized cells that can become any one of an organism;s body cells, making them valuable for research, and medical treatment
