Tissues, Organs, and Homeostasis (animals) Flashcards
There are four levels of organization. What are they?
Cells
Tissues
Organs
Organ Sytems
How many different cell types do humans have?
210
Cell
- The smallest division of life
- all life is cellular
- all cells come from pre-existing cells
Tissues
groups of cells that are similar in structure and function
Organ
combinations of different tissues that form a structural and functional unit
Organ System
groups of organs that cooperate to perform the major activities of the body
The vertebrate body contains how many principle organ systems?
11
The main body plan of all vertebrates is essentially a ____ within a _____
tube; tube
What is the “inner tube”?
the digestive tract
What is the “Outer tube”?
main vertebrate body
- supported by a skeleton
- outermost layer=skin and its accessories
In adult vertebrates there are four primary tissues. What are they?
- Epithelial
- Connective
- Muscle
- Nervous
Epithelial Tissue
Epithelium covers exposed surfaces of the vertebrate body
- all germ layers have it
- Can be membranes and glands
- provides a protective barrier
describe the characteristics of epithelial cells
- tightly bound together
- replaced throughout life
- attach to underlying connective tissues by a fibrous membrane
Epithelium has________
Polarity
Basal surface=secured side
Apical surface=Free side
describe the layers of the epithelial
one layer does_______; several create_______
- One layer allows for diffusion, absorption, and secretion
- Several layers creates a dense barrier to abrasion and chemicals
Epithelial: Cell size
Describe flat, cubed, and thick cells
Flat: allow for materials to diffuse through
Cubed: absorb and secrete moderately
Thick: absorb, secrete, and process chemicals at the greatest rate
How do glands form?
from invaginated epithelia
describe exocrine glands
- connected to epithelium by a duct
- sweat, sebaceous and salivary glands
describe endocrine glands
- ductless
- secretions (hormones) enter blood
Describe connective tissues
- Derive from embryonic mesoderm
- All have abundant extracellular meterial
Connective tissues are divided into two major classes. What are they and give examples
Connective tissue proper
-loose, dense, adipose
Special connective tissue
-cartilage, bone, and blood
Connective Tissues consist of:
Matrix: extracellular material
(protein fibers, gels, salts, fluids, fats, etc.)
-Cells that produce said matrix
What are fibroblasts?
cells that produce and secrete protein fibers in extracellular matrix
-fibers include thick, tough collagen fibers and stretchable elastic fibers
connective tissue proper consists of three main things (supposedly). What are they?
- loose connective tissue
- Dense connective tissue
- Adipose cells (Adipose tissue)
Describe loose connective tissue
contains large amounts of a gel-like substance and is strengthened by protein fibers
Describe Dense Connective tissue
Contains less gel and more collagen than loose connective tissue. Collagen fibers may be parallel to one another (tendons, ligaments) or go in many different direction (dermis of skin, whites of eyes)
Describe adipose cells
- adipose cells (fat cells) also occur in loose connective tissue
- develop in large groups in certain areas forming adipose tissue
Name 3 special connective tissues
Cartilage, Bone, Blood
Describe cartilage
- cartilage cells are called chondrocytes
- the matrix is called chondroitin (collagen/elastin fibers)
- flexible with great tensile strength
- found in joint surfaces and other locations
Describe bone
- bone cells are called osteocytes
- hardened with calcium salts around collagen fibers
describe blood
- extracellular material is the fluid plasma
- red blood cells
- white blood cells
- platelets
What are the three muscle types?
smooth, skeletal, and cardiac
describe smooth muscle
- walls of blood vessels and visceral organs
- mono-nucleated
- involuntary
describe skeletal muscle
- attached to bone by tendons
- cells are long and multi-nucleated
- voluntary
- striated
describe cardiac muscle
- smaller, interconnected cells in heart only
- mono-nucleated
- interconnections called intercalated disks
- muscle cells form a single functioning unit
Neurons consist of three parts. What are they and give a short description of each
Cell Body: contains the nucleus
Dendrites: highly branched extensions (conduct electrical impulses toward the cell body)
Axon: single cytoplasmic extension (conducts impulses away from cell body)
describe neuroglia
- do not conduct electrical impulses
- support and insulate neurons
- eliminate foreign materials in and around neurons
- form an insulating cover
Which organ systems are responsible for communication and integration?
- detect external stimuli
- coordinate the body’s resposes
Nervous, Sensory, and Endocrine
Which body organs are responsible for support and movement?
Musculoskeletal system (consists of two interrelated organ systems)
Which body organ systems are responsible for regulation and maintenance?
-regulate and maintain the body’s chemistry
Digestive, Circulatory, Respiratory, Urinary systems
Which body organ systems are responsible for defense?
Integumentary and Immune
Which body organ system is responsible for reproduction and development?
- spreading genes
- nurtures the developing embryo and fetus
reproductive system
