1. Unit One “From Cells to Organ Systems”

2. Levels of Organization All living things have a level of organization based on their specific composition All living things have a level of organization based on their specific composition A Prokaryotic organism is made of just one cell A Prokaryotic organism is made of just one cell A Eukaryotic organism is made of millions to trillions of cells depending on the species to which the individual belongs A Eukaryotic organism is made of millions to trillions of cells depending on the species to which the individual belongs Humans are, of course, Eukaryotic; a person is composed of trillions of cells functioning in concert to enable the individual to live Humans are, of course, Eukaryotic; a person is composed of trillions of cells functioning in concert to enable the individual to live

3. Levels of Organization Within a person, or any eukaryotic organism, there is a level of organization of structures which is as follows: Within a person, or any eukaryotic organism, there is a level of organization of structures which is as follows: Atoms - - > Molecules/Compounds - - > Organelles - - > Cells - - > Tissue - - > Organs - - > Organ Systems - - > Organism Atoms - - > Molecules/Compounds - - > Organelles - - > Cells - - > Tissue - - > Organs - - > Organ Systems - - > Organism

4. Epithelial Tissue Epithelial Tissue consist of layers of cells that cover and protect various surfaces and body cavities Epithelial Tissue consist of layers of cells that cover and protect various surfaces and body cavities Glands are specialized Epithelial Tissues because they synthesize and secrete a fluid Glands are specialized Epithelial Tissues because they synthesize and secrete a fluid Exocrine Glands – secrete fluid to the outside of the individual Exocrine Glands – secrete fluid to the outside of the individual Endocrine Glands – secrete a specific fluid known as a Hormone into the blood stream within the body Endocrine Glands – secrete a specific fluid known as a Hormone into the blood stream within the body

5. Epithelial Tissue Epithelial Tissues are classified by shape and number of cell layers Epithelial Tissues are classified by shape and number of cell layers Simple Epithelium are composed of a single layer of cells Simple Epithelium are composed of a single layer of cells Stratified Epithelium are composed of multiple layers of cells aka “Strata” Stratified Epithelium are composed of multiple layers of cells aka “Strata”

6. Categories of Epithelial Tissue

7. Connective Tissue Supports the softer organs of the body against gravity and connects parts of the body to each other Supports the softer organs of the body against gravity and connects parts of the body to each other Collagen Fibers – made of protein, add strength/integrity to organs and are slightly flexible Collagen Fibers – made of protein, add strength/integrity to organs and are slightly flexible Cartilage – is the transition tissue from which bone develops; maintains the shape of certain body parts (nose) and protects/cushions joints Cartilage – is the transition tissue from which bone develops; maintains the shape of certain body parts (nose) and protects/cushions joints

8. Connective Tissue Bone – specialized connective tissue that contains only a few living cells; most of bone structure consists of hard mineral deposits of calcium and phosphate Bone – specialized connective tissue that contains only a few living cells; most of bone structure consists of hard mineral deposits of calcium and phosphate Blood – consists of cells suspended in a fluid matrix called “Plasma”; considered connective tissue because all blood cells are derived from earlier cells located within bone Blood – consists of cells suspended in a fluid matrix called “Plasma”; considered connective tissue because all blood cells are derived from earlier cells located within bone

9. Connective Tissue Adipose Tissue – highly specialized for fat storage; located primarily under the skin where it serves as a layer of insulation and also forms a protective layer around internal organs Adipose Tissue – highly specialized for fat storage; located primarily under the skin where it serves as a layer of insulation and also forms a protective layer around internal organs

10. Muscle Tissues Consist of specialized cells that are able to shorten and contract, resulting in movement Consist of specialized cells that are able to shorten and contract, resulting in movement Skeletal Muscle Tissue – connects to tendons, which attach to bones; it is voluntary muscle because we can exert conscious control over it Skeletal Muscle Tissue – connects to tendons, which attach to bones; it is voluntary muscle because we can exert conscious control over it Cardiac Muscle Tissue – found only in the heart; individual cells are much shorter than Skeletal Muscle cells and this tissue is considered involuntary because the heart beats on its own Cardiac Muscle Tissue – found only in the heart; individual cells are much shorter than Skeletal Muscle cells and this tissue is considered involuntary because the heart beats on its own

11. Muscle Tissue Smooth Muscle Tissue – surrounds hollow organs and tubes (blood vessels, digestive tract, uterus, bladder); these cells are much smaller than Skeletal Muscle cells and it is involuntary like Cardiac Muscle Smooth Muscle Tissue – surrounds hollow organs and tubes (blood vessels, digestive tract, uterus, bladder); these cells are much smaller than Skeletal Muscle cells and it is involuntary like Cardiac Muscle

12. Nervous Tissue Consists primarily of cells that are specialized for generating and transmitting electrical impulses throughout the body Consists primarily of cells that are specialized for generating and transmitting electrical impulses throughout the body Neurons are those specialized cells that transmit electrical impulses Neurons are those specialized cells that transmit electrical impulses Glial Cells are found in Nervous tissue but do not transmit electrical impulses; their role is to surround and protect neurons and also supply them with nutrients Glial Cells are found in Nervous tissue but do not transmit electrical impulses; their role is to surround and protect neurons and also supply them with nutrients

13. Organs & Organ Systems Organ – structure composed of two or more tissue types that perform a specific function or multiple functions Organ – structure composed of two or more tissue types that perform a specific function or multiple functions Organ System – a group of organs that serve a broader function that is vital to the organism/species Organ System – a group of organs that serve a broader function that is vital to the organism/species

14. Body Position/Direction

15. The Skin The Skin aka Integumentary System has many functions: protect from dehydration, defense against microorganismal infection, regulation of body temperature, and aids in some sensory perception (touch, vibration, pain etc.) The Skin aka Integumentary System has many functions: protect from dehydration, defense against microorganismal infection, regulation of body temperature, and aids in some sensory perception (touch, vibration, pain etc.) Skin consists of the Epidermis (outer layer of cells) and the Dermis (inner layer of connective tissue) Skin consists of the Epidermis (outer layer of cells) and the Dermis (inner layer of connective tissue) Melanocytes – located near the base of the epidermis and produce a dark brown pigment known as Melanin (protects against UV Rays) Melanocytes – located near the base of the epidermis and produce a dark brown pigment known as Melanin (protects against UV Rays)

16. The Skin

17. Eukaryotic Species & Homeostasis Humans, who are Eukaryotic, must keep their bodies in a state of dynamic equilibrium where fluid amounts are always in flux but do not fluctuate greatly Humans, who are Eukaryotic, must keep their bodies in a state of dynamic equilibrium where fluid amounts are always in flux but do not fluctuate greatly Maintaining the body’s dynamic equilibrium is known as “Homeostasis” Maintaining the body’s dynamic equilibrium is known as “Homeostasis” Water levels - Nutrient levels Water levels - Nutrient levels Internal Temperature - Hormone levels Internal Temperature - Hormone levels