unit 2 chapter 6 part one

Question 1

Levels of Organization of the human body

Answer 1

cells - similar type join to form tissues
tissues - interact to form discrete units of function called organs
organs - interact to carry out common tasks and form organ system
organ systems - interact making an integrated functioning body

Question 2

cell structure

Answer 2

Nucleus, Mitochondria, Cytoplasm, Plasma membrane

Question 3

Nucleus

Answer 3

-the membrane-bound organelle in a cell that contains the chromosomes
-All cells in the body begin with a nucleus, except for red blood cells push them out
at maturity
-Contains deoxyribonucleic acid aka DNA
-DNA arranged in functional units called Genes

Question 4

Gene functions

Answer 4

1) normal life of a cell act as a blueprint for making proteins
2)act as a material of heredity, form copies of themselves so that each new cell
formed has a complete and identical set of blueprints

Question 5

responsible for hereditary diseases
(ex. hemophilia, and sickle cell

Answer 5

Defects in genes

Question 6

Genes

Answer 6

are linked together by long strings called chromosomes

Question 7

Mitochondria

Answer 7

Power plants of the cell
* Burn fuels ( sugars and fats) with oxygen to supply energy for the cell
* creates adenosine triphosphate (ATP)
- an energy carrier for cell processes
* Neurons and muscle cells contain high amounts

Question 8

Cytoplasm

Answer 8

Refers to all the cellular material except the plasma membrane and the nucleus
* Cytosol is the fluid portion of the cytoplasm

Question 8

Plasma Membrane

Answer 8

• encloses the cell
  -tightly regulates the flow of materials in and out of the cell
  -membranes are flexible, allowing cells to change shape
  ex: rbc must squeeze through tiny capillaries that are thinner
  than its normal diameter

Question 9

Epithelial tissue

Answer 9

Forms flat sheets
* found on
1) surfaces where exchange with the environment takes place
(example: lining of the gut)

2) where rapid regeneration must occur to protect internal structures
(example: skin, or surface of eyes)

-May contain glands
1) Produce and secrete substances (example: saliva, sweat, insulin)

Question 10

Muscle Tissue

Answer 10

Contractile, meaning can shorten its length
* Contain long fibers of the protein’s actin and myosin
* Contractions
* Caused by fiber movements

1) Receives stimulus to contract when axon terminals of motor
neurons make contact with the muscle
2) Neuron releases a chemical called neurotransmitter onto the
muscle cell surface at the neuromuscular junction
3) Causing the chemical changes within the muscle that leads to contraction

Question 11

3 forms of muscle tissue

Answer 11

1) skeletal muscle or striated voluntary muscle
2) cardiac muscle or striated involuntary muscle
3)smooth muscle or nonstriated

Question 12

Skeletal muscle (straited voluntary muscle)

Answer 12

• Most widespread type
• All the muscles in the skeleton
• Has a striated appearance under microscope

Question 13

Cardiac muscle (straited involuntary muscles)

Answer 13

• Found in the heart
  -Do not need stimulation by the Nervous System to start a contraction
  -Electrical stimulation is required to maintain the coordinated rhythm of the cells
• Formed by the heart’s pacemaker ( in the right atrium, sinus node)

Question 14

Smooth Muscle ( non-straited involuntary muscle)

Answer 14

• Lines blood and lymph vessels within the body below
  the epithelial tissue (around gut, bladder, Circulatory
  and respiratory system)
• Contractions regulates the passage of materials through
  the vessel (example: contractions of intestinal smooth
  muscle propels food along the digestion system)
• Found in the skin, responsible for hair erection

Question 15

Nerve Tissue

Answer 15

▪ Specialized for intercellular communication by the conduction of
electrical impulses and release of chemical messages.
▪ Composed of neurons and neuroglial cells

Question 16

Neurons

Answer 16

-Excitable cells, stimulate to undergo electrical and chemical
changes
-Found in the brain, spinal cord, and throughout the body

Question 17

Neuroglial cells

Answer 17

Nourish and support neurons in the brain and spinal cord

Question 18

3 major portions of a neuron

Answer 18

1) Dendrite
2) Cell body
3) Axon

Question 19

Connective Tissue

Answer 19

Function
* Bind and support the other three
* types of tissues

Characterized
* Relative scarcity of cells
* Relative abundance of extracellular
* ground substance secreted by the cells

Types of Connective tissue
* Bone
* Its ground substance is collagen
* Impregnated with mineral crystals