Test 2 Bio Lab

LEVELS OF ORGANIZATION OF THE HUMAN BODY

Cell(cardiac muscle cell) to Tissues(cardiac muscle) to Organs(heart) to System(circulatory system) to Organism(living individual)

Primary tissue types in vertebrate animals

Epithelial Tissue, Connective Tissue, Muscle Tissue(Muscular), Nervous Tissue

Epithelial Tissue

Epithelial cells provides critical functions like protection, secretion, and absorption. They cover the exterior of an organism, line the gut and other cavities, and line the coelomic cavity. 1)Protect underlying tissues from dehydration and mechanical damage. 2)Provide a selectively permeable barrier that facilitates or impedes passage of materials. 3)Provide sensory surfaces. 4)Secretes fluids.

Shapes of Epithelial Tissues

Squamous-flat, irregular(like fried eggs)

Cuboidal-cubes

Columnar-tall and rectanglar

Layers of Epithelial Tissues

Simple is 1 layer

Stratified is multiple layers

Pseudo-stratified is a single layer of cells that appear stratified because the nuclei appear in different positions within the columnar cells

Simple Squamous

Characteristic Feature: epithelial cells; single cell layer

Cell Shape/Characteristics: irregular and flattened; minimum barrier to diffusion

Function: cells form layer across which diffusion can readily occur

Location: line the alveoli of the lungs, capillary walls, the filtration system of the kidneys, and major cavities of the body

*Relatively inactive and are associated with the sites of passive movement of water, electrolytes, and other substances

Simple Cuboidal

• Characteristic Feature: gland cells; appear more full

• Cell shape/Characteristics: as tall as they are wide; cube-like shape; has cilia 

• Function: provide functions in secretion and absorption 

• Location: line the kidney tubules, some glands, and cover the ovaries

  • These cells are rich in specific transport channels

Simple Columnar

• Characteristic Feature: epithelial cells; appear more full

• Cell shape/Characteristics: taller than they are wide; column-like shape; has cilia

• Function: provides protection and functions in secretion and absorption

• Location: in the intestines, lining of the stomach, and parts of the respiratory tract

Simple Ciliated Columnar

epithelium contains cells with cilia, motile, hair-like processes that help to move fluids or particles along a surface. Most often seen in fallopian tubes and bronchioles.

Pseudo-stratified Ciliated Columnar

• Lines the respiratory tract and provides protection

• Secretes mucus, dense with cilia that aid in movement of mucus

• Found from the trachea and bronchii

Stratified Epithelium

animal tissue made up of 2 or more layers of stacked cells

Stratified Squarmous

• Characteristic Feature: epithelial cells; several layers thick

• Cell shape/Characteristics: upper layer, squamous; middle layer, cuboidal; basal (bottom) layer, columnar

• Function: tough layers of cells providing protection to underlying tissues

• Location: outer layer of skin and lining of mouth

NonKeratinized Stratified Squamous

• Characteristic Feature: epithelial cells; several layers thick

• Cell shape/Characteristics: upper layer, squamous; middle layer, cuboidal; basal (bottom) layer, columnar

• Function: tough layers of cells providing protection to underlying tissues

• Location: outer layer of skin and lining of mouth

Keratinized Stratified Squamous

epithelium, a tough layer of keratin (a protein resistant to friction and repels bacteria) is deposited in the surface cells. This is located on skin, hair and nails. This tissue will form a cutaneous membrane.

Connective Tissue

supports the body, fight pathogens, and store energy; these cells are loosely packed, and are typically suspended in an extracellular matrix of fibers 

• The most diverse and abundant tissues in animal bodies 

• They connect and support all other tissues

• 2 major classes: connective tissue proper & specialized connective tissue

  • Proper - divided into loose and dense connective tissues

  • Special - includes blood, cartilage, and bone

Bone Model(Connective Tissue)

Connective tissue proper

Loose(three types): Areolar, adipose, and reticular tissue. These tissues contain:

Fibroblasts-cells that secretes fibrous proteins that form the extracellular matrix.

Collagen-strong fibrous proteins

Elastin=allows to stretch(extensibility) and to recoil(elasticity)

Ground substance-protein sugar combination that can be a liquid, solid, or semisolid and fills spaces between cells and fibers

Dense(three types): Dense regular

Special connective tissue

Liquid(blood and lymph)

Cartilage(three types)

Bone(two types)

Areolar(Loose)Connective Tissue

• Characteristic Feature: loose connective tissue; extracellular matrix

• Cell shape/Characteristics: cells imbedded within a mesh-like fiber network

• Function: protective; wraps around blood vessels, nerves, and organs; connects skin to the underlying muscle

• Location: beneath epithelial tissue

  Fibroblasts- cells that secretes fibrous proteins that form the extracellular matrix.

  Collagen- strong fibrous proteins

  Elastin= allows to stretch(extensibility) and to recoil(elasticity)

Adipose(Loose) Connective Tissue

• Characteristic Feature: loose connective adipose tissue, fat cells, fibroblasts (active cells that create the extracellular matrix)

• Cell shape/Characteristics: can develop in large groups; fixed amount that enlarge and shrink; looks like bubbles

• Function: used for nutrient storage; hydrolyzes stored triglycerides and secretes fatty acids into blood for oxidation

• Location: under the skin, in bone marrow, and around kidneys 

Dense Regular Connective Tissue

• Characteristic Feature: loose connective adipose tissue, fat cells, fibroblasts (active cells that create the extracellular matrix)

• Cell shape/Characteristics: can develop in large groups; fixed amount that enlarge and shrink; looks like bubbles

• Function: used for nutrient storage; hydrolyzes stored triglycerides and secretes fatty acids into blood for oxidation

• Location: under the skin, in bone marrow, and around kidneys 

Hyaline Cartilage Connective Tissue

• Characteristic Feature: chondrocytes in lacunae (cavities) surrounded by chondrin extracellular matrix.

• Cell shape/Characteristics: pockets of cells.

• Function: provides flexible support, shock absorption, and reduction of friction on load-bearing surfaces.

• Location: in lacunae cavities within cartilage ground substances, spinal disks, knees, joints, ear, nose.

  Chondrocytes-cells that maintain the cartilage daily activity. The cell secretes protein-carbon hydrate complex that forms the extracellular matrix.

  Lacuna-cavities in cartilage where chondrocytes reside.

  Chondrin Sulfate-is the ground substance- gelatin-like (rubber-like) extracellular matrix of cartilage.

Compact Bone

• Characteristic Feature: surrounded by osteocytes - bone cells made of fibrous, crystalline extracellular matrix 

• Cell shape/Characteristics: looks like the rings or bark of a tree

• Function: protects internal organs, provides rigid support for muscle attachment

• Location: Most of the skeleton

  A is Haversian Canal-contain blood and nerves vessels

  B is Lacuna- cavities in the cartilage where chondrocytes reside

  C is Canaliculi- tiny passages that allow chondrocytes in lacunae to communicate with other cells

Blood

• Characteristic Feature: liquid connective tissue; erythrocytes (red), leukocytes (white), and thrombocytes (platelets); considered connective tissue

• Cell shape/Characteristics: circular, beanlike

• Function: highway of immune system carries nutrients and waste; primary means of communication between organs 

• Location: circulatory system 

Muscle Tissue Model

Smooth Muscle Model

Muscle Tissue

characterized by the ability to generate a force by converting chemical energy into mechanical energy; they are either smooth or striated (striped)

1. Distinguishes animals from the other multicellular organisms like plants, fungi, and protists

2. Affords internally initiated movement and behavior

Skeletal Muscle

• Characteristic Feature: skeletal muscle cells; voluntary contraction 

• Cell shape/Characteristics: long, tubular cells (muscle fibers), vertical stripes

• Function: powers walking, lifting, talking, and all other voluntary movements

• Location: voluntary muscles

Smooth Muscle

• Characteristic Feature: smooth muscle cells; contraction involuntary

• Cell shape/Characteristics: thin, horizontally packed; spindle shaped; single nucleus

• Function: powers rhythmic, involuntary contractions commanded by the central nervous system 

• Location: Walls of blood vessels, stomach, and intestines (gut)

Cardiac Muscle

• Characteristic Feature: striated; contraction involuntary; intercalated disks (interconnections or dark lines) between adjacent cells organizing into continuous functional fibers 

• Cell shape/Characteristics: smaller and interconnected; loosely packed, each with its own nucleus (single uninucleate)

• Function: highly interconnected cells; promotes rapid spread of signal initiating contraction

• Location: walls of heart

Neuron(or nerve cell)Model

Nervous Tissue

consists of neurons, supports cells called glia and Schwann cells which help propagate the nerve impulse and provide nutrients to neurons 

1. Neurons - cells specialized for transmitting nerve impulses; made up of:

   1. Cell body - contains the nucleus and cytoplasmic extensions that conduct nerve impulses

   2. Dendrites - thin, highly branched, short extensions that receive incoming stimulation and conduct electrical impulses to the cell body

   3. Axon - single, long extension of cytoplasm that conducts impulses away from the cell body

      1. It may carry an impulse to a muscle to make it contract or to the dendrites of another neuron

Neurons

• Characteristic Feature: nervous tissue; consists of cell body, dendrites, and axon

• Function: process and transmit information throughout the body using electrical impulses and chemical signals 

• Location: throughout the entire human body

Neuron

Neuroglia(glial cells)

• Characteristic Feature: they are instrumental in the regulation of neurotransmission

• Function: do not conduct impulses; they lend support, aid in nourishment, and provide protection for neurons 

• Location: through the entire nervous system (central and peripheral)

THE SKELETAL SYSTEM

Axial Skeleton

consists of bones along the longitudinal axis of the body that support the head, neck, and trunk 

1. Cranium

2. Zygomatic Arch

3. Maxilla (and Mandible)

4.Cervical 

Atlas 

Axis

1. Thoracic

2. Lumbar

3. Sacral (Sacrum)

4. Caudal (Coccyx)

5. Rib Cage

6. Sternum

Appendicular Skeleton

RAT DISSECTION