A&P review chapter 4

Random

100

Define histology.

Histology is the study of tissues and their microscopic structure.

200

Explain where tissues fit in the levels of organization of the human body.

Chemical → Cellular → Tissue → Organ → Organ System → Organism
Tissues are groups of similar cells working together to perform a common function. Third level

300

Compare and contrast the four major tissue types.

Tissue Type

Main Function

Key Features

Epithelial

Protection, secretion, absorption

Tightly packed cells, little ECM

Connective

Support, binding, protection

Cells widely spaced, abundant ECM

Muscle

Movement

Cells contract

Nervous

Communication

Conduct electrical impulses

400

Components of the Extracellular Matrix (ECM)

• Ground substance (gel-like material)

• Protein fibers

• 
  

  • Collagen fibers (strength)

  • Elastic fibers (stretch)

  • Reticular fibers (support network)

500

Types of Cell Junctions

• Tight junctions

• Adherens junctions

• Desmosomes

• Hemidesmosomes

• Gap junctions

Test yourself

100

Classification of Epithelia

Based on:

• Number of layers

• 
  

  • Simple (1 layer)

  • Stratified (multiple layers)

  • Pseudostratified

• Cell shape

• 
  

  • Squamous (flat)

  • Cuboidal (cube-shaped)

  • Columnar (tall)

Simple Squamous

• Location: Alveoli, capillaries

• Function: Diffusion & filtration

Simple Cuboidal

• Location: Kidney tubules, glands

• Function: Secretion & absorption

Simple Columnar

• Location: Digestive tract

• Function: Absorption, secretion

Pseudostratified Columnar

• Location: Respiratory tract

• Function: Secretes & moves mucus

Stratified Squamous

• Location: Skin, mouth, esophagus

• Function: Protection

Transitional Epithelium

• Location: Urinary bladder

• Function: Stretching

200

 Compare and contrast the general features of the four major tissue types.

1. Epithelial Tissue
   
   

2. 
   

   • Covers surfaces and lines cavities
     
     

   • Forms glands
     
     

   • Tightly packed cells
     
     

   • Little extracellular matrix
     
     

   • Avascular
     
     

3. Connective Tissue
   
   

4. 
   

   • Supports and binds structures
     
     

   • Cells widely spaced
     
     

   • Abundant extracellular matrix
     
     

   • Usually well vascularized (except cartilage)
     
     

5. Muscle Tissue
   
   

6. 
   

   • Specialized for contraction
     
     

   • Produces movement
     
     

   • Well vascularized
     
     

7. Nervous Tissue
   
   

8. 
   

   • Specialized for communication
     
     

   • Conducts electrical impulses
     
     

   • Found in brain, spinal cord, and nerves
     
     

300

Describe the components of the extracellular matrix (ECM).

 The extracellular matrix consists of:

1. Ground substance – Gel-like material that fills space between cells.
   
   

2. Protein fibers:
   
   

3. 
   

   • Collagen fibers (strength)
     
     

   • Elastic fibers (stretch)
     
     

   • Reticular fibers (support network)
     
     

400

Describe the types of junctions that unite cells in a tissue.

r:

• Tight junctions – Seal cells together to prevent leakage.
  
  

• Adherens junctions – Connect actin filaments between cells.
  
  

• Desmosomes – Provide strong adhesion.
  
  

• Hemidesmosomes – Anchor cells to basement membrane.
  
  

• Gap junctions – Allow communication between cells.
  
  

500

Classify and identify the different types of epithelial tissues.

 Epithelia are classified by:

Number of layers:

• Simple (one layer)
  
  

• Stratified (multiple layers)
  
  

• Pseudostratified (appears layered but is not)
  
  

• Transitional (specialized stratified type)
  
  

Cell shape:

• Squamous (flat)
  
  

• Cuboidal (cube-shaped)
  
  

• Columnar (tall)
  
  

Types include:

• Simple squamous
  
  

• Simple cuboidal
  
  

• Simple columnar
  
  

• Pseudostratified columnar
  
  

• Stratified squamous
  
  

• Stratified cuboidal
  
  

• Stratified columnar
  
  

• Transitional
  
  

Feeling lucky?

100

Describe the location and function of each type of epithelial tissue and correlate function with structure.

• Simple squamous:
   Location: Alveoli, capillaries
   Function: Diffusion and filtration (thin structure allows rapid exchange)
  
  

• Simple cuboidal:
   Location: Kidney tubules, glands
   Function: Secretion and absorption
  
  

• Simple columnar:
   Location: Digestive tract
   Function: Absorption and secretion (often contains microvilli and goblet cells)
  
  

• Pseudostratified columnar:
   Location: Respiratory tract
   Function: Secretion and movement of mucus (often ciliated)
  
  

• Stratified squamous:
   Location: Skin (keratinized), mouth/esophagus (nonkeratinized)
   Function: Protection from abrasion
  
  

• Transitional epithelium:
   Location: Urinary bladder
   Function: Stretching and distension
  
  

200

 Describe and classify the structural and functional properties of exocrine and endocrine glands.

Exocrine glands:

• Secrete through ducts
  
  

• Can be unicellular or multicellular
  
  

• Secretion methods:
  
  

• 
  

  • Merocrine (exocytosis)
    
    

  • Apocrine (portion pinched off)
    
    

  • Holocrine (entire cell ruptures)
    
    

Endocrine glands:

• Ductless
  
  

• Secrete hormones directly into bloodstream
  
  

• Highly vascularized
  
  

300

Question: Compare and contrast the roles of individual cell and fiber types within connective tissues.

Cells:

• Fibroblasts – Produce fibers and ground substance
  
  

• Adipocytes – Store fat
  
  

• Macrophages – Phagocytosis
  
  

• Mast cells – Inflammation
  
  

• Leukocytes – Immune defense
  
  

Fibers:

• Collagen – Strength
  
  

• Elastic – Stretch and recoil
  
  

Reticular – Supportive framework

400

Identify the different types of connective tissue and describe where they are found.

Loose connective tissue:

• Areolar – Under epithelia
  
  

• Adipose – Subcutaneous layer
  
  

• Reticular – Lymphoid organs
  
  

Dense connective tissue:

• Dense regular – Tendons/ligaments
  
  

• Dense irregular – Dermis
  
  

• Elastic – Large arteries
  
  

Supporting connective tissue:

• Cartilage (hyaline, elastic, fibrocartilage)
  
  

• Bone (compact and spongy)
  
  

Fluid connective tissue:

• Blood
  
  

Lymph

500

Describe the functions of each type of connective tissue and correlate function with structure.

• Areolar – Wraps and cushions organs
  
  

• Adipose – Energy storage and insulation
  
  

• Dense regular – Strong attachment
  
  

• Cartilage – Flexible support
  
  

• Bone – Protection and mineral storage
  
  

• Blood – Transport
  
  

Structure directly supports function (e.g., collagen = strength).

Punk?

100

 Clarify and identify the different types of muscle tissue based on their distinguishing structural characteristics and location in the body.

• Skeletal muscle:
   Striated, voluntary, multinucleated
   Attached to bones
  
  

• Cardiac muscle:
   Striated, involuntary, intercalated discs
   Found in heart
  
  

• Smooth muscle:
   Non-striated, involuntary
   Found in walls of hollow organs
  
  

200

Describe the functions of each type of muscle tissue and correlate function with structure.

• Skeletal – Movement (striations allow strong contraction)
  
  

• Cardiac – Pumps blood (intercalated discs coordinate contractions)
  
  

• Smooth – Moves substances through organs (slow, sustained contractions)
  
  

300

 Describe where in the body nervous tissue can be found and its general structural and functional characteristics.

Nervous tissue is found in the brain, spinal cord, and nerves all over the body. It’s what makes up the nervous system. It’s made of special cells called neurons that send electrical messages, and supporting cells called neuroglia that help protect and support the neurons. The main job of nervous tissue is to send and receive signals so your body can react to things. It controls movement, feelings, thoughts, and reflexes

400

Identify and describe the structure and function of neurons and neuroglial cells in nervous tissue.

• Neurons:
   Cell body, dendrites, axon
   Transmit electrical signals
  
  

• Neuroglia:
   Support, protect, nourish neurons
   Do not conduct impulses
  
  

500

 Explain the properties and locations of serous, synovial, mucous, and cutaneous membranes.

• Cutaneous membrane:
   Skin; dry membrane covering body surface.
  
  

• Serous membrane:
   Lines closed body cavities; produces serous fluid.
  
  

• Mucous membrane:
   Lines cavities open to exterior; produces mucus.
  
  

Synovial membrane:

 Lines joint cavities; produces synovial fluid.

touch grass dude

100

Describe how tissues work together to form organs.

Organs consist of two or more tissue types working together for a common function.
 Example: The stomach contains epithelial tissue (lining), connective tissue (support), muscle tissue (movement), and nervous tissue (control).

200

 Describe the general structure and function of membranes.

Membranes are sheets of tissue that cover surfaces, line cavities, or divide spaces. They consist of epithelial tissue plus underlying connective tissue (except synovial membranes).

300

Describe how injuries affect epithelial, connective, muscular, and nervous tissue

• Epithelial – Regenerates quickly
  
  

• Connective – Moderate repair ability
  
  

• Muscle – Limited regeneration
  
  

• Nervous – Poor regeneration in CNS
  
  

400

Describe the process of regeneration.

 Regeneration is replacement of damaged tissue with identical tissue through mitosis.

500

Explain the process of fibrosis.

 Fibrosis is the replacement of damaged tissue with scar tissue (dense connective tissue), often resulting in reduced function.