Notes: Ch.5 Tissues

BIO25 ch5

What is histology?

The study of tissues.

What are the four primary types of tissues in the human body?

Epithelial, Connective, Muscle, and Nervous tissues.

What defines epithelial tissue?

Composed of closely packed cells with little extracellular matrix, covering surfaces and forming glands.

What is the function of connective tissue?

It provides support, binding of structures, storage, and transport.

How are epithelial tissues classified?

By the number of cell layers (simple or stratified) and by cell shape (squamous, cuboidal, columnar).

What is a simple squamous epithelium?

A single layer of flattened cells that allows for rapid movement of molecules.

What role do goblet cells play in simple columnar epithelium?

They secrete mucin, which forms mucus when mixed with water.

What are the characteristics of stratified squamous epithelium?

Has multiple layers providing protection against abrasion and friction.

What distinguishes merocrine glands from holocrine glands?

Merocrine glands release their secretions through exocytosis, while holocrine glands release entire cells that are destroyed in the process.

Where is transitional epithelium found, and what is its function?

It is found in the urinary tract and allows for stretching.

What is the function of muscular tissue?

Contraction to produce movement.

What are the three types of muscle tissue?

Skeletal, Cardiac, and Smooth muscle.

What is the primary function of nerve tissue?

To transmit and process nerve impulses.

What is the extracellular matrix composed of?

Protein fibers and ground substance.

How does aging affect connective tissue?

Connective tissue loses pliability and resiliency; collagen declines.

What is the primary germ layer from which all connective tissues originate?

Mesenchyme.

How can epithelium be described in terms of polarity?

Epithelial tissue has an apical surface (exposed) and a basal surface (attached to basement membrane).

What are the roles of adipocytes in connective tissue?

They store energy and provide insulation and cushioning.

What type of epithelium lines the digestive tract?

Non-ciliated simple columnar epithelium.

What is unique about pseudostratified epithelium?

It appears layered because of differing cell heights, but all cells touch the basement membrane.

What are the functions of serous membranes?

They line body cavities and reduce friction between organs.

What is histology?

The study of tissues.

What are the four primary types of tissues in the human body?

Epithelial, Connective, Muscle, and Nervous tissues.

What defines epithelial tissue?

Composed of closely packed cells with little extracellular matrix, covering surfaces and forming glands.

What is the function of connective tissue?

It provides support, binding of structures, storage, and transport.

How are epithelial tissues classified?

By the number of cell layers (simple or stratified) and by cell shape (squamous, cuboidal, columnar).

What is a simple squamous epithelium?

A single layer of flattened cells that allows for rapid movement of molecules.

What role do goblet cells play in simple columnar epithelium?

They secrete mucin, which forms mucus when mixed with water.

What are the characteristics of stratified squamous epithelium?

Has multiple layers providing protection against abrasion and friction.

What distinguishes merocrine glands from holocrine glands?

Merocrine glands release their secretions through exocytosis, while holocrine glands release entire cells that are destroyed in the process.

Where is transitional epithelium found, and what is its function?

It is found in the urinary tract and allows for stretching.

What is the function of muscular tissue?

Contraction to produce movement.

What are the three types of muscle tissue?

Skeletal, Cardiac, and Smooth muscle.

What is the primary function of nerve tissue?

To transmit and process nerve impulses.

What is the extracellular matrix composed of?

Protein fibers and ground substance.

How does aging affect connective tissue?

Connective tissue loses pliability and resiliency; collagen declines.

What is the primary germ layer from which all connective tissues originate?

Mesenchyme.

How can epithelium be described in terms of polarity?

Epithelial tissue has an apical surface (exposed) and a basal surface (attached to basement membrane).

What are the roles of adipocytes in connective tissue?

They store energy and provide insulation and cushioning.

What type of epithelium lines the digestive tract?

Non-ciliated simple columnar epithelium.

What is unique about pseudostratified epithelium?

It appears layered because of differing cell heights, but all cells touch the basement membrane.

What are the functions of serous membranes?

They line body cavities and reduce friction between organs.

What are the characteristics of loose connective tissue?

It is characterized by a loose arrangement of fibers and cells, providing flexibility and support.

What is the primary function of dense connective tissue?

To provide strength and withstand tension.

What are the differences between dense regular and dense irregular connective tissue?

Dense regular connective tissue has fibers arranged in a parallel pattern, while dense irregular connective tissue has fibers arranged in various directions.

What is cartilage and how does it differ from bone?

Cartilage is a flexible connective tissue with a firm yet pliable matrix, while bone is a rigid connective tissue that provides structural support.

What type of cartilage is found in the nose and trachea?

Hyaline cartilage.

What is the primary function of elastic cartilage?

To provide flexible support.

What type of connective tissue connects muscles to bones?

Tendons.

What type of connective tissue connects bones to other bones?

Ligaments.

What cell type is primarily responsible for bone formation?

Osteoblasts.

What is the function of osteoclasts?

They are responsible for bone resorption.

What is the role of macrophages in connective tissue?

They engulf and digest cellular debris and pathogens.

What is reticular connective tissue?

A type of connective tissue that provides a supportive framework for organs.

What is the function of blood as a connective tissue?

It transports nutrients, gases, and waste products throughout the body.

What are the components of blood?

Red blood cells, white blood cells, platelets, and plasma.

What is muscle tissue characterized by?

The ability to contract and produce movement.

What is the role of intercalated discs in cardiac muscle?

They facilitate the synchronized contraction of cardiac muscle fibers.

What is unique about smooth muscle tissue?

It is involuntary and lacks striations.

Where is smooth muscle tissue found?

In the walls of hollow organs, such as the intestines and blood vessels.

What are the two types of epithelial glands?

Endocrine (secreting hormones into the bloodstream) and exocrine (secreting substances through ducts).

What is the function of mucus membranes?

They line body cavities that open to the outside, providing lubrication and protection.

What is the structure of glandular epithelium?

It consists of specialized epithelial cells that create glands.

What is adipose tissue?

A type of connective tissue that stores fat.

What is the primary function of fibroblasts in connective tissue?

To secrete fibers and components of the extracellular matrix.

What is the function of stratified cuboidal epithelium?

It provides protection and secretion in some glands.

What are the functions of synovial membranes?

They line the cavities of joints and secrete synovial fluid for lubrication.

What defines transitional epithelium?

It can change shape and stretch, such as in the bladder.

What is the role of keratin in stratified squamous epithelium?

It provides protection against water loss and pathogens.

What characteristics do cardiac muscle and skeletal muscle share?

They are both striated muscle types.

What type of epithelial tissue is found in the respiratory tract?

Pseudostratified ciliated columnar epithelium.

What type of connective tissue has a gel-like matrix?

Areolar connective tissue.

What is the average lifespan of a red blood cell?

About 120 days.

What is the definition of fibrosis?

The formation of excess fibrous connective tissue in an organ or tissue.

What is the primary role of nervous tissue?

To detect stimuli and transmit electrical signals throughout the body.

What are neurons?

The functional cells of the nervous system that transmit impulses.

What are neuroglial cells?

Supporting cells in the nervous system that assist and protect neurons.

What does dense irregular connective tissue provide?

It provides strength and support in multiple directions.

How does simple cuboidal epithelium function in the kidneys?

It aids in secretion and absorption.

What is the primary role of epidermal cells?

To form a protective barrier on the body surface.

What is the significance of the basement membrane?

It provides structural support and anchorage for epithelial tissues.

What type of connective tissue is blood classified as?

Liquid connective tissue.

What is the function of endocrine glands?

To secrete hormones directly into the bloodstream.

What is a key characteristic of skeletal muscle cells?

They are multinucleated and striated.

What is the primary function of simple columnar epithelium?

Absorption and secretion, particularly in the digestive tract.

What is the primary role of cilia on epithelial cells?

To move substances across the epithelial surface.

What is the primary role of epithelial tissue in the body?

To cover surfaces and line cavities, providing protection, absorption, and secretion.

What are the two surfaces of epithelial tissue called?

The apical surface (exposed) and the basal surface (attached to underlying tissues).

What is the difference between exocrine and endocrine glands?

Exocrine glands secrete substances through ducts, while endocrine glands secrete hormones directly into the bloodstream.

What is the structure of skeletal muscle tissue?

Skeletal muscle tissue is striated, voluntary, and composed of long, multinucleated fibers.

What are the main functions of cardiac muscle tissue?

To pump blood throughout the body and maintain heart rhythm involuntarily.

What defines smooth muscle tissue?

Smooth muscle is non-striated, involuntary, and found in walls of hollow organs.

What is the primary function of connective tissue?

To support, bind, and protect other tissues and organs in the body.

What is the distinctive feature of adipose tissue?

It is composed of adipocytes that store fat for energy and provide insulation.

What type of connective tissue has a liquid matrix?

Blood, which is classified as a liquid connective tissue.

What is cartilage and its primary function?

Cartilage is a flexible connective tissue that provides support and shape to various structures.

Where is elastic cartilage found, and why is it unique?

It is found in structures like the ear; its unique property is flexibility due to elastic fibers.

What is the primary role of fibroblasts in connective tissue?

They produce and secrete the components of the extracellular matrix.

How does stratified epithelial tissue differ from simple epithelial tissue?

Stratified epithelial tissue has multiple layers of cells, providing greater protection.