Biology Chapter on Tissues

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Questions and Answers

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

Conducts signals between organs

Protects against the outside environment (correct)

Facilitates muscle contractions

Connects and supports other tissues

Which type of tissue is responsible for holding the body together?

Muscle tissue

Nervous tissue

Connective tissue (correct)

Epithelial tissue

Which characteristic distinguishes epithelial cells from other types of cells?

Ability to contract

Exhibit polarity (correct)

Conduct electrical signals

Presence of blood supply

What are the two major classifications of epithelia?

Covering and glandular Signup and view all the answers

What is the role of the basement membrane in epithelial tissue?

Acts as a selective filtration barrier Signup and view all the answers

How are covering epithelia classified?

By the number of layers and shape Signup and view all the answers

What is the embryonic origin of epithelial tissues?

Ectoderm, mesoderm, and endoderm Signup and view all the answers

Which statement about muscle tissue is true?

It is contractile tissue. Signup and view all the answers

What type of glands secrete hormones directly into the bloodstream?

Endocrine glands Signup and view all the answers

What characteristic distinguishes cardiac muscle from skeletal muscle?

Cardiac muscle contains intercalated discs. Signup and view all the answers

How are skeletal muscle cells characterized?

They contain multiple nuclei and have striations. Signup and view all the answers

Which type of muscle tissue is characterized by slow, involuntary contractions?

Smooth muscle Signup and view all the answers

What is the primary function of connective tissue?

Binding and supporting various body structures Signup and view all the answers

Which germ layer do all connective tissues originate from?

Mesoderm Signup and view all the answers

Which of the following is a type of embryonic connective tissue?

Mesenchyme Signup and view all the answers

What is a key feature of exocrine glands?

They have ducts to transport their secretions. Signup and view all the answers

What type of connective tissue is characterized by a loose arrangement of fibers and a moderately viscous fluid matrix?

Loose connective tissue Signup and view all the answers

Which type of connective tissue contains a dense woven network of collagenous fibers and is impact resistant?

Dense irregular connective tissue Signup and view all the answers

What primary function does adipose connective tissue serve in the body?

Fat storage and insulation Signup and view all the answers

Which type of connective tissue is primarily involved in forming the supporting framework of lymphoid organs?

Reticular connective tissue Signup and view all the answers

What distinguishes dense regular connective tissue from dense irregular connective tissue?

The orientation of collagen fibers Signup and view all the answers

Where in the body is elastic connective tissue primarily found?

Arteries and the larynx Signup and view all the answers

What is the primary characteristic of cartilage compared to other connective tissues?

Large amount of matrix Signup and view all the answers

Which type of adipocytes are primarily found in newborns?

Brown adipocytes Signup and view all the answers

What are the main components of the Central Nervous System (CNS)?

Brain and spinal cord Signup and view all the answers

Which structure is NOT part of the Peripheral Nervous System (PNS)?

Spinal cord Signup and view all the answers

What primarily composes white matter in the CNS?

Myelinated nerve fibers Signup and view all the answers

Which function is carried out by the autonomic nervous system (ANS)?

Regulating unconscious body activities Signup and view all the answers

What role do neurotransmitters play in neuronal communication?

They bind to receptors and may induce a response in the postsynaptic cell Signup and view all the answers

What happens at a synapse when an electrochemical signal reaches it?

Vesicles fuse with the presynaptic membrane and release neurotransmitters Signup and view all the answers

What protects the brain and spinal cord in the CNS?

Meninges Signup and view all the answers

Which type of nerve fibers would be found in the grey matter?

Unmyelinated dendrites Signup and view all the answers

What is the primary function of chondrocytes in cartilage tissue?

To produce the matrix and fibers of the tissue Signup and view all the answers

Which statement accurately describes bone tissue?

Bone tissue is a type of dense connective tissue. Signup and view all the answers

What is a distinguishing feature of cortical bone compared to cancellous bone?

Cortical bone forms the exterior hard layer of the bone. Signup and view all the answers

From which type of stem cells do all blood cells originate?

Hematopoietic stem cells Signup and view all the answers

Which organs contribute to the regulation of blood cell production?

Liver and lymphatic system structures Signup and view all the answers

What characteristic of cartilage contributes to its poor healing after injury?

It relies on diffusion for nutrients. Signup and view all the answers

What role does the nervous system play in the body?

It coordinates and reacts to impulses from sensory receptors. Signup and view all the answers

Which components are included in the structure of bones?

Bone tissue, bone marrow, blood vessels, epithelium, and nerves Signup and view all the answers

Study Notes

Tissues

Tissues are groups of cells with similar structure and function, forming the building blocks of organs.
There are four main types of tissues: epithelial, connective, muscle, and nervous.

Epithelial Tissue

Function: Protection, covering surfaces, lining cavities, and forming glands.
Characteristics:
- Tightly packed cells with little intercellular material.
- Avascular (lack blood supply), relying on diffusion for nutrients and waste removal.
- Specialized cell-cell junctions for binding adjacent cells.
- Polarity, with distinct apical and basal surfaces.
Types:
- Covering Epithelia: Sheets of tissue covering external surfaces (skin, lungs, gut) and lining internal cavities (blood vessels, pleura). Classified by layers (simple or stratified) and cell shape (squamous, cuboidal, columnar).
- Glandular Epithelia: Consists of cells that produce and secrete specific substances. Classified into two groups based on product release:
  - Endocrine: Lack ducts, secrete hormones directly into the bloodstream.
  - Exocrine: Have ducts, secrete products into external environment.
- Also classified by cell number: unicellular (one-celled) or multicellular (more than one cell).

Muscle Tissue

Function: Contractility, responsible for movement.
Characteristics: Actin microfilaments and associated proteins generate contractile forces.
Types:
- Skeletal Muscle: Long, multinucleated cells with cross-striations. Quick, forceful, and usually voluntary contractions.
- Cardiac Muscle: Cross-striations, elongated, branched cells connected by intercalated discs. Involuntary, vigorous, and rhythmic contractions.
- Smooth Muscle: Fusiform cells lacking striations. Slow, involuntary contractions.

Connective Tissue

Function: Binding, support, protection, insulation, storage, and transport.
Origin: Mesoderm germ layer.
Types:
- Embryonic:
  - Mesenchyme: Immature connective tissue with multipotent cells.
  - Mucous connective tissue: Found in umbilical cord.
- Adult:
  - Connective Tissue Proper:
    - Loose Connective Tissue:
      - Areolar: For binding, packing, protection, and nutrient supply. Found deep to skin, surrounding muscles, vessels, and organs.
      - Adipose: Contains fat cells (adipocytes). Two types: white (most common in adults) and brown (more prominent in newborns).
      - Reticular: Contains reticular fibers, forms framework of lymphoid organs (spleen, lymph nodes, tonsils), bone marrow, and liver.
    - Dense Connective Tissue: Enriched in collagen fibers with little ground substance.
      - Regular: Collagen fibers oriented in one direction (e.g., tendons).
      - Irregular: Collagen fibers oriented in multiple directions (e.g., dermis).
    - Elastic Connective Tissue: Provides flexibility and distensibility. Located in arteries, larynx, trachea, and bronchi.
  - Specialized Connective Tissue:
    - Cartilage: Contains chondrocytes (cells) embedded in matrix. Avascular, relying on diffusion for nutrients. Flexible and provides support.
    - Bone (Osseous Tissue): Hard, rigid connective tissue, provides support, protection, and produces blood cells.
      - Cortical Bone: Dense, compact bone forming the outer layer.
      - Cancellous Bone: Trabecular, spongy bone filling the interior.
    - Blood: Contains plasma (matrix), red blood cells (erythrocytes), and white blood cells (leukocytes). Originates from hematopoietic stem cells, primarily in bone marrow.

Nervous Tissue

Function: Communication and coordination of impulses throughout the body.
Components:
- Neurons: Nerve cells, composed of a cell body (soma), dendrites, and an axon.
- Neuroglia: Supporting cells that provide structural and functional support to neurons.
Types:
- Central Nervous System (CNS): Brain and spinal cord.
- Peripheral Nervous System (PNS): Cranial, spinal, and peripheral nerves, conducting to and from the CNS, and ganglia (small aggregations of nerve cells outside the CNS).
  - Autonomic Nervous System (ANS): Regulates automatic body functions (e.g., heart rate, digestion).
Structure:
- Gray Matter: Contains neuron cell bodies, neuroglia, and unmyelinated dendrites.
- White Matter: Contains myelinated nerve fibers, no cell bodies.
Synapses: Specialized sites for communication between neurons, involving neurotransmitters released from presynaptic neurons to receptors on postsynaptic neurons.

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Description

Explore the fascinating world of tissues in this quiz. Understand the four main types of tissues: epithelial, connective, muscle, and nervous, along with their unique functions and characteristics. Test your knowledge on epithelial tissue's structure, functions, and classifications.