Introduction to Cells and Tissues

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Questions and Answers

What is the primary function of the plasma membrane?

To control the entry and exit of substances into cells (correct)

To provide energy for cell processes

To act as a storage area for organelles

To house the genetic material of the cell

Which type of tissue is responsible for connecting different parts of the body?

Connective tissue (correct)

Nerve tissue

Epithelial tissue

Muscle tissue

How are organs related to the body systems?

Organs are separate entities without a shared function

Organs collectively operate to support inter-related functions (correct)

Organs function independently of body systems

Organs are collections of tissues that do not interact

What structure surrounds the nucleus in a cell?

Nuclear envelope Signup and view all the answers

Which component is NOT part of the phospholipid bilayer of the plasma membrane?

DNA Signup and view all the answers

What are ribosomes primarily responsible for synthesizing?

Proteins Signup and view all the answers

Where can ribosomes be found within a cell?

In the cytoplasm and on the rough endoplasmic reticulum Signup and view all the answers

What is the primary function of the Golgi apparatus?

Export of proteins from the cell Signup and view all the answers

What process involves vesicles fusing with the plasma membrane to expel contents from the cell?

Exocytosis Signup and view all the answers

What is the primary role of epithelial tissue?

Transport and secretion Signup and view all the answers

What pH do lysosomes typically maintain for enzyme function?

pH 5 Signup and view all the answers

What is the composition of the cytosol?

Watery fluid that houses organelles Signup and view all the answers

Which type of muscle tissue is responsible for involuntary movements in the body?

Smooth muscle Signup and view all the answers

What is one primary function of the extracellular matrix (ECM)?

To provide structural support to tissues Signup and view all the answers

Which microscopy technique would be best for observing the surface of a specimen at high resolution?

Scanning electron microscopy Signup and view all the answers

How are tissues classified?

According to size, shape, and function of constituent cells Signup and view all the answers

How does the structure of epithelial tissue relate to its function?

It forms single or multiple layers for protection and absorption Signup and view all the answers

Which tissue type has a high amount of extracellular matrix and comparatively few cells?

Connective tissue Signup and view all the answers

What is a key feature of nervous tissue?

It forms interconnected networks for communication Signup and view all the answers

What characterizes stratified epithelial tissue?

Multiple layers of cells Signup and view all the answers

Which of the following correctly defines a function of the extracellular matrix (ECM)?

It regulates migration and influences development Signup and view all the answers

What is the primary function of white adipose tissue?

Thermal insulation and energy storage Signup and view all the answers

Where is brown adipose tissue primarily found?

In the new-born Signup and view all the answers

Which type of connective tissue has low cell numbers but high fiber content?

Dense connective tissue Signup and view all the answers

What is a characteristic of fibrous tissue?

Collagen fibers in closely-packed bundles Signup and view all the answers

What type of cartilage is primarily found in intervertebral discs?

Fibrocartilage Signup and view all the answers

What is the primary function of the nucleolus within the cell?

Synthesis of ribosomes Signup and view all the answers

Which type of muscle tissue is characterized as multinucleated?

Skeletal muscle Signup and view all the answers

Which type of tissue is known for its high degree of recoil?

Elastic tissue Signup and view all the answers

What cell type is embedded within the matrix of cartilage?

Chondrocytes Signup and view all the answers

What is a primary role of microtubules in the cytoskeleton?

Involved in cell movement Signup and view all the answers

What is the main function of mitochondria in cells?

Produce energy through aerobic respiration Signup and view all the answers

Which connective tissue contains reticular fibers and is found in lymphatic organs?

Reticular tissue Signup and view all the answers

Which statement best describes the smooth endoplasmic reticulum?

Involved in synthesizing lipids and detoxifying drugs Signup and view all the answers

What structure in the cell directs the organization of microtubules?

Centrioles Signup and view all the answers

Which cell type is characterized as anuclear?

Red blood cells Signup and view all the answers

Cell extensions are important for what specific function?

Movement Signup and view all the answers

What type of muscle is under involuntary control?

Smooth muscle Signup and view all the answers

Which type of cell is NOT involved in the nervous system?

Epithelial cells Signup and view all the answers

What is the main role of occluding junctions?

To seal cells together Signup and view all the answers

Which type of junction is responsible for communicating signals between cells?

Communicating junctions Signup and view all the answers

Where are the cell bodies of neurons typically located?

Central Nervous System Signup and view all the answers

Which type of anchoring junction connects adjacent cells to each other?

Desmosomes Signup and view all the answers

What type of junctions are septate junctions primarily associated with?

Invertebrates Signup and view all the answers

What is the primary function of glial cells in the nervous system?

Support and protect neurons Signup and view all the answers

Study Notes

Introduction to Cells, Tissues, Organs, and Body Systems

Over 100 types of cells group together to perform specific functions.
Four main types of tissues:
- Connective
- Epithelial
- Muscle
- Nerve
Tissues work together to perform particular tasks.
Organs are linked to perform inter-related functions.
Body systems are collections of organs with a shared function.

Cells

The plasma membrane is the outer layer of the cell, enclosing the cytosol.
It is a phospholipid bilayer, with hydrophilic heads and hydrophobic tails.
Sugars and proteins are embedded within the layer.
It controls the entry and exit of substances into cells.
The nucleus is the largest organelle, surrounded by a nuclear envelope.
It contains the cell's genetic material (chromosomes) and a nucleolus (ribosome synthesis).
Skeletal muscles are multinucleated.
Red blood cells are anuclear (lacking a nucleus).
Centrioles are important for cell division.
Cell extensions are projections of the plasma membrane, important for movement.
Mitochondria are the powerhouse of the cells, producing energy through aerobic respiration.
They are double-walled with cristae.
Abundant in cells with high energy demands (e.g., muscle, liver).

Endoplasmic Reticulum

There are two types: smooth and rough.
Smooth ER is responsible for producing lipids and steroid hormones, and drug detoxification.
Rough ER is studded with ribosomes and responsible for protein synthesis for export from the cell.

Ribosomes

Ribosomes are made of RNA and protein.
They are crucial for protein synthesis.
Cytoplasmic ribosomes produce proteins for use within the cell.
RER ribosomes produce proteins for export.

Golgi Apparatus

The Golgi apparatus is a stack of membrane-bound sacs (cisternae).
It's important for exporting proteins from the cell.
Proteins are received from the ER, packaged into vesicles, and stored until needed.
Vesicles move to the plasma membrane and fuse with it, expelling contents through exocytosis.
It also produces lysosomes.

Lysosomes

Spherical vesicles that are pinched off the Golgi apparatus.
Contain enzymes for breaking down large molecules (e.g., DNA, RNA, proteins, carbohydrates).
Internal acidic pH (pH 5).

Cytosol

Cytosol is the watery fluid containing organelles (pH 7).
Cytoplasm includes the cytosol and organelles, excluding the nucleus.

Microscopy Techniques

Light microscopy (LM)
Fluorescence microscopy (FM)
Scanning electron microscopy (SEM)
Transmission electron microscopy (TEM)

Tissues

Tissues are groups of similar cells performing a specific function.
Tissues are classified by the size, shape, and function of their cells.

Epithelial Tissue

Lines surfaces of body cavities, tubes, and glands.
Roles in transport, diffusion, and secretion.
Types include: simple squamous, cuboidal, and columnar (simple and stratified epithelium).

Muscle Tissue

Generates motile forces through contraction.
Types include skeletal, smooth, and cardiac.

Nervous Tissue

Interconnected networks allowing communication from the brain and spinal cord to other body parts.
It consists of neurons (excitable cells) and glial cells (supporting cells).

Connective Tissue

Most abundant tissue type in the body.
Consists of cells (e.g., fibroblasts, adipocytes) within an extracellular matrix (ECM).
Main functions: binding/structural support, protection, transport, and insulation.
Types include loose (areolar), adipose, reticular, dense (fibrous and elastic), cartilage (hyaline, fibrocartilage, elastic), and bone (compact and spongy).

Extracellular Matrix (ECM)

ECM differs between tissues; for example, epithelial tissue has little ECM.
ECM has structural functions, regulates cell mobility, influence development and growth, and change cells morphology and function.

Specialized Epithelial Tissues

Stratified squamous epithelium, a protective tissue found in the skin, hair, nails.
Transitional epithelium found in the urinary tract (mouth, pharynx, oesophagus, vagina).
Pseudostratified columnar epithelium found in the respiratory tract.

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Description

This quiz covers the basics of cells, tissues, organs, and body systems. Learn about the different types of cells and tissues, their functions, and how they work together to form organs and systems in the body. Test your understanding of key concepts in biology related to cellular structure and organization.