Tissues of the Body: Lecture 1.1 - Cell Ultrastructure

These flashcards cover the key concepts, definitions, and explanations from the lecture on cell ultrastructure and tissue types.

What are the four fundamental tissue types in the human body?

Epithelial tissue, connective tissue, muscle tissue, nervous tissue.

What is the main function of epithelial tissue?

Protection, as seen in skin and the lining of the digestive tract.

What process do lysosomes perform that is crucial for cellular health?

Autophagy, the breakdown of non-functioning organelles.

What is the Golgi apparatus responsible for?

Modifying, sorting, and packaging proteins for secretion.

Define 'autophagy'.

A normal homeostatic process where the lysosomal breakdown of non-functioning organelles occurs.

What are lysosomal storage disorders (LSDs)?

Diseases caused by defects in hydrolytic enzymes stored in lysosomes.

What are ribosomes and their primary function?

Electron-dense particles that catalyse protein synthesis.

What is the rough endoplasmic reticulum (RER) associated with?

Ribosomes and is involved in the synthesis of proteins destined for secretion.

What is the primary role of smooth endoplasmic reticulum (SER)?

Lipid biosynthesis and calcium ion storage.

What is the role of mitochondria in the cell?

ATP production through the citric acid cycle and oxidative phosphorylation.

What defines a cell's cytoskeleton?

A network of protein filaments that provides structural support and facilitates movement.

What is the significance of the nuclear envelope?

It protects the nucleus and is continuous with the rough endoplasmic reticulum.

What are intermediate filaments and their primary function?

Structural support for the cell, specific to cell type.

What is the main action of lysosomes?

To digest macromolecules and recycle cellular components.

How does the endoplasmic reticulum (ER) differ from rough and smooth types?

Rough ER has ribosomes and synthesizes proteins; smooth ER is involved in lipid synthesis.

Define 'peroxisomes'.

Organelles that contain enzymes for the oxidation of fatty acids and detoxification.

What is the primary purpose of the cytoskeleton's microtubules?

To facilitate movement and serve as tracks for organelle transport.

What is the risk of inhibiting autophagy in cancer cells?

It may lead to decreased cancer cell survival by preventing recycling of substrates.

How are lysosomes formed?

From the Golgi apparatus as vesicles containing hydrolytic enzymes.

What is the relationship between autophagy and cancer treatment?

Inhibition of autophagy is used as a strategy to induce cell death in cancer.

What occurs in Tay-Sachs disease?

Accumulation of GM2-ganglioside due to a lack of β-hexosaminidase A.

What are the main components of ribosomes?

rRNA and distinct proteins.

What is the diameter of a typical microtubule?

25 nm.

What features distinguish cilia and flagella?

Arrangement of microtubules in a '9+2' structure allowing rhythmic beating.

What is the main role of the cytoskeleton's actin filaments?

Provide structural support and facilitate movement by forming microfilaments.

What defines the anatomical structure of the Golgi apparatus?

Three functional parts: cis face, medial Golgi, and trans face.

What is the significance of the nucleolus?

Site of rRNA synthesis and ribosome assembly within the nucleus.

Describe the function of epithelial cells as a tissue type.

To protect and line surfaces of organs and cavities.

How do mitochondria reproduce?

Autonomously, through a process of fission and fusion.

What is the defining characteristic of smooth muscle tissue?

Involuntary control and found in walls of hollow organs.

List one major function of neurons.

To transmit electrical impulses throughout the body.

What type of tissue is connective tissue, and what is its relevance?

Support and bind other tissues; includes bone, blood, and cartilage.

What is the unique characteristic of skeletal muscle tissue?

Striated and under voluntary control.

What key process is associated with the endoplasmic reticulum?

Protein synthesis and processing.

What is the role of the Golgi apparatus in the secretory pathway?

To modify, sort, and route proteins and lipids for secretion.

What kind of enzymes do peroxisomes contain, and what do they do?

Oxidative enzymes that break down fatty acids.

How is the cytoskeleton involved in mitosis?

Microtubules form the spindle apparatus to separate chromosomes.

What important process involves lysosomes and phagocytosis?

Digestion of material ingested by a cell.

What type of cellular components are classified as 'neural tissue'?

Neurons and supporting glial cells.

Explain the composition of the cytoskeleton.

Made of microfilaments, intermediate filaments, and microtubules.

What role do kinesin proteins play in cells?

Transport vesicles along microtubule tracks.

What unique characteristic do cardiac muscle cells exhibit?

They are striated and involuntary.

What is the histological role of dense connective tissue?

To provide tensile strength and support to other tissues.

Which organelle is responsible for ATP production?

Mitochondria.

What defines the structure of the nucleus?

It contains genomic DNA and is surrounded by a double-membrane nuclear envelope.

Identify a main characteristic of secretory vesicles.

They carry proteins to be secreted outside the cell.

What is the empirical significance of microfilaments?

They are involved in cellular movement and changes in shape.

What is Epidermolysis bullosa, and its cause?

A skin condition caused by mutations in keratin genes.

What physiological process do the cilia facilitate?

Movement of fluid across epithelial surfaces.

How are residual bodies related to lysosomes?

They are remnants of lysosomes containing undigested material.

What is a primary feature of connective tissue cells?

They are dispersed within an extracellular matrix.