Histology Quiz 1 - copia
What is histology?
Histology is the study of the microscopic structure and function of cells and associated tissue.
What is the function of a cell?
To carry out vital processes of absorption, assimilation, respiration, irritability, conductivity, growth, reproduction and excretion.
What are common characteristics of cells?
-nucleus
-nucleolus
-cell membrane
- cytoplasm
-organelles
What is exocytosis?
Expulsion of materials out of bthe cell by fusing of a vesicle membrane with the cell membrane.
What is Endocytosis?
Uptake of materials into the cell, which includes pinocytosis and phagocytosis.
Is Pinocytosis;
a. "cell fighting"
b." cell eating"
c. "cell drinking"
d. "cell recyling"
a. "cell drinking"
Is Phagocytosis;
a. "cell fighting"
b." cell eating"
c. "cell drinking"
d. "cell recyling"
b. "cell eating"
a.What is the structure of the cell membrane?
B.What is the function of the cell membrane?
a.Also known as the plasma membrane. Thin membrane that surrounds every living cell.
b. The "gate-keeper" of the cell. Allows certain substances into the cell while keeping other substances out.
a. What is the structure of the Cytoplasm?
b. What is the function of the Cytoplasm?
a. Cytoplasm aka Cytosol is clear fluid in the cell's membrane.
b.Supports and suspends organelles and cellular molecules while performing processes such as cellular respiration for breathing, synthesizing proteins and having division of cells by both mitosis and meiosis.
a. What is the structure of the Nucleus?
b. What is the function of the Nucleus?
a. Nucleus aka Nuckei is the largest densest organelle
b.Control cell growth and multiplication.
What are the Components of a Nucleus?
- Nucleolus (produces rNA and RNA)
- Chromatin (contains chromosomes)
- Nucleoplasm( fluid portion thayt contains important proteins)
-Nuclear Envelope (a double layered membrane)
-Nuclear Pores (large complex of proteins, which is the double membrane surrounding the eukaryotic cell nucleus)
a. What is the structure of the Endoplasmic Reticulum?
b. What is the function of the Endoplasmic Reticulum?
a. The "highway system" consisits of parallel membrane- bound channels.Connected to call membrane, the nuclear membrane some organelles.
b. Modification, storage, segregation and transport of proteins that the cell manufactures. Could be rough or smooth.
Lets Break down Rough Endoplasmic Recticulum
Why is it rough, what is the function?
- Contains ribosomes(protein particle factories that ) on the outer surface (which makes it rough). The protein molecule can be transported to the Golgi Apparatus.
Lets Break down Smooth Endoplasmic Recticulum...
Why is it smooth, what is the function?
- No ribosomes
- Contains enzymes involved in manufacturing various lipid
molecules and steroid hormones
Now back to breaking down organelles...
a. What is the structure of the Golgi Apparatus?
b. What is the function of the Golgi Apparatus?
a."Chemical procressing and packaging center". Looks like pancakes :)
b.sorts,condenses, packages and delivers proteins from the RER.
a. What is the structure of the Mitochondria?
b. What is the function of the Mitochondria?
a. "Powerhouse" of the cell that is composed of two membranes.
b. Releases energy from food molecules and transform
energy into ATP
a. What is the structure of the Lysosome?
b. What is the function of the Lysosome?
a. “Sewer system” of the cell produced by the Golgi Apparatus(destroys worn cell parts
b.Contains hydrolytic (hyaluronidase) and
digestive enzymes capable of digesting substances that enter cells.
a. What is the structure of the Cytoskeleton?
b. What is the function of the Cytoskeleton?
a. " Cell's skeleton", gives basic stability to the cell as a whole
b.The cytoskeleton also compartmentalizes (sorts out) the cytoplasm, creating preferred “freeways” for the movement of molecules formed by cellular processes
Let's discuss the components of the Cytoskeleton...
– microfilaments
– intermediate filaments
– microtubules
Define Microfilaments
- Delicate, threadlike
- Arrange in a meshwork
- Cause various kinds of cellular movement
Define Microtubles
- Thick, stiff
- Form cell's internal skeleton
- Maintain the shape of the cell
- Contains cillia, flagella, centrioles, mitotic spindle
Define Intermediate Filaments
-Various types of thicker, treadlike microscopic structures within the cell
- Involved with intercellular junctions and mitosis
Define Inclusions
-store lipids and melanin pigmentation
- Metabolically inert substances that are transient over time in the cell
Next up Intercellular Junctions (bonds between cells)
What is Tight Junction?
Fuses cell membranes together (hint: "water tight" seal)
What is Gap Junction?
Tubular channels between cells
Remember Intercellular Junctions are bonds between cells.
There are two types;
1. Desmosomes
2. Hemidesmosomes
What is a Desmosomes?
Attach adjacent cells to each other
What is the Hemidesmosomes?
Attach cells to basement membrane
Next up Life Cycle of the Cell....
What is Interphase and the steps?
DNA is replicated , cell grows and forms new organelles
1. G1. The initial resting phase of cell growth
2. S.DNA replicationn (chromatin and centrosome replication)
3. G2. The second resting phase of cell growth
What is Mitosis and the stages?
Cell Division
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
What is Prophase?
-Chromatin condenses into chromosomes
-Nuclear membrane and nucleolus disappear
What is Metaphase?
-Chromosomes become arranged midway between the centrioles and the spindle fibers from the centrioles become attached to the centromeres of each chromosome.
What is the Anaphase?
Centromeres split and each chromosome separates into 2 chromatids
What is Teleophase?
- Division into 2 daughter cells
- Nucleoli appear
-Microtubules disappear
What is Cytoplasmic Division?
aka Cytokinesis
Cell division is the process by which a parent cell divides into two daughter cells
What is Differentiation?
is the process by which a less specialized cell becomes a more specialized cell type.
– Ex: ovum + sperm = fetus
What is Meiosis?
Occurs during the maturation of sex cells
Unit 2 - Basic Tissues
What are tissues?
Structure formed by the grouping of cells with similar characteristics of form and function.
4 Basic Types of Tissues
What is Epithelial Tissue?
• forms protective coverings
• function insecretion and sensory
What is the Connective Tissue?
• provides support for softer body parts
• binds structures together
What is Muscular Tissue?
Responsible for producing body movements
What is the Nerve Tissue?
Specialized to conduct impulses that help control and
coordinate body activities
Let's Breakdown Epithelial Tissue...
-Covers and lines both the external and internal
body surfaces, including vessels and small cavities
-Serves as a protective covering or lining
- absorption
- secretion
- sensory
- otherspecializedfunctions.
- Avascular has no blood supply
- high regenerative
What is Simple Squamous Epithelium?
- Cells are flat, arranged in one layer
- Function: covers connective tissue, performs a filtering function
- Location = pulmonary alveoli(lungs, inner & middle ear, blood and lymphatic vessels (network of capillaries)
0 heart
- serous cavities
What is Simple Cuboidal Epithelium?
- Cube- like cells (nucleolus in the centre)
- Function : protection/ covering for an organ, contributes to secretion
- Location (lines the ducts of various glands ex. salivary glands)
What is Simple Columnar Epithelium?
- cells are rectangular
- function , protection, secretion, absorption
- has goblet cells
- may be ciliated
- Location, non - ciliated (stomach, large, small intenstine)
- Ciliated (uterus, fallopian tubes, small intra - pulmonary bronchi)
What is Pseudostratified Columnar Epithelium?
- Crowded columnar
- Nuclei are at different levels
- Moistens , warms and cleans lining membranes
- may be ciliated
- location; upper respiratory tract including nasal cavity and paranasal sinuses
What is Stratified Squamous Non Keratined Epithelium?
- many layers of cells on an irregular basal layer "layered cake"
- no lyaer of keratin
- kept mopist from bodily secretions
- cells range in shape
- location; buccal and alveloar mucoa, ventral part of tongue, soft palate, floor of the mouth, cornea, esophagus
What is Stratified Squamous Keratined Epithelium?
- Located on dry or wet surfaces (skin, free gingiva, attached gingiva, hard palate, doral, tongue)
- has a keratin layer for protection
- Composed of 5 layers (stratum basale, spinosum, granulosum, lucidum (palms , soles not in oral cavity, corneum
What is Transitional Epithelium?
- Shape of the surface cells changes (undergoes transition) depending on the degree of stretch
- ranges between stratified non- kerarinized squamous and columnar epithelium
- range from polyhedral to done shaped flat cells
-cells are soft, pliable and loosely arranged
- location ; urinary bladder
What is basement membrane?
- Thin acellular structure
- located between the epithelium and connective tissue
- 3 layers ; lamina Lucida (clear layer) , Lamina Densa ( dense layer that makes up the basal lamina ) reticular fibers
What is Connective Tissue?
- Connects, supports, protects provides franeworks, fills spaces, stores fat, produce blood cells, provides protection against infection and helps repair tissues
- Cells are some distance apart andv have lots of matrix between them ( fibers and intercellular substance)
What are the major cell types found in connective tissue?
Fibroblasts
Macrophages (Monocytes) - most common WBC
Mast Cells (Basophils) involved in allergic responses
What is Fibroblasts
-Most common cell type found in all CT
- Synthesize certain types of protein fibers and intercellular substances need to sustain the connective tissue
- fixed cells (do not leave tissue)
What is Macrophages?
-Function as phagocytes (ingest bacteria, dead and dying cells
- important in fighting infections
What is Mast Cells?
- Basophils (involved in allergic responses)
- may release heparin (anticoagulant) and histamine
What is Loose CT
- Forms thin membranes between organs and binds them together
- Provides protective padding for the deeper structures
- Intercellular space contain
- Location ; beneath the skin, muscles
What is Adipose CT
- stores fat
- protective cushion and heat insulator
- cells packed tightly together
- location ; beneath the skin, adominal membranes , oral cavity , around the kidneys, heart , various joints
What is the Fibrous CT?
- Composed of strong collagenous fibers
- binds parts together
- location; tendons, ligaments, eyes, skin
What is Elastic CT?
- Composed mainly of elastic fibers
- Strength with elasticity
- location ; walls of some hollow internal organs
- Vocal cords
What is Reticular CT?
- Delicate network of interwoven reticular fibres forming a supportive framework
- Location; blood vessels, liver, spleen , lymphatic organs
What is Cartilage ?
- Provides support, framework, decreases friction
- Intercellular materials are composed collagen fibers and intercellular substance
- lacks direct blood supply , slow to heal
What is Perichondrium?
- surrounds the cartilage
- a fibrous connective tissue sheath containing blood vessels
- chondroblasts lie internal to it
What is the cells of the cartilage?
- Chondroblasts (produces matrix)
- Chondrocytes (maintain matrix)
What are the 3 main cartilage types and where are they located?
- Hyaline (a type of connective tissue found in areas such as the nose, ears, and trachea of the human body)
- Elastic (elastic cartilage is also recognized by its ability to snap back into an original form
- Fibrocartilage (is a transition tissue that should be viewed as a blend between hyaline cartilage and dense fibrous connective tissue
What is Connective Tissue ( Bone) ?
- Rigid connective tissue
- Intercellualr matrix contains mineral salts and collagen
- produces blood cells and stores calcium/ other minerals
What are the bone cells and their function?
- Osteogenic cells (stem cells)
- Osteoblasts (bone-building)
- Osteocytes (bone - maintaining)
- Osteoclasts (bone- crushing)
What is Osstification
The natural procress of bone formation
What is Intramembraneous?
Formation of osteoid within 2 defense connective tissue sheets
What is the turnover time for skin and the oral cavity?
Skin = 27 days
Oral cavity = 14 days
Where can intramenbranous bones be found?
infant, maxilla and mandible
What is Endochondral?
- Formation of osteoid within a hyline cartliage, can it be found vertebrae, ribs, head of mandible, base of skull.
What is a dendrite?
inpulses to the cell body
Axon?
impulses away from the cell body
Which metabolic activity of the cell has no impulse?
body