Final 1st semster Flashcards
Methods of fabrication of micro preparations. Stages. The types of micro preparations. Staining methods
- micro-fabrication technologies are used to fabricate micro-components and systems .A variety of Micro-Fabrication methods
exist for the fabrication of
1-microfluidic devices, including wet etching, reactive ion etching, conventional machining (),
2-photolithography, soft lithography, hot embossing, injection molding, laser ablation, in situ construction
3- and plasma etching
—STAGES :
1-taking a material
2-Fixation
3-Washing in water .
4. Dehydration and seal .
5-Filling in a dense condition : 1-Paraffin2- celloidin
6. Preparing of sections .
7–Colouring
–staining : is used to enhance the visualization of the cell or certain cellular components under a microscope OR basically to
recognize the cell structures under microscope.
-There are 2 types of Staining :-1- Stains for Electron microscope. 2- Stains for Light microscope
-Types of Histological preparation
1. Section ( Thin – half thin – ultra thin ). 2. Smear ( blood – bone marrow – slime ). b ( fresh body cut ).4. Film.
2- Fertilization. Distant and contact interaction. Zygote as a unicellular embryo
The fertilization is the fusion of male and female sexual cells to form the zygote with 46 chromosomes.
Fertilization of the ovum occurs in the ampulla of the uterine tube.The acrosome reaction of spermatozoa is a prerequisite for
the association between a spermatozoon and an egg, which occurs through fusion of their plasma membranes. After a
spermatozoon comes in contact with an egg, the acrosome, which is a prominence at the anterior tip of the spermatozoa,
undergoes a series of well-defined structural changes. A structure within the acrosome, called the acrosomal vesicle, bursts, and
the plasma membrane surrounding the spermatozoon fuses at the acrosomal tip with the membrane surrounding the acrosomal
vesicle to form an opening by Hyaluronidases enzyme. As the opening is formed, the acrosomal granule, which is enclosed
within the acrosomal vesicle, disappears. The dissolution of the granule releases a substance called a lysin, which breaks down
the egg’s vitelline coat, allowing passage of the spermatozoon to the egg. The zygote is a unicellular organism that eventually
turns into a multi-cellular one after 5 days, and when it does, it is called an embryo.
8-Epithelial tissues. Classification. General characteristics. The structure of the simple epithelium. The basement membrane:
structure, functions.
1- Simple epithelia consist of only one layer of cells.There are four types of simple epithelia:
1-1Simple squamous epithelium
1-2Simple cuboidal epithelium
1-3Simple columnar epithelium
1-4 Pseudostratified columnar ciliated
—The structure of basal lamina? IT connects the epithelium and subjacent connective tissue. With electron microscope the basal
lamina consists of2 layers: inner lamina lucida and outer lamina densa
-function: It acts as a point of attachment for cells IT connects the epithelium and subjacent connective tissue.
9- Epithelial tissues. Glands, their classification. Characteristics of the secretory ends and excretory ducts of the exocrine
glands. The types of the glandular secretion (holocrine, merocrine, apocrine). Features of the structure of the endocrine
glands.
- definition’s answer is mentioned in the previous answer
-glands: is a group of cells in an animal’s body that synthesizes substances (such as hormones) for release into the bloodstream
(endocrine gland) WITHOUT DUCTS or into cavities of body (exocrine gland)
Exocrine glands are classified based on six different morphological
-1. Number of secretory cells:1) Unicellular glands (goblet cells) 2)Multicellular glands consist of many cells
-2)Location of the secretory cells: 1- Intra epithelial glands are goblet cells. 2-Extraepithelial glands are all large exocrine glands.
-3. Nature of secretion:
1-Mucous glands contain mucous-secreting cells
2-Serous glands-, the secretory portions contain only serous cells
3-Mixed glands the secretory portions contain both mucous and serous cells
-4)Mechanism of secretion: 1- Merocrine: No part of the cell is lost, only the secretory product is expelled by the process of
exocytosis.
Apocrine: Part of the apical cytoplasm of the cell is lost. Secretion is discharged within unbroken, membrane-bound vesicles
(apocrine sweat glands and mammary gland).
Holocrine: The entire secretory cell is LOST
10- Epithelial tissues. Classification. General characteristics. The structure of the stratified epithelium. Reparative
regeneration of epithelial cells.
–Stratified epithelia contain more than one layer.There are three types of stratified epithelia:
-1- Stratified squamous non-keratinised epithelium: consists of 3 layers:
1-Stratum hasale, single layer of columnar or cuboidal cells
2-Stratum spinosum, consists of polygonal cells.
3- Surface layer, consists of squamous cells.
It is found in:* mouth cavity,* esophagus
-2-Stratified squamous keratinised epithelium: consists of 5 layers of 1-keratin-producing cells (keratinocytes):
-3-Stratum hasale,. 3-Stratum spinosum: consists of polygonal cells with a central nucleus
-4-Stratum granulosum: is characterized by 3 to 5 layers of flattened polygonal cells with thecytoplasm filled with coarse
basophilic granules called keratohyalin granules.
-5- Stratum lucidum: is thin layer of flattened eosinophilic cells
-6-Stratum corneum consists of 15-20 layers of flattened dead cells consisting keratin (in epidermis of skin)
-7-Transitional epithelium: it is highly specialized to give a degree of stretch, so it is found only in the urinary tract. Cells are
arranged in 3 to 5 layers
-Blood. Classification of the blood elements. The amount of the cells in the human blood. Platelets , Red blood erythrocytes, Basophils ,Еosinophils , Neutrophils : size, structure, lifespan,
function.
-Blood is a specialized type of connective tissue in which the fluid intercellular substance is called plasma
Quantity of the blood of an adult man is 5 - 6 litres, of an adult woman - 4-5 litres, about 7% of the body weight.
Components and classifcation of the blood
-I. Formed (cellular) elements constitute 40-45% of the total volume of blood:
1. Erythrocytes;
2. Leukocytes:1- granulocytes * neutrophils,* eosinophils,basophils
, 2-agranulocytes: * lymphocytes, monocytes
————–platelets—
—. Platelets.
II. Plasma constitutes 55-60% of the total volume of blood.
-normal concentration of erythrocytes in blood is 3,7- 4,9x1()I2/L in women and 3,9-5,5xlOl2/L in men.-The normal concentration of leukocytes in blood is 6-9x10’J/L.
- Eosinophils constitute 2 - 5 % of leukocytes - Basophils constitute 0 - 1 % of leukocytes.
-neutrophils constitute 65 - 75 % of circulating leukocytes
platletsare small,irregular,disc shaped non nucleated- platelet is Divide into 4 zones :(1) peripheral zone consist of cell
membrane covered by a glycocalyx.(2)structural zone Located beneath peripheral zone (3)organelle zone consists of granules
and cellular components (4)membrane zone include two types of membrane channels,
lifetime: the average lifetime of a platelets is normally just 5to 9days –
Function: maintenance of hemostasis by the formation of thrombi, when damage to the endothelium of blood vessels occurs
———erythrocytes ——
-Erythrocytes (red blood cells) are postcellular structures which have no nuclei. -Erythrocyte consists of only an outer plasma membrane enclosing the iron; respiratory protein hemoglobin (Hb).’
-Erythrocytes are circular biconcave discs; biconcave shape increases the surface area
-Size: Erythrocytes with diameter than 9 pm are called macrocytes and those diameters less than 6 pm are called microcytes.
-Life span: erythrocytes survive in the circulation for about 120 days
—– Basophils—–
- Basophils constitute 0 - 1 % of circulating leukocytes-Basophils have an average diameter of 12-15 pm in peripheral blood
They have lobated (2-3 lobes) or S-shaped nuclei.
Lifetime: Basophils circulate for a few hours in the blood, then migrate into the tissues and function for a few days
Functions :1-Basophils appear in many specific kinds of inflammatory reactions.
2-Basophils contain anticoagulant heparin, which prevents blood from clotting too quickly.
3- They also contain the vasodilator histamine, which promotes blood flow to tissues
—Neutrophils—
Neutrophils constitute 65 - 75 % of circulating leukocytes..size:from10to12µm
structure: Neutrophils have a multilobed nucleus, with 3 to 5 lobes joined by slender strands of genetic material. The cytoplasm
of neutrophils contains numerous purplish granules called azurophilic
life time: Neutrophils are short-lived cells w’ith a half-life of 6-7 hours in blood and of 1 -4 days in spleen and other tissues.
Function
Neutrophils are phagocytes, capable of ingesting microorganisms
—–Еosinophils—-
size: Eosinophil granulocytes have an average diameter of 10-12 pm in peripheral blood smears — Structure: Eosinophils also
have lobated nuclei (2-4 lobes)
Cytoplasm contains two types of granules: 1-primary azurophilic granules:, which are primary lysosomes and contain the
enzymes 2-specific eosinophilic granules: are large and elongated; contain crystalline cores oriented parallel to the long axis of
.the granules
Lifespan: Eosinophils circulate for 4-5 hours in the blood, then migrate into the tissues (skin, mucosa of digestive, respiratory
.and reproductive tracts) and function 8-12 days
Functions:
1- Participation in immune reaction
2- Destruction of parasites by the toxic basic protein
3- Limited ability to -
. participate in phagocytosis.4- Diapedesis
General characteristics of connective tissues. Classification. Sources of development. Fibrous connective tissues. -17 .
1-Fibroblasts, their varieties, structure. Synthesis of collagen fibers: The varieties of the fibroblast is different includes:
.fibroblasts and fibrocytes
2-Macrophages, their origin, types, structure, role in the protective reactions of the body.
3- Plasma
cells, their origin, structure, role in humoral immunity
4-Intercellular substance: general characteristics. Collagen and elastic fibers, their role, structure and chemical composition.
—-1-Structure of the fibroblasts: The fibroblast is elongated cell with an ovoid nucleus. The cytoplasm is rich in rough endoplasmic
reticulum, Golgi complex is well developed. The fibrocyte is spindle-shaped. It is more mature, small cell with dark elongated
nucleus.Fibroblasts are the dominant cells of the connective tissue. It is responsible for the synthesis of collagen fibers and
. components of intercellular matrix
————–
2-origin of macrophages: Macrophages derive mainly from precursor cells from the bone marrow, to producing monocytes that
.circulate in the blood. In a second step, these cells migrate into the connective tissue and becomes macrophages
Types of macrophages : it has 2 types M1 macrophages and M2 macrophages
.Structure of macrophages: The size of cells ranges between 10-30 Mm in diameter
.The cytoplasm: is basophilic . Nucleus: oval in shaped
.Function : it has protective and immune function against foreign body
————.
3-origin of plasma cells: plasma cells arises from antigen-B cells in the spleen or lymph nodes. Cytoplasm: is basophilic. Structure
.of plasma cells: the plasma cells are large cells and have eccentric round nucleus
Function of plasma cells: maintenance of humoral immunity by synthesis of antibodies
————–
4–connective tissues are the complex of derivatives of the mesenchymal origin, consisting of cellular differons and the
extracellular substance, participating in maintenance of a homeostasis of the internal environment of an organism. It consists of
1- connective tissue cells ,2- extracellular matrix 3- ground substance4- protein fibers (collagen)
Functions of connective tissue
1-Metabolic functions. All the metabolites from the blood pass from capillary beds and diffuse through the adjacent connective
tissue to cells and tissues.
2-Regulative. Connective tissues regulate the activity of other tissues
3-Defensive functions. connective tissue play roles in the defense or protection of the body (plasma cells, lymphocytes,
neutrophils, eosinophils, basophils, mast cells). Macrophages are important in tissue repair as well as defense against bacterial
invasion.
4-Structural support is to enable maintenance of anatomical form of organs and organ systems.
Classification of the connective tissues
1. Fiber connective tissue (connective tissue proper)
1 Loose (areolar) connective tissue:it is found out in all organs - it forms their stroma, fills in spaces between function elements of other tissues, accompanies with
nerves; it is flexible, well vascularized. -
It consists of cells and extracellular matrix.
cells of loose connective tissue are fibroblasts(specialized on the destructions of intercellular substance of connective tissue)
., fibrocytes. macrophages, mast cells:
are oval to round connective tissue cells, whose cytoplasm is filled with basophilic granules. The small and spherical nucleus is
centrally situated
, plasma cells, fat cell (adipocytes), pigment cells, leukocytes, pericytes, and adventitional cells.
2 Dense connective tissue: tissue 3 Regular 4 Irregular
2. Connective tissues with special properties
1 Adipose tissue 2 Reticular tissue 3 Mucous tissue 4 Pigment tissue
3. Supporting connective tissue
1 Cartilage 2 Bone
-source of development: Connective Tissue Formation During embryonic development, undifferentiated mesenchymal cells,
derived from mesodermal and mesectodermal (neural crest cells) origins, give rise to the different forms of CT: bones, cartilage,
tendons, ligaments, and irregular CT
Dense (fibrous) C.T:, is a type of connective tissue with fibers as its main matrix element. The fibers are mainly composed of
type I collagen. Crowded between the collagen fibers are rows of fibroblasts, fiber-forming cells, that generate the fibers. Dense
connective tissue forms strong, rope-like structures such as tendons and ligaments
intercellular substance: of the connective tissue is the matrix. It performs the transport function between different systems in
the body, supports it and, if necessary, transmits various signals from one organ to another.
1-Collagen fiber is made from fibrous protein subunits linked together to form a long and straight fiber. These fibers hold
connective tissues together, even during the movement of the body Function:This type of tissue supports muscle tissue, nerve
tissue and epithelial tissue. .
Elastic fiber contains the protein elastin along with lesser amounts of other proteins and glycoproteins
Function:play a structural and mechanical role in the arteries and their essential function is to provide elasticity and resilience to
the tissues.
The primary amino acid sequence of collagen is glycine-proline-X-Collagen is composed of 3 chains
Elastic fiber in the body is a mixture of amorphous elastin and fibrous fibrillin. Both components are primarily made of smaller
amino acids s glycine , valine, alanine, and proline .
23- Dense fibrous connective tissue, its varieties, structure and functions. Tendon as an organ:
1-Dense connective tissue, also called dense fibrous tissue, is a type of connective tissue with fibers as its main matrix element.
[1] The fibers are mainly composed of type I collagen. Crowded between the collagen fibers are rows of fibroblasts, fiberforming cells, that generate the fibers. Dense connective tissue forms strong, rope-like structures such as tendons and
ligaments. Tendons attach skeletal muscles to bones; ligaments connect bones to bones at joints. Ligaments are more stretchy
and contain more elastic fibers than tendons. Dense connective tissue also make up the lower layers of the skin (dermis), where
it is arranged in sheets-
2-Tendons are the most common example of dense regular connective tissue. Tendons are cord-like
structures that attach muscle to bone. Tendons consist of parallel bundles of collagen fibers separated by a small quantity of
amorphous intercellular substance.
Specialized connective tissues. Pigment tissue, structural features, meaning
Specialized C.T: it is a type of connective tissues include a number of different tissues with specialized cells and unique ground
substances. Like adipose tissue:
white (unilocular, or yellow),
brown (multilocular).
trophic,
Functions of adipose tissue:supporting, protective and plastic - adipose tissue surrounds organs and fills in spaces between
them; softening impacts, it protects them from mechanical traumas
, cartilage, bone, blood, and lymph.
Pigment tissue : is represented by Pigment cells are present in several regions of the body including the dorsum, trunk
hypodermis, head, fins, intestine, and abdominal wall
Function of melanin of pigment cells is to protect the organism against the damaging effects of nonionizing ultraviolet
irradiation
Cartilage tissue. Types. General characteristics: cells and intercellular substance. The structure of hyaline cartilage. Agerelated changes.
—Hyaline cartilage:the most common type. It appears translucent, with glassy appearance.Sites:1-fetal skeleton.2- Epiphyseal
plate.3 . Respiratory passages (nose, larynx, trachea and bronchi). Structure: 1-periochondrium :it is a Capsule of dense Fibrous
c.t that surrounds. His formed of 2 layers1-outer white fibrous.2-Inner Chondrogenic (cellular): rich chondroblasts.
*Function.:
1-Nutrition of non-vasCular cartilage, formation of new cartilage during growth.provides attachment for muscles.
2-Cartilage Cells:1-Chondroblasts (immature young chondrocytes).
Site: always on the surface of cartilage at the inner aspect of periochondrium.
- flat tooval or spindle is shape with deep basophilic cytoplasm.
They have ribosoms, rER, large, Golgi apparatuns and many mitoChondria.
Functions: formation of Cartilage matrix and change into Chondrocytes, formation of cartilage Collagen.
Chondrocytes:They are the mature Cartilge cells.Origin: they develop from Chondroblasts.
- shape rounded with Cytophasm.basopilic, Rounded darkly stained central nucleus.
Function: Maintain the cartilage matrix,
Muscle tissue. General characteristics. Striated muscle tissue. Development, morphological and functional characteristics,
regeneration. The structure of the muscle fibers, and its structural and functional unit - sarcomere.
—Structual and functional units are specialized elongated cell called muscle fibers. Contaning Contractile filaments (thin actin
and thick myosins).The cell membrane of muscle fibers is also called Sarcolemma and the cytoplasm Called Sacroplasm. The
smooth endoplasmic reiculcm is Called Sacroplasmic reticulum.-sarcoplasm is acidophilic rich in organells as mitochondria
Striated muscle fiber :Each skeletal muscle fiber is along wall with:
-Shape:cylindrical non branched (except face and tounges)
-Nuclei: each cell has multiple oval nuclei fused of mononucleated myoblasts.
-Sarcoplasm:is acidophilic.
-Sarcomere:It is apart of myofibril between 2 adjecent Z line, it is a functional unit in contraction.
Myofibrils are composed of thick myosin and thin actin.
Thick myosin filaments are restricted to the A band. - A bond appears dark because it is formed of both myosin and actin
filaments.- H bond appears pale due to the presence of myosin filaments only.- M line produced.by interconnections of adjecent
myosin filaments. - I band appear light as it is formed of only actin filaments.- Z line is dense by condensed actin filaments matrix
material and other proteins
-Development: from myotomes of mesoderm
Classification, general morphofunctional characteristics of muscle tissue. Smooth muscle tissue. Sources of development.
Morphological and functional characteristics. Regeneration
- Smooth muscle is an involuntary non-striated muscle.
Function:Smooth muscle may contract spontaneously as in arteries
Regeneration of muscle tissues:Smooth muscle is capable of an active regenerative response.
Mononucleate smooth muscle cells and pericytes from blood vessels undergo mitosis and provide for the replacement of the
damaged tissue.
Morphofunctional unit : is smooth muscle cell
Smooth muscle cell is long spindle-shaped cell Smooth muscle cell is from 20 pm in small blood vessels to 500 pm in the
pregnant uterus in length; greatest diameter is about 6 pm.
-Nucleus is single, rod-shaped, and central in position;
