Ch. 3 - Histology Flashcards
AKA “microscopic anatomy”, this is the study of tissues and their arrangement in an organ
Histology
Mass of similar cells + cell products forming a region of an organ and performing a certain function
Tissue
4 types of primary tissues:
Epithelia, muscular, connective, nervous
Tissue that lines body surfaces/cavities and is a major tissue in glands
Epithelial tissue
Tissue that contains more extracellular matrix than cells and functions to support, bind, and protect
Connective tissue
Tissue that contains excitable cells and functions in bodily control/coordination
Nervous tissue
Tissue that contains elongated, excitable cells that applies force through contraction
Muscular
This tissue can be found in the brain and spinal cord
Nervous
This tissue can be found in skeletal, smooth, and cardiac muscle
Muscular
This tissue can be found in bones and cartilage
Connective
This tissue can be found in the epidermis, lining of digestive tract, and in glands
Epithelial
A tissue cut in the long direction is A
Longitudinal section
A tissue cut perpendicular is a
Transverse section
Cross section
A tissue cut at a slant is a
Oblique section
Epithelia are categorized into 2 broad categories:
Simple and stratified
In this epithelial tissue, all cells reach the basement membrane
Simple epithelia
Is pseudostratified epithelia considered simple or stratified?
Simple - Even though not all cells reach apical surface, all cells meet basement membrane
These cells are often found in pseudostratified columnar and secrete protective mucus over the membrane.
Goblet cells
This tissue consists of 2-20 layers of cells
Stratified epithelia
In stratified epithelia, which layer of the cell determines its name?
The shape of the top layer of cells
This stratified epithelia is unique to the urinary tract:
Urothelium
What is the most widespread epithelium in the body and where can it be found?
Stratified squamous epithelium
Describe the structure and comings of stratified squamous epithelium
Tissue starts out as cuboidal and undergoes continual mitosis, as cells reach closer to the surface they flatter and become squamous cells until they die and flake off.
The separation of cells from the surface is called:
Exfoliation
What are the 2 subgroups of stratified squamous epithelia?
Keratinized and nonkeratinized
Describe a keratinized stratified squamous epithlium
-Found on the skin’s surface
-Covered in a layer of durable protein KERATIN
-Contains hydrophobic lipids making skin waterproof
Describe nonkeratinized stratified squamous epithelium
-Found on mucosal surfaces: Vagina, tongue, esophagus, etc.
-Des not contain keratin
-Easily durable to undergo stress of stretch and is moist
What kind of cell makes the urothelium unique?
Umbrella cells
This tissue type is highly vascular as there are large spaces in between the cells.
Connective tissue
This cell contributes to the formation of fibrous connective tissue and appears with thin, wispy branches.
Fibroblasts
Large phagocytic cells that wander through connective tissue, aiding in immune support
Macrophages
AKA White Blood Cells
Leukocytes
These cells secrete antibodies to fight disease, usually only seen in inflamed tissue
Plasma cells
Similar to a basophil, this cell secretes heparin/histamines involved in inflammation
Mast cells
AKA Fat Cells
Adipocytes
These fibers are made of collagen, are tough/flexible and resist stretch
Collagenous fibers
Thin collagenous fibers coated with glycoprotein that form a sponge-like framework for certain organs
Reticular fibers
This fiber is made of elastin coated with a glycoprotein and is able to stretch and recoil
Elastin fibers
Besides the small amount of cells in connective tissue, what makes up for the majority of the make-up of this tissue?
Ground substance
What is the function of ground substance in connective tissue?
“Packing Peanuts”
Cushion and protect delicate cells from injury
What are the 2 subgroups of fibrous connective tissue?
Loose connective tissue and dense connective tissue
What are the 2 subgroups of loose connective tissue?
Areolar tissue and reticular tissue
What are the 2 subgroups of dense connective tissue?
Dense regular and dense irregular
This connective tissue presents as loosely connected fibers and a lot of empty space.
Areolar tissue
*Remember “AIRY-olar”
This tissue is composed of reticular fibers, fibroblasts, and is filled with RBC’s in its empty spaces. Forms a “spongy” framework for organs
Reticular tissue
*Remember “Web-like”
This tissue contains fibers that are closely packed and parallel in position.
Regular dense tissue
This tissue contains fibers that are closely packed and in abnormal/irregular organization
Dense Irregular
AKA “fat” tissue
Adipose tissue
There are 2 types of adipose tissue:
White adipose and brown adipose
Which type of adipose tissue is found more in adults? In children?
White adipose tissue in adults, brown adipose tissue in children
This type of adipose tissue primarily insulates, anchors, and cuchions
White adipose
This type of adipose tissue primarily generates heat
Brown fat
This type of connective tissue provides structure in the ear and nose
Cartilage
Cartilage starts pit as this stem cell:
Chondroblast
As chondroblasts secrete matrix, it eventually becomes enclosed in a ?
Lacunae
Once a chondroblast is enclosed in a lacunae, it is called a
Chondrocyte
Does cartilage have blood vessels?
No
What are the 3 subtypes of cartilage?
Hyaline, elastic, fibrocartilage
Hyaline cartilage has an abundance of this fiber:
Collagen
Elastic cartilage has an abundance of this fiber:
Elastic
Fibrocartilage has an abundance of this fiber:
Collagen
Elastic cartilage and fibrocartilage are surrounded by a sheath of
Perichondrium
AKA osseous tissue, this is a hard calcified tissue that provides structure to the body
Bone
There are 2 bone tissue types
Spongy and compact
This kind of bone type fills the heads of long bones and has a spongy appearance
Spongy bone
This kind of bone lies right underneath the periosteum and forms the external surfaces of all bones
Compact bone
A complete cylinder and its surrounding lamellae is a
Osteon
Surrounded by concentric lamellae, this runs longitudinally through the bone
Central canal
These onion-like layers surrounding the central canal constitute the
Concentric lamellae
Mature bone cells
osteocytes
Channels that connect the central canals of osteons, allowing communication and transfer of nutrients
canaliculi
The entire bone is surrounded by the
periosteum
Which 2 components in bone allow it to bend under stress?
Collagen and glycosaminoglycans (GAGs)
Which 2 components of bone allow it to withstand the weight of the body?
Calcium and phosphate salts
What are the 3 types of blood cells?
Erythrocytes (RBC), Leukocytes (WBC), and platelets
This blood cell is anucleated and is the most abundant
Erythrocytes (RBC)
This blood cell is mainly in connective tissue and is made up of 5 different kinds of cells
Leukocytes (WBC)
This component of blood is described as “cell fragments”, they are not whole cells
Platelets
This cell functions to transport oxygen and carbon dioxide
Erythrocytes (RBC)
This cell aids in immune support
Leukocytes (WBC)
This blood component aids in clotting
platelets
This type of tissue aids in communication through transmission of electrical signals
Nervous tissue
These cells assist neurons in their job
Glial cells
This structure houses nervous cell nucleus, “cell body”
Neurosoma
This is a short-branched extension of the neurosoma
Dendrite
This is a much longer extension of the neurosoma that can reach all the way down to the feet
Axon / Nerve fiber
This tissue exerts force on other tissues, organs, and bodily fluid through contraction
Muscular tissue
What are the 3 types of muscular tissue?
Skeletal, cardiac, smooth
This muscular tissue consists of multi-nucleated long cells (muscle fibers)
Skeletal muscle
This muscular tissue is limited to the heart
Cardiac muscle
This muscular tissue is described as “striated” and “voluntary”
Skeletal muscle
This muscular tissue is described as “striated” and “invuluntary”
Cardiac muscle
Are cardiac cells multinucleated?
No - Cardiac muscle cells only have 1 nucleus
The cells of cardiac muscle are called
Cardiomyocytes
Each cardiomyocyte is joined end-to-end by junctions called
Interculated discs
Which kind of junction allows excitation stimuli to pass from cell to cell?
Gap junctions
This type of muscular tissue lacks striations and is involuntary
Smooth muscle
Muscular tissue that works automatically and involuntary, forming the walls of digestive, respiratory, and urinary tracts, etc.
Visceral muscle
This cell/organ secretes substances that are useful for the body or as a waste product
Glands
If something is synthesized and is useful for the body, this process is
Secretion
If something is released as a waste product to be eliminated, this process is
Excretion
Glands are primarily composed of this type of tissue
Epithelial tissue
What are the 2 classes of glands?
Endocrine and exocrine
This type of gland maintains contact with skin/cavity surface and excretes substances through an epithelial tube
Exocrine glands
These glands lose contact with surface and have no ducts
Endocrine glands
These glands contain a high number of blood capillaries and release substances directly into the blood stream
Endocrine glands
Chemical messenger which is secreted by endocrine glands
Hormones
Can some organs have both kinds of glands?
Yes
Secretory cells found in epithelium that can be either endocrine or exocrine and are predominantly non-secretory
Unicellular glands
Goblet cells and hormone-releasing cells are examples of
Unicellular glands
Most exocrine glands are enclosed in a
Capsule
Extending off the capsule of the exocrine glands are the
Septa
The septa of exocrine glands further divides into
Lobes
The lobes of exocrine glands can further divide into microscopic
lobules
The connective tissue framework of an exocrine gland that supports and organizes the glandular tissue is the
Stroma
These cells in exocrine glands perform synthesis and secretion
Parenchyma
Which kind of cells are parenchyma usually?
Simple cuboidal or simple columnar
Exocrine glands are classified as ? if they have a single duct and ? if they have a branched duct
Simple, Compound
In an exocrine gland, if the duct and sac have the same diameter, it is described as
Tubular
In an exocrine gland, if the sac is more dilated than the duct, it is described as
Acinar
A gland where both the tubule and acini secrete products is called
Tubuloacinar gland
What are the 2 types of exocrine secretions?
Serous and mucus
These exocrine glands produce thin, watery fluids
Serous glands
These exocrine glands produce a thick substance called ?
Mucin
Once mucin mixes with water once secreted, it is now called
Mucus
What are the 3 types of exocrine secretion and how are they classified?
Apocrine, eccrine, and holocrine
Classified on their methods of secretion
This gland releases its product by exocytosis
Eccrine gland
This gland releases its products with a lipid droplet that buds from a cell surface
Apocrine gland
This gland releases its product by accumulating and then dissolving the entire cell
Holocrine gland
AKA the skin, this membrane is the largest on/in the body and covers the external surface of the body
Cutaneous membrane
On the inside of the body, there are these 2 types of membranes
Mucous membranes and Serous membranes
These internal membranes line passageways that open to the exterior
*Respiratory and digestive tracts
Mucous membrane
A mucous membrane consists of these 3 layers:
1) Epithelium
2) Lamina Propria (thin layer of areolar connective tissue)
3) Muscularis mucosae (thin layer of smooth muscle)
This internal membrane lines the inside of SOME body cavities and covers some viscera
Serous membrane
The circulatory system is lined with a simple squamous endothelium called the
endothelium
The entire wall of the blood vessel wall is collectively called the
tunica interna
This membrane lines the chambers and valves of the heart
Endocardium
Some joins of the skeleton are enclosed by fibrous ?
Synovial membranes
These membranes span the gap between bones in a joint and secrete synovial fluid
Synovial membranes
This is the expansion of tissue through cell multiplication
Hyperplasia
This is the expansion of tissue through increase in cell size
Hypertrophy
Expansion of tissue through abnormal growth
Neoplasia
The development of a more specialized form/function in a tissue is
Differentiation
Change of one mature tissue form to another is
Metaplasia
What are the 2 ways tissue can be repaired?
Regeneration or fibrosis
This method of tissue repair replaces dead/damaged cells with the same cell type as before and restores function
Regeneration
This method of tissue repair replaces damaged cells with scar tissue and does not restore function
Fibrosis
Shrinkage of tissue through a decrease in cell number/size
Atrophy
Atrophy as a result of aging is called
Senile atrophy
Atrophy as a result of not using the muscle is called
Disuse atrophy
The premature death of tissue due to trauma/toxins/infections
Necrosis
Sudden death of a tissue
Infarction
Tissue necrosis resulting from infection or blood supply
Gangrene
