Histology Flashcards
Location of Simple Squamous Epithelium
Mesothelium (epithelial layer of serous membranes)
Alveoli (air sacs of lungs)
Function of Simple Squamous Epithelium
Secretion of serous fluid into serous cavity.
Single layer of squamous cells creates a short distance for
diffusion of oxygen and carbon dioxide.
Characteristics of Simple Squamous Epithelium
single layer of flat, scale-like cells. These cells are very thin, which allows them to facilitate the passage of materials across the tissue.
Location of Selected Siple Cuboidal Epithelium
Walls of Kidney Tubules
Glands
Function of Selected Simple Cuboidal Epithelium
Modify urine filtrate by absorption of substances from the filtrate and secretion of other substances into the filtrate.
Secretion of products made by the simple cuboidal epithelial cells.
Characteristics of Simple Cuboidal cells
Cells are roughly equal in height and width
arge, spherical nuclei, typically located near the center of the cell
May have microvilli on the apical surface for increased surface are
Location of Selected Simple Columnar Epithelium
Lining of stomach and intestines (nonciliated simple columnar epithelium)
Lining of Uterine tubes (ciliated simple columnar epithelium)
Characterstics of Simple Columnar epithelium
Cells are taller than they are wide
Nuclei are typically oval-shaped and located near the base of the cell
May have microvilli on the apical surface for increased surface area
Function of Selected Simple Columnar Epithelium
Secretion of digestive juices by epithelial cells and secretion of mucus by goblet cells. In the small intestine the epithelial cells have
microvilli (micro- = small; villi = shaggy hair) to increase surface area for absorption of nutrients.
Epithelial cells have cilia that help move the egg to the uterus.
Location of Selected Stratified Squamous Epithelium
Surface of skin (keratinized stratified squamous epithelium)
Lining of mouth, esophagus, anus, and vagina (nonkeratinized stratified squamous epithelium)
Function of Selected Stratified Squamous Epithelium
Epithelial layer of skin is a tough, dry, waterproof outer surface that forms a protective barrier.
Moist epithelial layer that forms a protective barrier in areas subject to abrasion and friction.
Characters of Selected Stratified Squamous Epithelium
Multiple layers of cells, with the shape of the cells varying depending on the layer
Location of Urothelium (Transitional Epithelium)
Provides a protective barrier that permits distension.
Characteristis of Urothelium
Ability to transition from Squamous to Columnar when necessary.
Location of Selected Pseudostratified Columnar Epithelium
Lining of nasal cavity, trachea, and bronchi (pseudostratified ciliated columnar epithelium)
Lines larger ducts of many glands, epididimis and part of male urethra (pseudostratified nonciliated columnar epithelium)
Function of Selected Pseudostratified Columnar Epithelium
Secretion of mucus by goblet cells. The epithelial cells have cilia, which move mucus toward the pharynx.
Epithelial cells are involved in absorption, secretion, and protection
Characteristics of Pseudostratified Columnar Epithelium
Pseudostratified columnar epithelium is a unique type of epithelium that creates an illusion of being multilayered while actually being a single layer of cells
Connective Tissue
The most abundant and widely distributed tissue in the body
Functions of Connective Tissue
- binds together / supports
- strengthens other body tissues
- protects and insulates internal organs
- compartmentalizes structures such as muscles
- major transport system eg. blood
Five major kinds of connective tissue:
a) Loose C.T. – areolar, adipose, reticular
b) Dense C.T. – dense regular, dense irregular, elastic
c) Cartilage – 3 types
d) Bone – compact and spongy
e) Blood
Basic elements of CT?
Cells, Ground Substance, Fibers
What are Ground Substance?
– is usually amorphous
– no shape
- produced by cells (fibroblasts) {not blood}
- supports cells / contains large molecules of
hyaluronic acid and chondroitin sulfate.
- medium through which substances exchanged
- active in tissue development, proliferation and
metabolic functions
What are fibers?
secreted by fibroblasts and provide
Strength and support for tissues.
Types of fiberrs?
1) Collagen 2) Elastic 3) Reticular
What makes Connective Tissue unique?
- Is highly vascular except for cartilage and tendons
- Has a nerve supply except for cartilage
Types of Cartilage?
hyaline (most abundant),
Fibrocartilage (strongest), and elastic (most flexible
Cartilage Characteristics?
- Endures considerable stress
- No blood or nerve supply except for perichondrium
- Dense network of collagen and elastic fibers
- Strength due to collagen fibers
- Resilience due to chondroitin sulfate
- Cells are chondrocytes in spaces called
lacunae
LOOSE CONNECTIVE
TISSUE TYPE
Areolar, Adipose and Reticular
Location of Loose Connective Tissues
Beneath all epithelial tissues
Under skin and surrounding organs
Liver, spleen, lymph nodes
Function of Loose Connective Tissues
Binds epithelium to underlying tissues and allows nutrients to diffuse to epithelial cells.
Stores lipids for fuel and thermal insulation; cushioning organs.
Forms support (framework) of these soft organs.
DENSE CONNECTIVE
TISSUE TYPE
Dense regular
Dense irregular Elastic
Location of Dense Connective Tissues
Forms ligaments (connects bone to bone), tendons (connects muscle to bone), and aponeuroses (sheet- like tendons that connect muscle to muscle or muscle to bone)
Skin
Lungs, trachea, and bronchi Aorta and other elastic arteries
Function of Dense Connective Tissues
Resists pulling forces at attachment points.
Resists pulling forces from many different directions that would tear skin when skin is stretched.
Allows respiratory organs to recoil after inhalation.
Recoil of elastic tissue helps push blood through cardiovascular system.
Location of Hyaline Cartilage
Hyaline
Ends of long bones (articular cartilage)
Trachea and bronchi
Anterior ends of ribs (costal cartilage)
Fiborus:
Embryonic skeleton Intervertebral discs
Cartilage pads in knee Pubic symphysis
Elastic:
External ear
Auditory tube
Epiglottis of larynx
Function of Hyaline Cartilage
Smooth surface that is resilient and reduces friction at joint.
Provide support and flexibility to ensure an open airway. Connect ribs to sternum with flexible joint (breastplate).
Provides template for bone formation.
Function of Fibrous cartilage
Provide strength to discs that form joints between vertebrae and act as shock absorbers.
Provide cushioning for bones forming knee joints.
Forms strong, flexible joint between hip bones.
Function of Elastic Cartilage
Provides support and maintains shape of external ear.
Provides support and elasticity to auditory tube as it changes diameter to equalize pressure in middle ear (ear pops).
Provides support and elasticity to epiglottis as it folds to block entrance to trachea while swallowing food and liquid.
Location of Fibrous Cartilage
Fiborus:
Embryonic skeleton Intervertebral discs
Cartilage pads in knee Pubic symphysis
Location of Elastic Catilage
Elastic:
External ear
Auditory tube
Epiglottis of larynx
Location of Compact Bone
Exterior of bones
Location of spongy bones
interior of bones
What are the functions of the Osseous Tissue? (Both Spongy and Compact)
Support, protection, storage of minerals.
Location of Plasma
Liquid part of blood in arteries, capillaries, veins
Function of Plasma
Transport of nutrients, blood gases, wastes, chemical messengers, blood cells and platelets.
Location of RBC
Formed element of blood in arteries, capillaries, veins
Function of RBC
Transport of blood gases.
Location of WBC
Formed element of blood in arteries, capillaries, veins. WBCs can also leave blood vessels and enter infected tissues.
Function of WBC
Attack pathogens and other substances that invade the body.
Location of Platelets
Also formed element of blood in arteries, capillaries, veins
Function of Platelets
Participate in blood clotting.
What is Muscle Tissue?
Muscle tissue is very cellular, with most of the tissue con- sisting of muscle cells
Characteristics of Muscles Tissue?
All muscle tissues are highly vascularized and are innervated.
Muscle cells are elongated cells called fibers that shorten (contract) when stimulated, causing movement.
Location of Skeletal Muscle
Attached to bones and skin
Function of Skeletal
Movement of bones and skin. Contraction generates heat.
Location of Cardiac Muscle
Wall of heart
Function of Cardiac Muscle
Movement of blood through cardiovascular system.
Location of Smooth Muscle Tissue
Walls of digestive tract organs Walls of arteries and veins
Walls of ureters, urinary bladder, and urethra
Intrinsic muscles of eye
What is Nervous Tissue?
forms the brain, spinal cord, and nerves, is very cellular.
Function of Smooth Muscle Tissue
Movement of food through digestive tract.
Contraction and relaxation controls blood flow and blood pressure.
Movement of urine through urinary tract. Contraction and relaxation controls pupil size.
The two basic types of Nervous Cells.
neurons and neuroglia
What are dendrites?
processes that receive signals from sensory receptors or other neurons.
What is an Axon?
a process that sends signals to other neurons, muscles, or glands
Summarize the differences in structure and function of each of the following tissues: epithelium of the skin with epithelium of the intestine
The epithelium in your skin is like a tough suit of armor, protecting you from the outside world.
The epithelium in your intestine is more like a work crew, efficiently absorbing nutrients and keeping things moving smoothly.
Summarize the differences in structure and function of each of the following tissues:
Think of your nose cartilage as a bendy straw, providing some shape but easily manipulated.
The intervertebral discs are more like tough shock absorbers in your spine, strong enough to handle pressure but with some give.
Explain why blood is considered to be a type of connective tissue.
Blood may be a fluid connective tissue, lacking the typical fibers of other connective tissues like bone or tendon.
However, its cellular components, fluid matrix, and connective functions solidify its place as a member of the connective tissue family.
