Unit 7: Histology Flashcards
What is histology?
The study of tissues
What type of tissue makes up the lining of an organ cavity?
Epithelial
What type of tissue makes up cartilage?
Connective
What types of tissue make up cardiac muscles?
Muscle
What type of tissue makes up the spinal cord?
Nervous
What forms cell junctions?
Cell membrane proteins
Which type of junction prevents material from passing between cells?
Tight junctions
What “rivets” cells together?
Anchoring junctions
Why do gap junctions allow the passage of molecules between cells?
It is important for the synchronization of contractions in smooth and cardiac muscles
True or false: Epithelial tissue has some room in between cells in order to allow for the passage of blood vessels
False. There are no blood vessels in epithelial tissues (avascular) and there little space between cells
The ________ _________ attaches the epithelium to underlying connective tissues
Basement membrane
What is the classification for epithelial tissue with more than 1 layer of cells?
Stratified
Name the 3 classifications of cell shapes in the apical layer of epithelial tissue
Squamous = flattened
Cuboidal = round or cube shaped
Columnar = rectangular
If a particular area of epithelial tissue consists of columnar cells that appear to be stratified, yet all sit on the basement membrane, how might they be referred?
Tissue that appears stratified yet is simple in reality can be called “pseudostratified epithelial” tissue
Transitional epithelia is made of stratified cells which can change shape based on how it stretches. Where can transitional epithelia tissue be found?
The inner lining of the urinary system
Glandular epithelium has 2 subtypes. What are they?
Exocrine glands and endocrine glands
What type of tissue makes up ductless glands that secrete hormones into the extracellular fluid which then enters the blood plasma?
Endocrine glands (e.g. thyroid gland)
Give an example of a unicellular and multicellular gland
Unicellular: goblet cells, which can be found in the digestive, urinary, reproductive, and respiratory tracts
Multicellular: sweat, oil, mammary, and digestive glands
What are the 3 main functions of epithelia?
Protection, secretion, and allowing selective passage of materials (e.g. nutrients, waste, water)
True or false: connective tissue cells are far apart, separated by extracellular matrix.
True. The extracellular matrix usually forms the bulk of the tissue and gives connective tissue subtypes their identifying characteristics
What do the endings of connective tissue cell types mean?
…blast?
…cyte?
…clast?
…blast = creates matrix
…cyte = maintains matrix
…clast = breaks down matrix
What may the Extracellular Matrix be composed of?
Fibres (proteins): collagen fibres (strength), elastic fibres (stretch), reticular fibres (form networks — CT part of basement membrane, for example)
Ground substance: water (ISF) and large organic molecules (proteins and carbs)
Name the 4 classifications of connective tissue
CT proper (includes loose and dense CT), cartilage, bone, and blood
If a tissue is described as having a “chicken-wire” appearance, what would the tissue be classified as?
Adipose CT <~ Loose CT <~ CT Proper
True or false: Of the 2 types of Loose CT, areolar CT is avascular and adipose CT is highly vascular.
False. Both the areolar and adipose tissues are highly vascular, meaning many blood vessels run through it
What is adipose CT more commonly known as and why?
Adipose CT is commonly known as “body fat” because it’s cells are large to store triglycerides, giving it the appearance of “chicken-wire”
Which classification of connective tissue could be described as having loosely arranged collagen and elastin fibres?
Areolar CT <~ Loose CT <~ CT Proper
What is the proper name for what is also known as “fibrous connective tissue” and why?
Dense connective tissue (part of CT Proper). It is known as fibrous because it has many fibres and is poorly vascular
What type of tissue would make up a ligament?
Dense regular CT <~ Dense CT <~ CT Proper
What is an example of irregular CT and why is it referred to as “irregular”?
An example would be the dermis of skin. It is called irregular CT because the collagen fibres are arranged irregularly, as opposed to running in the same direction as seen in regular CT
What is a major component of connective tissue which possesses great tensile strength?
Collagen fibres
What type of cells make up cartilage?
Chondrocytes and chondroblasts
What are 2 types of CT cells that can be found in a lacuna?
A chondrocyte (cartilage) or an osteocyte (bone) are 2 examples of of cells located in lacunae
Why does cartilage heal slowly?
It is avascular, meaning it has low blood supply
What is the most abundant type of cartilage? Provide an example
Hyaline cartilage (e.g. costal cartilage of ribs)
What type of cartilage makes up the pinna of the ear?
Elastic cartilage
What type of cartilage is used as a shock absorber? Provide an example
Fibrocartilage (e.g. intervertebral disks)
Osteocytes, osteoblasts, and osteoclasts are the cells that make up which kind of connective tissue?
Bone CT
What is the ground substance of bone CT mostly made of?
Inorganic elements such as calcium, and organic components like proteins and carbs which all serve to make the bone rigid
True or false: bone CT is very vascular
True
What is the name for the EC matrix in blood?
Plasma
What aspect of blood contains soluble fibres, such as fibrinogen?
Blood plasma
Which type of muscle tissue is NOT striated?
Smooth muscle
Name the types of nervous cells
Neurons and glial cells (which protect neurons)
What is the most important aspect of classifying the different subtypes of connective tissues?
The composition of the extracellular matrix
