4 Flashcards
Groups of cells work together
Tissues
Study of tissues
Histology
Histo-
Tissues
Junctions
Ways tissues are held together
Types of junctions
Tight
Gap
Anchoring
Tight junctions
Stops materials from traveling between cells
Creates regulated barrier.. makes sure everything is regulated by plasma membrane. Cellular control over input and output
Anchoring junctions
In areas that need additional strength.
Types of anchoring junctions
Desmosomes,
hemi desmosomes,
Adherens junctions
Desmosomes
Made by thickened plasma membranes joined by filaments
Prevents cells from being pulled apart because of mechanical stress
Important in skin and heart
Hemidesmosomes
Specialized structures found in cells that help anchor epithelial cells to the basement membrane
Adherens
Link the actin cytoskeletons between adjacent cells
Mechanical strength and stability of tissues
What type of junction prevents shearing forces
Anchoring junctions
Intercalated discs
Connections found in myocardial cells contain Gap junctions and desmosomes
Gap Junctions
Intercellular channels that let adjacent sales communicate
Connects the cytoplasm of adjacent cells
Connexons
Hollow cylinders that connect adjacent plasma membranes
Transmembrane proteins
Made of groups of proteins
uses of Gap junctions
Cells communicate with each other
Send electrical impulses quickly
Helps act like one large cell. Necessary for heart function alongside with intercalated discs
Myocardial cells work together to contract
Syncytium
Cells acting as one
How are Gap junctions used in smooth muscle
Requires smooth movements to move food through alimentary canal.
Coordinates movement of circular and longitudinal muscles.
Action potentials travel through Gap junctions to produce slow coordinated movement
Peristalsis
Involuntary constriction and relaxation of the muscles creates wavelike movements that push contents forward
Layers of smooth muscle along digestive system
Circular layer
Longitudinal layer
Four general categories of tissue types
Nervous tissue
muscle tissue
epithelial tissue
and connective tissue
Epi-
on the surface
Epithelial tissue
Lines surfaces of body
Surfaces of organs
Surfaces of tubes
Types of muscle tissues
Cardiac muscle
smooth muscle
and skeletal muscle
Nervous tissues types
Brain
Spinal cord
Nerves
What are the components of nervous tissue
Neurons
Glial cells
Glial cells
Important support cells for neurons
Types of connective tissues
Adipose and other soft padding tissue
Bone
Tendon
Blood
(If not nervous, epithelial or muscular)
Dense regular connective tissue found in
Tendons and ligaments
Dense irregular connective tissue is found in
Dermis
Three cell layers of embryonic development . Where all tissues come from in body
Ectoderm
Mesoderm
Endoderm
ECTODERM
Adrenal medulla
CNS PNS
Skin
Appendages
ECTODERM
Adrenal medulla
CNS PNS
Skin
Appendages
Mesoderm
1.Kidneys and ureters
2.Reproductive system
3.Bone and cartilage
4. Muscles
5. Vasculature
6. Lymphatics
7.spleen
8. Adrenal Cortex
Endoderm
GI tract
Liver
Endocrine system
Respiratory tract
Bladder
Urethra
What kind of cells make a membrane
Epithelial cells cemented with a basement membrane. Some loose connective tissue underneath it
Mucous membranes
Line cavities that are open to the outside. Digestive respiratory urinary and reproductive tracts.
Coated with secretions of mucus glands
Serous membranes
Body cavities closed to the exterior.
Peritoneal
pleural
pericardial
Cutaneous membrane
Skin,
Covers body surface
Synovial membranes
Line joint cavities
Produce fluid within the joint
Goblet cells
Help secrete mucous.
Secrete mucin
Pseudostratified ciliated columnar epithelium is found in
Trachea, sperm carrying duct
Type of mucous membrane because lots of goblet cells. Serous mucous glands. Help secrete mucous
What does mucus do?
1.Prevents airway from drying
- Traps particles of organic matter/pathogen
Pseudostratified ciliated columnar epithelium cilia function
Move things along respiratory tract to pharynx. Substances can be swallowed or spit out.
Protects alveoli
Respiratory escalator
Cilia+mucous
Importance of mucous membranes
Protect from external environment and pathogens that might be inside
Serous membranes
Layer of epithelial tissue that can secrete serous fluid to help reduce friction
Connective tissue layer. Loose areolar connective tissue
Apical surface
Top surface of epithelial cells that are exposed to the environment
Layers of epithelial tissue
Apical surface
Basement membrane
Connective tissue
Synovial membrane
Joints. Most common joint in human body. Synovial membrane secretes synovial fluid. Causes smooth gliding motion.
Actually connective tissue. Behaves like traditional membrane types
Hyaline
Glass, found where bones come together
Actions of a tissue happen on which part of the surface
Apical surface
Where can you find simple squamous epithelium
Blood vessels or alveoli of lungs
What are the layers of the basement membrane
Basal lamina and reticular lamina
Basal lamina
Made of glycoprotein secreted by epithelial cells. Adhesive supporting sheet. Faces epithelium
Reticular lamina
Has fine network of collagen fibers. Faces the connective side
Connective tissue under basement membrane is most often
Loose areolar connective tissue
Components of loose areolar connective tissue
Blood vessels
nerves
Fluid extracellular matrix
What makes up the basement membrane
Extracellular matrix of proteins. lipoproteins glycoproteins found there
Important for wound healing
Glue that cements epithelial cells to connective tissue cells
Basement membrane
What does it mean that epithelial tissues are avascular?
Rely on connective tissue below to survive
Epithelial tissue types 6
Simple
One cell layer
Stratified
More than one cell layer
Three shapes
Squamous-flat-need less energy to make
Cuboidal-equal size on all sides. Nucleus in center. Medium energy to make.
Columnar-nucleus in bottom third. More energy to make
Fish scale
Squamous
Function of cuboidal cells
Important for secretion
Simple squamous location and functions
Blood vessels diffusion, filtration
Covers alveoli of lungs
Stratified squamous locations and functions
Layered flat cells
Skin
Vagina
Esophagus
Protection
Simple cuboidal location and functions
Kidney tubule
Ovary surface
Secretion and absorption
Stratified cuboidal epithelium locations and functions
Protection and secretion
Sweat gland
Mammary glands
Stratified columnar epithelium locations and functions
Salivary duct
Male urethra
At transition junctions. Junctions between two other types of epithelia
Where does the pseudostratified appearance come from
Nuclei in different positions look like different layers
Each cell touches basement membrane
Transitional epithelium
Only found in urinary system
Can stretch lines ureters, bladder
Appearance depends on the amount of urine. Basal layer is cuboidal
Urothelium
Transitional epithelium
Endothelium is synonym for
Simple squamous epithelium
Thickest part of simple squamous epithelium
Nucleus
Lumen
Cavity inside of tube blood vessel or hollow organ
Simple columnar epithelium locations and functions
Small intestines .uterine tubes
Absorption and secretion of mucus
Have microvilli. Fine hairs, don’t move. Increase surface area.
Where does 90% of nutrient absorption occur
Small intestine
Microvilli structure and function
Small hairs
Increase surface area for proteins that
Allow for absorption
Difference between keratinized cells and non keratinized cells
Non keratinized cells have nuclei
Keratin
Structural protein found in skin and hair and nails. Fills up cells until killing them
Types of stratified squamous epithelium
Keratinized and non-keratinized
Secretory vesicles in goblet cells secrete
Mucin
Mucin
Glycoprotein. Forms mucus when it comes into contact with water
-in
Protein usually
-ase
Enzyme
What does mucus do in the digestive tract?
Protects proteins from some digestive enzymes
Helps food travel, bolus, acid chyme, and then feces
Cilia vs microvilli
Cilia move and require ATP, move in one direction. Cilia move ovulated egg
Microvilli, on surface of cells, increase surface area. In absorbative cells
Flagellum
Tail that whips and moves sperm cells
Glandular epithelium types
Exocrine and endocrine
Exocrine glands
Release things to surface of something like sweat or sebum
Apocrine sweat glands that release into axillary areas and groin
Secrete things into tube in body like surface of tube in open body system
Endocrine glands
Positioned in capillary bed, release into extracellular fluid which gets picked up by capillary bed. Hormones secreted, picked up by capillaries and transported via bloodstream
Examples of exocrine glands
Eccrine sweat glands
Apocrine sweat glands
Cerumenous glands
Mammary glamds
Shape of exocrine glands
Can be simple or highly branched
Exocrine glands are based on which kind of tissue
Epithelial cells
How are glandular secretions classified
Amount of cytoplasm in glandular epithelium that winds up in epithelium
Merocrine secretion
0
Merocrine (zerocrine)
Secretes none of the cytoplasm
Example of merocrine secretion
Sweat glands
Apocrine secretion amount
Part of the cell breaks off and becomes part of the secretion
Bacteria can feed off secretions causing body odor because there’s protein and fat
Holocrine secretions
Entire cell breaks down and becomes part of secretion
Sebaceous glands
Connective tissue can be vascular or avascular
True
Bone vascular or avascular
Vascular
Cartilage vascular or avascular
Avascular
Loose areolar connective tissue
All over body under epithelial tissues
Loose areolar connective tissue functions
- If epithelial tissues get pressed on, it lets connective tissue move below
- Blood vessels bring nutrients to epithelial tissues
- Immune cells right under epithelial tissues.
- Some fat cells, fibroblasts, mesenchymal cells, collagen fibers
Mesenchymal cells
Make and repair skeletal tissues like cartilage, bone and fat
Fibroblasts
Makes fibers of connective tissue
Immature
Secrete extracellular matrix of collagen
Help make tissue strong
Collagen
Structural protein,
Most abundant protein in body. Used to make connective tissue. Connects other tissues
Elastic fibers
Springy shape,
Let tissue spring back into shape when stretched out. Have elastin
Reticular fibers
Super small, thin strands of collagen fibers. Support resident cells that might need to be in a certain area.
Ex. Macrophages might fix onto reticular fibers
Types of connective tissues categories
Loose
Dense
Cartilage
Bone
Blood
Adipose tissue
Nucleus and organelles pressed against edge because it’s full of lipids.
Has blood vessels
Number one cause of early mortality in the US
Cardiovascular disease good to lose weight because adipose tissue needs blood supply so your heart has to pump harder to get blood to all the fat
Peripheral resistance
Friction encountered by blood as it flows through blood vessels
Connective tissues are generally surrounded by ___amount of extracellular matrix
large except for adipose connective tissue
Function of adipose tissue(loose)
storage
thermoregulation
Filled with stem cells
White fat cells
Really good at energy storage
Brown fat
Infants
Can’t make ATP with mitochondria
Generate a lot of waste heat
Helps infants stay warm.
Adults with it are less likely to suffer unexpected weight gain in lifetime
Beige fat cells
In the middle of white and brown fat cells
Structural fat example
Helps hold kidneys in place next to deep muscles of the back
Structural fat (loose)
Helps hold things in place protects organs
Loose reticular connective tissue
Found in
Spleen & some endocrine glands
Tiny collagen fibers. Let’s some things adhere or lets things move through
Loose connective tissue types
Areolar
Adipose
Reticular
Dense connective tissue types
Regular and irregular
Dense regular connective tissue
Gives tensile strength. Has parallel collagen fibers and fibroblasts
Where to find dense regular connective tissue?
Tendons and ligaments
Tendons
Connect muscle to bone
Ligaments
Connect bone to bone
Dense irregular connective tissue
Woven straw appearance. Collagen fibers in different directions.
Where to find dense irregular connective tissue?
Dermis. Makes dermis very strong.
Chondroblast
Immature cell that makes cartilage, gets trapped in a lacuna as it makes the extracellular matrix. Traps itself in its own matrix
Lacunae
Lake
Small space or cavity in bone or cartilage
Chondrocyte
Mature cell trapped in extra cellular matrix
Still alive and test cell health, but cannot secrete ECM
Types of cartilage
Hyaline cartilage
Fibrocartilage
Elastic cartilage
Hyaline cartilage
Surface of articulating bones.
Fetal skeleton
Costal cartilage of ribs
Slippery, glass like. Tightly laid down cartilage
Connect ribs to sternum
Strong
17 X slicker than ice
Hyaline cartilage
Elastic cartilage
Has lacuna and chondroblasts
Has collagen but also lots of elastic fibers in ECM
Lets structures spring back into shape .
Ears (pinna)!
Fibrocartilage
Lots of collagen in matrix
Oriented in a way that gives compression and tensile strength.
Intervertebral discs and disc , pubic symphysis
Meniscus
Helps femur and tibia function together at the knee joint
Compact bone
On outside.
Lamella
Look like tree rings surround lacunae. A layer of bone matrix that surrounds lamella
Osteocytes
In lacunae, surrounded by lamella .
Mature bone cell
Osteoblasts
Immature bone cells
Lay down collagen(gives flex) and calcium phosphate(makes bones strong)
Osteons
Unit of bone. Interconnecting canals in microscopic structure of adult compact bone
What is in central canal of osteon?
Arteriole, venuole, nerve, lymphatic vessels
Canaliculli
Small canals that allow osteocytes to communicate
Spongy bone unit
Trabeculae.
Purpose of spongy bone
Makes bone lighter
Place for bone marrow
Creation of blood cells
Trabeculae help resist
Stress
And lighten bone
Remodeling of bones occurs at which rates
Different
What do bone remodeling cones do?
Bone will be denser, stronger if good nutrition.
Osteoclasts purpose
Break down bone and right behind it lay down new bone
Extracellular matrix of blood
Plasma
Plasma
Water with some electrolytes, hormones
Formed elements of blood
Red blood Cells
White blood cells
Platelets
Erythrocytes
RBCs
Leukocytes
White blood cells
Thrombocytes
Platelets
Where are the formed elements of blood made?
In bone marrow
Tissue of contraction
Muscle
Actin
Static, like rope, thin
Myosin
Tug of war on rope
Major players of muscle contraction
Actin and myosin
Forceful shrinking of cell
Skeletal muscle characteristics
Multinucleate
Somatic, voluntarily controlled
Cardiac muscle cells characteristics
One nucleus per cell,
Branched
Striated
Two types of intercellular junctions found in intercalated discs
Adherens and GAP junctions
Smooth muscle
Long , large, sickle shaped.
GI tract, blood vessels, respiratory airways.
Important in involuntary homeostatic mechanisms.
Artery can constrict
Groups of nervous tissue
Neurons
Glial cells
Glial cells function
Health and function of nervous system
Epyndymal cells
Create CSF
Microglial cells
Macrophages of CNS
Astrocytes
Manage blood brain barrier
Oligodendrocytes
Myelinate in CNS
Let signals travel faster
Schwann cells
Myelinate in PNS
Explain wound healing
- Inflammatory chemicals are released by mast cells? (Histamine )
- Capillaries swell and squeeze out of blood vessels and into tissues
- WBCs seep to injured area
- Clotting is caused by clotting proteins and plasma proteins to form scab
- Granulation tissue restores the vascular supply
6.epithelial cells multiply and fill in over the granulation tissue
- Restored epithelium thickens, the area matures and contracts
Angiogenesis
Grow blood vessels
Why is granulation tissue sometimes called granulation organ
Multiple tissue types trying to heal Gap
Summary of tissue repair
1.inflammation calls immune system
2.granulation
3.restoration of blood flow
4.filling in gap with scar tissue
5.new epithelial cells laid down
Barrett’s esophagus
Cells change because of acide reflux.
Stratified squamous non keratinized epithelium changes into simple columnar epithelium.
Less protection
Increased risk of esophageal cancer
Carcinoma
Cancer arising in the epithelium 90% of human cancers
Adenoma
Neoplasm of glandular epithelium.
Adenocarcinoma
Malignant type of neoplasm of glandular epithelium
Neoplasm
New, abnormal growth of tissue in some part of the body
Glandular epithelium
One or more cells, specialized to secrete a product
Extracellular matrix
Nonliving material in connective tissue. Separates living cells
Fixed cells vs. Wandering cells
Fixed cells-make fibrous material or matrix
Wandering cells-move through cellular matrix
Migrating cells examples
Macrophages
Mast cells-histamine
Eosinophils
Monocytes
Fixed cells examples
Fibroblasts, adipocytes
Macrophages
Phagocytize bacteria
Engulfs and digests foreign materials
Mast cells
Release histamine that causes inflammation at sites of injury
Elastin
Protein that gives rubbery quality to matrix
Differentiate between epithelial and connective tissue
- Epithelial covers and lines surfaces and cavities, connective gives structure and support
- Epithelial has small ECM, connective tissue has lots of ECM
3.epithelial tissue is avascular. Connective tissue is highly vascularized. Epithelial tissue gets nourishment from lower connective tissues
Differentiate between dense regular connective tissue and fibrocartilage
1.Dense regular connective tissue ismade of parallel collagen fibers. Gives strength
Fibrocartilage
Contains collagen and chondrocytes. Give strength and support while allowing some flexibility
- Dense regular connective tissue makes strong attachments that resist tension
fibrocartilage is a shock absorber that provides support and cushioning like intervertebral discs
Where do you find dense regular connective tissue?
Tendons and ligaments
