Histology (Tissues)

Kidney - (Low mag.) 

Tissue: Simple Squamous Epithelial Tissue

Simple Cuboidal Epithelial Tissue

Presence of renal corpuscles along renal tubules allows one to identify this organ as the kidney.  

Kidney

Tissue: Simple Squamous Epithelial Tissue

Simple Cuboidal Epithelial Tissue

Low magnification slide image of the kidney. 

Presence of renal corpuscles along renal tubules allows one to identify this organ as the kidney.  

Often lower power allows initial identification of the organ.

Renal Corpuscles - (High mag. of two renal corpuscles)

Tissue: Simple Squamous ET

This magnification allows you to identify the outer Bowman’s capsule and the inner glomerulus.  

Function of glomerulus is diffusion.

Function of Bowman’s capsule is filtration.

Consist of a glomerulus which is surrounded by the Bowman’s capsule

Kidney Tubules

Tissue: Simple Cuboidal ET 

Function: selective reabsorption 

Near perfect cross-sections at high magnification of renal tubules

Things reabsorbed must leave the tubules, tubules must be permeable to substance for reabsorption to occur.

Examples of materials reabsorbed are glucose and amino acids.

Anything not permeable can’t be reabsorbed and these substances are lost as urine. 

Ex: Urea (waste).

Consist of a lumen and wall

Lung (Low mag.)

Tissue: Simple Squamous ET (alveoli)

Function: gas exchange; diffusion of gasses

Functional units of lungs = alveoli

Blood passes through lungs inspired oxygen passes from alveoli into blood where it binds hemoglobin and is transported to all of the body’s tissues. 

Carbon dioxide moves from blood to alveoli to be expired.

Lung (High mag.)

Tissue: Simple Squamous ET (alveoli)

Function: gas exchange; diffusion of gasses

When looking at alveolar wall you can tell that it is cellular and can initially pick out alveoli.

There are two alveolar walls; each belonging to their own alveolus: 2 cell layers thick; one layer corresponding to one alveoli.

Thyroid (Low mag.)

Tissue: Simple Cuboidal ET

Function: follicular cells produce thyroxine (T3/T4)

Structures visible are thyroid follicles

Material in center of follicle is a mixture called colloid.

When cells are actively producing thyroxine they are thicker and appear cuboidal.  

When cells are less active than they are not as thick and appear more squamous.

Call the tissue simple cuboidal epithelial tissue but differentiate between low and high cuboidal. 

Thyroid (Med mag.)

Tissue: Simple Cuboidal ET

Function: follicular cells produce thyroxine (T3/T4)

Structures visible are thyroid follicles

Material in center of follicle is a mixture called colloid.

When cells are actively producing thyroxine they are thicker and appear cuboidal.  

When cells are less active than they are not as thick and appear more squamous.

Call the tissue simple cuboidal epithelial tissue but differentiate between low and high cuboidal. 

Thyroid (High mag.)

Tissue: Simple Cuboidal ET

Function: follicular cells produce thyroxine (T3/T4)

Structures visible are thyroid follicles

Material in center of follicle is a mixture called colloid.

When cells are actively producing thyroxine they are thicker and appear cuboidal.  

When cells are less active than they are not as thick and appear more squamous.

Call the tissue simple cuboidal epithelial tissue but differentiate between low and high cuboidal. 

Small Intestine

Tissue: Simple columnar ET

Function: absorbs nutrients and water

Cross-sections at low magnification of the small intestine.

Identifiable because it is convoluted into villi. 

Contain a villus, villi, lumen.

Villi: finger-like projections 

Lining of stomach convoluted into villi to increase the surface area 

Small Intestine (intermediate mag.)

Tissue: Simple columnar ET

Function: absorbs nutrients and water

Villi more prominent. 

Goblet cell visible.

Goblet cells secrete mucin that combines with water to form mucous.

Small Intestine (Low mag.)

Tissue: Simple columnar ET

Function: absorbs nutrients and water

Cross-section at low magnification of small intestine.

Identifiable because it is convoluted into villi.

Small Intestine (Med mag.)

Tissue: Simple columnar ET

Function: absorbs nutrients and water

Villi more prominent 

Goblet cells visible 

Goblet cells secrete mucin that combines with water to form mucous.

Small Intestine (High mag.)

Tissue: Simple columnar ET

Function: absorbs nutrients and water

Cells lining the villi are columnar in shape.

Layer called the mucosa.

Three types of cells in mucosa: 

Columnar cells: function in absorption of nutrients (monomers)

Goblet cells: secrete mucin

Enteric cells: AKA brush border cells line digestive tract

Small Intestine (High mag.)

Tissue: Simple columnar ET

Function: absorbs nutrients and water

Layer of mucous also visible along the free surface of cells.

Cells lining the villi are columnar in shape

Layer called the mucosa

Three types of cells in mucosa: 

Columnar cells: function in absorption of nutrients (monomers)

Enteric cells: AKA brush border cells

Lines digestive tract 

Forms mucosa lining of villi in small intestine 

Goblet cells: that secrete mucin

Small Intestine (High mag.)

Tissue: Simple columnar ET

Function: absorbs nutrients and water

Goblet cells clearly visible.

Layer of mucous also visible along the free surface of cells. 

Cells lining the villi are columnar in shape.

Layer called the mucosa

Three types of cells in mucosa: 

Columnar cells: function in absorption of nutrients (monomers)

Goblet cells: secrete mucin

Enteric cells: AKA brush border cells line digestive tract

Low skin- keratinized (low mag.)

Tissue: Keratinized stratified squamous ET

Functions: strength and waterproofing

At this magnification can see overlying epidermis made of keratinized stratified squamous epithelial tissue .

Epidermis of skin

Underlying dermis made of dense irregular connective tissue.

Dermis becomes denser as you look deeper.

Low skin- keratinized (low mag.)

Tissue: Keratinized stratified squamous ET

Functions: strength and waterproofing

At this magnification can see overlying epidermis made of keratinized stratified squamous epithelial tissue .

Epidermis of skin

Underlying dermis made of dense irregular connective tissue.

Dermis becomes denser as you look deeper.

Epidermis (high mag.)

Tissue: Stratified Squamous ET

Function: acts as a barrier that protects the body.

High magnification of the deepest part of the epidermis, where it meets the dermis (interface). 

5 layers of the epidermis of thick skin

Epidermis (high mag.)

Tissue: Stratified Squamous ET

Function: acts as a barrier that protects the body.

High magnification of the deepest part of the epidermis, where it meets the dermis (interface). 

5 layers of the epidermis of thick skin

Epidermis (high mag.)

Tissue: Stratified Squamous ET

Function: acts as a barrier that protects the body.

High magnification of the deepest part of the epidermis, where it meets the dermis (interface). 

5 layers of the epidermis of thick skin

Stratum Corneum 

Tissue: Stratified Squamous ET

Function: acts as barrier that protects body.

High magnification of the most superficial aspect of epidermis, stratum corneum. 

Cells don’t look like cells because they are extremely flat, anucleated, keratinized, and dead.

Esophagus (low mag.)

Tissue: Stratified Squamous ET

Function: carry food and liquid from your mouth to your stomach.

Cross-section of non-keratinized stratified squamous tissue at low magnification 

Makes identification of organ easy

Non-keratinized stratified squamous epithelial tissue

Esophagus

Tissue: Stratified Squamous ET

Function: carry food and liquid from your mouth to your stomach.

Cross-section of non-keratinized stratified squamous tissue at low magnification 

Makes identification of organ easy

Non-keratinized stratified squamous epithelial tissue

Shows nature of the tissue.

Esophagus (High mag.)

Tissue: Stratified Squamous ET

Function: carry food and liquid from your mouth to your stomach.

Only most superficial cells are squamous, deeper cells are thicker.

Non-keratinized squamous epithelial tissue found in esophagus

Because tissue is non-keratinized cells are not dead.

Can see nuclei in even most superficial cells

Fallopian tube (low mag.)

Tissue: simple ciliated columnar ET

Function: transport the ova from the ovary to the uterus each month.

Are convoluted but convolutions are irregular when compared to the small intestine.  

Small intestine is convoluted into villi and villi are very regular. 

Cilia are on the free surface of tissue, creating currents that propel the oocyte and embryo toward the uterus. 

Forms mucosa.

Contains goblet cells that secrete mucin.

Mucous protective and lubricating.

Fallopian tube (med mag.)

Tissue: simple ciliated columnar ET

Function: transport the ova from the ovary to the uterus each month.

Are convoluted but convolutions are irregular when compared to the small intestine.  

Small intestine is convoluted into villi and villi are very regular. 

Cilia are on the free surface of tissue, creating currents that propel the oocyte and embryo toward the uterus. 

Forms mucosa.

Contains goblet cells that secrete mucin.

Mucous protective and lubricating.

Fallopian tube (high mag.)

Tissue: simple ciliated columnar ET

Function: transport the ova from the ovary to the uterus each month.

Are convoluted but convolutions are irregular when compared to the small intestine.  

Small intestine is convoluted into villi and villi are very regular. 

Cilia are on the free surface of tissue, creating currents that propel the oocyte and embryo toward the uterus. 

Forms mucosa.

Contains goblet cells that secrete mucin.

Mucous protective and lubricating.

Neck of mouse– Trachea and Esophagus

Purpose is to study trachea.

Trachea lined with pseudostratified ciliated columnar epithelial tissue (PSCCE).

Also contains hyaline cartilage: form C-shaped rings that prevent trachea from collapsing.

Presence of these two different types of tissue in trachea reminds us  that organs are composed of two or more types of tissue. 

Lines trachea and bronchi

Function: to remove foreign material and bacteria; form lower respiratory tract

Trachea

Trachea lined with pseudostratified ciliated columnar epithelial tissue (PSCCE).

Also contains hyaline cartilage

This is an intermediate magnification of the trachea showing the PSCCE and the hyaline cartilage.

Trachea

Trachea lined with pseudostratified ciliated columnar epithelial tissue (PSCCE).

Also contains hyaline cartilage

High magnification image of trachea 

Cilia are visible 

PSCCE appear stratified because different types of cells found here are different heights and have nuclei at different heights

PSCCE is not stratified because every cell does contact basement membrane.  

Nuclei at different heights create the illusion there are multiple layers of cells.

Trachea

Trachea lined with pseudostratified ciliated columnar epithelial tissue (PSCCE).

Also contains hyaline cartilage

Three types of cells found here: 

Ciliated columnar cells

Goblet cells

Basal cells

Trachea

Trachea lined with pseudostratified ciliated columnar epithelial tissue (PSCCE).

Also contains hyaline cartilage

Particulate matter is trapped in mucous layer

Cilia move causing mucous layer to move. 

Constant movement of the mucous layer across the free surface brings up debris from the respiratory tract.  

Basal cells mitotically active (stem cells) replacing the other cells

Trachea

Trachea lined with pseudostratified ciliated columnar epithelial tissue (PSCCE).

Also contains hyaline cartilage

Lines trachea and bronchi

Function: to remove foreign material and bacteria; form lower respiratory tract

Ureter (low mag. through abdominopelvic region)

Tissue: Transitional ET

Both ureters visible

Can see abdominal aorta and inferior vena cava

Aorta: round cross-section 

Vena cava: collapsed tube above and to right of aorta

Transitional epithelial tissue

Lines ureters and bladder

Function: distension

Ureter (Higher magnification of one ureter, nature of transitional epithelial tissue begins here)

Tissue: Transitional ET

Both ureters visible

Can see abdominal aorta and inferior vena cava

Aorta: round cross-section 

Vena cava: collapsed tube above and to right of aorta

Transitional epithelial tissue

Lines ureters and bladder

Function: distension

Ureter (high mag.)

Tissue: Transitional ET

Tissue is stratified, cells are somewhat oval/egg-shaped.

Unique tissue because tissue undergoes transition (hence name) when the urinary bladder or ureters change from being empty to full.  

When organs full with urine they are able to distend and cells become wider and thinner 

Pancreas (differential stain)

Tissue : Glandular ET

easy to pick out Islets of Langerhans versus acinar cells 

Function in two different systems: 

Endocrine 

Islets of Langerhans: endocrine system cells

Alpha cells: secrete glucagon in response to low blood sugar. 

Glucagon stimulate hydrolysis of glycogen (glycogenolysis).  Also stimulates hydrolysis of fat (lipolysis) when glycogen stores are low.

Ex: fasting or prolonged exercise

Digestive: an exocrine system 

Pancreatic acinar cells produce pancreatic enzymes. 

Enzymes travel through pancreatic duct to duodenum of small intestine

Pancreas (differential stain)

Tissue : Glandular ET

easy to pick out Islets of Langerhans versus acinar cells 

Function in two different systems: 

Endocrine 

Islets of Langerhans: endocrine system cells

Alpha cells: secrete glucagon in response to low blood sugar. 

Glucagon stimulate hydrolysis of glycogen (glycogenolysis).  Also stimulates hydrolysis of fat (lipolysis) when glycogen stores are low.

Ex: fasting or prolonged exercise

Digestive: an exocrine system 

Pancreatic acinar cells produce pancreatic enzymes.

Enzymes travel through pancreatic duct to duodenum of small intestine

Pancreas (non differential stain)

Tissue : Glandular ET

Function in two different systems: 

Endocrine 

Islets of Langerhans: endocrine system cells

Alpha cells: secrete glucagon in response to low blood sugar. 

Beta cells secrete insulin in response to high blood sugar. Insulin stimulates the uptake of glucose. Glucose may be oxidized for ATP or may be used to synthesize glycogen (glycogenesis)

Pancreas (non differential stain)

Tissue : Glandular ET

Function in two different systems: 

Endocrine 

Islets of Langerhans: endocrine system cells

Alpha cells: secrete glucagon in response to low blood sugar. 

Beta cells secrete insulin in response to high blood sugar. Insulin stimulates the uptake of glucose. Glucose may be oxidized for ATP or may be used to synthesize glycogen (glycogenesis)

Pancreas (non differential stain)

Tissue : Glandular ET

Function in two different systems: 

Endocrine 

Islets of Langerhans: endocrine system cells

Alpha cells: secrete glucagon in response to low blood sugar. 

Beta cells secrete insulin in response to high blood sugar. Insulin stimulates the uptake of glucose. Glucose may be oxidized for ATP or may be used to synthesize glycogen (glycogenesis)

Loose connective tissue (Med mag.)

Thicker (wider) fibers: collagen fibers

Thinner (narrower) fibers: elastic fibers 

Dark spots are nuclei of fibroblast cells: cells that produce collagen and elastic fibers

Surrounds blood vessels and nerves. Fluid matrix which facilitates diffusion.

Forms->

Superficial fascia - binds skin to muscles

Deep fascia - binds groups of muscles together

Loose connective tissue (High mag.)

Thicker (wider) fibers: collagen fibers

Thinner (narrower) fibers: elastic fibers 

Dark spots are nuclei of fibroblast cells: cells that produce collagen and elastic fibers

Surrounds blood vessels and nerves. Fluid matrix which facilitates diffusion.

Forms->

Superficial fascia - binds skin to muscles

Deep fascia - binds groups of muscles together

Skin– Dense Irregular Connective Tissue

Similar to slides 32 &33 

Focus on dermis

Can see interface between epidermis (keratinized stratified squamous epithelial tissue) and dermis, dense irregular connective tissue.  

Superficial aspect of dermis (papillary region) more of a loose connective tissue and deeper you go, into reticular region, denser dermis becomes, dense irregular connective tissue

Dense irregular connective tissue

Densely packed collagen fibers, interwoven in all directions, and contains fibroblast

Forms reticular region of dermis (lower ¾ and ⅘ ), fibrous capsules of organs, joints, and periosteum of bone

Skin– Dense Irregular Connective Tissue

Similar to slides 32 &33 

Focus on dermis

Can see interface between epidermis (keratinized stratified squamous epithelial tissue) and dermis, dense irregular connective tissue.  

Superficial aspect of dermis (papillary region) more of a loose connective tissue and deeper you go, into reticular region, denser dermis becomes, dense irregular connective tissue

Dense irregular connective tissue

Densely packed collagen fibers, interwoven in all directions, and contains fibroblast

Forms reticular region of dermis (lower ¾ and ⅘ ), fibrous capsules of organs, joints, and periosteum of bone

Intermediate of dermis and hypodermis (adipose connective tissue)

Hypodermis is one’s largest aggregation of adipose connective tissue

Adipose Connective Tissue

Located throughout body but mainly in hypodermis 

Covers surface of: 

Heart 

Omentum

Around kidneys

Back of eye

Surrounds joints

Adipose:

Protects

Pads

Stores fat (energy)

Insulates

Epidermis– Dermis Interface 

High magnification showing interface between epidermis and dermis. 

Epidermal components that project inferiorly are called epidermal parallel pegs, dermal components that project superiorly are called dermal papilae

Dermis– Dense Irregular 

High magnification deep in dermis (reticular region) of integument where connective tissue is true dense irregular connective tissue

Fibers are collagen fibers and are arranged irregularly

Fibers interwoven and interlocking

Part of an animal’s skin from which leather is made

Hypodermis– Adipose

High magnification of adipose connective tissue in hypodermis or subcutaneous of integument

Structure (cells) are adipocytes: store triglycerides 

Cells nuclei located at periphery rather than near the center 

When cells were living they were filled with triglycerides and all the organelles were forced to the periphery.

Intermediate magnification of dense regular connective tissue 

Dense regular connective tissue collage fibers are predominant type of fiber, just as in dense irregular connective tissue

Difference is dense regular connective tissue the collagen fibers are arranged in parallel fashion

Collagen fibers are parallel to each other and run parallel to long axis of tendon or ligament

Dense regular connective tissue (white fibrous connective tissue)

Densely packed collagen fibers, parallel to long axis of tendon or ligament.  Form tendons or ligaments 

Collagen: strong, not flexible

High magnification of dense regular connective tissue 

Dense regular connective tissue collage fibers are predominant type of fiber, just as in dense irregular connective tissue

Difference is dense regular connective tissue the collagen fibers are arranged in parallel fashion

Collagen fibers are parallel to each other and run parallel to long axis of tendon or ligament

Dense regular connective tissue (white fibrous connective tissue)

Densely packed collagen fibers, parallel to the long axis of tendon or ligament.  Form tendons or ligaments 

Collagen: strong, not flexible

Dense regular– AKA white fibrous connective tissue 

Densely packed collagen fibers, parallel to long axis of tendon or ligament

Form tendons and ligaments

Wall of artery– elastic connective tissue 

Elastic connective tissue in wall of aorta

Low magnification 

At bottom of image is lumen of the aorta

Elastic connective tissue in arteries in sheets which run perpendicular to wall of vessel. 

Arteries rich in elastic connective tissue, compared to veins, because blood pressure is much higher in arteries than in veins

Elastic fibers interwoven into sheets.  Found in walls of arteries and lower respiratory tract; contain fibroblast.

Extensible- stretch

Elastic - recoils

Wall of artery– elastic connective tissue 

Elastic connective tissue in wall of aorta

Low magnification 

At bottom of image is lumen of the aorta

Elastic connective tissue in arteries in sheets which run perpendicular to wall of vessel. 

Arteries rich in elastic connective tissue, compared to veins, because blood pressure is much higher in arteries than in veins

Elastic fibers interwoven into sheets.  Found in walls of arteries and lower respiratory tract; contain fibroblast.

Wall of artery– elastic connective tissue 

Elastic connective tissue in wall of aorta

Low magnification 

At bottom of image is lumen of the aorta

Elastic connective tissue in arteries in sheets which run perpendicular to wall of vessel. 

Arteries rich in elastic connective tissue, compared to veins, because blood pressure is much higher in arteries than in veins

Elastic fibers interwoven into sheets.  Found in walls of arteries and lower respiratory tract; contain fibroblast.

Reticular connective tissue

Reticular connective tissue taken from spleen

Predominate fibers are reticular fibers and spots are reticulocytes or reticuloblast: cells that produce reticular fibers

Reticulocyte refers not only to cells which produce reticular fibers but also to an immature erythrocyte. 

Large space that is copper colored is called a sinusoid: cavity or space filled with blood

Actually see erythrocytes in sinusoid because make up 94% of blood cells.

Reticular connective tissue

Reticular fibers are irregularly arranged.

Found in: 

Liver

Spleen

Lymph Nodes

Thymus

Bone Marrow

Contains: 

Reticuloblast

Mast cells

Macrophages 

Reticulocyte/Reticuloblast: produces reticular fibers

Adipose connective tissue

Located throughout body but mainly in hypodermis

Covers surface of: 

Heart

Omentum

Around kidneys

Back of eye

Surrounds joints

Adipose

Protects

Pads

Stores fat (energy)

Insulates

Adipose connective tissue

Located throughout body but mainly in hypodermis

Covers surface of: 

Heart

Omentum

Around kidneys

Back of eye

Surrounds joints

Adipose

Protects

Pads

Stores fat (energy)

Insulates

Same images as slides 52 and 58; taken from the trachea

C-shaped rings of the trachea are made of hyaline cartilage connective tissue to prevent it from collapsing 

Connective tissue provides support, physical and metabolic, for epithelial tissue

Epithelial tissue is avascular and connective is vascular, mature cartilage is avascular,  why it is very difficult for torn cartilage to heal 

Cartilage tissue

Composed of chondrocytes contained within elastic matrix 

Chondrocytes contained within spaces called lacunae.  Lacunae may contain one of many chondrocytes.

Mature cartilage avascular so very slow to heal after injury

Same images as slides 52 and 58; taken from the trachea

Hyaline Cartilage

Most common in the body 

Known as gristle in meat

Forms: 

Articular surfaces of bones (articular cartilage) 

Rings in trachea and upper respiratory tract

Nasal septum

Costal cartilage between ribs and sternum (sternocostal joints)

Fetal skeleton 

High power of hyaline cartilage, can discern spaces called lacunae that contain chondrocytes

Elastic cartilage connective tissue

Intermediate magnification of external ear of Mus musculus: common mouse

Intermediate aspect of external ear is composed of elastic cartilage connective tissue 

There is skin of either side of the elastic cartilage

On each side of the elastic cartilage is dense irregular connective tissue (dermis) and keratinized stratified squamous epithelial tissue (epidermis)

Elastic cartilage connective tissue: 

Very flexible cartilage containing elastic fibers that are found in: 

External ear

Epiglottis 

Larynx 

Auditory canal

Elastic cartilage connective tissue

High power magnification of external ear of Mus musculus: common mouse

Intermediate aspect of external ear is composed of elastic cartilage connective tissue

Same ultrastructure as discussed in hyaline cartilage, lacunae and chondrocytes.  

Very easy to see elastic fibers.

Elastic cartilage connective tissue:

Very flexible cartilage containing elastic fibers that are found in:

External ear

Epiglottis

Larynx

Auditory canal

Elastic cartilage connective tissue (skin of ear)

High power magnification view of area above (not anatomical) elastic cartilage

Easy to see this is skin

Elastic cartilage connective tissue:

Very flexible cartilage containing elastic fibers that are found in:

External ear

Epiglottis

Larynx

Auditory canal

Fibrocartilage connective tissue

Intermediate magnification 

Fibrocartilage: strong,built to withstand compression; well suited for menisci of knees, intervertebral joints, symphysis pubis.

Blue fibers: collagen fibers; characteristic of fibrocartilage

Red spots: chondrocytes within their lacunae, same ultrastructure as discussed in hyaline cartilage

Fibrocartilage connective tissue

Intermediate magnification 

Fibrocartilage: strong, built to withstand compression; well suited for menisci of knees, intervertebral joints, symphysis pubis.

Blue fibers: collagen fibers; characteristic of fibrocartilage

Red spots: chondrocytes within their lacunae, same ultrastructure as discussed in hyaline cartilage

Blood connective tissue– AKA whole blood

Shows two of three basic types of blood cells: erythrocytes and leukocytes; thrombocytes not seen 

Most cells erythrocytes: comprise 94% of blood cells

One large cell in center is a leukocyte, specifically a neutrophil

There are few leukocytes seen because they only make up 0.14% of blood cells.  

Some erythrocytes are lighter in center and presents like a nucleus

Blood: about 45% cells (formed elements) and 55% plasma

Erythrocytes (RBC): 94% of formed elements

Function: carry oxygen

Mature blood cells: anucleated and packed with hemoglobin

Hemoglobin: protein that binds oxygen

diffusion of gasses (simple squamous et)

filtration (simple squamous et)

diffusion (simple squamous et)

line blood vessels to provide smooth surface (simple squamous et)

cover organs, support (simple squamous et)

diffusion of gasses (simple squamous et)

selective reabsorption (simple cuboidal et)

secretion (simple cuboidal et)

secretion (simple cuboidal et)

produce hormones:

thyroxine (t3, t4) - increase metabolic rate.

calcitonin-inhibit osteoclasts, stop decrease in bone mass

parathyroid hrmone (pth)- stimulates osteoclasts, increase bone Ca, decrease bone mass

Lines the digestive tract. Forms the mucosa lining of the villi in the small intestine.  Contains goblet cells which secrete mucin.  Mucin and water combine to form mucous.  Mucous is protective and lubricating.  The function is absorption of nutrients.

Epidermis of skin. Functions are strength and waterproofing

Lines oral cavity, nasal cavity, pharynx, esophagus, vagina, anal canal. Functions are to protect against abrasion and maintain moisture.

(AKA stratified cuboidal) ducts of sweat glands and mammary glands. The function is to provide structural support.

parts of the epiglottis, pharynx, anus, urethra, and excretory ducts function is to provide protection.

Lines uterine tubes (fallopian tubes) function is to transport material through lumen.

Lines trachea and bronchi. Function is to remove foreign material and bacteria and form lower respiratory tract.

Lines ureters and urinary bladder. Function is distension.

pancreas functions in two different systems: endocrine and digestive

(endocrine system cells)

secrete glucagon in response to LOW blood sugar.

Glucagon stimulates hydrolysis of glycogen. (glycogenolysis).

Glucagon stimulates hydrolysis of fat (liposis) WHEN glycogen stores are low. (fasting or prolonged exercise)

secrete insulin in response to HIGH blood sugar.

Insulin stimulates uptake of glucose.

Glucose may be oxidized for ATP or may be used to synthesize glycogen (glycogenesis).

acinar cells produce pancreatic enzymes.

These enzymes travel through pancreatic duct to the duodenum of the small intestine.

produce collagen and elastic fibers

Produce reticular fibers

cartilage cell

Bone cell

fat cell

produces heparin and histamine

Phagocytic WBC in the vasculature

A monocyte that is in the interstitial space

produces antibodies

strong, not flexible