Lecture 2: Microanatomy & Histology

Question 1

What are the 4 basic tissue types?

Answer 1

1.) Epithelia
2.) Connective Tissue
3.) Muscle Tissue
4.) Nervous Tissue

Question 2

What are the 3 germ layers from embryonic development from which all tissues are derived?

Answer 2

1.) Ectoderm
2.) Mesoderm
3.) Endoderm

Question 3

3 important parts of the ECTODERM

Answer 3

1.) Neuroectoderm (neural tube)
2.) Neuroectoderm (neural crest)
3.) Surface Ectoderm

Question 4

Structures derived from the NEURAL TUBE (Can Robots Pee Periodically?)

Answer 4

(Can Robots Pee Periodically?)
C - central nervous system
R - retina
P - pineal body
P - posterior pituitary gland

Question 5

Structures derived from the NEURAL CREST

Answer 5

• Cranial & sensory ganglia / nerves
  *adrenal medulla
  *melanocytes
  *pharyngeal arch cartilages
  *head mesenchyme & connective tissue
  *Schwann cells
• Odontoblasts

Question 6

What are Schwann cells?

Answer 6

Major glial cell of the peripheral nervous system.

Question 7

What are Odontoblasts?

Answer 7

Cells that produce dentin & protect teeth.

Question 8

Structures derived from the SURFACE ECTODERM

Answer 8

• Epidermis
  *Hair & nails
  *Cutaneous & mammary glands
  *Anterior pituitary gland
  *enamel
  *internal ear
  *corneal epithelium & lens

Question 9

4 important parts of the MESODERM

Answer 9

1.) Head mesoderm
2.) Paraxial mesoderm
3.) Intermediate mesoderm
4.) Lateral mesoderm

Question 10

Structures derived from the HEAD MESODERM (CCD)

Answer 10

*cranium
* connective tissue of head
*dentin

Question 11

What is the Dentin?

Answer 11

A layer of material that lies immediately underneath the enamel of the tooth

Question 12

Structures derived from the PARAXIAL MESODERM

Answer 12

*Skeletal muscle (not cranium)
*muscles of head
*dermis of skin
*connective tissue

Question 13

Structures derived from the INTERMEDIATE MESODERM

Answer 13

*urogenital system (gonads, ducts, glands)

Question 14

Structures derived from the LATERAL MESODERM (6)

Answer 14

• connective tissue and muscle of viscera
  *serous membranes of pleura, pericardium, & peritoneum
• blood & lymph cells
  *cardiovascular & lymphatic systems
• spleen
  *adrenal cortex

Question 15

Structures derived from the ENDODERM (ENDO = EPI)

Answer 15

*Epithelial parts & linings
Lining - resp tract, gi tract, bladder & urachus
Epithelial Parts - thyroid, tympanic cavity, auditory tube, tonsils, parathyroids, liver, pancreas

Question 16

What is a dermoid cyst (teratoma)?

Answer 16

a type of cyst found almost exclusively in the ovaries, can have structures from all 3 germ layers.

Question 17

Describe the general characteristics of Epithelial tissue.

Answer 17

*cover body’s surface, line cavities, form glands
*avascular (get from connective tissue)
*joined by specialized junctions
* surface specializations
* separated from underlying tissue by basal lamina

Question 18

What is the basil lamina?

Question 19

By what two characteristics do we classify epithelia?

Answer 19

1.) Number of Layers
2.) Cell Shape

Question 20

Number of layer categories for epithelia

Answer 20

1.) Simple = 1 layer
2.) Stratified = 2+ layers
3.) Pseudostratified = appears 2+ but is only 1

Question 21

Cell shape categories for epithelia

Answer 21

1.) Squamous = flat
2.) Cuboidal = square
3.) Columnar = tall

Question 22

What is transitional epithelia?

Answer 22

a special kind of tissue found exclusively in the urinary system.

Question 23

Describe the general characteristics of Connective tissue.

Answer 23

• derived from mesoderm
  *separated from each other by extracellular matrix

Question 24

What are the two classifications of connective tissue?

Answer 24

1.) Dense - more fibres (collagen) than cells
2.) Loose - more cellular (usually under epithelia)

Question 25

What is adipose?

Answer 25

Fatty tissue, common in abdominal areas and around coronary vessels.

Question 26

What are some examples of specialized connective tissues?

Answer 26

Bone, cartilage, and blood

Question 27

Regular pattern of connective tissue

Answer 27

typical of ligaments and tendons

Question 28

What is the function of fibroblasts?

Answer 28

Form connective tissue by excreting collagen

Question 29

What color does collagen stain under H&E stain?

Answer 29

Pink

Question 30

What color do proteoglycans stain under H&E stain?

Answer 30

Blue

Question 31

What are proteoglycans?

Question 32

Describe the general characteristics of Muscle tissue.

Answer 32

* derived from mesoderm * help with temperature regulation & movement

Question 33

What are the two basic types of muscle tissue?

Answer 33

1.) Striated (skeletal & cardiac) 2.) Smooth

Question 34

Describe skeletal muscle tissue

Answer 34

large cells, long cylindrical, multinucleate, peripheral nuclei, usually voluntary

Question 35

Describe cardiac muscle tissue

Answer 35

branched cells, central nuclei, connected by intercalated discs with gap junctions for comms. Non-voluntary

Question 36

Describe smooth muscle tissue

Answer 36

fusiform, no striations, common in layers, small cells, look like round targets in cross sections.

Question 37

3 important parts of the nervous system (tissues)

Answer 37

1.) Peripheral Nervous System (PNS) 2.) Autonomic Nervous System (ANS) 3.) Central Nervous System (CNS)

Question 38

What is the Node of Ranvier?

Question 39

Describe the PNS

Answer 39

* derived from neural crest * sensory neurons in ganglia * motor neurons in spinal cord anterior horn or brain stem motor nuclei * Schwann cells myelinate axons

Question 40

Describe the ANS

Answer 40

* 2 parts - sympathetic & parasympathetic sympathetic - parasympathetic -

Question 41

Where are preganglionic sympathetic neurons found?

Answer 41

lateral horn of thoracic spinal cord

Question 42

Where are preganglionic parasympathetic neurons found?

Answer 42

brainstem nuclei or sacral spinal cord

Question 43

Where are postganglionic neurons found?

Answer 43

in the ganglia

Question 44

Describe the CNS

Answer 44

* brain & spinal cord * oligodendroglia cells myelinate axons