LAB 1 histology

Question 1

5 functions epithelium

Answer 1

1. Protection
   
   2. Sensory function
   3. Secretion-glandular epithelium
   4. Absorption
   5. Extrection

Question 2

3 steps to classify of covering and lining epithelia

Answer 2

1. NUMBER OF CELL LAYERS
   - one layer: simple epithelium. They are very thin, allow passage between lumen and tissues
   - several layers: STRATIFIED epithelium: main function iis to protect tissue that they cover
2. SHAPE OF THE CELLS:
   - flat: SQUAMOUS epithelium (nuclei are flat and parallel)
   - square: CUBOIDAL epithelium (nuclei are oval and parallel)
   - rectangular: COLUMNAR epithelium (nuclei are round and middle of the cell)
3. SPECIALIZATION OF THEIR CELL SURFACES (cilia, microvilli)

Question 3

simple and stratified squamous

Answer 3

SIMPLE SQUAMOUS:

- Location: air sacs of lungs, blood vessels, kidney glomeruli,
- Function: lubrification * * thinnest of all so good for diffusion, secretion, filtration

STRATIFIED SQUAMOUS

• • thickiest of all the epithelium
    
    • Location: skin, mouth..
    • Lubrification, protection
    • May contain keratin (skin) or not (wet surfaces such as vagina, tongue, esophagus..)

Question 4

simple, pseudostratified and stratified columnar

Answer 4

SIMPLE COLUMNAR:
- Location: stomach, intestines, uterus
- Function: protective, SA, secrete mucus
** non-ciliated: contains microvilli on the apical surface (increase surface area) so found in the digestive
Ciliated: found in the respiratory system, part of the uterus and uterine tubes

PSEUDOSTRATIFIED COLUMNAR:

- Location: trachea, fallopian, tubes
- Role: movement * * cilia: trachea, upper respiratory * * non-cilia: male urethra

STRATIFIED COLUMNAR:

- Location: vas defense, male urethra
- Function: support and some movement

Question 5

simple and stratified cuboidal

Answer 5

SIMPLE CUBOIDAL:

- Location: ovaries, kidney tubules, thyroid glans
- Role: secretion and absorption

STRATIFIED CUBOIDAL:

- Location: mammary glands, sweat glands
- Role: secretion, absorption and protections

Question 6

transitional epithelial

Answer 6

TRANSITIONAL

- Location: bladder
- Role: stretch, protection against seepgae

Question 7

exocrine vs endocrine glands

Answer 7

EXOCRINE GLANDS: discharge secretions into ducts (not going in the blood but outside)
Ex: salivary or sweat gland

ENDOCRINE GLANDS: ductless glands; discharge secretions directly into the blood or intestitial fluid
Ex: pineal gland, pituitary gland, thyroid gland, thymus, adrenal gland, pancreas, ovary, testis

Question 8

types of glandular epithelium

Answer 8

1. APOCRINE: product pinches off and is released from Apex
   
   • Mammary glands
   • Hair follicle sweat glands (at the junction of the dermis and subcutaneous fat, from which a straight portion inserts and secretes into the hair follicle; produce an odorless, oily, opaque secretion that gains its characteristics odor upon bacterial decomposition
   • Goblet cells (in colon)
   2. HOLOCRINE: product collect in the cell, then when product is released the plasma membrane ruptures
      Ex: sebaceous gland
   3. MEROCRINE (or eccrine): secrete product through plasma membrane. Most common type
      Ex: salivary gland, gastric glands, sweat glands in body acting in cooling system

Question 9

functions connective tissue

Answer 9

Functions:

1. Binding, support and packaging
2. Protection, defense and repair
3. Insulation (by adipose tissue)
4. Transportation (blood)

General characterisics: ECM predominates in most connective tissues and determines its physical characteristics

Question 10

Cells that secrete the extracellular matrix that is characteritsic of the tissue:

Answer 10

1. Connective tissue proper: FIBROBLASTS
   
   2. Cartilage: CHONDROBLASTS
   3. Bone: OSTEOBLASTS
   4. Blood: hemocytoblast

** other things in the matrix: white blood cells, mast cells, macrophages, antibody…

Question 11

4 types connective tissue

Answer 11

1. FIBROUS (connective tissue proper)
   
   • LOOSE (aerolar): ex: fascia, fat (protection and insulation) ** lots of fibroblasts, elastic fiber…
   • DENSE REGULAR: ex: tendons and ligaments (flexible but strong)
   • DENSE IRREGULAR: ex: symphysis pubis joint
   2. CARTILAGE (elastic- fibrocartilage- hyaline)
      Gives firm but flexible support.
      - Elastoc: ear, epiglottis
      - Hyaline: trachea rings, joint surface of bone, larynx
      - Fibrocartilage: symphysis pubis joint
   3. BONE
      - Compact bone
      - Spongy bone - mineralized ECM
   4. BLOOD
      - Transportation and protection

Question 12

3 types of fiber in the ECM of connective tissue

Answer 12

1. COLLAGEN fiber: the thoughest, resist longitudinal stress
2. ELASTIC fibers: can be stretched but retake their initial form. Found in lungs and blood vessels walls
3. RETICULAR fibers: form a branching network suporting soft organs such as the liver and spleen

Question 13

composition ground substance connective tissue

Answer 13

• INTERSTITIAL FLUID
• CELL ADHESION PROTEINS: all connective tissue cells to attch themselevs to the matrix elements
• PROTEOGLYCANS: where polysaccharides are attached

functions : support cells, bind them together and a medium for nutrients

Question 14

cartilage

Answer 14

• • a lot of collagen fibers, elastin fibec fibers and proteoglycan
    
    • Differs from other tissue in that only one cell type is present: CHONDROCYTE
    • LACUNAE house cells: lacuna hole or pit- is a small space containing a chondrocyte in cartilage or an osteocyte in bone
    • Cartilage is avascular!!! Unlike other connective tissue, so repair more slowly

(( ECM is secrete by chondroblasts foun din the outer covering layer of cartilage. As it secrete the ECM it become trapped inside it so it matures in chondrocytes

Hyaline cartilages exists on the ventral ends of ribs; in the larynx, trachea and bronch +articular surface of bones

Question 15

role of bone tissue

Answer 15

1. Support
   
   2. Protection
   3. Point of attachment for muscles
   4. Reservoir for muscles
   5. Supports blood-forming tissue

Question 16

epiphysis line growth of tibia, humerus and radius

Answer 16

Tibia:

- Upper end fuses at 16-18 years
- Lower end fuses at 15-17 years

humerus:

- Upper end during 20th year
- Lower end at about 16 years

Radius:

- Upper end during 18th year
- Lower end at 20 years

Question 17

parts of the compact bone

Answer 17

1. HAVERSIAN CALA (blood vessels, nerves, connective tissue)
   
   2. CANALICULI (small canal allowing for nutrients to travel between lacunae)
   3. LAMELLAE (concentric rings- form the bone matrix)
   4. LACUNAE (spaces in the bone where the osteocytes are located)
   5. OSTEON: basic structural unit of compact bone

Question 18

functions of blood

Answer 18

1. Transportation
   
   2. Regulation of body temp.
   3. Regulation of body pH
   4. White blood cells destroy bacteria
   5. Circulating blood tissue is formed in the red bone marrow by a process called HEMATOPOIESIS

Question 19

6 types of connective tissues with their function and location

Answer 19

1. LOOSE FIBROUS:
   - location: under skin, in muscle
   
   • Function: nourishment, stretch
   2. ADIPOSE
      - Under skin, in muscle
      - Insulation, cushioning
   3. CARTILAGE:
      - Ears, nose, bone ends
      - Cushion, support
   4. DENSE FIBROUS
      - Ligaments and tendons
      - Pulling/pushing, forces
   5. BONE
      - Skeleton
      - Suppoet, protection
   6. BLOOD
      - Veins, arteries, heart
      - transport

Question 20

3 types of muscle with their microscopic characteristics

Answer 20

1. SKELETAL MUSCLE (striated voluntary)
   
   • Cross striations
   • MULTINUCLEATED (normal)
   2. SMOOTH MUSCLE (nonstriated involuntary or visceral)
      - Elongated, fusiform shaped cells
      - No cross striations
      - ONE nucleus per cell
   3. CARDIAC MUSCLE (striated involuntary)
      - Branched cells with INTERCALATED DISKS (formed by meeting of plasma membranes of 2 cells)