Histology (Ch 4)

Question 1

What are the four types of tissues in the human body?

Answer 1

1. Epithelia
2. Connective
3. Muscle
4. Neural

Question 2

What is epithelial tissue? (basic)

Answer 2

• layers of cells that cover body surfaces/line a body cavity
• on outside/inside of an organ
• sheet of cells at a boundary

Question 3

What are the functions of epithelial tissue?

Answer 3

1. Protection
2. Gate-keeping- passage of material in and out
3. Secretion- glands
4. Sensory Reception- have nerves

Question 4

What is simple epithelial tissue?

Answer 4

• single layer of cells
• typically in protected areas of body
• specialized for secretion/absorption
• -> found in air sacs of lungs, intestines, blood vessels

Question 5

What is stratified epithelial tissue?

Answer 5

• multiple layers of cells
• found in areas subjected to wear
• -> found in vagina, esophagus, palm of hand
• named according to the cell shapes at the top surface

Question 6

Simple Squamous Epithelium

Answer 6

• thin/flat –> gas exchange (diffusion/filtration)

- alveoli of lungs, capillary beds, lining of heart/blood vessels

Question 7

Stratified Squamous Epithelium

Answer 7

• function: protect against abrasion
• typically found where mechanical stresses are severe
• ->surface of skin, mouth, esophagus, anus

Question 8

keratinized vs. non-keratinized

Answer 8

keratinized: dryer environment, composed of dead cells on surface (ex. palm)
non-keratinized: may dry out (ex. mouth, vagina)

Question 9

Simple Cuboidal Epithelium

Answer 9

• function: secretion/absorption

- -> kidney tubules, surface of ovaries, glands

Question 10

Stratified Cuboidal Epithelium

Answer 10

• function: protection/secretion

- -> ducts of sweat glands and in mammary glands

Question 11

Simple Columnar Epithelium

Answer 11

• function: absorption/secretion
• may be ciliated or have microvilli
• -> stomach, small intestine, large intestine, uterine tubes

Question 12

cilia

Answer 12

hairlike projections found on apical surface of epithelia,

–> most found in bronchial tubes to move mucus from lungs to throat

Question 13

microvilli

Answer 13

tiny, cytoplasm projections on cells apical surface that increase surface area for absorption/secretion
-appear fuzzy under microscope

Question 14

(Ciliated) Pseudostratified Columnar Epithelium

Answer 14

• function: secretion, population of mucus w/cilia

- found along most of respiratory tract (nasal cavity, bronchi, trachea)

Question 15

Stratified Columnar Epithelium

Answer 15

• rare
• function: protection/excretion
• -> portions of male urethra

Question 16

What is Connective Tissue? (basic)

Answer 16

• fills internal spaces
• provides structural support for other tissues
• transports materials within body
• stores energy

Question 17

What are the characteristics of Epithelial Tissue?

Answer 17

• supported by CT
• have apical (free) and basal (fixed) surfaces
• avascular (nutrients gained from apical and basal surfaces), but innervated (nerves but no blood vessels)
• regenerative, replace lost cells quickly b/c of mitotic division

Question 18

What are characteristics of Connective Tissue?

Answer 18

1. few cells

2. lots of extracellular matrix (ground substance + fibers)

Question 19

What is ground substance?

Answer 19

part of CT extracellular matrix

-secreted by cells, functions as cushion/support, may be gel-like or hard

Question 20

What are the protein fiber types of CT extracellular matrix?

Answer 20

1. Collagen: strong/flexible, resist pulling, most abundant
2. Elastic: rubber band, allows for stretching, thin
3. Reticular: mesh-like, thinnest, form interwoven framework, tough but flexible, physically supports organs

Question 21

What is a tissue?

Answer 21

groups of cells of similar structure that work together to perform a common function

Question 22

What are the functions of Connective Tissue?

Answer 22

1. Structural framework for body (holds things together)
2. Transports fluids/dissolved materals (ex. nutrients/wastes –> blood)
3. Protects organs, supports blood vessels/nerves
4. Supports, surrounds, and is interconnected with other types of tissues
5. Stores energy reserves (ex. fat)
6. Defends body from infection

Question 23

What are the divisions of connective tissue?

Answer 23

1. CT Proper: many types of cells and extracellular fibers in a ground substance (loose/dense)
2. Bone: structure/support
3. Cartilage: structure/support
4. Blood: fluid, RBC, WBC, carry nutrients, fight infection

Question 24

What is Loose Connective Tissue? Types?

Answer 24

fibers widely spaced in ground substance

1. Areolar
2. Adipose
3. Reticular

Question 25

Loose Connective Tissue: Areolar

Answer 25

- -> widespread, least specialized - loose organization, mix of all three fibers - found beneath most epithelial tissue, surrounds most small nerves/blood vessels - functions: supports/binds other tissues, holds body fluids, defends against infection, stores nutrients

Question 26

Loose Connective Tissue: Adipose

Answer 26

- -> made of fat cells (adipocytes) - stores nutrients, pads, absorbs shock, insulates - located below dermis in Sub Q, in body cavities, and surrounding organs

Question 27

Loose Connective Tissue: Reticular

Answer 27

- -> only reticular fibers + cells - forms a scaffold to support other tissue/cell types - found in spleen, bone marrow, and LN

Question 28

What are the Dense Connective Tissue types?

Answer 28

1. Regular 2. Irregular 3. Elastic

Question 29

What is Dense Connective Tissue (Regular)?

Answer 29

- -> have collagen fibers packed tightly together, organized includes: - tendons: attach skeletal muscle to bones - ligaments: attach bone to bone - aponeurosis: thin, sheet-like tendons that attach flat muscle to another muscle or several bones

Question 30

What is Dense Connective Tissue (Irregular)?

Answer 30

- -> have collagen fibers with NO consistent pattern - strengthen/support areas subject to stresses from many directions (dermis, periosteum - over bone) - found in fibrous capsule around organs such as liver, kidneys, spleen, bon, and joint cavities

Question 31

What is Dense Connective Tissue (Elastic)?

Answer 31

- -> dominated by elastic fibers, stretchy | - found in walls of elastic arteries (aorta) and respiratory passageways (trachea)

Question 32

What is Muscular Tissue? (basic)

Answer 32

three types of muscle cells that contract to create movement

Question 33

What is Neural Tissue? (basic)

Answer 33

specialized for the conduction of nervous impulses, in brain/spinal cord

Question 34

What is Marfan Syndrome?

Answer 34

autosomal dominant disorder that affects connective tissues - symptoms: long arms/legs/fingers, concave chest, flexible joints - risk of death due to aortic dissection

Question 35

What are glands? Types?

Answer 35

epithelial tissues that secrete a product 1. endocrine: secrete directly into tissue around them, have NO duct (ex. pancreas) 2. exocrine: secrete onto body surfaces/cavities, have a duct (ex. sweat, mammary)