Histology (Ch 4) Flashcards Preview

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Flashcards in Histology (Ch 4) Deck (35):
1

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

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

2

What is epithelial tissue? (basic)

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

3

What are the functions of epithelial tissue?

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

4

What is simple epithelial tissue?

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

5

What is stratified epithelial tissue?

-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

6

Simple Squamous Epithelium

-thin/flat --> gas exchange (diffusion/filtration)
-alveoli of lungs, capillary beds, lining of heart/blood vessels

7

Stratified Squamous Epithelium

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

8

keratinized vs. non-keratinized

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

9

Simple Cuboidal Epithelium

-function: secretion/absorption
--> kidney tubules, surface of ovaries, glands

10

Stratified Cuboidal Epithelium

-function: protection/secretion
--> ducts of sweat glands and in mammary glands

11

Simple Columnar Epithelium

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

12

cilia

hairlike projections found on apical surface of epithelia,
--> most found in bronchial tubes to move mucus from lungs to throat

13

microvilli

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

14

(Ciliated) Pseudostratified Columnar Epithelium

-function: secretion, population of mucus w/cilia
-found along most of respiratory tract (nasal cavity, bronchi, trachea)

15

Stratified Columnar Epithelium

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

16

What is Connective Tissue? (basic)

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

17

What are the characteristics of Epithelial Tissue?

-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

18

What are characteristics of Connective Tissue?

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

19

What is ground substance?

part of CT extracellular matrix
-secreted by cells, functions as cushion/support, may be gel-like or hard

20

What are the protein fiber types of CT extracellular matrix?

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

21

What is a tissue?

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

22

What are the functions of Connective Tissue?

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

23

What are the divisions of connective tissue?

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

24

What is Loose Connective Tissue? Types?

fibers widely spaced in ground substance
1. Areolar
2. Adipose
3. Reticular

25

Loose Connective Tissue: Areolar

--> 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

26

Loose Connective Tissue: Adipose

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

27

Loose Connective Tissue: Reticular

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

28

What are the Dense Connective Tissue types?

1. Regular
2. Irregular
3. Elastic

29

What is Dense Connective Tissue (Regular)?

--> 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

30

What is Dense Connective Tissue (Irregular)?

--> 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

31

What is Dense Connective Tissue (Elastic)?

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

32

What is Muscular Tissue? (basic)

three types of muscle cells that contract to create movement

33

What is Neural Tissue? (basic)

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

34

What is Marfan Syndrome?

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

35

What are glands? Types?

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)