Lesson 14 - Body Tissue

Question 1

Cell Junctions

Answer 1

Connects cells together and three types

Gap Junctions
Tight junctions
Desmosome -adhering junctions

Question 2

Tight junctions

Answer 2

Allows no movement between cells. Only way is through cell

ex: gut, kidney, skin, blood-brain barrier

Question 3

Gap junctions

Answer 3

Allows for movement of ions
-transmisson of charge

ex: heart, gut

Question 4

Desmosomes

Answer 4

Structural junction
-with standstress by preventing pulling apart of tissue

ex: Skin, heart, uterus

Question 5

Tissues

Answer 5

Cells with similar structure and function

4 types:

-Epithelial
-Connective tissue
-Nerve
-Muscle

Question 6

Function of Epithelial Tissue

Answer 6

Covering sheets
- everything has epithelial lining and skin

Glands
-exocrine - secrete into duct (sweat and oil glands)
-endocrine - secretes hormones into blood

Functions:
-Protection (skin)
-Absorption, secretion (glands)
- ion transport/diffusion (membranes)
-filtration (membranes)
-forms slippery surface (mucus layers)

Question 7

Types of Epithelial Tissue

Answer 7

Simple vs Stratified
-Single layer vs multi layered

Shape: Cuboidal vs columnar cells
- cube vs columns
ex: gut

Squamous cell
-Flattened
ex: lungs

Question 8

Simple Epithelium (1)

Answer 8

Simple Squamous epithelium
(single layer squish cell)

areas subject to little wear and tear
-adapted for diffusion and filtration

ex: lung alveoli

Question 9

Stratified Epithelium (2)

Answer 9

Stratified squamous epithelium
(many layer squish cell)

-protects areas of wear and tear
-defend against microbes

ex: outer layer of skin, lining of mouth

Transitional Epithelium
(can change shape)

contains cells that can change shape
in areas subject to stretching

Ex; bladder

Question 10

Glands

Answer 10

Specialized epithelial cells

exocrine glands
- secretes substances into ducts
ex: sweat glands

endrocrine glands (ductless)
-secretes hormones into blood
ex: thyroid

Paracrine glands (endocrine but close by)
-secretes of short distances, to cells around

Question 11

Unicellular exocrine glands (goblet cell)

Answer 11

Goblet cell makes mucin
Mucin+water=mucus

-protects and lubricates many internal body surfaces

Question 12

Duct classification

Answer 12

Simple vs Compound (complex)

Variety of ducts, more then one branch= compound

Question 13

Classes of connective tissue and function

Answer 13

Most diverse and abundant tissue

Main classes:

Connective tissue
Cartilage
Bone tissue
Blood
Fat

Different structure same func

Function: binds together and supports/strengthens

protects and insulates internal organs
compartmentalizes muscle

Question 14

Connective Tissue Proteins

Answer 14

Collagen - stuff seen in tendons

Elastin - stretchy in Lungs

Ratio of collagen and Elastin determines function

Question 15

Structural elements of connective tissue

Answer 15

Extracellular matrix
-collagen and elastin fibers
-viscous, gel like ground substance
-cushions and protect body (made up differently depends on where is)

difference in structure properties due to: cell types and different composition of matrix

Question 16

Connective tissue Proper

Answer 16

Two subclasses
-lose connective tissue (areolar, adipose)
-dense connective tissue (regular vs irregular)

Question 17

Loose connective tissue: Areolar

Answer 17

Everywhere, filler (chicken goop)

Gel like matrix with all three fibers
Contains:
fat cells
white blood cells
mast cells
fibroblasts

Underlines epithelial tissue
-surrounds blood vessels and organs
- borders all other tissues in the body

Question 18

Dense irregular connective tissue

Answer 18

Irregularly arranged collagen and elastin

Withstands pulling/tension in every direction (can pull on skin and not pull apart)

Location:
-skin
-gut
-fibrous capsules of joints and organs

Question 19

Dense regular connective tissue

Answer 19

Know which way stress is coming from

Parallel collagen fibres (too withstand stress)
-Some elastin
-Poorly vascularized

Muscle and Bone attachments
Withstands stress (in 1 direction)
Eg. Tendons, ligaments

Knee joint, hit from side bad

Question 20

Specialized Connective Tissues
Serve Special Functions

Answer 20

Bone:
-forms the skeleton
* Spongy vs compact

Blood: transports materials such as
glucose and Oxygen (primarily matrix)
fluid matrix of
* plasma (fluid)
* red blood cells
* white blood cells
* platelets

Question 21

Bone types

Answer 21

Compact bone:
Harder – haversian systems
* Yellow bone marrow (mostly
fat) in marrow space

Spongy bone:
* Spaces may contain red bone
marrow

Question 22

Bones Are the Hard Elements of
the Skeleton

Answer 22

Bone is made 10% cells and 90% matrix

The extracellular matrix contains:
-Calcium and phosphate
-Collagen
-Proteins
-Water

Cells:
Osteoblasts (make bone)
Osteoclasts (resorb bone)
Osteocytes (mature cells)

Question 23

Specialized Connective Tissues
Serve Special Functions

Answer 23

Cartilage:
- transitional tissue from which bone develops
maintains shape of certain body parts (nose, ears)
cushions vertebrae (vertebral disks), lines joint cavities

Adipose tissue:
-fat cells
functions in insulation, protection, and energy storage

Question 24

Cartilage lends support

Answer 24

Provides structure and support under compression

Types:

Fibrocartilage (harder, protection)
* Intervertebral disks between vertebrae
* Menisci in knee joints

Hyaline (in the end of bones)
* Covers and protects ends of long bones in joints

Elastic cartilage
* Flexible, outer ear, tip of nose

Question 25

Muscle tissue

Answer 25

Contractile
-Force and movement

Three types:
Cardiac - heart (striated)
Smooth - gut (striated)
Skeletal - on skeleton

Skeletal muscle tissue
-Voluntary – moves skeleton

Cardiac muscle tissue
- Heart – pacemaker controlled

Smooth muscle tissue
-Involuntary – eg. Gut, blood vessels

Question 26

Nervous tissue

Answer 26

Signal transmission:

Brain, Nerves, spinal cord
-Transmit electrical signals

Contains two types of cells
* Neurons—excitatory cells
* Supporting cells (neuroglial cells)

Question 27

Tissue repair

Answer 27

Regeneration
- Of damaged site with same
type of tissue

Fibrosis
- Proliferation of scar tissue (extra connective tissue)

• Organization
  Clot is replaced by granulation tissue

Question 28

Capacity for Regeneration

Answer 28

Good to excellent:
* ET, bone CT, areolar CT, dense irregular CT, and blood forming CT

Moderate:
* Smooth muscle

Weak: (tissue itself, low blood supply)
* Skeletal MT, cartilage, dense regular CT

None or almost none:
* Cardiac MT, Nervous Tissue

Heart attack, can’t regerante tissue

Question 29

The Tissues Throughout Life

Answer 29

With increasing age:
-Skin thin (wrinkles)

-Collagen decreases (80 yr old lost 50% of muscle)

• Bones, muscles, and nervous tissue begin to atrophy
• Poor nutrition and poor circulation lead to poor health of tissues
• Decreased healing