Chapter 20a: Animal Structure and Function

Question 1

What is tissue and what is it made of? What are the four categories of animal tissue?

Answer 1

A group of similar cells that perform a specific function made up of cells, cell junctions, and extracellular material. Includes epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

Look at pics of tissue as you study. Learn to identify and draw the stuctures.

Question 2

What are the 2 themes in biology that relate to this chapter?

Answer 2

• The diversity of life can be organized in a hierarchy, and emergent properties arise at each level of organization.
• There is a close relationship between structure and function, even at the cellular level.

Question 3

What is the difference between anatomy and physiology?

Answer 3

Anatomy is the study of an organism’s structure, and physiology is the study of the function of those structures.

Question 4

Describe the structures and functions of epithelial tissue

Answer 4

Structure:
* sheets of closely packed cells joined by tight junctions (contains nerves, no blood vessels)
* always exposed to air or fluid.
Function:
* Covers body surfaces and lines internal organs and cavities (e.g. epidermis, stomach lining).
* Acts as barrier to mechanical injury, microbial invasion, and fluid loss.
* Some are specialized for absorption and secretion.

All glands are made of epithelial tissue.

Question 5

Classification of epithelial tissue

Answer 5

1. Cell shape
   Cuboidal
   Columnar
   Squamous
2. Number of layers
   Simple
   Stratified

cuboidal and columnar epithelia are specialized in secretion and absorption (larger internal volume = more space to absorb and release).

Question 6

Simple Squamous Epithelium

Answer 6

Structure: single layer of flat cells; thin.
Function: specialized for exchanging materials by diffusion.
Location: lung, blood vessels.

Question 7

Stratified Squamous Epithelium

Answer 7

Structure: several layers of squamous cells.
Function: protection from abrasion, microbial invasion, fluid loss, irradiation.
Location: epidermis (skin), lining the vagina, esophagus, inside of mouth.

These tissue regenerate rapidly

Question 8

Simple Cuboidal Epithelium

Answer 8

Structure: a single layer of cube-shaped cells.
Function: specialized for absorption or secretion of substances.
Location: kidney tubules (filters blood to urine), thyroid gland, pancreatic ducts.

Question 9

Non-Ciliated Simple Columnar Epithelium

Answer 9

Structure: a single layer of rectangular cells; may contain microvilli.
Function: speciliazed for secretion (of digestive juices or mucus) or absorption (of nutrients from the intestinal tract).
Location: lining the stomach and intestines.

Microvili are made of microfilaments, meaning they DON’T move.

Question 10

Ciliated Simple Columnar Epithelium

Answer 10

Structure: single layer of rectangular cells that contain cilia, microtubule extension covered in membrane that move mucus.
Function: protection from microbial infections.
Location: lining respiratory tract and uterine tube.

Cilia made of microtubules, meaning they move.

Question 11

Transitional Epithelium

Answer 11

Structure: several layers of cells; can change shape- stratified cuboidal (at rest) to stratified squamous (stretched).
Function: provides protection and ability for hollow organs to expand.
Location: urinary bladder, ureters, and urethra.

Question 12

Describe the Structure and Functions of Connective Tissue

Answer 12

Structure: sparse popultion of cells scattered thoughout extracellular matrix. Cells produce and secrete the ECM with fibers embedded.
Function: make up basic support structure for the body:
* Connects the body’s other tissues in a framework.
* Holds organs in place.
* Attached epithelial to underlying tissues.

Question 13

Classification of
Connective Tissue

Answer 13

• Loose connective tissue
• Fibrous connective tissue
• Adipose tissue
• Blood
• Bone
• Cartilage

Question 14

Loose Connective Tissue

Answer 14

Structure: loosely arranged protein fibers and sparse cells.
Function: Acts as glue that binds epithelia to underlying tissues, packs body cavities, and holds organs in place.
Location: surrounding organs in the abdominal cavity, directly underneath skin.

Question 15

Fibrous Connective Tissue

Answer 15

Structure: densely packed collagen fibers, plus sparse cells.
Function: supports body tissues and provides tensile strength (resists pulling/stretching).
Location: tendons (connect muscle to bone) and ligaments (connect bones to other bones).

Question 16

Adipose Tissue

Answer 16

Structure: closely packed adopse cells in a sparse matrix of loose fibers and fluid; each adipose cell contains a fat droplet.
Function: store fat; insulates and stores energy.
Location: surround organs.

Question 17

Cartilage

Answer 17

Structure: collagen fibers embedded in a rubbery matrix, plus cells.
Not vascularized; heals poorly.
Function: absorbs shock.
Location: Nose, ears, trachea, and intervertebral discs.

Question 18

Bone

Answer 18

Structure: matrix of collagen fibers embedded in a hard substance of calcium salts.
Vascularize, heals relatively quickly.
Function: provides support and protection for the vertebrate body and its organs.
Location: skeleton.

Question 19

Blood

Answer 19

Structure: cells in liquid matrix called blood plasma (made of water, salts, and proteins).
Function: Red blood cells transport oxygen.
White blood cells have immune functions.
Cell fragments assist in blood clotting.

Question 20

Describe the Structures and Functions of Muscular Tissue

Answer 20

The most abundant tissue in animals.
Structure: long, excitable cells capable of contraction.
Properties:
Contractibility- ability to shorten with force.
Excitability- capacity to respond to stimuli.
Extensibility- can be stretched beyond resting length.
Elasticity - recoils to original resting length when stretched.
Function: supports body movement and generates heat.

Question 21

Classification of Muscular Tissue

Answer 21

• Skeletal muscle
• Smooth muscle
• Cardiac

Question 22

Skeletal Muscle

Answer 22

Structure: striated (striped), long cells with many nuclei, attached to bone.
Function: Responsible for voluntary body movements.

Question 23

Cardiac Muscle

Answer 23

Structure:striated, branched cells with a single nucleus; joined by thick connections; exclusively heart.
Function: Pumps blood; involuntary.

Question 24

Smooth Muscle

Answer 24

Structure: NOT striated, spindle-shaped cells with single nucleus.
Function: moves wall of internal organs (e.g. stomach, blood vessels); involuntary.

Question 25

Describe the Structures and Functions of Nervous Tissue

Answer 25

Structure: Includes neurons (major cells) and supporting cells.
Functions:
* sense stimuli and transmits electrical impulses from one part of the body to another.
* Coordinates and controls body activities.
* Supporting cells provide electrical insulation and nourishment.

Location: Brain and spinal cord.

Neurons, in general, consist of dendrites, a cell body, and an axon.

Question 26

Cell Junctions

Answer 26

Tight junctions: BInds cells together in a leak proof sheet (ie. bladder, stomach).
Anchoring junctions: Link adjacent cells together (ie. skin).
Gap junctions: Hollow chanels that allows substances to flow between cells (ie. heart cells).