Chapter 40: An Introduction to Animal Structure and Function

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anatomy: the study of an organism's structure

physiology: the study of function

Life is organized through levels of hierarchy, resulting in three main categories:

1. tissues - collections of cells with a common structure or function

2. organs- combinations of tissues

3. organ systems- combinations of organs

There are four types of tissue - epithelial tissue

connective tissue

nervous tissue

muscle tissue

Epithelial tissue

• covers outside of body
• lines tissues and organs
• tightly packed
• simple --> one layer
• stratified --> multiple layers
• functions against mechanical injury, fluid loss, invasive microorganisms
• shape at free surface squamous (flat), cubodial, or columnnar (pillarlike)

Collagenous fibers

• type of connective tissue
• made of collagen (abundant)
• nonelastic --> does not easily

fibroblasts

• common cell meshed in loose connective tissue
• secretes extracellular fibers protein

macrophage

• other most common cell found in loose connective tissue
• amoeboid cells
• engulf bacteria and cellular debris

tendon

• contains fibrous connective tissue
• attach muscles to bones

ligament

• contains fibrous connective tissue
• joins bones with joints

chondryocytes

• secretes chondroitin sulfate --> embeds cartilage in rubbery substance

*Cartilage is made of collagenous fibers.*

Osteoblast

• bone-forming cells
• deposit matrix of collagen --> calcium, magnesium, and phosphate ions combine and harden = mineral hydroxyapatite
• combination makes bones harder and less brittle

Nervous tissue

• senses stimuli
• transmits electrical signals
• functional unit = neuron

Smooth muscle tissue

• lacks striations
• found in walls of digestive tract, urinary bladder, arteries, and other internal organs
• spindle-shaped cells
• remain contracted longer
• control involuntary body activities (ex. stomach churning)

Skeletal muscle tissue

• attached to bones by tendons
• control voluntary body movements (ex. walking)
• striated muscle (overlapping filaments)

*The organ systems of an animal are interdependent (cooperative network)*

abdominal cavity

• primarily houses components of digestive system, excretory system, and reproductive system
• separated from thoracic cavity by diaphragm

Multiple Choice Quiz

1. Which of the following is not an organ system?

a) skeletal

b) connective

c) digestive

d) excretory

e) immune and lymphatic

2. A stratified squamous epithelium would be composed of

a) several layers of flat cells attached to a basement membrane

b) a layer of ciliated, mucus-secreting, flattened cells

c) a hierarchal arrangement of boxlike cells

d) an irregularly arranged layer of pillarlike cells

e) several layers of flat cells underneath columnar cells.

3. Which of the following is not true of connective tissue?

a) it consists of few cells surrounded by fibers in a matrix.

b) it includes diverse tissues as bone, cartilage, tendons, adipose, and loose connective tissue

c) it connects and supports other tissues.

d) it forms the internal and external lining of many organs.

e) it can have a matrix that is a liquid, gel, or solid.

4. Which of the following is the best description of smooth muscle?

a) striated, branching cells; involuntary control

b) spindle-shaped cells; involuntary control

c) spindle-shaped cells connected by intercalated disks

d) striated cells containing overlapping filaments; involuntary control

e) spindle-shaped striated cells; voluntary control