Support, Protection, and Movement Ch 29

Question 1

what is Integument and its functions?

Answer 1

Outer covering of the body
* Functions
– Protection against abrasion & bacteria
– Prevents fluid loss
– Protects from UV rays
– Temperature regulation
– Sensory
– Excretory (e.g., sweat)
– Respiration for some animals
– Absorb nutrients for some animals

Question 2

Invertebrate Integument

Answer 2

• Unicellular animals = cell membrane
• Most Invertebrates – single layer epidermis
• Phylum Platyhelminthes (some flatworms)
  – Syncytial tegument = multinucleate outer layer; no individual cells
• Phylum Mollusca
  – Mantle (tissue layer) secretes outer shell
• Phylum Arthropoda
  – Cuticle functions as exoskeleton
  – Epidermis (hypodermis) secretes cuticle

Question 3

Syncytial tegument

Answer 3

= multinucleate outer layer; no individual cells

Question 4

Vertebrate Integument

Answer 4

• Epidermis (ectoderm derived); stratified squamous epithelium
  – Cells contain Keratin (fibrous protein)
• Keratinization causes cells to become cornified; form stratum corneum
  – Chromatophores contain pigments (e.g. melanins)
• Dermis (mesoderm derived); dense connective tissue layer
  – Contains nerves, blood vessels, collagen fibers, fat cells, glands,
  immune cells, etc.
  – May contain dermal bone

Question 5

Epidermis

Answer 5

The outer layer of the two main layers of the skin.
-(ectoderm derived); stratified squamous epithelium
-– Cells contain Keratin (fibrous protein)
* Keratinization causes cells to become cornified; form stratum corneum
– Chromatophores contain pigments (e.g. melanins)

Question 6

Dermis

Answer 6

The inner layer of the two main layers of the skin. The dermis has connective tissue, blood vessels, oil and sweat glands, nerves, hair follicles, and other structures.
-(mesoderm derived); dense connective tissue layer
– Contains nerves, blood vessels, collagen fibers, fat cells, glands,
immune cells, etc.
– May contain dermal bone

Question 7

in the epidermis Cells contain Keratin (_______ _________)

Answer 7

fibrous protein

Question 8

Hydrostatic Skeletal

Answer 8

(sometimes just called “hydrostats”) use a cavity filled with water; the water is incompressible, so the organism can use it to apply force or change shape.
-Plants use osmotic pressure to pressurize the cavity, whereas animals do it with muscle layers in the hydrostat’s walls.

Question 9

29.5 What are the two types of rigid skeletons?

Answer 9

• Exoskeleton e.g., cuticle, shell
• Endoskeleton – formed inside body

Question 10

Notochord

Answer 10

a longitudinal flexible rod of cells that in the lowest chordates (such as a lancelet or a lamprey) and in the embryos of the higher vertebrates forms the supporting axis of the body

Question 11

bone forms in what two ways? and how are they different?

Answer 11

– Endochondral bone
* Cartilage model is invaded by osteocytes
* Bone tissue replaces cartilage (ossifies)
– Intramembranous (dermal) bone
* Forms in dermis
* No cartilage precursor; osteocytes gather and form bone

Question 12

Spongy vs. Compact Bone

Answer 12

• Spongy = framework of bony tissue in center of bone
• Compact = dense, solid outer bone; typically long bones

Question 13

• Concentric rings form an ________; blood vessels in center

Answer 13

Osteon

Question 14

What is a bone cell called?

Answer 14

osteocyte

Question 15

What builds bone and what breaks it down/ resorbs bone?

Answer 15

Osteoblast = build bone; Osteoclast = resorb bone

Question 16

Axial Skeleton

Answer 16

Skull, vertebral column, sternum & ribs

Question 17

Appendicular Skeleton

Answer 17

Limbs (fins or wings)

Question 18

Sliding Filament Hypothesis

Answer 18

1. Dynein arms bind to tubulin subunit
2. Bend to move tubulin subunit up
3. Release and bind to subunit below
4. Repeat rapidly; then reverse
5. Result = bending of cilia or flagellum

Question 19

What are the three types of movement?

Answer 19

Ameboid
Ciliary (tiny cilia) and Flagellar (long flagellum)
3. Muscular Movement

Question 20

Ameboid movement

Answer 20

resembling an amoeba especially in moving or changing shape by means of the flow of cytoplasm
-(pseudopodia)
Outer layer of gel-like ectoplasm surrounds inner, more fluid, endoplasm
Hydrostatic pressure of endoplasm pushes against ectoplasm Involves interaction of actin and actin-binding proteins

Question 21

Ciliary (tiny cilia) and Flagellar (long flagellum) movement

Answer 21

Cilia and Flagella have the same structure
Comprised of Microtubules composed of tubulin
Microtubules are arranged as 9 doublets in a peripheral circle + 1 central doublet
(9 + 2 arrangement = 9 doublets + 2 microtubules)
Anchored in cytoplasm by a basal body (Kinetosome); triplets
Microtubule-Associate Protein, MAP (Dynein) forms arms that bridge doublets

Question 22

Flagellum

Answer 22

propel parallel long axis
(perpendicular to cell)

Question 23

Cilia

Answer 23

propel perpendicular to long axis
(parallel to cell)
Cilia beat
in waves

Question 24

Muscular Movement and what are the three types?

Answer 24

Three Types of Muscle
* Skeletal (striated)
– Multinucleate
– Attach to skeleton; movement
* Cardiac (striated)
– Uninucleate; branching cells
– Heart; involuntary control (myogenic)
* Smooth
– Uninucleate; lacks striations
– Typically around organs & glands
– Involuntary control (autonomic)
Invertebrates have smooth & striated
muscle; many variations

Question 25

Striated muscle structure:
_________(pl. fascicles) = bundle of muscle fibers (1 fiber = 1 cell)
Each muscle fiber (cell) comprised of many _______
Myofibrils are ______ and_______ filaments
______ = functional unit; defined by Z-lines

Answer 25

Fasciculus
myofibrils
Actin and Myosin
Sarcomere

Question 26

29.11 Describe how the sliding-filament hypothesis of muscle contraction works.

Answer 26

Step 1: Action potential; influx of Calcium
Active sites exposed
Step 2: Myosin binds; requires ATP to move head
Step 3: Myosin bends; pulls actin filaments closer
Step 4: Myosin releases
Step 5: Repeat until contraction is complete
Cross-bridge cycling; 50-100x/sec
Energy source is glucose (aerobic), glycogen
(aerobic & anaerobic), & creatine phosphate

Question 27

Motor unit

Answer 27

motor neuron + muscle fibers; each terminal
branch of a neuron innervates one fiber

Question 28

Muscle Fiber Types and Function

Answer 28

• Slow oxidative fibers (red muscles)
  – High blood supply; aerobic; Lots mitochondria and myoglobin
  – Slow, sustained contraction (e.g., posture)
• Fast fibers
  – Fast glycolytic fiber (white muscle; anaerobic); Burst of speed; requires rest
  – Fast oxidative fiber (aerobic); High blood supply, lots mitochondria &
  myoglobin
• Rapid, sustained activities (e.g., migration; marathon running)
• Invertebrate muscle
  – Have smooth, striated & oblique striated muscle (many variations)