chapter 30: how animals move

Chapter 30: How animals Move

NEW AIM: What types of motor systems have evolved?

I. Ciliates and FlagellatesA. Unicellular organisms w/o skeletal-muscular systemsB. Protozoans (unicellular heterotrophic protists) and primitive algae

flagellate ciliate



I. Ciliates and FlagellatesA. Unicellular organisms w/o skeletal-muscular systemsB. Protozoans (unicellular heterotrophic protists) and primitive algae

Fig. 4.18 (9 + 2 arrangement)



II. PseudopodiaA. Used by amoeba to moveB. Cell extensions (no microtubules)

pseudopod



IIB. Chemotaxis vs. Phototaxis

A. Chemotaxis – process by which a cell directs their movement depending on a chemical in the environment – taxis = to move (hence the word taxi).

Ex. 1. Movement of sperm towards the egg (egg secretes chemicals that sperm are attracted to);

2.Movement of macrophages to a site of bacterial infection (broken cells release a chemical attractant)

3. Movement of bacteria to a high concentration of glucose

These are all examples of positive chemotaxis (move towards the chemical)

There can also be negative chemotaxis (move away from the chemical).



IIB. Chemotaxis vs. Phototaxis

b. Phototaxis – process by which an entire organism directs their movement depending the stimulus of light (this is NOT a plant moving towards light, which is called phototropism.

Ex. 1. Algal cell moves toward light (positive phototaxis)

Mov

emen

tEx. 2. Moths or fruit flies attracted to light



III. Hydrostatic skeletonsA. Fluid held under pressure in a closed body compartmentB. Helps protect other body parts (cushion from shocks)C. Gives body shapeD. Gives support for muscle actionE. Cnidarians (hydra) and annelids (earthworms)

Fig. 18.7

Fig. 30.1

Earthworms crawl by peristalsisEach segment expands and contracts independently

(setae)

http://www.biology.ualberta.ca/facilities/multimedia/uploads/zoology/oligochaete.swf

http://www.biology.ualberta.ca/facilities/multimedia/uploads/zoology/oligochaete.swf



III. Hydrostatic skeletonsA. Fluid held under pressure in a closed body compartmentB. Helps protect other body parts (cushion from shocks)C. Gives body shapeD. Gives support for muscle actionE. Cnidarians (hydra) and annelids (earthworms)

Hydrostatic skeleton of hydra in 2 stages

Fig. 30.2



IV. ExoskeletonA. Hard external skeleton covering all the muscles and organs of some invertebratesB. Made of chitin in Arthropods

C. Calcium carbonate in mollusks

D. Protection

Fig. 30.2E. Limits growth (periodic molting and deposition of new exoskeleton necessary)F. Muscles attach to inside of exoskeleton

JOINTED APPENDAGES

Chitin is a polysaccharide of N-acetylglucosamine (glucose with an acetyl group)



V. EndoskeletonA. Hard or leathery support tissue situated AMONG the soft tissues of animals

B. Sponges (Porifera)

i. Reinforce by tough protein fibers or hard calium salts/silica called spicules

Calcium salts

A rigid sponges thanks to spicules

Spongin - fibrous protein



V. EndoskeletonA. Hard or leathery support tissue situated AMONG the soft tissues of animals

C. Echinoderms (sea stars, sea urchins, etc…)

i. Have hard plates beneath skin (the spikes are not an exoskeleton)

Dead sea urchin (endoskeleton)Sea Urchin



V. EndoskeletonD. Vertebrates

i. Site of muscle attachment

- permits movement when muscle contracts bringing bones closer together

ii. Protection and overall support

- bones enclose vital organs

- Ex. Rib cage surrounds thoracic organs (heart and lungs)

- Ex. Skull and vertebral column surround brain and spinal cord

iii. Contains both cartilage and bone

- Both connective tissue




iv. cartilage

- firm, but flexible

- makes up skeletons of lower vertebrates (rays and sharks)

- principle component of embryonic skeletons in higher vertebrates

- NO blood vessels (avascular) or nerves

- takes a longer time to heal than bone

Fig. 30.2EAmphibian endoskeleton (cartilage in blue)




iv. cartilage

- articular surface of the bones (sites where 2 bones contact each other), the rib cage, the ear, the nose, the bronchial tubes/trachea and the intervertebral discs.

- Location

Cartilage in yellow




v. bone

- composed of calcium phosphate salts and strands of collagen protein- skeleton of mature higher vertebrates

- cells in bone

1. Osteoblasts - build bone (bbb)2. Osteoclasts - break down bone

You should know which hormones interact with each cell type…

- Osteoporosis - imbalance between osteoblasts and osteoclasts leading to weak bones




v. bone- spongy vs. compact bone- yellow marrow vs. red marrow

Fig. 30.5 Fig. 30.3




v. bone- highly vascular unlike cartilage

Fig. 30.5

Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surround a central canal, the Haversian canal through which blood vessels and nerves run.

Lacuna = the region where osteocytes reside.




v. bone- connected at joints- can be movable (your elbow) or immovable (bones of the skull)

Fig. 30.3




v. bone- axial (blue - skull, ribs, vertebrae) vs. appendicular (yellow - appendages) skeleton

Fig. 30.3



VI. Muscle contraction and movementA. The skeleton and muscles interact in movementB. Muscle system is an EFFECTOR of the nervous system

Fig. 30.7

D. Insertion of a muscle

i. Portion attached to bone that moves Insertion of bicep

Insertion of tricep

C. MUSCLES CAN ONLY CONTRACT (SHORTEN)

E. The ORIGIN is the attachment to the non-moving bone

Origin of bicep

Origin of tricep



VI. Muscle contraction and movementE. Extensor

Fig. 30.7Extensor

i. Muscle that extends or straightens the bones at a jointEx. Tricep is an extensor - it contracts and straightens arm at elbow

F. Flexori. Muscle that bends a joint to an acute angle

Ex. Bicep is a flexor - it contracts and bends arm at elbow

Flexor

Bicep and Tricep are antagonistic muscles

ALL animals have pairs of antagonistic muscles



VI. Muscle contraction and movementG. Tendons (dense connective tissue)

i. Connect muscles to bonesEx. Achilles tendon

Fig. 30.7



VI. Muscle contraction and movementH. Ligaments

i. Connect bones to bones



VI. Muscle contraction and movementI. Three types of muscles

i. smoothii. cardiac

iii. skeletal

- movement caused by CONTRACTION in ALL 3 types

- Contraction caused by sliding of actin and myosin filaments past each other inside cells…




i. Smooth muscle

a. involuntary muscles (autonomic NS) in arteries and veins, gastrointestinal tract, bladder, uterus

b. nonstriated- simply means that actin and myosin do not have clear organized arrays

c. smooth muscle cells connected by gap junctions in tissues (allow action potential to pass from one cell to next) - electrical synapsed. Single nucleus per cell




ii. Cardiac muscle

a. Single nucleus per cellb. striated

- actin and myosin have clear organized arrays

c. connected by gap junctions in tissues (allow action potential to pass from one cell to next) - electrical synapsed. Involuntary (autonomic NS)




iii. Skeletal muscle

a. Voluntary (intentional physical movement; somatic NS)

c. striated- actin and myosin have clear organized arrays

d. Stimulated by nerves at neuromuscular synapses

b. Muscle cell = single, large, multinucleated fiber

e. Action potential in cell stimulates calcium release into cytoplasm, which in turn causes contraction


AIM: How do muscle fibers contract?

VIII. Neuromuscular junction

Fig. 30.10



IX. How does a motor neuron make a muscle fiber contract?Fig. 30.10

1. Action potential (AP) reaches synaptic knob 2. Acetylcholine released into synaptic cleft3. Sodium moves through muscle fiber (just like a neuron)

4. AP travels along T-tubules (membranous tubules that fold in through cells) deep into the fiber

Neuromuscular junction video on website



IX. How does a motor neuron make a muscle fiber contract?

Fig. 30.10

1. Action potential (AP) reaches synaptic knob 2. Acetylcholine released into synaptic cleft3. Sodium moves through muscle fiber (just like a neuron)

4. AP travels along T-tubules (membranous tubules that fold in through cells) deep into the fiber

5. AP causes Ca++ to be released from sarcoplasmic reticulum (SR = ER) of fiber into cytoplasm

Muscle action potential video on website


NEW AIM: How do muscle fibers contract?

VII. Muscle contractionA. Skeletal muscle

i. Muscle composed of bundles of fibers (cells)

- striation = alternating light and dark band of myofibrils

iii. Sarcomere - repeating unit of the myofibril (region b/w two Z lines) – you see sarco- you think muscle

ii. Muscle fibers (cells) contain numerous myofibril (contractile protein structures)

- thin filament: two strands of actin polymers and one strand of regulatory protein- thick filament: staggered array of multiple myosins

- dark band vs. light band

Fig. 30.8


NEW AIM: How do muscle fibers contract?

VII. Muscle contractionB. Sliding-filament model

Fig. 30.9

Sarcomere contraction video on website




Fig. 30.9

1. ATP binds to myosin head (causes detachment from actin)

2. ATP hydrolyzes to ADP and Pi- energy used ratchet back the head

- head is now in an unstable (high energy) state

3. Head binds to actin

4. ADP and Pi are released resulting in the power stroke

5. ATP binds, head releases, repeat again, but grab the next actin closer to Z-line

Sliding filament video on website




Fig. 30.8

1. ATP binds to myosin head (causes detachment from actin)

2. ATP hydrolyzes to ADP and Pi- energy used ratchet back the head

- head is now in an unstable (high energy) state

3. Head binds to actin

4. ADP and Pi are released resulting in the power stroke

5. ATP binds, head releases, repeat again, but grab the next actin closer to Z-line

Aside: Rigor Mortis– when an animal dies, it becomes stiff (hence why we call dead people stiffs). This is because ATP is needed to release the myosin head from the actin filaments. No ATP, no release, muscle can’t relax.




Fig. 30.10

6. Myosin binding sites on actin usually blocked by regulatory strand (troponin and tropomyosin)

7. Ca++ binds to part of regulatory strand (troponin) of thin filament, which causes tropomyosin to move off myosin binding site so myosin can bind.

Muscle action potential video on website




Fig. 30.10

http://www.tvermilye.com/pmwiki/pmwiki.php?n=Animation.Video12

http://www.tvermilye.com/pmwiki/pmwiki.php?n=Animation.Video12



X. Vocabulary for a skeletal muscle cellA. Sarcolemma: plasma membrane

B. Sarcoplasmic reticulum (SR): endoplasmic reticulum

C. Sarcomere: single unit of the myofibril

D. Sarcoplasm: cytoplasm



XI. MalfunctionsA. Arthritis

- inflammation of joints causing swelling and severe pain

- inflammation of tendon usually at site of attachment to bone caused by physical stress and irritation (common in athletes)

B. Tendonitis

- causes: autoimmune, infection (septic), gouty arthritis, etc…

EXTRAS

I. Heart Attack:A. Coronary Thrombosis

B. Angina pectoris- narrowing of coronary arteries resulting in an inadequate supply of blood (oxygen) to heart muscle and intense pain in chest/shoulder/arm (referred pain).- typically caused by arthrosclerosis

EXTRAS

II. oxyhemoglobinA. Hemoglobin with oxygen bound

A. Inflammation of bronchi, caused by bacteria, virus or other irritant (i.g. tobacco smoke)

III. Bronchitis

EXTRAS

IV. Asthma- chronic disease where airways constrict, become inflamed, and are lined with excessive mucus.- triggered by exposure to an allergen, tobacco smoke, cold or warm air, perfume, pet dander, moist air, exercise or exertion, emotional stress.

- genetic / environmental- allergic response

EXTRAS

IV. AsthmaAlbuterol (Salbutamol)

- typical used in inhalers- stimulates -2 adrenergic (adrenalin) receptors, which relaxes airway smooth muscle

EXTRAS

V. CO2 carried mostly in blood as bicarbonate (carbonic acid), which acts as a buffer in the blood (pH 7.4)

VI. Habits

- acquired by repetition, which established pathways for nerved impulse transmission, which permit rapid automatic responses to various stimuli.- performed without thinking- DO NOT confuse with habituation

EXTRAS

VII. Filament

EXTRAS

VIII. Photolysis

EXTRAS

VIII. Enzyme/Substrate relationship

EXTRAS

IX. Enzyme/Temperature and Enzyme/pH Relationship

chapter 30: how animals move

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