Exam 4 Flashcards
Ch 41- Animal Nutrition
Essential Nutrients
What do they do?
What do they Include?
Do they need specific nutrients among species?
- Preassemble organic molecules
( nutshell: we don’t synthesize them) - Amino Acids, Fatty acids, Vitamins, Minerals
- Yes, specific nutrients vary among species
Animal Nutrition
Essential Nutrients [AA]
How many Amino Acids do we require?
What do most enzymes do?
What are remaining energy called & where is required?
Require 20 AA
- Most enzymes synthesize half of AA
Remaining energy is called essential AA
- Must be obtained from food in prefabricated forms
Animal Nutrition
Essential Nutrients [AA]
What food provide “Complete” ( provide all AA) ?
- Meat
- Eggs
- Cheese
[ animal products ]
Animal Nutrition
Essential Nutrients [AA]
What food provide “Incomplete”?
Plant products
If taken, you have to consume wider variety
Animal Nutrition
Essential Nutrients [ Fatty Acids ]
What do fatty acids do?
Difference from animals?
Fatty acids => synthesize cellular components
Animals can synthesize but lack enzymes to form double bonds found in certain required fatty acids
Animal Nutrition
Essential Nutrients [Fatty Acids]
What is the name of the essential fatty acid for mammals and where can it be obtained?
Linoleic Acid
Can be obtained from:
- Seeds
- Grains
- Vegetables
Animal Nutrition
Essential Nutrients [Vitamins]
Do organic molecules require the diet to be in very small amounts?
Yes
Animal Nutrition
Essential Nutrients [Vitamins]
Name Diverse Functions & Where Found:
- B2 (Riboflavin)
- B7 (Biotin)
-B9 (Folic Acid) - A (Retinol)
- D
- B2 (Riboflavin)
=> components of coenzyme FAD (e- carrier in cellular respiration pathway)
=> Diary/ Meat - B7 (Biotin)
=> Coenzyme in synthesis of fat, glycogen, & AA
=> Legumes - B9 (Folic Acid)
=> Coenzyme in Nucleic Acid & AA Metabolism ( break down to small components) [ build new things ]
=> Veg, oranges, nuts - A (Retinol)
=> component of visual pigments; maintenance of epithelial cells
=> Dark, leafy greens - D
=> Absorption of calcium and phosphorus
=> Egg Yolks
Animal Nutrition
Essential Nutrients [Minerals]
Are they inorganic or organic?
Are they required in small amounts?
Minerals are inorganic that they are required in small amounts
Ex. Iron & Sulfur
Animal Nutrition
Essential Nutrients [Minerals]
Diverse Functions in Animal Physiology
- Calcium (Ca)
- Potassium (K)
- Magnesium (Mg)
- Iron (Fe)
- Iodine (I)
- Calcium (Ca)
=> Bone and tooth formation
=> Blood clotting
=> Nerve and Muscle Function - Potassium (K)
=> Acid Base Balance
=> Water Balance
=> Nerve Function - Magnesium (Mg)
=> ATP bioenergetics - Iron (Fe)
=> Component of hemoglobin and of electron carriers - Iodine (I)
=> component of thyroid hormones
Animal Nutrition
Essential Nutrients [ Diseases ]
Iodine Deficiencies can lead to ________?
Excess salt can lead to _________?
- Lead to Goiter ( swelling of thyroid gland)
- Can lead to high blood pressures
Animal Nutrition
Regulation of Digestion
Are Digestive Systems continually active?
- Digestive systems are not continually active
Animal Nutrition
Regulation of Digestion
What are def: ?
Enteric Division?
Endocrine System?
Enteric Division:
=> Nervous system that regulates churning, release of gastric juices, and peristalsis
Endocrine System:
=> Hormones released by stomach and duodenum ensure digestive secretions are present only when needed
Animal Nutrition
Food Processing
What are the 4 steps of Food Processing?
- Ingestion
- Digestion
- Absorption
- Elimination
Animal Nutrition
Food Processing
Def of Ingestion
Act of eating or feeding
Animal Nutrition
Food Processing
Def of Digestion
2 Types of Digestion & Functions
Food is broken down into molecules small enough for body to absorb
- Mechanical Digestion: Mouth (physically chew )
- Chemical Digestion: Hydrolysis (enzymes coming in & break cmplx molec dwon to small molec
Animal Nutrition
Food Processing
Def of Absorption
Cells take up small molecules
Animal Nutrition
Food Processing
Def of Elimination
Undigested materials pass out of the digestive system
Animal Nutrition
Organs of Mammal Digestive System
What are accessory glands, what do they do, and which are they?
- Secrete digestive juices thru ducts into canal
- They consist
=> 3 pairs of salivary glands
=> Pancreas
=>Liver
=>Gallbladder
Animal Nutrition
Organs of Mammal Digestive System
What contraction of ring- like muscles help push food thru alimentary canal?
Peristalsis ( Esophagus)
Animal Nutrition
Organs of Mammal Digestive System
What regulate passage of materials b/w compartments & is muscular layer forms ringlike valves
Sphincters
Animal Nutrition
Organs of Mammal Digestive System
1st Step in digestion?
- Oral Cavity (Ingestion)
Animal Nutrition
Organs of Mammal Digestive System
What does 1st step in digestion do?
Do any other glands help?
- Mechanical digestion by teeth
- Salivary Glands (Access gland) deliver saliva automatically
Animal Nutrition
Organs of Mammal Digestive System
Enzymes (-ase) secreted in oral cavity
- Amylase = hydrolyzes starch & glycogen into smaller polysaccharides & maltose
- Mucus = protects oral cavity, mixture of water, salts, cells and slippery glycoproteins (mucins)
= Lubricates food, easier swallowing - Buffers = prevent tooth decay by neutralizing acid
- Antimicrobial agents = protect against bacteria
Animal Nutrition
Organs of Mammal Digestive System
Function of Oral Cavity, Pharynx, & Esophagus
Tongue using _____ to manipulate mixture of food and saliva into a ball.
2 passageways in pharynx?
What does Epiglottis do?
- Bolus
- Trachea & Esophagus
- Epiglottis prevents food from entering the trachea
Animal Nutrition
Organs of Mammal Digestive System
Stomach
What does it do?
What does it secrete and forms what?
Involuntary or voluntary muscle?
- Stores food and begins digestion of proteins
- Elastic wall w/ multiple folds
- Secretes digestive fluid called gastric juice
=> mixes food via churning action forming chyme - involuntary (smooth muscle)
Animal Nutrition
Organs of Mammal Digestive System
Stomach
What does Gastric Juices contain?
- HCL (Hydrochloric Acid): disrupts extracellular matrix that bind cells together in meat and plant material
- Pepsin: (protease) breaks proteins into smaller polypeptides
Animal Nutrition
Organs of Mammal Digestive System
Why don’t HCL and pepsin eat thru lining of stomach?
- Mucus prevents self- digestion
- new layer of epithelial cells added every 3 days
- Damaged areas result in Gastric Ulcers
- Acid Reflux is backflow of chyme (throwing up)
Animal Nutrition
Organs of Mammal Digestive System
Accessory Organs
What do they do? What do they contain?
- Pancreas
- Liver
- Pancreas
= Produces alkaline soln rich in bicarbonate and several enzymes (trypsin & chymotrypsin)
= Bicarbonate neutralizes acidity of chyme and acts a buffer - Liver
= Bile aids in emulsification (large droplets to small lead to absorption & process to body) of fats and other lipids
=STORES AND CONCENTRATED in gallbladder
Animal Nutrition
Organs of Mammal Digestive System
Small Intestine
What occurs most in Small Intestine?
What does it do?
Most enzymatic hydrolysis of macromolecules
- chyme enters duodenum, mixes w/ digestive juices
- Site of MOST Digestion
Animal Nutrition
Organs of Mammal Digestive System
Small Intestine Absorption
Where does it occur?
What helps contribute absorption?
Occurs in Jejunum (2nd smi) and Ileum (3rd smi)
- Villi (fingerlike projecting lining intestine)
- Microvilli (cover surface ) (increase surface area)
Animal Nutrition
Organs of Mammal Digestive System
Distribution of Nutrients
What do they do & functions
Capillaries and veins carry nutrient-rich blood away from villi and join with hepatic portal vein (leading to liver)
- blood travels to heart and other organs & tissues)
Function:
- Liver regulates distribution of nutrients to rest of body
- Allows liver to remove toxic substances
- Store energy rich molecules
- Storage spot for mineral
Animal Nutrition
Organs of Mammal Digestive System
Large Intestine
What do they do & Function?
Colon lead to rectum & anus (reabsorption of water )
- Cecum
= important for fermenting ingested material (esp animals that eat primarily plant tissue)
Animal Nutrition
Organs of Mammal Digestive System
Def of Diarrhea & Constipation
Diarrhea :
lining becomes irritated and LESS WATER than normal is reabsorbed (cannot absorb water)
Constipation :
Feces move along colon too SLOWLY and comes compacted (TOO MUCH WATER ABSORB)
Animal Nutrition
Digestive compartments
Intracellular Digestion
Occurs in lysosomes
Unicellular organism (sponges, amoeba)
Animal Nutrition
Digestive compartments
Extracellular Digestion
Breakdown of food that are continuous w/ outside of animal’s body
mouth to anus
Animal Nutrition
Digestive compartments
Simple body plans (def)
Gastrovascular Cavity
Simple BP: digestive compartment w/ single opening
Gastro cavity: functions in digestion and distribution of nutrients thruout body (hydras & flatworms)
Animal Nutrition
Digestive compartments
complete digestive tract ( 2 opening)
Another name called?
Function?
Alimentary Canal
- Food moves in single direction in stepwise fashion
- organized into specialized compartments w/ specific function
- Allows animals to ingest food while earlier meals still being digested
Ch 42: Circulation and Gas Exchange
Open vs Closed Circulatory Systems
Open Circulatory System
= Circulating Fluid: hemolymph & interstitial fluid that bathes body cells
Closed Circulatory System
= Blood confined to vessels and distinct from interstitial fluid
Ch 42: Circulation and Gas Exchange
Structure & Function of 3 vessel Types:
- Arteries
- Veins
- Capillaries
Arteries (thick walls) (high hydrostatic pressure)
> Carry blood AWAY from heart
> w/in organs - branch into arterioles - later branch to capillaries
Veins (Drain tissue)
> Carry blood back TO the heart
> Connect to Venules that collect fluid from capillaries
Capillaries (Thin/Leaky)
> Microscopic vessels w/ very thin, porous walls
> networks are called capillary beds
> ONLY VESSEL WHERE EXCHANGE OCCURS
Ch 42: Circulation and Gas Exchange
Circulation of blood through heart:
Compare single vs double circulation
Single Circulation : Bony fishes, rays, sharks
> two chambered hearts (atrium and ventricle)
> Act of swimming = aid in circulation
Double Circulation : amphibians, reptiles, mammals
> Two circuits
- Pulmonary circuit (right side)
- Systemic circuit (left side)
Ch 42: Circulation and Gas Exchange
Circulation of blood through heart:
Compare Circulation in Mammals, fish, & Amphibian
Amphibian: 3 chambers : Pulmocutaneous Circuit
Mammal : 4 chambers : Pulmonary Circuit
Fish: single Circulation : Gill capillaries :
Ch 42: Circulation and Gas Exchange
Components of Blood
Plasma: Main function
water- 90%
Function: solvent
ion
Function: pH buffering
Plasma Proteins; immunoglobulin (antibodies)
Function: Defense
Apoliproteins: Lipid Transport
Ch 42: Circulation and Gas Exchange
components of Blood
Erythrocytes (red blood cells)
Function?
Lack?
Contain?
- Function: transport O2
- lack nuclei and mitocondria (generate ATP by anaerobic metabolism)
- Contain hemoglobin (iron containing protein that binds O2)
Have 4 subunits
2 alpha subunits & 2 Beta subunits
Ch 42: Circulation and Gas Exchange
components of Blood
Leukocytes (fight infection)
Function?
Function: Defense and Immunity; Fight injection
some phagocytic
Ch 42: Circulation and Gas Exchange
components of blood
Platelets (bone marrow/ blood clotting)
Contain?
Function?
What do they need?
Contain no nuclei
They are pinched of cytoplasmic fragments of specialized bone marrow
Function: blood clotting
Need: plasma, Enzymatic cascade, prothrombin, thrombin, fibrinogen, fibrin
Pos= high thrombin
Ch 42: Circulation and Gas Exchange
Structure and Function of Heart
Chambers - atria and ventricles
Atria: Thin walled and serve as collection chambers
Ventricles: Thick walled and contract more forcefully
Ch 42: Circulation and Gas Exchange
Structure and Function of Heart
Valves (4)
Function: prevent backflow
Made of connective tissue
Atrioventricular (AV) Valve- b/w R atrium & R ventricle
Semilunar Valve: 2 exits of heart (pulmonic & aortic)
Pulmonary artery: leaves R ventricle
Aortic: Leaves L Ventricle
Ch 42: Circulation and Gas Exchange
Structure and Function of Heart
Nerves that regulate heart rate
Sympathetic Division: acts accelerator
Parasympathetic Division: acts as brakes
Sinoatrial (SA) node: sets rate & timing which all cardiac muscles cells contract
Atrioventricular (AV) node: signals travel to relay point (b/w atria)
Bundle Branches: pass signals to heart apex
Signals spread thruout ventricles (Purkinje fibers)
Ch 42: Circulation and Gas Exchange
Characteristics of respiratory surfaces
a. Understand structure & function of respiratory surfaces discussed in diff animal groups
b. Where does gas exchange occur in each system
CUTANEOUS RESPIRATION
Earthworms and some amphibians
Respiration across skin
- Dense network of capillaries below skin facilitate the exchange of gases
Evolutionary soln?
Modifications that increase surface area
Ch 42: Circulation and Gas Exchange
Characteristics of respiratory surfaces
a. Understand structure & function of respiratory surfaces discussed in diff animal groups
b. Where does gas exchange occur in each system
GILLS IN AQUATIC ANIMALS
- Total surface area much greater than rest of body’s surface
- VENTILATION: movement of water over gills
- Mechanisms of VENTILATION
= Walking (ventilation; attach to gills)
= Swimming ( water to actively flow over gills)
Bony fishes = operculum (protect/ ventilate)
Ch 42: Circulation and Gas Exchange
Characteristics of respiratory surfaces
a. Understand structure & function of respiratory surfaces discussed in diff animal groups
b. Where does gas exchange occur in each system
COUNTERCURRENT EXCHANGE
- Exchange b/w two fluid flowing in opp directions
- blood flows in opp direction to water passing over gills
Ch 42: Circulation and Gas Exchange
Characteristics of respiratory surfaces
a. Understand structure & function of respiratory surfaces discussed in diff animal groups
b. Where does gas exchange occur in each system
TRACHEAL SYSTEM IN INSECTS
INSECTS - open circulatory system
TRACHEAL SYSTEM: terrestrial animals
- Functions w/o circulatory system
- TRACHEAE= network of air tubes that branch throughout the body
Ch 42: Circulation and Gas Exchange
Characteristics of respiratory surfaces
a. Understand structure & function of respiratory surfaces discussed in diff animal groups
b. Where does gas exchange occur in each system
LUNGS
SPIDERS & LAND SNAILS, VERTEBRATES
Infolding, subdivided into numerous pockets
not in direct contact w/ parts of body, must be bridged by circulatory system
Ch 42: Circulation and Gas Exchange
Pathway that air moves during inhalation & exhalation in mammals
HOW IS THIS ACCOMPLISHED?
neg pressure breathing: air pulled into lungs
Diaphragm: sheet of skeletal muscle
Air entering nostrils
- filter by hairs, warmed, humidified, sampled for odors
Air flow: pharynx, larynx, trachea
Gas exchange in alveoli
Ch 42: Circulation and Gas Exchange
Pathway that air moves during inhalation & exhalation in mammals
What controls respiratory rate in humans?
Involuntary Mechanisms:
= Ensure gas exchange is coordinated w/ blood circulation & metabolic demand
Breathing control center is located in MEDULLA OBLONGATA
= Neg feedback mechanism prevent lungs from overexpanding
Ch 44: Osmoregulation & Excretion
Osmoregulation
a. Unit of measurement of solute concentration
Osmoregulation: process by which animals control solute conc and balance water gain and loss
Diffusion of water from area of HIGH FREE WATER CONC to AREA OF LOWER FREE CONC: OSMOSIS
Unit of measurement of solute conc: OSMOLARITY (# of moles per solute per L of soln)
Ch 44: Osmoregulation & Excretion
Osmoregulation
a. Unit of measurement of solute concentration
i. Meaning of hyperosmotic, hypoosmotic, isosmotic
Hypoosmotic: LOW solute conc, HIGH free water conc
= discharge water
Hyperosmotic: HIGH SOLUTE CONC, LOW free water conc
= take water from envir
Isosmotic: equal, no net movement of water
Ch 44: Osmoregulation & Excretion
Osmoconformers vs Osmoregulators
Osmoconformer: animals isosmotic w/ its surroundings
> live in water w/ stable composition
> all marine animals
> no tendency to gain or lose water
Osmoregulators: animals controls internal osmolarity independent of that external environ (eg. salmon)
> freshwater and terrestrial habitats; some can move b/w fr water and marine environ
> must discharge or take on water accordingly
Ch 44: Osmoregulation & Excretion
Osmoregulators
in fishes (marine and freshwater)
Osmoregulation in Marine fish:
> EXCRETION of salt ions from gills
> EXCRETION of salt ions and small amount of water in scanty URINE from kidneys
Osmoregulation in Freshwater fish:
> UPTAKE salt ions by gills
> EXCRETION of salt ions and large amounts of water in dilute urine from kidneys
Ch 44: Osmoregulation & Excretion
Adaptation that reduce water loss in terrestrial animals
Structural & Behavioral
Structural adaptions:
> Waxy cuticle, shells of land snails, exoskeleton, keratinized skin cells
Behavioral adaptions:
> nocturnal behavior in deserts
Ch 44: Osmoregulation & Excretion
Excretion
Excretion
process that rids body of nitrogenous metabolites and other metabolic wastes
(Breakdown of proteins and metabolic acids)
Ch 44: Osmoregulation & Excretion
Excretion
Types of nitrogenous waste produced by animals
Pros and cons of each
- Ammonia (NH3)
> Most aquatic animals, most bony fishes
> Pros: takes very little energy
> Cons: Very toxic - Urea
> Mammals, most amphibians, sharks, some bony fishes
> Pros: Low toxicity
> Cons: Requires more energy (high energy cost) - Uric Acid
> Many reptiles (include birds), insects, land snails
> Pros: Nontoxic
> Cons: Not dissolve readily in water, semisolid paste (conserve most water)
> Most energically expensive but conserves most water
Ch 44: Osmoregulation & Excretion
Excretion
Process of excretion ( 4 steps )
- Filtration
- Reabsorption
- Secretion
- Excretion
Ch 44: Osmoregulation & Excretion
Excretion
Organs involved
Excretory and osmoregulatory function/ organs
Kidney, Ureter, Urinary Bladder, Urethra (male: Large) (female: small), renal cortex, renal medulla
Ch 44: Osmoregulation & Excretion
Excretion
Structure and Function of nephrons
Nephrons: functional units of kidneys
Cortical nephrons: reach a short distance into the medulla
Juxtamedullary nephrons: extend deep into medulla
*Key component to water conservation
* Essential for production of urine that is HYPEROSMOTIC (high solute conc) to body fluids
Ch 44: Osmoregulation & Excretion
Excretion
Structure and Function of Nephrons
1st step filtration
- Glomerulus: single long tubule and ball of capillaries
- Bowman’s Capsule: surrounds glomerulus
> FILTRATE forms when blood pressure forces fluid from blood in glomerulus into lumen of bowman’s capsule
> Permeable to water and small solutes, NOT blood cells or large plasma proteins
Ch 44: Osmoregulation & Excretion
Excretion
Structure and Function of Nephrons
2nd step reabsorption
Three regions:
- Proximal Tubule: near point of attachment (closest to glomerulus & bowman’s capsule)
- Loop of Henle
- Distal Tubule: far from point of attachment (connects to collecting duct)
- Collecting Duct: receives and processed filtrate and delivers it to renal pelvis
Ch 44: Osmoregulation & Excretion
Excretion
Structure and Function of Nephrons
3rd step
Proximal Tubules:
> reabsorption of water, ions, and nutrients
> reabsorbs 90% of bicarbonate
Descending limb of loop of Henle
> reabsorption of water continues
> AQUAPORIN: proteins make transport epithelium freely permeable to water
Ch 44: Osmoregulation & Excretion
Excretion
Structure and Function of Nephrons
4th step
Ascending limb of loop of Henle
> no water channels, NaCl moves into interstitial fluid
> filtrate becomes more dilute
Distal Tubule
> Regulates K+ and NaCl conc of body fluids
> controlled secretion of H+ and reabsorption of bicarbonate
Ch 44: Osmoregulation & Excretion
Excretion
Structure and Function of Nephrons
5th step
Collecting Duct
> Final processing forms urine as filtrate travels to renal pelvis
Ch 46. Reproduction
Sexual vs Asexual Reproduction
Sexual Reproduction:
- fusion of haploid gametes to form a diploid cell (zygote)
- Use Egg and Sperm
Pros: increase variation w/in population
Cons: find mate for survival & contribute offspring
Asexual reproduction
- New offspring generate w/o fusion of egg and sperm
- relies entirely on mitotic cell division
- uncommon in animals
Ch 46. Reproduction
Sexual vs Asexual Reproduction
Structure and Function of male reproductive organs
Testes - male gonads
> produce sperm in highly coiled SEMINFEROUS TUBULES
> scrotum: temp maintained
Ducts:
- seminiferous tubules to epididymis
- during Ejaculation, sperm go through muscular VAS DEFERENS
> Extends around bladder and joins Ejaculatory duct
> Open to urethra
Penis: contains urethra and three cylinders of spongy erectile tissue
Accessory Glands
- Seminal vesicles: produce fluid that is thick and alkaline
> contains mucus fructose, coagulating enzyme, prostaglandins
- Prostate Gland: secretes a thin and milky fluid directly to urethra
> contains anticoagulant enzymes and citrate - Bulbourethral Glands: pair of small gland along urethra below the prostate
> secrete mucus to neutralize any acidic urine remaining in the urethra
Ch 46. Reproduction
Sexual vs Asexual Reproduction
Structure and Function of female reproductive organs
Ovaries: flank the uterus and held by ligaments
> outer layer packed with FOLLICLES
– each contains an oocyte surrounded by support cells
Oviduct: extends uterus toward funnel-like opening at each ovary
> OVULATION: cilia on epithelial lining of oviduct help collect egg by drawing fluid from body cavity into oviduct
Uterus: Muscular organ that expand during pregnancy
- ENDOMETRIUM: inner lining
- CERVIX : opening to vagina
Vagina: muscular but elastic
-opens to outside of vulva (external female genitalia)
- LABIA MAJORA: enclose that protect the vulva
- LABIA MINORA: border vaginal opening and opening of urethra
Clitoris: erectile tissue that supporting a rounded glans covered by small hood of skin
Ch 46. Reproduction
Sexual vs Asexual Reproduction
Male: Spermatogenesis
Ch 46. Reproduction
Sexual vs Asexual Reproduction
Female: Oogenesis
Motor Mechanics
Know def of bold terms
THICK and THIN FILAMENTS
ACTIN
MYOSIN
CHEMICAL ENERGY
CREATINE PHOSPHATE
GLYCOGEN
TETANUS
OXIDATIVE FIBERS
GLYCOYTIC FIBERS
FAST FIBERS
SLOW FIBERS
Thick and Thin Filaments (striations): muscle cell contraction relies on interaction b/w protein structures
Actin: major component in globular protein in thin filaments (2 strands coil around each other)
Myosin: Staggered arrays in thick filaments (aid in muscle contraction)
Chemical energy: Require ATP, product of filament movement, muscle extension only passively
Creatine phosphate: Transfers phosphate group to ADP to synthesize ATP; resting supply can sustain contraction for ~ 15 sec
Glycogen: Restores ATP when broken down to glucose, metabolized by aerobic respiration during light or moderate muscle activity
> HIGHLY EFFICIENT process that yield enough power to sustain contraction for nearly an hour
Tetanus: rate so high that muscle fiber cannot relax, twitches fuse into one smooth, sustained contraction
Oxidative Fibers: rely mostly on aerobic respiration, specialized to make steady energy supply (many mitochondria), large amount of oxygen- storing myoglobin
Glycolytic Fibers: large diameter and less myoglobin, glycolysis primary source of ATP, fatigue more readily
Fast Fibers: brief, rapid, powerful contractions
> can be oxidative or glycolytic, eyes and hands are exclusively fast twitch
Slow Fibers: less sarcoplasmic reticulum and pumps Ca 2+ slowly, muscle twitch last around 5x
> running, walking, swimming, riding bicycles
Motor Mechanics
Muscle Anatomy
components of Muscle fibers
Thin: ACTIN: two strands of actin coil around each other
> Major component of globular protein
Thick: MYOSIN: staggered arrays of molecules
Motor Mechanics
Muscle Anatomy
Contractile unit of Muscles
Sarcomere: muscle that shorten the extraction
Contracting muscle SHORTENS but filaments STAY SAME LENGTH
Require ATP and phosphate group for myosin energy to move the actin
Motor Mechanics
Muscle anatomy
Levels of organization
Microscopic level (sarcomere and myofibrils), Cell level (myoblasts & myofibers), Tissue levels (neuromuscular junctions) , Organ level (major skeletal muscles)
Motor Mechanics
Control of Muscle Contraction
Know step by step
- Motor neurons trigger the release of Ca 2+ into cytosol of muscle cells (regulation of Ca 2+ is a multistep process)
- Release of neuron transmitter (ACh) Acetylocholine
- An action potential @ synaptic terminal of a motor neuron release acetylcholine (ACh)
> Binds to receptors on muscle fiber leading to depolarization
Motor Mechanics
Control of Muscle Contraction
How is it regulated?
Tropomyosin= regulatory protein
Troponin complex= actin strands of thin filaments
At rest tropomyosin covers the myosin-binding sites
When Ca 2+ accumulates in cytosol, it binds in troponin complex
> shifts position exposing the myosin-binding sites
Increase Ca 2+ => Contraction
Decrease Ca 2+ => Extension/ Relaxation
Motor Mechanics
Types of Skeletal Muscle fibers
Dark meat = oxidative fibers
Light meat = glycolytic fibers
Oxidative Fibers:
- rely on AEROBIC respiration
- specialized to make steady energy supply
- rich blood supply
- large amount to oxygen-storing MYOGLOBIN
Glycolytic Fibers:
- LARGE diameter & LESS myoglobin
- glycolysis primary source of ATP
- fatigue more readily
Fast Twitch Fibers; 2-3xfaster than slow twitch
- brief, rapid, powerful contractions
- can be oxidative or glycolytic
- eyes and hands
Slow Fibers: less sarcoplasmic reticulum and pumps Ca 2+ slowly
- Ca 2+ remain longer in cytosol, muscle twitch last about 5x
- running, walking, dancing, swimming, riding bicycle
Immune System
Know Def of bold terms
PATHOGEN
IMMUNE SYSTEM
Pathogen: any disease- causing agent
Immune system: first lines of defense help prevent pathogens from gaining entrance to body
Immune System
Active vs Passive Immunity
Active Immunity: develop introduction of antigens into body through IMMUNIZATION (making your own)
Passive Immunity: IgG antibodies in blood of pregnant female cross placenta to her fetus
> antibodies in the recipient are produced by another individual (transferred) ( does not involve recipients B or T cells)
Immune System
Innate vs Adaptive immunity (in detail)
Innate immunity: General (all animals)
- traits shared by broad ranges of pathogens, using SMALL set of receptors
- rapid response
Adaptive Immunity: (vertebrates only)
- Traits SPECIFIC to particular pathogens, using VAST ARRAY of receptors
- slower response
Immune System
Innate vs. Adaptive Immunity
Cell types involved and their functions
Innate Immunity:
-Phagocytic cells: (cellular eating) Neutrophils = circulate in blood, Macrophages = attract signals from infected tissues “Help” Signals & encounter pathogens;
Dendritic cells: tissues that contact external environment
-Natural Killer Cells: release chemicals that lead to cell death
-Antimicrobial proteins: ward off microbial pathogens
Interferons: proteins provided innate defense by interfering with viral infections
-Inflammatory response:
Histamine: Signaling molecule stored in vesicles of MAST cells in connective (released at site of damage and triggers nearby blood vessels to dilate and become more permeable (swelling)
Cytokines: promote blood flow to the site of injury or infection
Adaptive Immunity
-Cytotoxic cells
- T cells: mature in thymus gland
Effector: Helper T & Cytotoxic T cells
- B cells: mature in bone marrow
Effector: Plasma Cells
Memory: Long- lived
Effector: short lived
Immune System
What contributes to inflammatory response?
Severe tissue damage or infection that leads to response that is SYSTEMIC
- fever
- # of white blood cells increase
- signaling may recruit additional neutrophils from bone marrow
Immune System
How antibodies are formed and how they work?
Antibodies are produced by B cells,
Antigen comes in contact, B cells divide and Clone
Cloned B cells -plasma cells- release million antibodies in your bloodstream
Viruses
Structure of a Virus
Viruses are NOT Cells
Consist of
- protein coat (capsid)
- Genetic material (DNA or RNA)
- some have membraneous envelopes
- some have accessory structures that facilitate entry into a cell
Viruses
Bacteriophages
a. Structure
Viruses that infect bacteria
- elongated capsid head that encloses their DNA
- protein tail attaches the phage to the host and injects the DNA phage inside
Viruses
Bacteriophages
b. Host
Obligate intracellular parasites (cannot survive w/o a host)
- cannot replicate on their own
- Has HOST RANGE: limited # of host cells that can infect
Viruses
Bacteriophages
c. Replicative cycles (lytic vs lysogenic)
Lytic Cycle = Virulent Phage
- results in death of the host cell
Lysogenic Cycle = Temperate Phage
- Replicates phage genome W/O destroying the host
- ONLY REPLICATE GENOME
Viruses
Classification & Characteristics of viruses (esp how retroviruses diff from others)
Viral Envelopes:
- viral glycoproteins= bind specific receptor molec on surface to a host cell
- Retroviruses: REVERSE TRANSCRIPTASE (enzyme) to copy their RNA genome into DNA
– Lead to HIV (retrovirus) that causes AID - Provirus: Viral DNA that is integrated into host genome
– permanent resident of host cell
–RNA, DNA, host genome, Provirus
Viruses
Prions- What are they? How do they cause infection?
Prions: infectious proteins that appear to cause degenerative brain diseases in animals
How? Incorrectly fold proteins that can be transmitted in food, act slowly, and are virtually indestructible
