Zoology Lecture Exam 4
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- What does the ENDOCRINE system do?
- Allows for communication between different parts of the body
- What is the endocrine's signal like compared to that of the nervous?
- The signal is slower, and is longer lasting
- Horomone (def.)
- molecules that act as messengers. They stimulate cells with specific receptors
- Target Cells (def.)
- The specific cells that a horomone stimulates.
- Endocrine Glands
- Organs that secrete hormones directly into the blood stream. (DUCTLESS)
- In, or at the surface of target cells, the _________ will bind to a ___________ ___________, therby stimulating the cell.
-
Hormone
Receptor Molecule - Membrane bound receptor molecules
- bound to plasma membrane- hormone usually CANT cross
- Pathway of hormone
- Hormone-binds to membrane bound receptor- initiates signal-transduction pathway-affects reactions in the cytoplasm
- Nuclear Receptor Molecules
- Found in Nucleas- hormone must cross cell membrane. Steriod-receptor complex interacts with DNA
- Feedbacks
- The amount of a hormone produced is often controlled by the stimulating gland monitoring the levels of the effected character
- Pituitary Gland
- small gland at the ventral base of the brain- there are two parts (anterior and posterior pituitary)
- Anterior Pituitary
- (adenohypophysis)- develops from tissue at the roof of the mouth
- The anterior pituitary and brain are connected by a ______ _______
- Portal System
- Neurosecretory cells of the hypothalmus produce hormones that stimulate or inhibit the production of anterior pituitary hormones --
- TRH, PIF, PRF
- The anterior pituitary produces:
- TSH, FSH, LH, PL, GH, ACTH, MSH, endorphins
- TSH
- Thyroid Stimulating Hormone
- FSH
- Follicle Stimulating Hormone
- LH
- Lutenizing Hormone
- PL
- Prolactin
- GH or hGH
- Growth Hormone
- ACTH
- Adrenocorticotropic Hormone
- MSH
- Melanophore Stimulating Hormone
- Endorphins
- natural pain killer
- Posterior Pituitary (neurohypophysis)
- develops from tissue from the brain (hypothalmus) it is connected to the hypothalmus by the infundibulum, a narrow stalk
- The hormones are produced by the ____________ cells of the ____________ and then are transported down the ______ to the ___________pituitary where they are released into the blood stream
-
neurosecretory
hypothalmus
posterior - The posterior pituitary produces:
-
Oxytocin
Antidiuretic Hormone (ADH) - Oxytocin
- used to induce labor
- Antidiuretic Hormone (ADH)
- Stimulate absorption of water in kidney
- Pineal Gland (location)
- found on top of brain, just under the skull in many species
- Pineal Gland (functions)
-
**produces melatonin when not exposed to light. **Important in regulation of circadian rhythms
** involved in reproductive cycle in seasonal breeding species - Thyroid (functions)
- produces Thyroxin (T4) and Triiodothyronine (T3)and calcitonin
- T4 and T3 (affect what?)
- metabolic rate
- Calcitonin (affects what?)
- reduces calcium withdrawl from bone
- Parathyroid (produces)
- Parathyroid Hormone (PTH)
- PTH
- regulates calcium levels in the blood by releasing calcium stored in bones
- Thymus
- involved in the development of the immune system and maturation of T cells (immune system)
- Adrenal Glands (location)
- sit atop the kidneys (have 2 parts in mammals)
- Cortex (Outter part of adrenal gland): Glucocortids
- make glucose from proteins and lipids, decrease inflammation and stress. Controlled by pituitary
- Mineralocorticoids
- regulate salt balance in body
- Medulla (inner part of adrenal glands)
- epinephrine (adrenaline) simmilar effect to the sympathetic nervous system
- Norepinephrine
- (noradrenaline) antagonistic to epinephrine
- Pancreas
- exocrine function in producing pancreatic juices
- Islets of langerhans
- produce insulin and glycogon
- Insulin
- allows liver to store most of the glucose as glycogen
- Glycogon
- release of glucose
- Digestive Hormones
- (look it up in digestion lecture)
- Juvenile Hormone and Ecdysone
- controls metamorphosis in insects. Produced by neurosecretory cells (nervous tissue) and is released into bloodstream
- Juvenile Hormone (induces what?)
- production of juvenile features
- Ecdysone (induces what?)
- development of adult features
- 5 Major Hurdles stopping fish from invading land
-
1) Gills do not function out of water
2) Water conservation is difficult, especially across respiratory surfaces
3) Support, air is less dense than water so animals have to support body off substrate
4) Sensory organs need to be modified to work in air lateral line lost in terrestrial forms
5) Evolution of physiological traits that allow survival at a greater range of temperatures- isozymes - Adaptation
- lungs (some fish already had them)
- Thickening of what support structures?
- Pelvic and pectoral fins
- Elongation of bones that support-
- the base of fins
- Development of ear
- uses bones from the second gill arch
- Eye Lids
- to keep eyes moist
- To help with greater range of terrestrial temperatures- isozymes
- to help maintain constant internal body temperature regardless of outside temperature
- Water is much more ___________ in its physical characteristics than air
- stable
- Amphibians did not completely leave the aquatic habitat (T OR F)
- true
- Most eggs are laid in ______ and the young go through an ________ ________ stage before metamorphsing into adults
-
water
aguatic larval - Amphibians evolved during the Devonian and diversified during the __________ ________
- Carboniferous Period
- There are 3 orders of amphibians:
-
1) Order Apoda
2)Order Caudata
3)Order Anura - Order Apoda
-
(Caecilians)- small, snake-like
many vertebrae
no legs
limited vision, blind - Order Caudata
-
(Urodela) salamanders
Legs come off body parallel to ground
Larvae and adults are predators
Have gills as aquatic larvae and use skin and lungs as adults - Plethodontid Salamanders
- lungless- use cutaneous respiration
- Where is the center of salamander diversity??
- Southern Appalachian Mtns!
- Salamander Reproduction
-
aquatic- release egg and sperm into water
larval stage with gills- indirect development - Terrestrial
-
spermatophore passed from male to female
young hatch as miniature adults (NO LARVAL AQUATIC STAGE) direct development - Order Anura
-
(without a tail) frogs and toads
** most diverse group
**adult body specialized for jumping and swimming
** long hind legs
** fused vertebrae near pelvis
** skin has epidermis and underlying dermis - Chromatophores
- how organisms change their surface color
- Xanthophores
- yellow, orange, red
- Iridophores
- (blue) guanine crystals
- Melanophores
- dark pigments
- What makes a frog green?
- Iridophores are over-layed by xanthopores
- Frog Reproduction
- aquatic- males grab onto back of femule (amplexus)
- Indirect Development
- Gametes are released simultaneously
- How do animals get energy??
- By consuming organic molecules (eat other organisms, food is processed to release nutrients and energy)
- Intracellular Digestion
-
Phylum Porifera
Specialized cells used called collar cells - Extracellular Digestion
- Involves 4 stages of food processing
- Ingesting
- Capturing and eating
- Digestion
- breaking down of molecules
- Absorption
- absorbing nutrients in the body
- Elimination
- undigestable material released from digestive tract
- Classifications
-
Herbivores
Carnivores
Omnivores
Saprophagous - Herbivores
- feed on plants (autotrophs)
- Carnivores
- feed on animals (heterotrophs)
- Omnivores
- digesting either auto or hetero
- Saprophagous
- feed on dead material
- 3 Various specializations
-
1) Suspension feeders
2) Deposit Feeders
3) Fluid Feeders - Suspension Feeders
- collect prey items suspended in water column, use mucus or hairs to collect matter from water
- Deposit Feeders
- ingest sediment or collect matter as it settles from water
- Fluid Feeders
- ingest matter rich fluids- (spiders)
- Oral Cavity
- chemical and physical digestion
- Physical
- mastication by teeth breaks food into smaller particles and mixes in saliva
- Chemical
- saliva contains enzymes. AMYLASE breaks down starches and long carbs. Saliva also lubricates food
- Bolus
- chewed up food mass
- Esophagus
- tansports by the use of smooth muscle
- Cardiac Sphincter
- ring-shaped structure around esophagus (stops material from coming back up to esophagus from stomach)
- Stomach
- food exposed to harsh conditions for chemical
- Gastric juices (released by..)
- Epithelium of stomach
- Parietal Cells
- (HCl- pH of 1.5)
- Chief Cells
- Pepsinogen
- Pepsinogen
- converted to pepsin by HCl (when exposed to acidic environments)
- Acid Chyme
- passes through the pyloric sphincter into the duodenum, first section of the small intestine
- Pancreatic Juice (fuctions..)
- released into the duodenum, it neutralizes the acid (pH=7)
- Pancreatic Juice
- also contains proteases, nucleases, and lipases (digestive enzymes)
- Bile (produced where?)
- in liver, stored in gall bladder
- Bile (functions...)
- is released into the duodenum and emulsifies fats and lipids (breaks down fat)
- Small Intestine
- membrane enzymes (specific enzymes work on specific molecules)
- Jejunum and Ileum (function)
- absorption of nutrients
- What 3 things help increase surface area of the jejunum and ileum?
- Folds, villi, and microvilli
- Hepatic Portal System (process)
- heart- vessel- capillary- vessel- capillary-vessel- heart- hepatic portal vein
- Hormones
- Gastrin, Secretin, Cholecystokinin
- Colon
- (large intestine) and rectum remove water before defecation through the anus
- Saliva's main component
- H20
- Examples of specialization of digestive tracts
- Teeth of mammals
- Incisors
- grasping, cutting
- Canines
- tearing
- Premolars
- shearing, cutting
- Molars
- grinding
- General Trends of Digestive Tract Length- Herbivores
- longer, harder to break down materials, allows longer time for chemical digestion
- Ruminates (mammals)
- Have a four-chambered stomach filled with bacteria that help digest cellulose
- Cecum
- non-rumincant animals (bacteria that helps in digestion)
- Stomach produces _________ acid
- hydrochloric
- Homeostasis
- maintenance of an internal steady state by means of self-regulation. Keeps the internal environment of the body constant
- Homeostasis Regulates Osmotic Pressure
- created by osmosis- liquids going from an area of higher concentration to lower
- marine animals
- salt in environment- water leaves body
- freshwater animals
- water enters body
- terrestrial animals
- water leaves body
- temperature
- more of a problem for terrestrial animals in water- ambient temperature does not vary much
- Levels of Metabolic Waste
- ammonia is produced when proteins are catabolized- ammonia is toxic
- Temperature Regulation (Q10)
- the multiple by which a reaction will increase with a 10C increase in temperature
- Poikilothermic
- body temp. varies with the environment
- Homeothermic
- body temp. held constant
- Ectothermic
- body heat from an outside source
- Endothermic
- body heat generated from inside the body
- Conduction
- heat transfer between 2 substances (sand)
- Convection
- loss of heat through flow of fluids
- Radiation
- laying out
- Evaporation
- adjust temp. by having molecules evaporate
- Adaptations by ENDOTHERMS in cold environments (5)
-
1) Stout Bodies
2) Decrease conductance
3) Increase Heat production
4) Counter current heat exchange
5) Daily torpor
5) Hibernation - Allen's Rule
- ????????
- Decrease Conductance
- thick fur, fat layer
- Increase heat production
- brown fat (lipid when matabolized produces huge amount of heat) and shivering
- Counter Current Heat Exchange
- extremeties lose heat quickly (feet on snow)
- Daily Torpor
- animals cool down at night
- Hibernation
- temp. decreases to ambient respiration and circulation decrease (bears and racoons)
- In Warm Environments
-
1) Temp. Fluctuation
2) Evaporative Cooling
3) Concentrated urine and feces
4) Light fur- reflective - Endothermy
- in reptiles, fishes, invertebrates
- Osmotic Conformers
- animals that allow the concentration of salts in the body to change as the salt concentration in the environment changes
- Osmotic Regulators
- maintain the osmotic pressure in the bodies tissues by using active transport to take salt into the body or release it from the body
- Stenohaline
- animals that can only survive in a narrow range of salinities- typical of animals living in the ocean
- Euryhaline
- animals that can survive in a wide range of salinities- typical of animals in estuaries
- Freshwater Animal
- body has higher salt concentration than the water around it- water diffuses in, salts diffuse out.
- Gills
- Secrete salt produce concentrated urine
- Saltwater Animals
- body has lower salt concentration than the water around it. Water diffuses out, salts diffuse in
- Chondrichthian fishes never invaded freshwater--
- they have higher levels of urea whcih stops water from diffusing out
- Terrestrial Animals are in a similar situation to saltwater fishes-
- they need to conserve water
- Water is lost by:
-
1) evaporation at respiratory surfaces
2) evaporation at body covering
3) urine production
4) feces- water added to digestive tract during digestion - Water is gained by:
-
1) drinking, eating
2) meatbolic water- o2 accepts the electron at the ETS and binds to H's - Excretion of metabolic wastes (in small animals)
- ammonia diffuses out
- Excretion of metabolic wastes (in large animals)
- ammonia is excreted from body by excretory system, often after being converted to less toxic forms
- What animals convert ammonia into non-toxic urea?
- Chondrichthian fishes, amphibians, and mammals
- What animals convert urea to uric acid?
- Reptiles, birds, and terrestrial insects
- Uric acid
- is a solid that can be excreted with minimal water loss
- Protonephridium
- blind end system of tubulues
- Metanephridia
- excretory tube is open on both ends
- Antennal Gland (green gland)
- blind end sacs attached to a bladder that opens to the ventral surface of head
- Malpighian Tubules
- blind end sacs attached to the intestine
- Archinephros
- kidney found in embryo of hagfish, this is the inferred ancestral condition of the vertebrate kidney
- pronephros
- functional kidney in adult hagfish
- mesonephros
- transient function in embryonic lampreys, fishes, amphibians, reptiles, birds and mammals
- metanephros
- functional kidney of adult reptiles, birds, and mammals
- opisthonephros
- functional kidney of adult lampreys, fishes, amphibians
- Human Kidneys
-
it filters 2000 liters of blood a day
blood enters only through renal artery and leaves through the renal vein
only 10% of plasma is actually cleaned as blood flows through the kidney - Cortex
- outter most region
- Medulla
- inner region- high salt concentration
- Renal Pelvis
- large duct in medulla
- Ureter
- duct that transports urine to bladder
- Nephron
-
functional unit of the kidney- 1 million per kidney
fluid enters nephron from blood stream in the cortex - Glomerulus
- a ball of capillaries, small blood vessels
- Blood Plasma
- but no cells or blood proteins--- enters nephron
- Bowman's Capsule
- cup structure that surrounds the glomerulus
- Proximal Convoluted Tubule
- short section of the nephron, 60% of the filtrate is reabsorbed including sugars, amino acids, and other valuable nutrients
- Loop of Henle
- a long, thin section of the tube takes the filtrate into the medulla, and then back into the cortex
- As the fluid descends.....water diffuses _____ and salt diffuses _____
-
out
in - As the fluid ascends, salt is actively transported ________ ________
- back out
- Distal Convoluted Tubule
- more water and salt are reabsorbed. Substances (ions and drugs) can be secreted into the tubule
- Collecting Duct
- fluid will travel back through the medulla and into the renal pelvis
- ADH
- Antidiuretic Hormone (pituitary gland) increases uptake of water from the collecting duct
- Amniotic Egg
- allowed reptiles to be truly terrestrial vertebrates
- Amniotic Egg contains 4 membranes
-
1) amnion
2) allantois
3) yolk sac
4) chorion - Amnion
- surrounds the developing embryo
- Allantois
- storage of metabolic waste- blood vessels in the membrane used for exchange of gases with atmosphere
- Yolk Sac
- contains yolk rich in energy
- Chorion
- surrounds the other three membranes and exchanges gases with the environment
- Other characteristics of Reptilia
-
tough dry skin
keratin scales
copulatory organ for internal fertilization
more efficient legs
more efficient lungs, ciruclation, jaws - Subclass Anapsids
- turtles, no temporal opening in skull
- Body protected by shell of
- bone and keratin
- Turtle Jaw composed of....
- bony plates
- Subclass Diapsida
- 2 temporal openings in the side of skull
- Order Squamata
-
lizards, snakes, and worm lizards
*most diverse group
*kinetic skull allows for more mobility of bones - Snake sensory organs
- ears internal, jacobson's organ, pits of pit vipers sense heat
- Order Sphenodonta- Tuatara
- Two species in New Zealand- ancient morphology similar to that of many Mesozoic diapsids
- Parietal Eye
- third eye under top of skull with cornea, lens and retina
- Order Crocodilia
- crocodiles, alligators, caiman
- Thecodont Dentition
- teeth set in sockets
- Four chambered heart
- completely separates oxy and deoxy blood
- Gender of young is dependent on ________ _________
- incubation temperature
- Paraphyletic Group
- gave rise to mammals and dinosaurs (birds)