Verts 10.1 - Osmoregulation pt 2

General structure of Vertebrate Excretory System

1) Blood

2) Collecting area

3) Proximal tubule

4) Distal tubule

5) Storage bladder

6) final duct --> external medium

high, fenestrated, collecting area, cells, large

Blood is moved at _____ pressure and pushed through _____ (leaky) capillaries --> pushes fluid and solutes into a _____ ______ (only ____ and very _____ molecules are not moved)

*** safest paradigm (vs. active secretion of selected solutes)

Reclimation

- Take back what is needed

- Lots of active transport

Secretion

- Nitrogenous wastes / toxins moved into filtrate

urine, distal tubes

Control of _______ concentration for water balance occurs in ____ _____ (salts and/or water moved & species specific fashion) --> HELD IN STORAGE

afferent vessels, glomerulus, smooth muscle

(vertebrate nephron)

- ______ ____ bring blood to capillary network = ________

- ______ ____ controls the flow and pressure in each nephron

Bowman's Capsule

(vertebrate nephron)

- Ultrafiltrate collected in ____ _____ = Only cells and large solutes are not collected

(vertebrate nephron)

Ultrafiltrate is processed through the ______ ______

- Reclamation

- Secretion

- Water balance

Synapsid Nephron

- Long proximal tubule for reabsorption (solutes)

- Loop of Henle (conditioning/only in some clades)

- Distal tubules (ion/water balance)

Strategy for fish

- Can't avoid the environment (conform or regulate)

- Most are in stable environments (fresh or salt / Stenohaline or Euryhaline)

Stenohaline

Referring to organisms that can withstand only slight changes in salinity

Euryhaline

Referring to organisms that can withstand wide swings in salt

Freshwater Teleost

- Body fluids are more concentrated than external environment (NO EXCHANGE THROUGH SKIN)

- Gills provide LOTS of area for simple diffusion (water moving into blood, salts moving out)

counteractions

Freshwater Teleosts ______=

- Salts actively transported from water into BLOOD at gills

- Excess water removed in very DILUTE URINE

Branchial Exchangers in Freshwater

- Link salt import to acid/base balance

- Carbonic acid in blood

- Utilize ANTIPORT SYSTEM

Proton/sodium, Bicarb/Cl-

Branchial exchangers in freshwater utilize carbonic acid in the blood for....

1) ______/_____ antiport

2) _____/ ______ antiport

(both ACTIVE TRANSPORT)

Marine/Saltwater Teleosts

- Water has higher concentrations than internal fluids

- Water LOST at gill surface

- Salts GAINED at gills

water, urine, gills

Marine/Saltwater Teleosts Counteractions:

1) Ingests ______

2) Very little ______

3) Active removal of salts from _____

Chloride cells

specialized cells in the gills of marine teleosts

- Active chloride transport OUT of the body

- Pushing against the gradient

Mitochondria rich cells (MRC)

Chloride cells are also called ______ due to being chocked full of mitochondria to push salt out

Terrestrial life

- Major problem is water loss (land is DRYYYY)

- Evaporation through the integumentary system

- Loss via the respiratory sys

Keratin

- Unique to vertebrates

- Ectodermal derivative in the integumentary system (highly organized)

- External protection (outer skin of terrestrial / Appendages like, scales, horns, beaks, hair, cornified epithelium

Reptilian scales

- are epidermally derived (KERATINIZED PATCHES)

- Segmented pattern to the epidermal thickenings

- have hinges

hinges

thinner regions of reptilian scales are called _____ = allow for flexible skin during locomotion

Mammalian skin

- Cornified epidermal layers

- Appendages

- Additional structures

Cornified epidermal layers

(mammalian skin)

- Keratin and lipids for waterproofing

- thicknesses vary due to frictional contact

Appendages

_____ of the mammalian skin =

- Hair follicle

- Sweat gland

- Sebaceous glands

Additional

______ structures of mammalian skin =

- Arrector pili muscle

- Sensory receptors

- Melanocytes

Nasal water recovery

- Vascular countercurrent systems in mucous membranes

- Heats and moisturizes INHALED air

- Air picks up moisture in lungs (warm & 100% humidity)

- cool nasal mucosa cools EXHALED AIR (cool air holds less moisture)

concha and turbinates

Various nasal ____ and ______ allows for convoluted pathway of air

Nitrogenous wastes

- Sources are protein and nucleic acid breakdown

- More food needed = MORE NITROGEN PRODUCED

Ammonia

is the first product produced in nitrogenous waste

= very soluble in water

= very TOXIC

BUT .... a problem in species that store or concentrate urine

Urea

____ is much less toxic and a major nitrogenous waste product in synapsids

(can be concentrated in urine and stored in bladder ex: mammals & some aquatic org)

Synapsid Nephron

Descending loop:

- Water is leaving passively

- Urea is actively secreted into urine

Uric acid

In Sauropsids nitrogenous waste is turned into ____ _____ =

- readily precipitates out with salts

- NOT TOXIC (but rlly expensive metabolic cost for building this nitrogenous waste)

Extra renal salt processing

- Salts reclaimed by sauropspids can't stay in the blood

- removed by SALT GLANDS (goal = max water retention)

- More efficient than handling salts in urine (ALMOST NO WATER LOST)

Salt glands

- Nasal ____ _____

- expelled by sneezing (Lizards) or shaking heads

orbits

- Enlarged lacrimal glands

- Release salt around the ______ (crying in sea turtles)