Exam 3 Comp Vert

Respiratory and circulatory systems

What are three respiratory structures?

• gills

• lungs

• skin

What are the requirements for a respiratory surface?

• moist surface (mucus or water)

• simple squamous epithelium (thin epithelial lining)

• vascularization

What kind of respiration occurs in fish and amphibian embryos?

They get their oxygen from the environment

What is the relationship between the spotted salamander and algae?

Algae grows inside of the egg

As the embryo releases waste, the algae absorbs it, and as the algae photosynthesizes, it provides the embryo with oxygen

How does respiration occur in amniotic embryo?

Non-placental

• Chorioallentois get oxygenated from the environment

Placental

• Placental gets oxygenated from the mother

What are the odd exceptions for embryonic respiration?

• Ovoviviparous shelled live birth (sharks, snakes) chorioallentois still

• Caecilian “placenta” gill placenta

Do gills develop with invagination or evagination?

Evagination, they fold from the inside out, not the outside in

How many gill arches do agnathans have? What structure supports them?

5-7 gill arches, up to 15

The splanchnocranium supports them, with cartilage and the branchial basket

What do we need to know about the gills of chondrichthyes?

• 5 gill pairs “pentanchid”

• supported by demibranch made of cartilage

• lack operculum

• vestigial gill opening called spiracle

• counter current flow

How does counter current flow work?

Exchange flows in opposite directions

Way more effective than concurrect flow

How do sharks ventilate?

Through constant swimming and the spiracle

What do we need to know about the gills of osteichthyes?

• four pairs of gills

• supported by bony arches

• operculum present

• countercurrent flow

Describe bony fish ventilation

When the mouth is open, the operculum closes so water comes in through the mouth

When the mouth is closed, the operculum opens and water is expelled out of gills

What do we need to know about the gills of larval amphibians?

External gills

• lungfish and salamanders

• develop before opercular

Internal gills

• frogs/toads

• form beneath opercular fold

Where do the lungs develop from?

The digestive tract, in the pharyngeal region, branches off into the trachea which branches off into lungs

What cavity are the lungs in?

The plural cavities

What are the lung respiratory structures?

• pharynx - shared with the digestive system

• larynx - voice box

• glottis - opening to trachea

• trachea

• bronchi - cartilage rings to keep them open

What kind of endothelium (inner lining) do airway tubes have?

Psuedostratified epithelium (false-stratified, appears stratified but is not)

Ciliated

What is the purpose of the cilia and mucus in airway tubes?

They help to filter out nasties by catching them, wrapping them in mucus, and coughing them out

What kind of “walls” do the tubes of airways have?

They form from the mesoderm

Contain smooth muscle, connective tissue and cartilage

What kind of lungs do salamanders possess?

• simple

• capillaries along the side to catch oxygen

• very little surface area

• many breathe through their skin

What kind of lung do frogs and toads possess?

• more complex than salamanders

• lungs contain folds which increase surface area

• breathe through skin like salamanders

How do frogs take air in?

They “force” air in with buccal pump muscles, “positive pressure”

They also use this for vocalizations

What kind of lungs do most reptiles possess?

• extensive folds which improves on surface area in comparison to amphibians

• this is because they do not breathe through their skin

• they are cold blooded with low metabolism so do not need excessive folding like mammals

What is unique about snake lungs?

• vestigial left lung that they do not use, they have one lung that goes down

What kind of creature has lungs that look like this?

Lungfish and salamanders

What kind of creature has lungs that look like this?

Frogs

What kind of creature has lungs that look like this?

Reptiles

What kind of lungs do mammals possess?

• lobed around branches of bronchioles

• alveoli at the ends of the branches where gas exchange occurs

• mammals also have diaphragms

What muscles are involved in breathing for mammals? Vaguely describe the process

• diaphragm

• sternocleidomastoid

• scalenes

• external and internal intercostals

• external and internal obliques

• rectus and transversus abdominis

Chest cavity expands, creating negative pressure and pulling air in, and then contracts, pushing air out.

What structure do mammals use to make sound?

The larynx

What structure do birds use to make sound?

Syrinx

Describe the syrinx of birds

• down by where their bronchi are, allowing them to make two sounds at once

What kind of lungs do birds possess?

• most efficient

• one way flow

• have air sacs

• air is constantly looping through the system

• two breath cycle

• counter current exchange

Describe the breathing cycle of a bird

Inspiration 1

o2 rich air Trachea —> posterior air sacs

Expiration 1

o2 rich air post. air sacs —> lungs (parabronchi)

Inspiration 2

o2 rich air lungs —> rest of body

co2 rich air —> anterior air sacs

Expiration 2

co2 rich air anterior air sacs —> out the trachea

Be able to draw the breathing loop that occurs in bird lungs

Which organisms breathe almost exclusively if not exclusively through the skin?

Plethodontids

Cryptobranchis (hell benders :o)

List some miscellaneous respiratory structures

• oral cavity

• cloaca

• conjunctiva of eye

What are the blood cells? What are they made up of?

Fluid connective tissue that comes from red bone marrow

• erythrocytes

• leukocytes

• platelets

• thrombocytes

Contains plasma (liquid part)

• water

• dissolved gases

• nutrients

• plasma proteins

Which blood cells have a nucleus?

All vertebrates but mammals