Lesson 2 (1/12) Flashcards
what makes a vertebrae
- bones in your back (vertebra)
- 4th tissue layer
bilateria
all animals except for sponges are derived from bilateria
- have bilateral symmetry during some form of their life
chordata (phylum)
3 major groups (subphylum)
- vertebrate
- tunicates (urochordata)
- Cephalochordata (amphioxus)
traits of chordata
- Notochords → dorsal stiffening rod
–> In development - notochord is replaced by spinal cord – vertebrate (not necessarily bony in chordates) - Dorsal neural tube/dorsal hallow nerve cord
- muscular and segmented post-anal tail
- endostyle
endostyle
- Generally it is a ciliated glandular groove on the floor of the pharynx
- Secretes mucus for feeding purposes
- Finds the endostyle present in adult stages in urochates and cephalochordates but not vertebrates
- In vertebrates → it thyroid is a homolog of the endostyle
blastula
- 3D structure
- visualize as a basketball
- single layer of cells - but over the course of development, the blastula invaginates
- cells are differentiating so they can take on different roles
- hollow inside
- imagine pressing the air out of the basketball and wrapping it around itself to form a second cell layer (ectoderm) –> more pinching and invagination will occur to form a third cell layer (ectoderm)
triploblasty
where the 3rd tissue layer forms
- bilateral symmetry
lancelet
- larva are active
- is a chordate
- don’t have the gill tissue that would normally be uses
- because they are so small – it is thought that they exchange all their gas via diffusion
lancelet characteristics
- pharangeal slits are used for feeding
- have dorsally positioned aorta
- have ventrally positioned heart
- have excretory cells –> similar to kidney cells of vertebreates
what kind of tissues do vertebrates have
mineralized tissues
- tissues that get hard and rigit
- for us its bones and teeth
–> don’t assume that the bones and teeth are the only mineralized tissues –> cartilage can get mineralizzed
what is the fundamental difference between bone and cartilage
whether or not it has a blood supply and can fix itself or not
Hox Duplication
a group of genes that are really fundamental of the pattern of development
- the amount of Hox genes have been duplicated in vertebreates
neural crest
4th germ layer
- quadroblastic
what is a huge driver of diversification in vertebrates
size and activity levels
- when you’re big you have thermal inertia
ectoderm becomes
the the cells of the outer body
ectoderm becomes
the the cells of the outerbody
what do the 4th tissue layers go onto form
(neural crest cells)
– bones and cartilage of the face and neck
osteichthyan
bony fish
what are the biggest vertebrate groups
vertebrates with jaws and the vertebrates without jaws
3 components of the skull
chondochranium
splanchnocranium
dermatochrium
chondochranium
- that which surrounds the brain
- usually formed of bone
- in most vertebrates - during development it replaces cartilage
endocondral bone
bone that replaces cartilage
dermal bone
bone that does not replace cartilage
splanchnocranium
- derived from pharyngeal arches
- jaw – lower portion that forms gills
- endochonral and dermal in others
dermatocranium
forms in the skin as an outder cover of the head
cranial muscles
- many groups don’t have cranial muscles
- not until we get into the mammals where we have cranial muscles (cheek suckling, communicatin)
branchiomeric muscles
important for vertebrates
- feeding and respiration
axial region
- things associated with the vertebrae – spinal column
- notochord (not bone, but replaced by bone in some vertebrayes)
axial muscles – myomeres – allow fish to swim rapidly
vertebrate circulatory system
- straight from heart to gills (in some fish)
- we have a double circulatory system
thermoregulation
adjusting blood flow to periphery
- ex: blood vessels lose up and restrict blood flow to the fingers
- periphery has all the surface area –> easier to lose heat with the large amount of surface area
functions of circulatory system
- blood carries oxygen throughout the cells
- carries nutrients and trasports has
- hormones
- oxygen
- cellular waste
- homeostasis –> balance of water/salt/sugar
- immune system
- more or less a closed system
portal system
situations where blood is carried strictly by the cardiovascular system from one organ to another organ (normally it goes straight to the heart)
excretory and reproductive system
- formed from structures called nephrotomes –> from a nephric ridge
- in jaw vertebrates there is the archinephric duct –> drains the kidneys
- in fishes the kidney will extend the length of the dorsal body wall
parts that the kindey divides into
- pronephros
- mesoneophros
- metanephros
opisthonephros – mesonephros + metanephros
nephron
- functional unit of the kidney
- does all the filtering and exchange of ions
in terms of egg produciton
- seasonal in most vertebrats
- human gamete production (egg) are more or less continuous - but htere is a small seasonal signal –> slight bias of births in september
semelparity
some fishes only reproduce once in their life
who has no special duct for their gametes
for jawed vertebrates
gametes are transported by way of ducts
nervous system
- dual type of nervous system
- ## unique to vertebrates
what does the dual type of nervous system mean
- the somatic and visceral nervous stem
general traits of vertebrate neurons
- axon
- myelin sheath
- nucleus
- dendrite
- schwann cell
usually how many parts of the brain do vertebrates have
3 parts: forebrain/midbrain/hindbrain
in more developed vertebrares how many sense organs are there
5
can aquatic fishes detect vibrations, and detect and process electrical signals
yes
semicircular canals
- lamprey have 2
- sharks have 3
- part of the vestibular system
vestibular system
associated with hearing
- really important for detecting things such as balance and hearing and orientation
- because of fluid –> there is interia –> lag of fluid, sloshing bends
big broad trends to know
- vertebrates become more mobile and active overtime
- ^^^ requires a better vestibular system –> if you are sessile, you do not need a complex system to do sensory processing
fundamental role of endocrine
-hormone signaling – also receptors for hormones so signal can be conveyed
- hormone glands - receptors
- often used for communiction – can work on a much broader time scale
is the brain an endocrine gland
yes
negative feedback
- think of it as a thermostat
- starts to warm up in the house – heat is the stimulus to elict a response
- output of system serves to regulate the subsequent system
- in response to a stressor to combat it
ex: animal detects a stressor - releases hormones
- gives rise to production of cortisol
- ^^ stimulating metabolic response
positive feedback
cold air drives more cold air
- parturition – giving birth in a animal
endoderm becomes
lining of the gut
mesoderm
contributes to many organ systems - making it triploblastic
