Cardiovascular System
functions
transport gas, nutrients, hormones and other compounds to cells and tissues
Transport waste away from cells and tissues of the body
Blood
special connective tissue
plasma 55%
Water 90%
Gasses 10%
Glucose, hormones, waste, and amino acids
Intracellular fluid
in the cytosol within the cell
Extra cellular fluid
surrounds the cells and serves as circulating reservoir
Divided into the interstitial fluid which bathes the outside of the cells and intravascular fluid
Formed elements
platelets
clothing pieces of cells (blood clotting)
Leukocytes
nucleated
5 types: granulocytes (neutrophils, eosinophils, and basophils), monocytes and lymphocytes (T cells and B cells)
Neutrophils
first cells to inflamed areas
Phagocytes (eat cells)
Lymphocytes
B cells
produced in bone marrow; form antibodies
T cells
produced in thymus gland
Killer cells (attack viruses)
Monocytes
killer cells- viral infection
Eosinophils
limit inflammation
Provide protection against parasitic worm infection
Basophils
help with inflammation response
Involve with regulating BV flow
Erythrocytes
anucleated/mammals (5000000 c/c)
Produced in red bone marrow and spleen
Contain hemoglobin (200000 hemoglobin molecules per RBC)
oxygen binds to hemoglobin (oxygen transport)
120 day life I span
Biconcave
Blood vessels
tubes carrying blood
lined by epithelium (simple squamous)
Arteries and arterioles (away from heart)
Veins/venules (towards heart)
Capillaries
smaller diameter
Arranged in beds
Thin walls, one cell thick (ss)- efficient in secretion and absorption
Veins/venules
carry towards heart
thinner smoother tissue
Lower pressure vessels
Some have valves to prevent back flow
Gas exchange
site between blood and organs; oxygen diffuses out of vessel and CO2 diffuses in
Mammals 4 chambers
2 atria (left/right) smaller/thinner walls
2 ventricles (left/right) larger/thicker walls “left thickest”
Right “pulmonary loop”
Left “system loop”
Valves
Ventricular valve (AV) between atria and ventricles
Semilunar valve (SV) pulmonary SV between righ t ventricle and pulmonary artery; aortic SV between left ventricle and aortic trunk
Pathway of blood flow around heart
vena Cavae (deoxygenated blood)- right atrium- AV valve- Right ventricle- pulmonary SV- pulmonary arteries- lungs (oxygenated)- pulmonary veins- left atrium- AV valve- left ventricle- aortic SV- aorta- body
Evolutionary advances of vertebrate heart
increases in the number of chambers (Atrium and ventricle) 2,3,4
Increase in size of heart
Decrease in pseudo chambers (outside of heart receiving blood)
Sinus venusos: outside atrium receives blood from body
Conus arteriosus: outside ventricle receives blood from heart
Fish
two pseudo chambers (SV and CA)
Two chambers (atrium/ 1 ventricle)
Amphibians
two pseudo chambers (sv and ca)
Three chambers (right and left atrium/ 1 ventricle)
Reptiles
sinus venous only
Most with three chambers (rigth and left atrium/ 1 ventricle)
Crocs with 4 chambers (right and left atrium/ right and left ventricle)
Birds
4 chambers (right and left atrium/ right and left ventricle)
Mammal
4 chambers (right and left atrium / right and left ventricle)
Most advanced and larges t
Sinoatrial node
remnant of the sinus venous of earlier vertebrates; not a chamber outside of heart but a patch of cells in right atrium
Pacemaker: initiates heartbeat
Nodal tissue
specialized cardiac muscle cells (involuntary) capable of spontaneous contraction (impulse)
Conus srteriosus no longer a pseudo chamber but beginning of aortic trunk
Respiratory system
Gas Exchange
process of moving CO2 and O2 in opposite directions between the environment, bodily fluids and cells
Respiratory system- all structures that contribute to this process
Physical drops of gasses
air
21% oxygen
78% nitrogen
Approximately 1% carbon dioxide and other gasses
Nitrogen gas is usually ignored because it is not part of the respiratory system
Solubility of gases
gases dissolved in water- whether freshwater, seawater, or bodily fluidas
Most gasses dissolve poorly in water
Factors influencing solubility in water
pressure of the gas- higher pressures will result in more solution, up a limit for each gas at a given temperature
Temperature of water- cold water holds more gas than warm water
Presence of other solutes- other solutes decrease the amount of gas that dissolves into the solution
Ventilation is the process of bringing oxygenated water or air into contact with a gas-exchange organ
All respiratory organs share common features
moist surfaces on which gasses dissolve and diffuse
High surface for gas exchange
Extensive blood circulation (lots of capillary beds)
Thin, delicate structure (simple epithelium)
Water breathing vs Air breathing
different Challenges for gas exchange
Aquatic animals
less available oxygen
When temperatures change in water, oxygen availability also fluctuates
Moving dense water over respiratory membranes takes more energy than moving air
water also removes heat from gill surface
Terrestrial animals
deal with desiccation of respiratory membranes (drying out)
Vertebrate gas exchange types
gills: fish, some amphibians, come invertebrates
aquatic organisms- difficult due to low oxygen concentration
Air- about 21% O2
H2O- O2 concentration is less than 1% of air
Design must be effective and efficient
Gills
specialized respiratory structures in water breathing animals
external gills
uncovered extensions from the body surface
Found in many invertebrates and larval form of amphibians
Vary widely in appearance but all have a large surface area with extensive projections
Limitations
unprotected and subject to damage
Energy is required to wave Gil’s back and forth
Appearance and motion may attract predators
Internal gills
gills of fishes, many with a cover called operculum
Gill arches- main support beam/strucuture
contain filaments which are composed to lamellae (epithelial sacs of blood)
Blood vessels run the entire length of the filaments
O2 poor blood travels through afferent vessels
O2 rich blood travels through efferent vessel
Countercurrent exchange of water and blood flows in different directions and maximizes O2 diffusion into blood
H2O flows from the front of the gill region to the back; blood enters the gills at the back and flows to the front. The opposite flow of water and blood maintains the gradient of O2 along the length of the capillaries
Mechanisms of internal gill ventilation
buccal pumping- hydrostatic pressure gradient created by lowering the jaw to suck H2O in and opening the operculum to draw H2O through
flap of tissue prevents fish from swallowing h2o
Ram ventilation- swimming with mouth open
more energy efficient than buccal pumping
Many fish use both methods
Both are flow-through systems (water moves unidirectionally)
Countercurrent exchange mechanism
oxygen (and co2) diffuse as long as there is a gradient of O2 (and CO2)
Diffusion occurs along the entire length of the gill region
Highly efficient in water- only energy expended for swimming and/or opening the mouth and operculum
Cutaneous respiration
gas exchange through the integument (skin)
Highly efficient
Some fish. Some amphibians
Both have thin, moist skin, lots of capillaries, no barriers to diffusion (meaning no scales, hair or feathers to stop diffusion)
Buccopharyngeal respiration
epithelial lining of the mouth cavity
Moist, thin, lots of capillaries
Some amphibians
Lungs
a lung is like a “‘vascularized sponge” they are sponge-like sacs that, when squeezed or pressed, shrink to get rid of all air spaces. Constricting forces air out, so when it is released, it expands to let air in
With few exceptions, all air breathing terrestrial vertebrates use lungs for gas exchanged
Fish-lungfish (simple sacs)
Amphibians- simple sacs
Reptiles/brids- larger sacs and more lobes= more exchange area
Mammal lungs- largest of vertebrates; more exchange area
Pathway of the mammalian respiratory system
nose and mouth
air is warmed and moistened
Mucus and hairs in the nose cleans the air of dust
Pharynx
back of the mouth cavity; respiratory and digestive tracts cross
Larynx
upper part of the trachea (windpipe)
Vocal cords- voice box
Trachea- opening (glottis)
rings of cartilage provide rigidity
Lined with cilia and mucus to trap and expel inhaled particles
Branched into bronchi (right and left) (helps hold the airway open)
Bronchi leads to the lungs
repeated branching of bronchi eventually form bronchioles
contain circular rings of smooth muscle to dilate or constrict passage
Bronchioles empty into alveoli (site of gas exchange)
alveolus- air sac
Exhaled air follows the pathway in reverse
bronchioles- bronchi- trachea- larynx- pharynx- nose/mouth
Diaphragm
large muscular organ separating thoracic and abdominal cavities
Smooth muscle- involuntary (not consciously controlled)
The diaphragm flattens out to expand the chest cavity, allowing air to flow into the lungs due to ventilation. It will push back up to constrict and push air out
alternating because of the intercostal muscles
Urinary system
function
waste disposal (ions, urinary wastes)
Filtering of blood (cleaning)
Water movement
redistribution by osmosis
if ions are taken out, h2o is also going to leave because at this point it is too high in the concentration gradient. Meaning it will leave to try to maintain the balance
Osmosis- diffusion of water across a selectively permeable membrane
Osmoregulation
regulation of salt/h20 balances of body fluids and cells/tissues of the body
Excretory system of animals
animals make use of one or more organs to remove metabolic wastes, excess h2o, ions and toxins
Most excretory organs contain tubular structures lines with epithelial cells that have the capacity to actively transport ions
using energy o go from low concentration to high concentration and push against the gradient (active transport)
In mammals, there are simple cuboidal epithelial
Excretory systems
critical for removing waste from body fluid and maintaining homeostasis
Salt and h2o balance
salt- a compound formed from an attraction between positively charged ions and negatively charged ions
ionic bonds are broken when dissolved in water
Changes in concentration of ions from dissolved salts in extracellular and intracellular fluids can disrupt cellular function
Principles of homeostasis of internal fluids
an animals internal fluids exist in compartments
invertebrate: intracellular fluid
Vertebrate: intracellular fluid and extracellular fluid
h2o is
major portion of an animals body mass
Solvent for chemical reactions
Transport Neville
Dehydration occurs when water volume is reduced below the normal range
comprises the circulatory system and regulation of body temperature
Gains of water
drinking 48%
Free h2o in food 12%
Losses of water
urine 60%
Evaporation/sweat 34%
Feces 6%
Nitrogenous wastes
produced when proteins and nucleic acids are broken down and metabolized
Molecules include nitrogen from amino groups
Toxic at high concentrations
cannot be eliminated from body through exhalation or diffusion
Can be eliminated as urinary waste
Forms of nitrogenous waste
ammonia (NH3) and Ammonium (NH4)
most toxic of nitrogenous wastes
Animals that excrete wastes in this form typically live in water
Easily diffuse in water
Aquatic animals can excrete it as soon as it forms
Chief advantage is that energy is not required for conversion to a less toxic product
Urea
all mammals, most amphibians, some marine fishes, some reptiles, some terrestrial invertebrates
Produced by metabolic conversion of ammonia
Less toxic
Does not need as large a volume of h2o for excretion
Can tolerate some urea accumulation
Drawback is conversion of ammonium to urea requires atp and time
Uric acid
birds, insects, and most reptiles
Less toxic than ammonia
More energetically costly to make from ammonia than urea and more time
balance against h2o conserved by excreting semisolid, partly dried precipitate
The white part of “bird poop” is uric acid. The black part is feces
Kidney
major organ in the urinary system
Vertebrates- kidneys are paired
Fishes/amphibians- kidneys are simple sacs
Mammals/birds/reptiles - metanephric kidnets
most advanced kidneys; drained by a ureter; lots of nephrons; filter at much higher pressures
best design for terrestrial lifestyle- mammals
Organs of the urinary system
kidney
forms urine from the blood
Urine forming structure: nephrons (structural/functional unit of the kidney)
Ureter
transports urine from kidney to urinary bladder
Urinary bladder
stores urine until it is voided from the body
Urethra- conducts urine from bladder during urination
Nephron
functional unit of the kidney
18 liters filtered per day
Total blood volume: 5L
Composed of
renal corpuscle
Renal tubule (surrounded by simple epithelium)
Renal- kidney related
Nephron structure
blood that goes to glomerulus. It is intense enough to force material into the tubule. It enters the proximal tube- lower tube-distal tube. It exits through the collecting duct
3 stages of urine formation
filtration
cleaning/filtering blood
Glomerulus- bowman’s capsule
Reabsorption
proximal tubule
Secretion
pushing material into the distal tube
Renal corpuscle
glomerulus
capillary network
Blood filtered here
Filtered material
glomerular filtrate (GF): stuff pushed out due to pressure (can’t call it waste because goodies are still inside)
Bowman’s capsule
blind-ended pouch
Receives glomerular filtrate (GF) from glomerulus
Renal tubule
proximal tubule
Lower loop
Distal tube
Collecting duct
Proximal tubule
receives GF from bowman’s capsule
Primary site of tubular reabsorption
approx 60% of GF volume and nearly all glucose, amino acids, and vitamins are reabsorbed here (removing goodies from tubule)
Tubular reabsorption
movement of GF out of renal tubule back into blood
Occurs along length of the renal tubule
Most reabsorption of solutes is by active transport
ATP expenditure (low concentration to high concentration)
Water follows passively by osmosis
now GF is less water, less goodies but higher percentage of waste ions
For most substances (except glucose )
upper limit reabsorption
Lower loop
most enhanced with metanephric kidneys (mammals, birds, reptiles)
Best in mammals
Distal tubule
primary site of tubular secretion
movement of substances out of blood into renal tubule
push material into tubule (ATP expenditure; low-high)
Collecting duct
waste (mostly)
Filtrate that has reached this point should mostly be waste material; h2o reabsorption in collecting duct to be just enough water to release waste from the body
Urine- renal pelvis of kidney- released out of ureter- urinary bladder (temporary storage)- urethra to outside
Vertebrates nephron differences
freshwater fish
concentration environmental ions < concentration body ions
Concentration environmental water > concentration body water
constantly taking in water; doesn’t drink water because they already take it in
Large glomerulus to filter blood
Short tubule doesn’t reabsorb or keep water
Dilute waste- ammonia (getting rid of lots of water)
Marine fish (seawater)
opposite of freshwater
Concentration environmental ions > concentration body ions
Concentration environmental water < concentration body water
constant loss of water; drinks water to compensate
Small glomerulus
Long tubule to reabsorb ions/h2o
Stores ions in tissue (urea) to slow osmotic ions of h2o
Produce concentrated waste (urea)
some urea is stored in tissue to increase ion balance
Mammalian nephron
loop of henle- lower loop is greatly constricted (narrow tube); slows down GF
By slowing it down, more water reabsorption occurs
Allows more goodies reabsorption
Allow more concentration (secretion) os wastes 20% more concentration
Plan-concentrated wastes, minimal goodies, minimal h2o- waste product of urea
Loop of henle is the reason mammal kidneys are better
Endocrine System
pituitary gland and hypothalamus
anterior pituitary- secretes hormones that regulate or act upon other endocrine glands
Thyrotropic hormones- acts on thyroid gland
Adrenocorticotropin- acts on adrenal gland
Gondatropins- acts on gonads (LH- luteinizing hormons and FSH follicle stimulating hormone)
Prolactin- stimulates mammary glands for milk production
Growth hormone- stimulates cell division
Melanophore stimulating hormone- pigment dispersion
Hypothalamus- produces releasing hormones that regulate pituitary hormones
LH-RH- luteinizing hormones/ releasing hormones
FSH-RH- follicle stimulating hormone/ releasing hormone
Posterior pituitary- also regulated by hypothalamus
Vasopressin- acts on kidney to reduce urine flow
Oxytocin- stimulates contraction of uterus during birth and the release of milk by mammary glands
Metabolic hormones and associated glands- alter enzyme activity
thyroid gland
thyroxine- promotes normal development of nervous system
Adrenal glands
cortisol- anit-inflammatory hormone
Aldosterone- promotes tubular reabsorption of NaC by nephron
Epinephrine (adrenaline)-
Norepinephrine (noradrenaline)-
Digestive hormone
gastrin- stimulates secretion of HCl in stomach
Cholecystokinin- stimulates gallbladder contraction to increase flow bile into duodenum and stimulates pancreas to secrete enzymatic juices
Animal Reproduction and Development
overview of asexual reproduction and sexual reproduction
asexual reproduction
offspring are produced from a single parent and are clones of the part
Three parts of asexual reproduction
budding- portion of parent pinched off to form a completely new individual
Regeneration/fragmentation - complete organism formed from a fragment of parents body
Fission- parent divides mitotically into 2 nearly equal parts
Same genes, no genetic variation
Sexual reproduction
requires meiosis followed by cytokinesis reduction division
2 haploid gametes fuse to produce a new individual
offspring are genetically different from both parents
genetics variation/ new gene combo
Most animal species reproduce sexually
Energetically expensive, especially on female side
requires time for sexual maturity, sex organs, and sex cells
Fertilization is the union of a haploid egg and haploid sperm to produce a diploid zygote
Development of the zygote forms the embryo
1n egg + 1n sperm 2N zygote- cell division- 2N multicellular embryo
Advantages and disadvantages
asexual reproduction
one parent; no gametes; no reproductive organs
Simple way to produce many copies of an individual
Result of mitosis/cytokinesis
Can reproduce even if isolated alone
Can reproduce rapidly and at any time
Energetically cheap
Genetically the same
More prevalent in species from stable environments with lots of resources and little selection pressure for genetic diversity
If the selection pressure increases, it would wipe out the population due to the lack of genetic variation (genetic variation allows for survival of the fittest so if there’s no variation then the whole population will be on the same level)
Sexual reproduction
2 types of gametes must be made
Male and female requires specialized body parts and must find each other to mate
Allows for greater genetic variation due to genetic recombination
may allow rapid adaptation to environment changes
Types of sexual reproduction
hermaphroditism
individuals have both male and female reproductive organs- each individual usually capable of producing offspring
Monoecious- condition where both types of sex organs in same individual
most examples exhibit cross-fertilization (2 individuals); self fertilization uncommon
Sex reversal on occasion (fish)
Parthenogenesis:
development of an embryo from an unfertilized egg
Sperm may or may no be involved with initiation of development
this means sperm does not fuse with egg but it does trigger certain hormonal developments to help drop the egg
Amniotic- no meiosis and egg forms by mitosis/cytokenisis
Meiotic- egg forms by meiosis (haploid) an develops without fusing sperm
Has been described in vertebrate animals (all groups but mammals)
Biparental reproduction
2 genetically different individuals
2 types of sex organs producing 2 types of gametes (sex cells)
Dioecious- condition of separate sexed individuals
Fusion of egg and sperm
Reproductive modes (vertebrates)
oviparous
condition of egg-laying outside of the body
Fertilization may be external or internal
Eggs may be abandoned
Fish, amphibians, reptiles, birds, mammals (3 species)
Simple (but wouldn’t call it primitive)
Ovoviviparous
condition of eggs (within some form of shell-like structure) retained in female’s body
Fertilization must be internal
All nourishment derived from yolk of egg
No maternal connection
Offspring are both “live” (but enclosed)
enclosed in sac but emerges quickly after “birthing”
Fish, amphibians, reptiles
Viviparous
condition of live-bearing with a maternal connection
Placenta- connecting structure with uterus
Requires internal fertilization
Nourishment and gas exchange with placenta
Live-bearing is highest degree of parental care
Fish, reptiles, mammas
Why sexual reproduction of asexual reproduction
vertebrates
much more common
Energetically costly, takes time, complex structures and sex cells
Advantage: results in genetic variation (most important)
Gametogenesis and fertilization
gametes (sex cells) are formed in gonads
testes in males, ovaries in females
Gametogenesis begins with germ cells that multiply by mitosis to produce spermatogonia (diploid) or oogonia (diploid)
Primordial germ cells arise from yolk sac and migrate to primitive gonad
Vertebrate gonads arise from pair of genital ridges along the dorsal body wall and migrate lower trunk region
Some spermatogonia and oogonia multiply again by mitosis to produce primary spermatocytes and primary oocytes
These undergo meiosis to form haploid gametes (sperm and egg) eventually
Spermatogenesis
primary spermatocytes undergo mitosis I to produce 2 haploid secondary spermatocytes
Eventually develops into sperm
One diploid cell becomes 4 gametes (haploid)
Spermatogonia 2n- primary spermatocytes 2n- secondary spermatocytes 1n- spermatids 1n- mature sperm cells 1n
Oocytes
1 gamete produced from each primary oocyte
Meiosis 1 produces 1 large secondary oocyte plus a smaller polar body which eventually degenerates
1 or many ova can develop at a time
Oocytes develop within follicles in the ovaries and are released during ovulation (rupturing of the follicles)
Timing is longer on females and there’s dormancy at a certain period
Mammalian oogenesis
begins in the fetus before birth
cohort of germ cells enter meiosis 1 and arrest- will not resume development until pubert
Meiosis 1 is completed in some primary oocytes to produce haploid secondary oocytes
Meiosis in
Fusion of the 1n egg muscles with a haploid sperm nucleus produces a 2N zygote (fertilized egg)
Oogonia 2n- primary oocytes 2n- secondary oocyte 1n- secondary polar body 1n degenerates and haploid egg 1n (diploid zygote once the egg and sperm nuclei fuse)
Fertilization
haploid egg and sperm unite to form a 2n zygote
Sperm swims toward egg
Sperm uses proteolytic enzymes in acrosome (protective cap) to digest the plasma membrane of egg
Mammalian reproductive structure and function
male genitalia
consists of penis and scrotum
Scrotum holds tests where sperm develops at 2 degrees Celsius lower than core body temp
Each testis is composed of seminiferous tubules (site of spermatogenesis) and leydig cells (endocrine cells that secrete testosterone)
spermatogenesis begins at puberty and continues throughout life
Sertoli cells provide nutrients and protection to developing sperm
Sperm
sperm are released into lime of seminiferous tubules
Move into epidiymis to complete their differentiation by become in motile and capable of fertilization
Then to vas deferents leading to ejactulatory ducts and urethra
Semen constrains fluid and sperm
sperm abt 50% of volume
Fluid from seminal vesicles (fructose), bulbourethral glands (fluid) and prostate gland (fluid)
Hormonal control of male reproductive system
hypothalamus (secretes LH and FSH)- bloodstream- pituitary glans (secretes LH and FSH) - bloodstream- gonads (male=testes)
FSH (follicle stimulating hormone)- initiates sperm production in seminiferous tubules
LH (luteinizing hormone)- stimulates leydig cells to secrete testosterone
Testosterone
actions of testosterone
stimulates growth of male reproductive reach and genitalia during development and puberty
Stimulates development of male secondary sexual characteristics- facial hair in humans, horns in bulls, bright feather in peacocks
Ovary (female gonad)
production of ovum (egg)
Hormone secretion- estrogen and progesterone
Primordial cells producing oogonia form during embryonic development
Much more time and energy required than with male
Female reproductive tissue
female genitalia differentiate from the same embryonic tissue as male genitalia
labia majora- same tissue as scrotum
Labia minora- same tissue as urethral primordial tissue
Clitoris- same erectile tissue as penis
Urthera is not part of the reproductive tract in females
Opening of reproductive tract and urethra are separate
External opening of the reproductive tract leads to vagina, cervix, and into uterus
Uterus has inner glandular lining (endometrium)
endometrium builds up for implantation
Oocytes
develop in 1 orf 2 ovaries
Typically, 1 secondary oocyte released and is quickly drawn to oviduct (uterine tube/ fallopian tube)
moves down oviduct by cilia
Fertilization usually in oviduct (upper 40%)
zygote develops into blastocyst (a ball o f32-150 cells) and entera the uterus
Fertilization
uterus is the implantation site
many cell division to become blastocytes
Endometrium builds up with vessels and epithelial tissue
If fertilization happens and implantation occurs endometrium continues to develop and is maintained by hormonal activity
connection in the placenta
If fertilization/implantation does not occur- endometrium sloughs off and is discharged
Hormonal control of female reproductive system
hypothalamus (secretes LH and FSH)- bloodstream- pituitary gland (secretes LH and FSH)- bloodstream- gonads (female=ovaries)
FSH- stimulates development of ovarian follicles and estrogen (and progesterone) by follicle
LHH- stimulates secretion of progesterone (and estrogen) by corpus luterum (remnant of follicle after ovulation-release oocyte)