Exam 3 Flashcards
amniotes
Terrestrial vertebrates: reptiles, birds, and mammals; animals whose embryos are enclosed by an amnion.
articulated
tracheated
hexapod
jointed
having tracheal tubes for gas exchange
having six feet
cranial nerves
The 10 to 12 pairs of nerves in vertebrates that emerge directly from the brain.
transverse section or cross section
cuts at right angles to the body axis and seperates anterior and posterior parts.
positive feedback system
positive feedback system, a change in some steady state sets off a response that intensifies (rather than reverses) the changing condition. Although some positive feedback mechanisms are beneficial, they do not maintain homeostasis. For example, a positive feedback cycle operates during the birth of a baby. As the baby’s head pushes against the cervix (lower part of uterus), a reflex action causes the uterus to contract. The contraction forces the head against the cervix again, stimulating another contraction, and the positive feedback cycle repeats again and again until the baby is born
peristalsis
peristalsis, waves of muscular contraction that push the food in one direction
medusa
A jellyfish-like animal; a free-swimming, umbrella-shaped stage in the life cycle of certain cnidarians.
ventral
the underside (belly) surface
schizocoely
The process of coelom formation in which the mesoderm splits into two layers, forming a cavity between them; characteristic of protostomes.
classification of modern amphibians?
classify modern amphibians (class Amphibia) in three orders. Order Urodela (“visible tail”) includes salamanders, mud puppies, and newts, all animals with long tails; order Anura (“no tail”) is made up of frogs and toads, with legs adapted for hopping; and order Apoda (“no feet”) contains the wormlike caecilians
phoronids
wormlike, sessile animals found in coastal marine sediments.
secrete chitinous tubes in which they live.
They extend their lophophores from their tubes for feeding.
connective tissue
Almost every organ in the body has a framework of connective tissue that supports and cushions it.
Animal tissue consisting mostly of an intercellular substance (fibers scattered through a matrix) in which few cells are embedded, e.g., bone.
nature/function of each kind of connective tissue are determined in part by the structure and properties of the intercellular substance.
motility
the mixing and propulsive movements of the digestive tract are referred to as motility. T
pedipalps
second appendages
The chelicerae and pedipalps are modified to perform different functions in various groups, including manipulation of food, locomotion, defense, and copulation.
incisors
chisel-shaped incisors are used for biting and cutting food
vital functionsof the liver
A single liver cell can carry on more than 500 separate, specialized metabolic activities! The liver performs these vital functions:
1. Secretes bile that mechanically digests fats
2. Helps maintain homeostasis by removing or adding nutrients
to the blood
3. Converts excess glucose to glycogen and stores it
4. Converts excess amino acids to fatty acids and urea
5. Stores iron and certain vitamins
6. Detoxifies alcohol and other drugs and poisons
cardiac muscle tissue
Location: walls of heart
Type of control: Involuntary Shape of fibers: Elongated, cylindrical, fibers that branch and fuse Striations: Present Number of nuclei per fiber: 1 or 2 Position of nuclei: central Speed of contraction: intermediate (varies) Resistance to fatigue (with repetitive contraction): intermediate
protosomes
A major division of the animal king- dom in which the blastopore develops into the mouth, and the anus forms secondarily; includes the annelids, arthropods, and mollusks.
mesoderm
The middle germ layer of the early embryo; gives rise to connective tissue, muscle, bone, blood vessels, kidneys, and many other structures.
hemocoel
Blood cavity characteristic of animals with an open circulatory system.
this is not a coelom
placenta
Most mammals develop a placenta, an organ of exchange between developing embryo and mother. As the mother’s blood passes through blood vessels in the placenta, it delivers nourishment and oxygen to the embryo and carries off wastes.
actin
The protein of which microfilaments consist. Actin, together with the protein myosin, is responsible for muscle contraction.
key role in muscle fibers
chelipeds
The appendages of the first three segments of the thorax are the maxillipeds, which aid in chopping up food and passing it to the mouth. The fourth segment of the thorax has a pair of large chelipeds, or pinching claws. The last four thoracic segments bear walking legs.
water vascular system
Unique hydraulic system of echinoderms; functions in locomotion and feeding.
network of fluid filled canals and chambers
clasper
In the mature male, each pelvic fin has a slender, grooved section, known as a clasper, used to transfer sperm into the female’s cloaca.
setae
Bristlelike structures that aid in annelid locomotion.
blastopore
The primitive opening into the body cavity of an early embryo that may become the mouth (in protostomes) or anus (in deuterostomes) of the adult organism.
epithelial membrane
epithelial membrane consists of a sheet of epithelial
tissue and a layer of underlying connective tissue. Types
of epithelial membranes include mucous membranes and serous membranes.
submucosa
submucosa, a connective tissue layer rich in blood vessels, lymphatic vessels, and nerves.
collar cells
Sponges have flagellate cells called collar cells, or choanocytes,
make up the inner layer of certain sponges. Each cell equipped with a tiny collar surrounding the base of the flagellum.
extension of the plasma membrane and consists of microvilli. Collar cells create the water current that brings food and oxygen to the cells and carries away carbon dioxide and other wastes. Collar cells also trap and phagocytize food particles. Together, the collar cells of some sponges can pump a volume of water equal to the volume of the sponge each minute!
Craniates
distinctive head (skull, brain, sense organs) active predators, duplicated hox genes
new neural crest tissue (unique), 2 chamber heart (ventral), kidneys
*Haikouella *
Hox genes
Clusters of homeobox-containing genes that specify the anterior-posterior axis of various animals during development.
all animals but sponges
hermaphodites
the same individual can produce both eggs and sperm.
pentaradial symmetry
the body is arranged in five parts around a central axis.
What are some of the main types of connective tissue?
Some of the main types of connective tissue are (1) loose and dense connective tissues; (2) elastic connective tissue; (3) reticular connective tissue; (4) adipose tissue; (5) cartilage; (6) bone; and (7) blood, lymph, and tissues that produce blood cells. These tissues vary widely in their structural details and in the functions they perform
Ingestion
process of taking food into the digestive cavity
heterotrophs
An organism that cannot synthesize its own food from inorganic raw materials and therefore must obtain energy and bodybuilding materials from other organisms. Also called consumer.
evisceration
in which the digestive tract, respiratory structures, and gonads are ejected from the body, usually when environmental conditions are unfavorable. When conditions improve, the lost parts are regenerated.
pheromones
substances secreted to the external environment
Brachiopoda
lamp- shells, are solitary marine animals that inhabit cold water. suspension feeders that superficially resemble clams and other bivalve mollusks. Their body is enclosed between two shells and has a mantle and mantle cavity, shells are dorsal and ventral, each shell is symmetrical about the midline, and the two shell valves are typically of unequal size.
attach to the substrate by a long stalk. The action of cilia on the lophophore brings water with suspended food into the slightly opened shell.
larva
a sexually immature form that may look very different from the adult.
atria
receive blood
spongocoel
Water passes into the central cavity, or spongocoel (not a digestive cavity), and then flows out through the sponge’s open end, the osculum.
plasma
the liquid, noncellular part of the blood
Plasma consists of water, proteins, salts, and a variety of soluble chemical messengers such as hormones that it transports from one part of the body to another.
bone
Bone
Main Locations: Forms skeletal structure in most vertebrates
Functions: Supports and protects internal organs; calcium reservoir; skeletal muscles attach to bones
Description and Comments: Osteocytes in lacunae; in compact bone, lacunae embedded in lamellae, concentric circles of matrix surrounding Haversian canals.
cuticle
The outer covering of some animals, such as roundworms.
crop
An interesting feature of the bird digestive system is the crop, an expanded, saclike portion of the digestive tract below the esophagus, in which food is temporarily stored.
physiology
the study of how the body functions
villi
microvilli
The lining of the small intestine appears velvety because of its millions of tiny fingerlike projections, the intestinal villi (sing., villus). The villi increase the surface area of the small intestine for digestion and absorption of nutrients. The intestinal surface is further expanded by microvilli, projections of the plasma membrane of the simple columnar epithelial cells of the villi.
triploblastic
have 3 tissue layers. third germ layer, the mesoderm,
tube feet
Structures characteristic of echinoderms; function in locomotion and feeding.
extend when filled with fluid
interstitial fluid
The fluid that bathes the tissues of the body; also called tissue fluid.
acoelomates
an animal lacking a body cavity (coelom).
Food passes in sequence through the following specialized regions?
Various regions of the vertebrate digestive tract are specialized to perform specific functions. Food passes in sequence through the following specialized regions:
mouth –> pharynx (throat) –> esophagus –> stomach –> small intestine –> large intestine –> anus
secondary mycelium
A dikaryotic mycelium formed by the fusion of two primary hyphae
bone
Bone, the main vertebrate skeletal tissue, is like cartilage in that it consists mostly of matrix material.
pedicellariae
pincerlike, modified spines on the body surface.
These structures, found only among the echinoderms, keep the surface of the animal free of debris.
bolus
After being chewed and fashioned into a lump called a bolus, the bite of food is swallowed—moved through the pharynx.
chondrocytes,
Cartilage is firm yet elastic. Its cells, called chondrocytes, secrete a hard, rubbery matrix that surrounds them. They also se- crete collagen fibers, which become embedded in the matrix and strengthen it. Chondrocytes eventually come to lie, singly or in groups of two or four, in small cavities in the matrix called lacunae.
cochlea
The evolution of the cochlea, the organ of hearing in the inner ear, gives mammals an excellent sense of hearing.
Tiktaalik
was a transitional form between fishes and tetrapods. Biologists consider Tiktaalik, which lived about 375 mya (during the Devonian period), a fish because it had scales and fins. However, Tiktaalik also had tetrapod features such as a movable neck and ribs that supported lungs.
proventriculus
The stomach is divided into a proventriculus, which secretes gastric juices; and a thick, muscular
segmentation
a body plan in which certain structures are repeated, producing a series of body compartments. Each compartment can be regulated somewhat independently of the others, which means that various parts of the body can become specialized to perform various functions.
open circulatory system
A type of circulatory system in which the
blood bathes the tissues directly; characteristic of arthropods and many mollusks.
Body plan of a sea star
(a) A sea star viewed from above, with its arms in various stages of dissection. Similar structures are present
in each arm, but some organs are not shown in order to highlight certain structures. The two-part stomach is in the central disc with the anus on the aboral (upper) surface and the mouth beneath on the oral surface. (b) Cross section through arm and tube feet. (c) LM of tube feet of a sea star.
protonephridia
The flame-cell excretory organs of flatworms and some other simple invertebrates.
function in osmoregulation (fluid balance) & metabolic waste disposal (excretion).
Amoeboid cells
wander about in mesophyll, secrete the spicules.
transports nutrients to epidermal cells
rugae
folds of the stomach wall, called rugae, give the inner lining a wrinkled appearance. As food enters, the rugae gradually smooth out, which expands the capacity of the stomach to more than a liter.
pancreas
The pancreas is an elongated gland that secretes both digestive enzymes and hormones that help regulate the level of glucose in the blood. The cells that line the pancreatic ducts secrete an alkaline solution rich in bicarbonate ions. This pancreatic juice neutralizes the stomach acid in the duodenum and provides the optimal pH for action of the pancreatic enzymes. Pancreatic enzymes include trypsin and chymotrypsin, which digest polypeptides to dipeptides; pancreatic lipase, which degrades fats; pancreatic amylase, which breaks down almost all types of complex carbohydrates, except cellulose, to disaccharides; and ribonuclease and deoxyribonuclease, which split the nucleic acids ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) to free nucleotides.
elctroreceptors
A receptor that responds to electrical stimuli.
sharks may detect other animals electrically before sensing them by sight or smell. Electroreceptors on the shark’s head sense weak electric currents generated by the muscular activity of animals.
muscle layer
muscle layer, consisting of two sublayers of smooth muscle, surrounds the submucosa.
In the inner sublayer, the muscle fibers are arranged circularly around the digestive tube. In the outer sub- layer, the muscle fibers are arranged longitudinally
cleavage
Series of mitotic cell divisions, without growth, that converts the zygote to a multicellular blastula.
mesoglea
a thick, jellylike separates thin layers
mainly acellular.
embryonic development
Zygote undergoes cleavage, during cleavage zygote develops into blastula —-> larva —-> adult
epithelial tissue
aka epithelium
The type of animal tissue that covers body surfaces, lines body cavities, and forms glands.
consists of cells fitted tightly together to form a continuous layer, or sheet, of cells.
closely packed, often with tight junctions
forms the outer layer of the skin and the linings of the digestive, respiratory, excretory, and reproductive tracts.
functions, including protection, absorption, secretion, and sensation.
planula
A ciliated larval form found in cnidarians–> anthrozoans
premolars and molars
The flattened surfaces of the premolars and molars are specialized for crushing and grinding
Elastic fibers
branch and fuse to form networks.
can be stretched by a force and then (like a stretched rubber band) return to their original size and shape when the force is removed. Elastic fibers, composed of the protein elastin, are an important compomnent of structures that must stretch.
endotherms
endotherms: they have homeostatic mechanisms that maintain body temperature despite changes in the external temperature. The most important benefit of endothermy is the high metabolic rate, which can be as much as six times higher than that of ectotherms. Their constant body temperature allows a higher rate of enzyme activity than is possible for ectotherms living in the same habitat. Endotherms respond more rapidly to internal and external stimuli and can be active even in low winter temperatures. However, these animals must pay the high energy cost of thermoregulation during times when they are inactive. You must maintain your body temperature even when you are asleep.
biramous appendages
Appendages with two jointed branches at
their ends; characteristic of crustaceans.
visceral mass
The concentration of body organs (viscera) located
above the foot in mollusks.
differentiation of teeth
incisors, canines, pre- molars, and molars;
gastrovascular cavity
A central digestive cavity with a single opening that functions as both mouth and anus; characteristic of cnidarians and flatworms.
carapace
The five segments of the lobster’s head and the eight segments of its thorax are fused into a cephalothorax, which is covered on the top and sides by a shield, the carapace, composed of chitin impregnated with calcium salts.
superior
refers to a structure located above some point of reference, or toward the head end of the body.
notochord
dorsal, longitudinal rod composed of cartilage. The notochord is firm but flexible, and it supports the body.
The flexible, longitudinal rod in the anterior-posterior axis that serves as an internal skeleton in the embryos of all chordates and in the adults of some.
oviparous
Bearing young in the egg stage of development; egg laying.
canines
long, pointed canines are adapted for piercing prey and tearing food
tracheae, or tracheal tubes
(1) Principal thoracic air duct of terrestrial vertebrates; windpipe. (2) One of the microscopic air ducts (or tracheal tubes) branching throughout the body of most terrestrial arthropods and some terrestrial mollusks.
vertebral column
backbone
mantle
In the mollusk, a fold of tissue that covers the visceral mass and that usually produces a shell.
amniotes
The reptiles and mammals form a clade known as amniotes, animals fully adapted to life on land.
chylomicrons
Protein-covered fat droplets produced in the intestinal cells; they enter the lymphatic system and are transported to the blood.
dorsal
the back surface of an animal
synapses
Neurons communicate at junctions called synapses.
pseudocoelom
A body cavity between the mesoderm and endoderm; derived from the blastocoel.
elimination vs excretion
A distinction should be made between elimination and excretion.
Elimination is the process of getting rid of digestive wastes— materials that have not been absorbed from the digestive tract and did not participate in metabolic activities.
In contrast, excretion is the process of getting rid of metabolic wastes, which in mammals is mainly the function of the kidneys and lungs. The large intestine, however, does excrete bile pigments.
What three types of fibers do connective tissue typically contains?
Connective tissue typically contains three types of fibers: collagen, elastic, and reticular.
ectothermic
their body temperature fluctuates with the temperature of the surrounding environment. Some reptiles have behavioral adaptations that help them maintain a body tem- perature higher than that of their environment
tooth structure
biradial symmetry
For example, sea anemones and ctenophores (comb jellies) have biradial symmetry, in which parts of the body have become specialized so that only two planes can divide the body into similar halves.
cambrian radiation (explosion)
A span of 40 million years, beginning about
542 mya, during which many new animal groups appeared in the fossil record.
uniramous appendages
unbranched appendages
amnion
In terrestrial vertebrates, an extra embryonic membrane that forms a fluid-filled sac for the protection of the developing embryo.
Pseudostratified Epithelium
Pseudostratified Epithelium
Main Locations: Some respiratory passages; ducts of many glands
Functions: Secretion; protection; moves layer of mucus
Description and Comments: Ciliated, mucus-secreting, or with microvilli; comparable in many ways to columnar epithelium except that not all cells are the same height; so, though all cells contact the same basement membrane, the tissue appears stratified
hemolymph
The fluid that bathes the tissues in animals with an open circulatory system, e.g., arthropods and most mollusks.
haustoria
In parasitic fungi, a specialized hypha that penetrates a host cell and obtains nourishment from the cytoplasm.
lophophorates
With a few exceptions, marine animals adapted for life on the ocean floor.
coelomates, distinguished by their lophophore, do not have a distinct head.
The three lophophorate groups are Brachiopoda lamp- shells, Phoronida, and Bryozoa (also known as Ectoprocta).
endostyle
a groove in the floor of the pharynx that secretes mucus and traps food particles in the sea water passing through the pharynx.
The endostyle is present in the urochordates, cephalochordates, and lamprey larvae.
The thyroid gland evolved from the endostyle and is present in all other chordates.
mandibles
hard mandibles, used for biting and grinding food, are the third pair of appendages; they lie on each side of the ventral mouth.
parynx
pharynx into the esophagus. The pharynx, or throat, is a muscular tube that serves as the hallway of both the respiratory system and the digestive system. During swallowing, a small flap of tissue, the epiglottis, closes the opening to the airway.
Simple Cuboidal Epithelium
Simple Cuboidal Epithelium
Main Locations: Linings of kidney tubules; gland ducts
Functions: Secretion and absorption
Description and Comments: Single layer of cells; LM shows cross section through tubules; from the side each cell looks like a short cylinder; some have microvilli for absorption
conformers
Some of their internal states vary with changes in their surroundings. For example, most marine invertebrates conform to the salinity of the surrounding sea water.
large intestine
Undigested material, such as the cellulose of plant foods, along with unabsorbed chyme, passes into the large intestine. Although only about 1.3 m (about 4 ft) long, this part of the digestive tract is referred to as “large” because its diameter is greater than that of the small intestine.
the small intestine joins the large intestine about 7 cm (2.8 in) from the end of the large intestine, forming a blind pouch, the cecum.
paedomorphosis
Retention of juvenile or larval features in a sexually
mature animal.
operculum
A lateral bony flap, the operculum, extends posteriorly from the head and protects the gills.
Simple Columnar Epithelium
Simple Columnar Epithelium
Main Locations: Linings of much of digestive tract and upper part of respiratory tract
Functions: Secretion, especially of mucus; absorption; protection; moves layer of mucus
Description and Comments: Single layer of columnar cells; sometimes with enclosed secretory vesicles (in goblet cells); highly developed Golgi complex; often ciliated
duodenum
the portion of the small intestine into which the contents of the stomach first enter.
The earliest vertebrate fossils?
The earliest vertebrate fossils include Haikouichthys, conodonts, and a group known as ostracoderms
metamorphosis
a developmental process that converts the immature animal into a juvenile form that can grow into an adult.
fibroblasts
connective tissue cells that produce the fibers, as well as the protein and carbohydrate complexes, of the matrix.
release protein components that become arranged to form the characteristic fibers. These cells are especially active in developing tissues and are important in healing wounds. As tissues mature, the number of fibroblasts decreases and they become less active.
basidia
the clublike spore-producing organ of basidiomycetes that bears sexual spores called basidiospores.
arboreal
tree dwelling
furcula
furcula, or wishbone, which is formed by the two clavicles (collarbones) fusing in the midline. Some biologists classify modern birds as theropods.
Loose Connective Tissue
Loose Connective Tissue
Main Locations: Everywhere that support must be combined with elasticity, such as subcutaneous tissue (the layer of tissue beneath the dermis of the skin)
Functions: Support; reservoir for fluid and salts
Description and Comments: Fibers produced by fibroblast cells embedded in semifluid matrix and mixed with miscellaneous other cells
skeletal muscle tissue
Location: attached to skeleton
Type of control: Voluntary Shape of fibers: Elongated, cylindrical, blunt ends Striations: Present Number of nuclei per fiber: many Position of nuclei: Peripheral Speed of contraction: Most rapid Resistance to fatigue (with repetitive contraction): least
lacteal
the wall of a villus is a single layer of epithelial cells. Inside each villus is a network of capillaries and a central lymph vessel, called a lacteal.
white blood cells
White blood cells defend the body against disease-causing microorganisms.
bilateral symmetry
A body shape with right and left halves that are approximately mirror images of each other.
Plankton
consists of the mainly microscopic animals and protists that are susended in water and float with its movement
provide a ready source of food for many aquatic animals
Ichthyostega
earliest amphibian fossil found. had strong legs supported by well- developed shoulder & hip bones & muscles.
Natural selection favored animals such as Ichthyostega that could explore shallow wetlands and make their way onto dry land. The ability to move about on land, however awkwardly, provided access to new food sources. Terrestrial plants were already established, and terrestrial insects and arachnids were rapidly evolving. A vertebrate that could survive on land had less competition for food.
tube within a tube
With the evolution of the coelom
came a new body design, the tube-within-a-tube body plan. The coelom is a space that separates the body wall,
the outer tube, from the digestive tube
(gut), which is the inner tube. The digestive tube is attached to the body wall at its ends.
We can distinguish three types of epithelial cells on the basis of shape. What are they?
Squamous-epithelial cells are thin, flat cells shaped like flagstones.Columnar epithelial cells look like columns or cylinders when viewed from the side.
Cuboidal-epithelial cells are short cylinders that from the side appear cube-shaped, like dice. Actually, each cuboidal cell is typically hexagonal in cross section, making it an eight-sided polyhedron.
Columnar-epithelial cells look like columns or cylinders when viewed from the side. The nucleus is usually located near the base of the cell. Viewed from above or in cross section, these cells often appear hexagonal. On its free surface, a columnar epithelial cell may have cilia that beat in a coordinated way, moving materials over the tissue surface. .
primary mycelium
A mycelium in which the cells are monokaryotic
and haploid; a mycelium that grows from either an ascospore or a basidiospore.
major organ systems in mammals
We can identify 11 major organ systems that work together to carry out the physiological processes of a mammal: integumentary, skeletal, muscular, digestive, cardio- vascular, immune (lymphatic), respiratory, urinary, nervous, endocrine, and reproductive systems. FIGURE 39-4 summarizes the principal organs and functions of each organ system.
frontal plane
divides a bilateral body into dorsal and ventral parts.
Bryozoans
also known as ectoprocts or “moss animals,” are microscopic aquatic animals. They form sessile colonies by asexual budding. Each colony can consist of millions of individuals
cartilage
the supporting skeleton in the embryonic stages of all vertebrates. In most vertebrates, bone replaces cartilage during development. However, cartilage remains in some supporting structures
pit organs
Pit vipers and some boas also have a prominent pit organ on each side of the head that detects heat from endothermic prey. These snakes use their pit organs to locate and capture birds and small nocturnal mammals.
adipose tissue store fat
The cells of adipose tissue store fat and release it when fuel is needed for cellular respiration. Adipose tissue is found in the sub- cutaneous layer and in tissue that cushions internal organs.
vertebrae
The vertebral column consists of cartilaginous or bony segments called vertebrae.
neocortex
In mammals, the highly specialized cerebral cortex, called the neocortex, has six layers of neurons. Specific regions in the neocortex are specialized for functions such as vision, hearing, touch, movement, emotional response, and higher cognitive functions.
myofibrils
Tiny threadlike structures in the cytoplasm of striated and cardiac muscle that are composed of myosin filaments and actin filaments; these filaments are responsible for muscle contraction;
coelom
pronounced “see’-lum”
The main body cavity of most animals; a true coelom is lined with mesoderm.
endoskeleton
Bony and/or cartilaginous structures within the body that provide support.
an internal skeleton, covered by a thin, ciliated epidermis. The endoskeleton consists of calcium carbonate (CaCO3) plates and spines.
cloaca
opens on the underside of the body and is characteristic of many vertebrates
An exit chamber in some animals that receives digestive wastes and urine; may also serve as an exit for gametes.
determinate cleavage
For example, if the first four cells of an annelid embryo are separated, each cell develops into only a fixed quarter of the larva; this pattern of cleavage is called determinate cleavage.
If a few cells are removed from the blastula of an embryo undergoing determinate cleavage, some structure, such as a limb, does not develop.
Loose connective tissue
Loose connective tissue is the most widely distributed connective tissue in the vertebrate body. Together with adipose tissue, loose connective tissue forms the subcutaneous (below the skin) layer that attaches skin to the muscles and other structures beneath. Nerves, blood vessels, and muscles are wrapped in loose connective tissue. This tissue also forms a thin filling between body parts and serves as a reservoir for fluid and salts. Loose connective tissue consists of fibers running in all directions through a semifluid matrix. Its flexibility permits the parts it connects to move.
osculum
sponge’s open end, the osculum, where water flows out of.
sea daisies
a curious group of asteroids characterized by small, disc-shaped, flat bodies (less than 1 cm in diameter) with no arms or mouth. They inhabit bacteria-rich wood sunk in deep water and apparently absorb bacteria through their body surface.
radial cleavage
The pattern of blastomere production in which the cells are located directly above or below one another; characteristic of early deuterostome embryos.
Simple epithelium
Epithelial tissue is also classified by number of layers. Simple epithelium is composed of one layer of cells. It is usually located where substances are secreted, excreted, or absorbed, or where materials diffuse between compartments.
For example, simple squamous epithelium lines the air sacs in the lungs. The structure of this thin tissue allows diffusion of gases in and out of air sacs.
A benefit of ectothermy?
A benefit of ectothermy is that very little energy is used to maintain a high metabolic rate. In fact, an ectotherm’s metabolic rate tends to change with the weather.
nemerteans
include free living ribbonworms
burrow in marine sediments, inhabit deep seawater, fresh water, or damp soil
carnivorous proboscis –> to capture prey
no heart, blood circulated by contractions of muscular blood vessels and movement of the body.
circulatory system and complete digestive tract
rhynchocoel –> chamber surrounding the proboscis is a coelomic space
blastula
In animal development, a hollow ball of cells produced by cleavage of a fertilized ovum. In mammalian development, known as a blastocyst.
Reticular connective tissue
composed mainly of interlacing reticular fibers. It forms a supporting internal framework in many organs, including the liver, spleen, and lymph nodes.
positive feedback system
coelacanths
A genus of lobe-finned fishes that has survived to the present day.
nocturnal predators on other fishes.
thought to be extinct than found again
gave rise to tetrapods
Thermoregulation
Thermoregulation is the process of maintaining body temperature within certain limits despite changes in the surrounding temperature. Animals produce heat as a byproduct of metabolic activities. Body temperature is determined by the rate at which heat is produced and the rate at which heat is lost to, or gained from, the outside environment.
different hyphas?
spiracles
tiny openings in the body wall
endocrine gland
A gland that secretes hormones directly into the blood or tissue fluid instead of into ducts.
Endocrine glands lack ducts. These glands release their products, called hormones, into the interstitial fluid (tissue fluid) or blood; hormones are typically transported by the cardiovascular system.
crop
thin walled crop where food is stored formed by the esophagus
Stratified epithelium
has two or more layers, protects underlying tissues. For example, stratified squamous epithelium, which makes up the outer layer of your skin, is continuously sloughed off during normal wear and tear. It must also continuously regenerate.
foot
a broad, flat located ventrally, which is used for locomotion.
cephalization
development of a head where sensory structures are concentrated.
Elastic Connective Tissue
Elastic Connective Tissue
Main Locations: Structures that must both expand and return to their original size, such as lung tissue and large arteries
Function: Confers elasticity
Description and Comments: Branching elastic fibers interspersed with fibroblasts
lateral
a structure is said to be lateral if it is toward one side of the body
spongin
The fibrous part of the sponge skeleton consists of spongin, a form of collagen.
nerve nets
Cnidarians have nerve cells that form nerve nets connecting sensory cells in the body wall to contractile cells and gland cells.
A system of interconnecting nerve cells found in cnidarians and echinoderms.
germ layers
In animals, three embryonic tissue layers: endoderm, mesoderm, and ectoderm.
macrophages
the body’s scavenger cells, commonly wander through connective tissues, cleaning up cell debris and phagocytosing foreign matter, including bacteria.
large phagocytic cell capable of ingesting and digesting bacteria and cell debris, also antigen-presenting cells.
blood
Blood
Main Locations: Within heart and blood vessels of circulatory system
Functions: Transports oxygen, nutrients, wastes, and other materials
Description and Comments: Consists of cells dispersed in fluid intercellular substance (plasma).
smooth muscle tissue
Location: walls of stomach, intestines, etc. Type of control: Involuntary Shape of fibers: Elongated, spindle shapedl, pointed ends Striations: Absent Number of nuclei per fiber: 1 Position of nuclei: Central Speed of contraction: slowest Resistance to fatigue (with repetitive contraction): greatest
aflatoxins
few species of Aspergillus, for example, produce potent mycotoxins
pulmonary circulation
The part of the circulatory system that delivers blood to and from the lungs for oxygenation.
auricles
appear to be crossed “eyes” and flapping “ears”
mucosa,
mucosa, which consists of a layer of epithelial tissue and underlying connective tissue, lines the lumen (inner space) of the digestive tract.
In the stomach and intestine, the mucosa is greatly folded to increase the secreting and absorbing surface. Surrounding the mucosa is the submucosa
deuterostomes
Major division of the animal kingdom in which the anus develops from the blastopore; includes the echinoderms and chordates.
viviparous
Bearing living young that develop within the body of the mother.
Not only do the embryos develop within the uterus, but much of their nourishment is delivered to them by the mother’s blood. Nutrients are transferred between the blood vessels in the lining of the uterus and the yolk sac surrounding each embryo.
Mammals descended from?
Mammals descended from therapsids, a group of synapsid rep- tiles, during the Triassic period more than 200 mya. The therapsids were doglike carnivores with differentiated teeth and legs adapted for running.
vermiform appendix
The vermiform appendix projects from the end of the cecum. (Appendicitis is an inflammation of the appendix.)
Haikouichthys
Haikouichthys was a fishlike animal about 2.5 cm (1 in) long. It had several characters found in vertebrates, and some researchers think it was an early jawless fish.
Bilateria
The Bilateria, the lineage of animals with bilateral symmetry, are triploblastic. (They have three germ layers: ectoderm, endoderm, and mesoderm.) As explained in the last section, biologists classify bilateral animals into protostome and deuterostome clades.
Note that the phylogeny we have described assigns bilateral animals to three major clades: Lophotrochozoa, Ecdysozoa, and Deuterostomia.
stressors
Stressors, changes in the internal or external environment that affect normal conditions within the body, continuously challenge homeostasis.
ganglia
A mass of neuron cell bodies; in vertebrates, refers to aggregations of cell bodies in the peripheral nervous system.
cerebral cortex
The cerebrum is especially large and complex, with an outer gray region, the cerebral cortex.
Lophotrochozoa
Molecular data show that the protostomes split into two major clades: Lophotrochozoa and Ecdysozoa. Animals assigned to the Lophotrochozoa are characterized by (1) a lophophore, a ciliated ring of tentacles surrounding the mouth that serves as a feeding organ, or (2) a type of larva called a trochophore larva. The Lophotrochozoa include the flatworms, ribbon worms, mollusks, annelids, and three groups sometimes referred to as the lophophorate phyla.
regulation of temperature in the human body
Dense Connective Tissue
Dense Connective Tissue
Main Locations: Tendons; many ligaments; dermis of skin
Functions: Support; transmits mechanical forces
Description and Comments: Collagen fibers may be regularly or irregularly arranged
smooth muscle
Involuntary muscle tissue that lacks transverse striations; found mainly in sheets surrounding hollow organs, such as the intestine.
medial
a structure is said to be medial if it is located toward the midline of the body.
elastic connective tissue
elastic connective tissue consists mainly of bundles of parallel elastic fibers. This tissue is found in structures that must expand and then return to their original size, such as lung tissue and the walls of large arteries.
liver
liver, the largest internal organ and also one of the most complex organs in the body, lies in the upper-right part of the abdomen just under the diaphragm
true coelomate
An animal with a true coelom is referred to as a true coelomate animal.
Paired, jointed appendages
Paired, jointed appendages, from which this group gets its name (arthropod means “jointed foot”), are modified for many functions. They serve as swimming paddles, walking legs, mouthparts for capturing and manipulating food, sensory structures, or organs for transferring sperm.
Hibernation
Hibernation is long-term torpor in response to winter cold and scarcity of food. Animals that hibernate store unsaturated fats as energy sources.
osteocytes
the bone cells, called osteocytes, are contained within lacunae. Osteocytes secrete and maintain the matrix. Unlike cartilage, however, bone is a highly vascular tissue, with a substantial blood supply. Osteocytes communicate with one another and with capillaries by tiny channels (canaliculi) that contain long cytoplasmic extensions of the osteocytes.
posterior (or caudal)
toward the tail end
gastrodermis
gastrodermis, lines the gastrovascular cavity and functions in digestion.
endoderm givess rise to gastrodermis in cnidarians
lateral line organ
found in all fishes, is a groove along each side of the body with many tiny openings to the outside. Sensory cells in the lateral line organ detect vibrations caused by waves and other movement in the water, including movements by predators or prey
goblet cells
Unicellular glands that secrete mucus.
mucus lubricates these surfaces, offers protection, and facilitates the movement of materials.
Tendons
the cords that connect muscles to bones
test
Sea urchins and sand dollars (class Echinoidea) have no arms, their skeletal plates are flattened and fused to form a solid shell called a test.
compare
bile
The liver secretes bile, which mechanically digests fats by a detergent-like action. Bile consists of water, bile salts, bile pigments, cholesterol, salts, and lecithin (a phospholipid). Because it contains no digestive enzymes, bile does not enzymatically digest food
mucous membrane
A mucous membrane, or mucosa, lines a body cavity that opens to the outside of the body, such as the digestive or respiratory tract. Goblet cells in the epithelial layer secrete mucus that lubricates the tissue and protects it from drying.
swim bladder
an air sac that helps regulate buoyancy
diaphragm
A muscular diaphragm helps move air into and out of the lungs.
radial symmetry
the body has the general form of a wheel or cylinder, and similar structures are regularly arranged as spokes from the central axis.
(a) Radial symmetry. Multiple planes can be drawn through the central axis; each divides the animal into two mirror images.
small intestine
Digestion of food is completed in the small intestine, and nutrients are absorbed through its wall. The small intestine, which is 5 to 6 m (about 17 ft) in length, has three regions: the duodenum, jejunum, and ileum.
chelicerae
First appendages, located immediately anterior to the mouth, are a pair of chelicerae (sing., chelicera), fanglike feeding appendages.
The chelicerae and pedipalps are modified to perform different functions in various groups, including manipulation of food, locomotion, defense, and copulation. The
regulators
They have complex homeostatic mechanisms that maintain relatively constant internal conditions despite changes in the outside environment.
somites
A series of paired blocks of mesoderm that develop on
each side of the notochord in cephalochordates and vertebrates. Somites define the segmentation of the embryo, and in vertebrates, they give rise to the vertebrae, ribs, and certain skeletal muscles.
osteons
Compact bone consists of spindle-shaped units called osteons. Within each osteon, osteocytes are arranged in concentric layers of matrix called lamellae. In turn, the lamellae surround central microscopic channels known as Haversian canals, through which capillaries and nerves pass.
ostia
In the simple asconoid canal system, the beating flagella of collar cells create a current that pulls water through 100’s of tiny pores, called ostia.
endoderm
The inner germ layer of the early embryo; becomes the lining of the digestive tract and the structures that develop from the digestive tract—liver, lungs, and pancreas.
Epidermal cells
Epidermal cells form the outer layer of the sponge and line the canals.
hemichordates
a small group of wormlike marine animals, as deuterostomes.
Hemichordates have a three-part body including a proboscis, collar, and trunk. These animals also have a characteristic ring of cilia surrounding the mouth. The most familiar of the hemichordates are the acorn worms, animals that live buried in mud or sand.
negative feedback system,
negative feedback system, a change in some steady state (for example, normal body temperature) triggers a response that counteracts, or reverses, the change.
Note that the response of the integrator is opposite (negative) to the output of the sensor. When some condition varies too far from the steady state (either too high or too low), a control system using negative feedback brings the condition back to the steady state. For example, when the glucose concentration in the blood decreases below its homeostatic level, negative feedback systems increase its concentration. Most homeostatic mechanisms in the body are negative feedback systems.
pharyngeal slits (also called pharyngeal gill slits)
Chordates have pharyngeal slits (also called pharyngeal gill slits) or pharyngeal pouches during some time in their life cycle. In the embryo, a series of alternating branchial (gill) arches and grooves develop in the body wall in the pharyngeal (throat) region. Pharyngeal pouches extend laterally from the anterior portion of the digestive tract toward the grooves. In aquatic chordates, the tissue breaks through where the pouches meet the grooves, forming slits.
polyp
The polyp form, represented by Hydra, typically has a dorsal mouth surrounded by tentacles.
nervous tissue
A type of animal tissue specialized for transmitting electrical and chemical signals.
torpor
otrpor, a short-term state in which metabolic rate decreases, sometimes dramatically. Torpor saves the energy that the animal would use to maintain a high body temperature.
cardiac muscle
Involuntary, striated type of muscle found in the vertebrate heart.
axon
The single axon transmits signals, called nerve impulses, away from the cell body.
malpighian tubules
The excretory organs of many arthropods.
eumetazoa
Animals with two or three germ layers (diploblastic or triploblastic) make up the eumetazoa.
Blood and lymph
Blood and lymph are circulating tissues that help other parts of the body communicate and interact. Like other connective tis- sues, they consist of specialized cells dispersed in an intercellular substance.
In mammals, blood consists of red blood cells, white blood cells, and platelets, all suspended within plasma, the liquid, noncellular part of the blood.
scolex
hooks on the “head” enables parasite to attach to intestine.
hepatic portal vein
the portion of the circulatory system that
carries blood from the intestine through the liver.
tadpoles
embryos of most frogs and toads develop into larvae called tadpoles
platelets
Platelets, small fragments broken off from large cells in the bone marrow, play a key role in blood clotting.
septa
transverse partitions that seperates segments internally from one another
epithelial cells sensory organs?
Other epithelial cells are sensory receptors that receive information from the environment. For example, epithelial cells in taste buds and in the nose specialize as chemical receptors.
basidiospore
One of a set of sexual spores, usually four, borne on a basidium of a basidiomycete.
Note that basidiospores develop on the outside of a basidium, whereas ascospores develop within an ascus.
dorsal, tubular nerve cord
Present at some time in chordates life cycle
The chordate nerve cord differs from the nerve cord of most other animals in that it is located dorsally rather than ventrally, is hollow rather than solid, and is single rather than double.
heterotrophs
all animals are chemoheterotrophs,
organisms that must obtain their energy and nourishment from the organic molecules manufactured by other organisms.
polyp
A hydralike animal; the sessile stage of the life cycle of certain cnidarians.
ectoderm
The outer germ layer of the early embryo;
gives rise to the skin and nervous system.
ostracoderms
consisted of several groups of small, armored, jawless fishes that lived on the bottom and strained their food from the water. Thick bony plates protected their heads from predators, and thick scales covered their trunks and tails. Most ostracoderms lacked fins. Fragments of ostracoderm scales have been found in rocks from the Cambrian period, but most ostracoderm fossils are from the Ordovician and Silurian periods. They became extinct by the end of the Devonian period.
gas exchang in cartilaginous fishes?
Cartilaginous fishes have no lungs. Gas exchange takes place through their five to seven pairs of gills. A current of water enters the mouth and passes over the gills and out the gill slits, constantly providing the fish with a fresh supply of dissolved oxygen. Sharks that actively swim depend on their motion to enhance gas ex- change. Rays, skates, and sharks that spend time on the ocean floor use muscles of the jaw and pharynx to pump water over their gills.
gastrulation
Process in embryonic development during which the three germ layers (ectoderm, mesoderm, and endoderm) form.
a process that forms and segregates the 3 germ layers.
sagittal plane
divides the body into right and left parts. passes from anterior to posterior and from dorsal to ventral.
coelentrates and likes
shared characteristics
- have tissues, no organs 2. radial symmetry
- respiration & excretion - body surface 4. diploblastic development
Dendrites
Dendrites are cytoplasmic extensions specialized for receiving signals and transmitting them to the cell body.
oral surface
location of the mouth
statocyst
a sensory organ called a “statocyst,” which coordinates beating of the cilia in the combs. The coordinated beating of the cilia moves the animal through the water. The statocyst also functions in balance and helps the animal orient itself.
What are the characteristics of an animal?
multicellular eukaryote, lack cell walls, structural support depends on collagen/ structural proteins, heterotrpohs, digestie systems, most capable of locomotion at some time durng life cycle, nervous systems and muscle systems (most), diploid organisms, period of embryonic development,
describe stomach
The stomach is lined with a simple, columnar epithelium that secretes large amounts of mucus. Tiny pits mark the entrances to the millions of gastric glands, which extend deep into the stomach wall. Parietal cells in the gastric glands secrete hydrochloric acid and intrinsic factor, a substance needed for adequate absorption of vitamin B12. Chief cells in the gastric glands secrete pepsinogen, an inactive enzyme precursor. When it comes in contact with the acidic gastric juice in the stomach, pepsinogen is converted to pepsin, the main digestive enzyme of the stomach. Pepsin hydrolyzes proteins, converting them to short polypeptides.
medusa
In the medusa (pl., medusae), or jellyfish form, the mouth is located in the lower concave, or oral, surface; the convex upper surface is the aboral surface
Ectotherms
Ectotherms are animals that depend on the environment for their body heat. Their body temperature is determined mainly by the changing temperature of their surroundings. Most of the heat for their thermoregulation comes from the sun. most animals are ectotherms.
lamprey notochoed?
As in hagfish, the notochord persists throughout life and is not replaced by a vertebral column. However, lampreys have rudiments of vertebrae, cartilaginous segments called neural arches that extend dorsally around the spinal cord.
tunic
a protective covering, that may be soft and transparent or quite leathery.
consists of a carbohydrate much like cellulose.
has two openings: the incurrent siphon, through which water and food enter; and the excurrent siphon, through which water, waste products, and gametes pass to the outside.
negative feedback system
negative feedback in temp regulation
amniotic egg
Evolution of the amniotic egg was an extremely important event because it allowed terrestrial vertebrates to complete their life cycles on land. The amniotic egg contains an amnion, a membrane that forms a fluid-filled sac around the embryo. The amnion provides the embryo with its own private “pond,” permitting independence from a watery external environment. In addition to keeping the embryo moist, the amniotic fluid serves as a shock absorber that cushions the developing embryo.
visceral peritoneum
the outer connective tissue coat of the digestive tract is called the visceral peritoneum. By various folds it is con- nected to the parietal peritoneum
Stratified Squamous Epithelium
Stratified Squamous Epithelium
Main Locations: Skin; mouth lining; vaginal lining
Functions: Protection only; little or no absorption or transit of materials; outer layer continuously sloughed off and replaced from below
Description and Comments: Several layers of cells, with only the lower ones columnar and metabolically active; division of lower cells causes older ones to be pushed upward toward surface, becoming flatter as they move
muscle fiber
Muscle cells are called muscle fibers because of their length. Each muscle fiber contains many thin, longitudinal, parallel contractile units called myofibrils.
A characteristic of deuterostomes
characteristic of deuterostomes is the presence of pharyngeal slits (openings in the pharynx) at some time in their life cycle. Hemichordates and chordates have pharyngeal slits.
cranium
braincase
metazoa
refers to animals
hydrostatic skeleton
A type of skeleton found in some invertebrates in which contracting muscles push against a tube of fluid.
two sets of contractile cells act on the water-filled gastrovascular cavity, forming a hydrostatic skeleton. This skeleton supports the body and allows movement.
schwann cells
Supporting cells found in nervous tissue outside the central nervous system; produce the myelin sheath around peripheral neurons.
poriferans
Molecular data suggest that the poriferans ( phylum Porifera) are not a monophyletic group. The name Porifera, meaning “to have pores,” aptly describes the sponges, whose bodies are perforated by tiny holes.
the principal organ systems of humans
nematocysts
A stinging structure found within cnidocytes (stinging cells) in cnidarians; used for anchorage, defense, and capturing prey.
gallblader
The pear-shaped gallbladder stores and concentrates bile and releases it into the duodenum as needed.
basidiocarp
The fruiting body of a basidiomycete, e.g., a mushroom.
ampulla
Any small, saclike extension, e.g., the expanded structureat the end of each semicircular canal of the ear.
A rounded muscular sac, or ampulla, at the base of the foot, stores fluid and is used to operate the tube foot.
placoid scales
toothlike structures
Eumetazoa
Other animals have true tissues and were classified as Eumetazoa (eu, “true”; meta, “later”; and zoa, “animals”).
spiral cleavage
A distinctive spiral pattern of blastomere production
in an early protostome embryo.
Ruminants
Ruminants (cattle, sheep, deer, giraffes) are hooved animals with a stomach divided into 4 chambers. Symbiotic bacteria and protists living in the first two chambers digest cellulose, splitting some of the molecule into sugars, which are then used by the host and the bacteria themselves. The bacteria produce fatty acids during their metabolism, some of which are absorbed by the animal and serve as an important energy source.
Anterior (or Cephalic)
toward the head of the animal
epedermis
The outer layer of vertebrate skin.
The epithelial layer of the skin, the epidermis, covers the entire body and protects it from mechanical injury, chemicals, bacteria, and fluid loss.
jawed extinct fish
jawed fishes, now extinct, were the acanthodians, armored fishes with paired spines and pectoral and pelvic fins, and
placoderms, armored fishes with paired fins (FIG. 32-10). The success of the jawed vertebrates probably contributed to the extinction of the ostracoderms.
Estivation
Estivation is a state of torpor caused by lack of food or water during periods of high temperature. During estivation some mammals retreat to their burrows. The cactus mouse enters a state of hibernation during the winter in response to cold and scarcity of food. In summer, it estivates in response to lack of either food or water.
atrium
chamber
middle-ear bones
three middle-ear bones (malleus, incus, and stapes) that transmit vibrations from the tympanic membrane (eardrum) to the inner ear.
conneective tissue shapes/structure?
The cells of various kinds of connective tissues differ in their shapes and structures and in the kinds of fibers and matrices they secrete.
maxillae
Posterior to the mandibles are two pairs of appendages, the first and second maxillae, used for manipulating and holding food.
cryptic coloration
Colors or markings that help some organisms hide from predators by blending into their physical surroundings.
simple squamous epithelium
Simple Squamous Epithelium
Main Locations: Air sacs of lungs; lining of blood vessels
Functions: Passage of materials where little or no protection is needed and where diffusion is major form of transport
Description and Comments: Cells are flat and arranged as single layer.
metanephridia
The excretory organs of annelids and mollusks; each consists of a tubule open at both ends; at one end a ciliated funnel opens into the coelom, and the other end opens to the outside of the body.
homeostasis
the balanced internal environment of the body; the automatic tendency of an organism to maintain such a steady state.
conodonts
simple fishlike chordates with gill arches, mus- cular segments, and fins. They had large eyes, and complex tooth-like hooks that were probably used in capturing prey. Conodonts were abundant from the Precambrian to the Late Triassic period; they have been identified in several fossil beds around the world. Cladistic analyses suggest that conodonts were early vertebrates
neural crest cells
Many characters common to vertebrates have been derived from a group of cells called neural crest cells.
These cells, found only in vertebrates, appear early in development and migrate to various parts of the embryo.
Neural crest cells give rise to or influence the development of many structures, including nerves, head muscles, cranium, and jaws.
diploblastic
cnidarians and ctenophores as diploblastic because they have two tissue layers.
swimmerets
small paddlelike structures used by some decapods for swimming and by the females of all species for holding eggs
mammary glands
produce milk for the young
ligaments
the cables that connect bones to one another, consist of dense connective tissue in which collagen bundles are arranged in a definite pattern.
collagen
Proteins found in the collagen fibers of connective tissues.
torsion
The twisting of the visceral mass characteristic of gastropod mollusks.
proglottids
long chain of segments
each segment equipped with both male/female reproductive parts
incomplete metamorphosis
Most insects, including bees, butterflies, and fleas, undergo complete metamorphosis with four distinct stages in the life cycle: egg, larva, pupa, and adult
esophagus
The part of the digestive tract that conducts food from the pharynx to the stomach.
Parazoa
basal group, Parazoa (para, “alongside”; and zoa, “animals”).
regions of the large intestine?
From the cecum to the rectum (the last portion of the large intestine), the large intestine is known as the colon. The regions of the large intestine are the cecum; ascending colon; transverse colon; descending colon; sigmoid colon; rectum; and anus, the opening for the elimination of wastes.
parapodia
Paired, thickly bristled paddlelike appendages extending laterally from each segment of polychaete worms.
pseudocoelomates
An animal having a pseudocoelom
flame bulbs
collecting cells that eqipped with cilia
anatomy
the study of the organisms structure
pharynx
a tubelike, muscular pharynx ( the 1st portion of the digestive tube)
planarians project pharynx outwad through its mouth, using it to suck in prey.
exoskeleton
An external skeleton, such as the shell of mollusks or outer covering of arthropods; provides protection and sites of attachment for muscles.
Glial cells
Glial cells support and nourish the neurons, destroy pathogens, and modulate transmission of impulses
collagen fibers
mosst numerous type in connective tissues
wavy and flexible allowing them to remain intact when tissue is stretched.
systemic circulation
The part of the circulatory system that delivers blood to and from the tissues and organs of the body.
myosin
A protein that together with actin is responsible for muscle contraction.
key role in muscle fibers
ileocecal valve
Most of the nutrients in the chyme are absorbed by the time it reaches the end of the small intestine. What is left (mainly waste) passes through a sphincter, the ileocecal valve, into the large intestine.
endothelium
The lining of blood and lymph vessels is called endothelium. Endothelial cells have a different embryonic origin from “true” epithelium. However, these cells are structurally similar to squamous epithelial cells and can be included in that category.
ovoviviparous
A type of development in which the young hatch from eggs incubated inside the mother’s body.
During development, the young depend on stored yolk for their nourishment rather than on transfer of materials from the mother. The young are born after hatching from the eggs.
How are glands classified?
Glands are classified as exocrine or endocrine.
cnidocytes
Stinging cells characteristic of cnidarians.
nocturnal
active at night
red blood cells
In humans and other vertebrates, red blood cells contain the respiratory pigment that transports oxygen.
inferior
located below some point of reference, or toward the feet.
mesophyll
Between the outer and inner cell layers, the sponge body has a gelatin-like layer, the mesohyl, which is supported by slender skeletal spikes, or spicules.
Dense connective tissue
found in the dermis (lower layer) of the skin, is very strong, but is somewhat less flexible than loose connective tissue. Collagen fibers predominate. Tendons and ligaments, consist of dense connective tissue in which collagen bundles are arranged in a definite pattern.
Reticular Connective Tissue
Reticular Connective Tissue
Main Locations: Framework of liver; lymph nodes; spleen
Function: Support
Description and Comments: Consists of interlacing reticular fibers
glands
Some epithelial cells form glands that secrete cell products such as hormones, enzymes, or sweat.
consists of one or more epithelial cells specialized to produce and secrete a product such as sweat, milk, mu- cus, wax, saliva, hormones, or enzymes
skeletal muscle
The voluntary striated muscle of vertebrates, so
called because it usually is directly or indirectly attached to some part of the skeleton
muscle tissue
Most animals move by contracting the long, cylindrical or spindle- shaped cells of muscle tissue.
mycotoxins
Poisonous chemical compounds produced by fungi, e.g., aflatoxins that harm the liver and are known carcinogens.
Adipose Tissue
Adipose Tissue
Main Locations: Subcutaneous layer; pads around certain internal organs
Functions: Food storage; insulation; supports organs such as mammary glands, kidneys
Description and Comments: Fat cells are star shaped at first; fat droplets accumulate until typical ring-shaped cells are produced.
radula
A rasplike structure in the digestive tract of
chitons, snails, squids, and certain other mollusks.
gizzard
a thick-muscular gizzard
inside foods are grind to bits by sand grains
exocrine gland
gland that excretes its products through a duct that opens onto a free surface, such as the skin (e.g., sweat glands).
Exocrine glands, like goblet cells and sweat glands, secrete their products onto a free epithelial surface, typically through a duct (tube).
instars
The immature stages between molts
steady state
it is a dynamic equilibrium in which conditions are maintained within narrow limits, which we call a steady state.
cerebral ganglia
a simple brain
air sacs
Birds have lungs with air sacs, thin-walled extensions that oc- cupy spaces between the internal organs and within certain bones. The unique “one-way” flow of air through their respiratory system is metabolically efficient because they do not need to pump air in and out of the lungs.
postanal tail
Chordates have a larva or embryo with a muscular postanal tail, an appendage that extends posterior to the anus.
Acanthostega
one of the earliest known tetrapods. Fossils from the Devonian period show that this animal had four legs with well-formed digits. However, its limbs were not sufficiently strong for walking effectively on land. Acanthostega was an aquatic animal, not an amphibian.
compound eyes
composed of many light-sensitive units called omma- tidia. The compound eye can form an image and is especially adapted for detecting movement.
closed circulatory system
A type of circulatory system in which the
blood flows through a continuous circuit of blood vessels; characteristic of annelids, cephalopods, and vertebrates.
endotherms
used metabolic energy to maintain a constant body tem- perature despite changes in the temperature of the environment. An advantage of endothermy is that it allows animals to be more active.
parietal peritoneum
parietal peritoneum, a sheet of connective tissue that lines the walls of the abdominal and pelvic cavities
enterocoely
The process by which the coelom forms as a cavity within mesoderm produced by outpocketings of the primitive gut (archenteron); characteristic of many deuterostomes.
Reticular fibers
Reticular fibers are very thin, branched fibers that form delicate networks joining connective tissues to neighboring tissues. Reticular fibers consist of collagen and some glycoprotein
basidiomycetes life cycle ….
forming diploid zygote nuclei. These are the only diploid cells that form during a basidiomycete’s life cycle. Meiosis then takes place, forming four haploid nuclei with different genotypes. These nuclei move to the outer edge of the basidium. Fingerlike extensions of the basidium develop, into which the nuclei and some cytoplasm move; each of these extensions becomes a basidiospore. A septum forms that separates the basidiospore from the rest of the basidium by a delicate stalk that breaks when the basidiospore is forcibly discharged. Each basidiospore can germinate and give rise to a pri- mary mycelium.
pseudostratified epithelium
cells of pseudostratified epithelium falsely appear layered. Although all its cells rest on a basement membrane, not every cell extends to the exposed surface of the tissue. This arrangement gives the impression of two or more cell layers. Some of the respiratory passageways are lined with pseudostratified epithelium equipped with cilia.
symmetry
refers to the arrangement of the body structure in relationship to the body axis.
indeterminate cleavage
Deuterostomes typically undergo indeterminate cleavage. For example, if the first four cells of a sea star embryo are separated, each cell can form a complete, though small, larva. If a few cells are removed from a blastula undergoing indeterminate cleavage, other cells compensate, and the embryo develops normally.
In contrast, if a few cells are removed from the blastula of an embryo undergoing determinate cleavage, some structure, such as a limb, does not develop.
Ecdysozoa
The name Ecdysozoa is derived from the fact that animals in this group molt, a process called ecdysis. The Ecdysozoa include the nematodes and arthropods.
Cartilage
Cartilage
Main Locations: Supporting skeletons in sharks and rays; ends of bones in mammals and some other vertebrates; supporting rings in walls of some respiratory tubes; tip of nose; external ear
Function: Flexible support
Description and Comments: Cells (chondrocytes) separated from one another by intercellular substance; cells occupy lacunae
gastrovascular cavity
gastrovascular cavity, a central digestive cavity with a single opening.
porocytes
Specialized tubelike cells, called porocytes, form the pores (ostia). These cells regulate the diameter of the pores by contracting.
