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all animals cells have similarities in the ways in which they:
exchange materials with surroundings(plasma membrane), obtain energy from organic nutrients, synthesize complex molecules (glycogen), reproduce themselves, detect and respond to signals in immediate environment (responsiveness), lack cell walls
levels of organization
cellular- phylum porifera
tissue- phylum Cnidaria and ctenophora
organ- phylum platyhelminthes
organ systems- advanced animal groups (vertebrates)
internal organization
cells with similar properties and group to form tissues, tissues combine together to form organs, organs are linked to form organs systems
tissues
an association of many cells that have similar structure and function
what are the four types of tissues
epithelial, muscle, connective, nervous
epithelial tissues
sheets of densely packed cells that: cover the body or enclose organs and line the walls of body cavities and organs
epithelial tissues function
specialized to protect and secrete/absorb ions and organic molecules
what shapes are the epithelial tissues
cuboidal, squamous, columnar
simple, stratified, and pseudistratified epithelial tissues
simple- one layer that secretes and absorbs
stratified- multiple layers that protect
pseudostratified- one layer but appears stratified
types of epithelial tissues
simple squamous- single layer flat
simple cuboidal- single layer square
simple columnar- single layer rectangle
pseudostratified columar- 1 cell thick with all attached at basement layer
stratified squamous- multilayer flat (skin)
connective tissues
connect, surround, anchor, bind, transport, and support; form extracellular matrix around cells
function of connective tissues
provide scaffold for attachment (muscle to bone), protect and cushion, mechanical strength (ligaments and tendons), transmit information (plasma)
types of connective tissues
blood- transport and protect
adipose- insulation (fat), energy, support and protect
bone- hardened and support and protect
cartilage- support and flexible (between joints)
loose- hold internal organs in place (loose attachment to body wall)
dense- strength and support (tendons and ligaments)
muscle tissues
cells specialized to contract and generating mechanical force
types of muscle tissue
skeletal, smooth, cardiac
skeletal muscle
attached to bone or exoskeleton for locomotion, elongate fiber, voluntary control
smooth muscle
surrounds tubes and cavities for propulsion of contents, flat cells, involuntary control (nervous)
cardiac muscle
found only in the heart, branched fibers, involuntary control
nervous tissue
complex networks of neurons (nerve cells and others)
functions of nervous tissue
initiate and conduct electrical signals from one part of an animals body to another
electrical signals produced in one neuron may stimulate or inhibit other neurons to:
initiate new electrical signals, stimulate muscle cells to contract, stimulate glandular cells to release chemicals also contain neuroglial cells, provide metabolic support and maintence and ion balance and cleaning, produce new glial cells and neurons
organs
composed of two or more kinds of tissues, may form sheets, tubes, layers, bundles, or strips
organ system
different organs work together to perform an overall function, these system work together, play a part in the overall body plan
what controls the body plan
highly conserved family of genes with homologs in all animals (hox genes) especially vertebrates which have the most cluster
structure and function of an organism
organization of structure (form) usually can predict the function of structure, increasing complexity of structure to increase complex function and emphasis on vertebrate function
homeostasis
process of adjusting to the external environment and maintaining a stable internal environment; changing variables in the environment: air temperature, water temperature, food supply, water supply, pH, O2 concentration in water especially; body will make changes to get normal state; slight differences (imbalance) are normal; more complicated organizms is harder and takes longer
integumentary system
the ineguement and its derivatives
functions of integumentary system
protection from abrasion, protects against water loss, barrier to disease causing pathogens, protection from UV light, temperature regulation (sweat), contains sensory receptors (touch), limited excretion (evaporative cooling)
integument
skin and all other accessories (hair and feathers)
skin
largest organ of vertebrates, consists of 2 layers: epidermis is outer and dermis is inner
epidermis
thinner outer layer, nutrients diffuse from dermis (no blood), stratified squamous epithelium (primary), lots of dead cells
integumentary cell types
langer Hans cells- defensive
melanocytes- pigment melanin, skin color, protect UV light
Merkel cells- touch receptors (advanced in mammals)
keratinocytes- primary, keratin, increase from in to out, fill cytoplasm then die
dermis
thicker and inner layer, highly vascular (blood vessels), contains vessels and nerves and glands (sensory), origin of hair and feathers and scales, meissner’s corpuscles - light touch, Pacinian corpuscles- deep pressure and vibration
sweat glands
temperature regulation, 2.5 million in human, produces sweat (water), release heat
sebaceous glands
all over body except for palms of hands and soles, large on face and neck and upper chest, produce sebum
hypodermis
subqutaneous layer, beneath dermis, not skin layer, lots of fat tissue, females have thicker adipose layer (softer skin)
functions of hypodermis
body contour, insulated supports skin, energy skin, hold in heat
nutrient
any substance taken in by an organism that is needed for survival and growth and development and maintenance or reproduction
nutrition
process of consuming and using food and nutrients
heterotrophic
cant make own food, require already synthesized organic compounds
in heterotrophs organic compounds of plants or other animals to supply for:
survival, maintence, growth, reproduction, more food intake, more energy (ATP)
gut tract
blind gut and tube with in a tube
blind gut
no cavity between gut and body wall, one opening and primitive
tube with in a tube
flow through digestive tube, body cavity between gut and BW, separate openings (mostly), advanced form
digestive enzymes
hydrolases, require water, carbohydrates, lipases, proteases, nucleases
food processing
ingestion, digestion, transport, absorption, egestion
ingestion
food taken into body and move to alimentary canal
digestion
food broken down into smaller molecules, chemical and mechanical
absorption
ions and water and small molecules diffuse into circulatory system (nutrients and vitamins and hormones)
egestion
undigested materials and other wastes (eliminate)
alimentary canal
digestive tract, elongated tube open on each end, smooth muscle in the walls, lined by simple epithelial cells
in the alimentary canal what does the lining of epithelial cells do
synthesize and secreted digestive enzymes, secrete hormones, transport materials
structure if GI tract
some general structure from midpoint of esophagus to the anus, lumen lined by epithelial and glandular cells, secretory cells release protective layer of mucus, other cells release hormones, gland cells release acid and enzymes and water and ions
region of reception
buccal cavity- mouth and associates, ingestion site and digestion (mechanical and chemical), jaws and teeth and cheek muscles and tongue and salivary glands (saliva- amylase), pharynx- back of mouth cavity and the point that digestive and respiratory system cross paths
region of conduction
esphogus- tube carrying materials from mouth to rest, conducts food from pharynx to stomach, peristalsis- rhythmic wave like contraction with smooth muscle that propel food down the GI tract
region of storage and more digestion
stomach (mostly), sac-like organ evolved to store food, muscular nature to help break up food and partial protein digest, regulate rate of emptying into SI, secrets HCl - kill microbes and dissolve particulate matter and pepsinogen- converted pepsin to begin protein digestion, epithelium coated with alkaline mucus
region of terminal digestion and absorption
small intestine, nearly all digestion and absorbtion (99.5%), hydrolytic enzymes found on apical surface of epithelial cells or secrete by pancreas into lumen, products of digestion are absorbed across epithelial cells and enter the blood, length is 8x height, most absorption
if food is not digested or broken down in the small intestine will it be digested
no
surface area specializations
small intestine specialized to carry out the bulk of digestion and absorption, mucosal infolding, villi- finger like projections, increase SA by 600 fold, increases likelihood of food particle encountering digestive enzyme and being absorbed
3 regions of the small intestine
duodenum- receive lots of secretion into here, jejunum and ileum- absorb
plicae circulares
large folds of epithelial lining and increase surface area 2-3 times
villi
finger like projections, increase surface area 10 x, lined with simple epithelium
microvilli
folding of the plasma membrane of cells lining the villi, increase surface area 20 x
region of water absorption and concentrated solid
conserve water and package waste, large intestine, mammals- about 1.5 meters, no plicae villi or microvilli, water absorbs through the epithelium
function of the large intestine
human absorb about 1400 mL of water per day, compacts and elimate feces
components of waste
75% water, 5% inorganic substances- broken down but not absorbed, 8% roughage- no absorb, 5% fat, 2% undigested protein and dead cells and bile
anus
opening at posterior end of the alimentary canal for release of waste material, cloaca- chamber of recieving contents of digestive repro and urinary tract
accessory digestive glands
not part of alimentary canal, salivary gland, pancreas, liver, gall bladder
salivary gland
necessary for proper digestion and absorption
pancreas
secrete enzymatic juices through the pancreatic duct into the duodenum
liver
produces bile that assists enzymes in the break down of large fat globules into smaller forms
gall bladder
storage of bile- secrete into SI if needed with increased fat
biomolecules
carbohydrates, proteins, fats, nucleic acids, enzymatic activity for chemical reactions at biological temperatures that weaken the bond enough to be broken down
carbohydrates
polysaccharides- mono and disaccharides, starch or glycogen- fructose and glucose and sucrose
proteins
polypeptides convert to amino acid by the pepsin bond breaking
fats
glycerol and fatty acids
nucleic acids
dna and rna into nucleotides or the individual subunit
nervous system
central nervous system is the brain and spinal cord, peripheral nervous system is all neurons and projections outside of the CNS, in some invertebrates with simple the distinction is less clear, mammals have complex peripheral nervous system
cellular components of nervous system
neurons- nerve and glia- support
neurons
send and receive electrical and chemical signals to and from each other and other cells throughout the body, structural and functional units of NS, present in all animals except sponges, varies widely as function of size and behavior complex
neuron structure
cell body or soma, dendrites, axon; typically occur in bundles wrapped around by connective tissue called neurons
cell body or soma
has nucleus and organelles
dendrites
extension of cells body, single and branched, receive signal
axon
extension of cells body, single and carry signal to other cells, away from cell body, length depend on complexity, branches wrapped in myelin sheath (coating)
axon hillock
base and near cell body
axon terminals
tips convey signals to other cells
glia
surround neurons and perform various functions, 1000x more numerous than neurons, astrocytes, microglia, oligodendrocytes, Schwann cells, radial glial cells
astrocytes
metabolic support, maintain stable concentration of ions in extracellular fluid
microglia
participate in immune functions, remove cellular debris
oligodendrocytes and Schwann cells
produce myelin sheath interrupted by non insulated nodes of Ranvier
radial glial cells
can produce all other neurons, including itself
sensory neurons
detect information from outside or internal body conditions= afferent
motor neurons
send signals away from CNS to get response, efferent
interneurons
form interconnections, small cell body, critical inpretation of information and get response
reflex arc
stimulus from sensory neurons to CNS, little to no interpretation, transmitted to motor neurons to elicit response, quick and automatic response
electrical properties of neurons
membrane potential- gate keeper of channels and its the membranes discretion, only neurons and muscle cells generate electrical signals, cell is polarized due to membranes permeability, difference in ions between inside and outside the neuron, causes both chemical and electrical differences, imbalances (slight) are normal, chemicals or electrical charge never equal they are just small
resting membrane potential
when neuron not sending a signal, selectively permeable to cations and anions, polarity is inside more negative and outside more positive and vice versa because of attraction between charges, can be movement if membrane lets channels open up for a short time, the closer the ion is to the membrane the quicker and ion can diffuse in or out
electro-chemical gradient
imbalance due to difference inside and outside of neuron, charge with chemical either positive or negative, positive charge gates, chemicals- K+, Na+, Cl-
three factors affecting resting potential
sodium- potassium pump, ion specific channels allow passive movement (more permeable to K and open more frequently open at resting), polarity- more negative inside neuron
sodium potassium pump
atp spent and pump 3 Na+ for every 2K+