Final Flashcards
Define physiology
Function, how body structures work
Four primary tissues
Muscle: movement
Nervous: control
Epithelial: cover, protect
Connective: support, connect
Muscular tissue
Skeletal: attached to skeleton to move bones at will, voluntary, cells are long and cylindrical, striated, multi nucleated
Cardiac: involuntary, found only in heart
Striated, smaller than skeletal, branched, intercalated discs that connect cells so they contract as one
Smooth: involuntary, non striated (smooth), smaller than skeletal, in GI tract, eyes, uterus, smaller arteries
Nervous tissue
Neurons: fast communication
Glia: help neurons do their job
Epithelial tissue
Membranes: cover body and organs and line the inside of hollow organs
Like sheets bc they’re tightly bound
Glands: derived from membranes
Characteristics of epithelial tissue
Have polarity
Apical surface: exterior open space
Basal surface: attached to substratum
Non vascularized
What are epithelial tissue cells classified as?
Squamous
Cuboidal
Columnar
Simple
Stratified
Squamous
Flattened and scale like
Nucleus flattened
For rapid diffusion in lungs
Cuboidal
Boxlike
Nucleus round
Secretion or absorption in kidney tubules
Columnar
Tall; column shaped
Nucleus elongated
For absorption in gut
Simple
One layer
Stratified
More than one laying of cells
Basement membrane
Thick separation between two types of tissue made of extra cellular molecules that cells of tissue on either side secrete
Gland
One or more cells that makes and secretes an aqueous fluid:secretion
Unicellular: goblet cells
Multicellular
Endocrine glands
Ductless, release into bloodstream
Exocrine
Have ducts, release outside of body or into into cavity of hollow organ
Sweat, salivary, mucous, oil glands
Connective tissue
Most abundant of primary tissues
Relatively few cells in a sea of matrix made of protein fibers collagen and elastin and interstitial fluid
Vascularized except for cartilage
Collagen fibers
Like a rope for strength and cushioning
Elastic fibers
For elasticity
Connective tissue proper
Fibroblast/cyte (cyte=mature)
Extra cellular matrix is gel like
Can be loose (areolar, adipose, riticular) or dense (regular, irregular, elastic)
Loose connective tissue areolar
Loosely arranged collagen and elastic fibers
Packaging tissue: wraps and cushions organs
Areolar refers to open spaces between fibers
Loose connective tissue proper adipose
Fat tissue
Adipocytes store fat molecules as fuel reserve
Insulated against heat loss and supports and protects organs
Dense connective tissue proper regular
Collagen fibers arranged parallel in order to resist stress when pulled from ONE direction
Found in tendons and ligaments
Dense connective tissue proper irregular
Arranged irregularly to resist stress in ANY direction
Dermis of skin cancer
Cartilage
Chondroblasts/cytes
Gel like matrix to resist compression
Hyaline cartilage
Amorphous but firm matrix
In embryonic skeleton, nose, ribs, trachea, larynx
Elastic cartilage
Elastic matrix
Outer ear, epiglottis
Fibrocartilage
Fibrous (more thick collagen fibers)
More fibrous to be a better shock absorber
I’m intervertebral discs, knee joint
Bone
Osteoblasts/cytes/clasts
Gel like matrix but hardened w calcium salts
Spongy bone and compact bone
Spongy bone
Space between red bone marrow, where blood cells are born
Compact bone
Minerals like calcium stored here, harden bone
Blood
Erythrocytes(RBC)
Leukocytes(WBC)
Platelets
Matrix in liquid plasma to carry molecules throughout the body like nutrients, wastes, and respiratory gases
Homeostasis
Dynamic constancy of the internal environment
Ex: body temp constant at 37 degrees C
Negative feedback
Go in opposite direction if stimulus
Positive feedback
Go in same direction as stimulus
Negative feedback example
If body temp falls above or below normal
Sensor: senses this stimulus (hypothalamus in brain)
Integrating center: integrates sensory info and alerts effector (hypothalamus in brain)
Effector: effects a response (sweat glands secrete sweat to cool) (skeletal muscles contract to shiver and generate heat)
pH
A measure of the concentration of H+ (hydrogen ions or protons) in an aqueous solution
7 neutral
Below 7 acidic
Above 7 basic or alkaline
Scale is logarithmic
NonPolar molecules
Charges equally distributed
CH4
Polar molecules
Partial negative and partial positive
Unequal
NH3
Hydrolysis
If cells are hungry they can hydrolysis glycogen and feed monosaccharides to cells
Hydro (water) lyse (break off units)
One disaccharide–> 2 monosaccharides (carbs)
Triglycerides
1 glycerol + 3 fatty acids= 1 triglyceride
Plasma membrane
Phospholipid bilayer: phosphor heads polar, fatty acid tails nonpolar, desperate in from out of cell
Bilayer is fluid so proteins can move along its plane
Cholesterol (yellow) makes membrane more rigid
Proteins (purple) communicate signals in and out of cell(integral), can be structural, receptors, enzymes, transporters
Carbohydrates (green) on outer surface only and involved in cell-cell recognition and cell signaling
Lysosomes
Organelles that digest
Have digestive enzymes and acidic pH to help digest
Food vacuoles: engulf food and fuse with lysosomes
Autophagosomes: engulf dead organelles and fuse with lysosomes to have organelles recycled
Process of making a protein
Transcribed into mRNA (copy of the gene made in the nucleus)
mRNA leaves nucleus through nuclear pores and comes across a ribosome where the message is TRANSLATED into a polypeptide
After the transcript(mRNA) is made TRANSFER RNA (tRNA) read the transcript code and transfer the amino acid to the growing polypeptide chain
Once the polypeptide is made it only has primary structure so it must be further processed and folded to become functional (first happens in ROUGH ER)
From rough ER the polypeptide is transported to the GOLGI COMPLEX to be further processed and sent to its final destination
If it’s a secreted protein it makes it to the plasma membrane
Chromatin remodeling
Not all genes are turned on (made into protein) all the time. One way to regulate which genes are turned on or off is by this
Euchromatin
DNA loosely wound so easily turned on
Heterochromatin
Tightly wound so not easily turned on
RNA interference
Cells must regulate how much protein to make at a given time, by upregulating or downregulating gene expression
Downregulating is an example of this
Small pieces of RNA bind to mRNA to block transcription
Alternative splicing
Human proteome has more proteins than we do genes bc of this
After transcript is made introns are removed and exons spliced back together and this allows for >1 protein per gene
Enzymes
Molecules the speed up chemical reactions by energizing reactants, thus lowering the activation energy of the chemical reaction
Kinases
Add phosphate groups
Phophatases
Remove phosphate groups
Synthases
Dehydration synthesis
Hydrolases
Hydrolysis
Dehydrogenases
Remove hydrogen atoms
Isomerases
Rearrange atoms
What factors affect enzymatic activity and how?
Temperature (optimal temp)
pH (optimal pH)
Concentration of enzyme and substrate
(The more substrate the higher the enzymatic activity, faster the reaction rate)
Concentration of cofactors (metal ions like Ca, Mg, Mn, Cu, Zn) and coenzymes(organic molecules that transport hydrogen atoms and small molecules between enzymes (all Help enzymes)
Products of reaction (reduce and oxidizing)
Endergonic reactions
Requires and input of energy to synthesize like molecules
Exergonic reactions
Releases energy by breaking down large molecules into small
Respiration of glucose
Glucose is first energized with 2 ATPs then metabolized to yield 2 molecules of pyruvic acid
A net of 2 ATP is produced
Respiration of glucose anaerobic
Referred to as lactic acid fermentation
Wo O2 pyruvic acid cannot be further metabolized but NADH must regenerate which it does by reducing pyruvic acid to lactic acid
Pyruvic acid is the final electron acceptor
Respiration of glucose aerobic
Pyruvic acid enters the mitochondrial on and is converted to acetyl CoA
Next acetyl CoA enters the citric acid (krebs cycle) where it is completely metabolized
From each of the 2 acetyl CoA one ATP as product and two CO2 as byproduct
The electrons carried by NADH and FADH2 are then transported via redox reactions through a series of molecules (ETC) in the inner mitochondrial membrane (this releases energy that’s used to pump protons H+ up a concentration gradient)
The protons then move back to matrix through the channel protein ATP synthase
This movement down the concentration gradient releases energy that is used to add phosphates to ADPs and make about 30ATPS
The protons and electrons combine w O2 (the final electron acceptor) to form water the other biproduct of cellular respiration
Glycogenesis
Glucose that does not enter glycolysis can be stored as glycogen through this process
Stored in skeletal muscle and to a lesser extent cardiac muscle and liver store more
Glycogenolysis
If glucose is needed cells perform this process to break down glycogen
Liver has enzymes for this
Molecules that freely diffuse across membrane
Hydrophobic molecules
Non polar like steroids or O2
Molecules that can’t freely diffuse across membrane
Hydrophilic molecules and inorganic ions(ca, na, cl)
They need channel or carrier to help them
Passive transport
Doesn’t require energy
Exergonic
Active transport
Requires energy
Bc pumping molecules up concentration gradient is endergonic
Primary active transport
The pump (carrier protein) is an ATPase. When ATP is hydrolyzed the energy released is used to pump molecules up their concentration gradient
Ca+ pump
Na/K+ pump
Secondary active transport (coupled transport)
Diffusion of Na+ into the cell releases energy that is then used to pump a molecule or ion
What types of cells are excitable?
Neurons, cardiac, and skeletal muscle cells
Resting membrane potential
Vm at rest cells are not excited
But when excited cells conduct impulse or AP that accumulates a cellular response ex a muscle cell contracts
Paracrine signaling
Target cells are nearby so signaling molecule diffuses to target
Synaptic signaling
Communication happens at synapse, special connection between neuron and another cells
Neurotransmitter is the signaling molecule
Endocrine signaling
Target cell is far away so the signaling molecule, the hormone, enters the bloodstream
CNS
Brain and spinal cord
PNS
Nerves and their ganglia
Sensory (input) PNS and Motor (output) PNS
Sensory PNS senses incoming info from outside or inside of body and sends it to CNS
CNS integrates input and tells motor PNS how to respond
Motor PNS (output) responds
Sensory or afferent
Nerves send signals from both outside and inside of body to CNS
5 senses
From skin or tendons (are u sitting up straight?)
Internal organs
Motor or efferent
Nerves send signals from CNS to effector organs which effect a response
Somatic
Autonomic
Somatic
Voluntary control
Skeletal muscles
Autonomic
Involuntary control
Smooth muscle, cardiac muscle, glands
Parts of a neuron
Dendrites: receive incoming info
Cell body:nucleus and integrates info
Axons: conduct impulses or AP
Axon hillock
Node of ranvier
White matter
Myelinated axons appear whitish
So axonal tracts are this
Gray matter
Areas with cell bodies that are darker
Schwann cells
Surround and myelinate axons
Myelin sheath: wraps around many times on bigger axons increasing speed of conduction
Satellite cells
Support cell bodies
Ependymal cells
Like cavities of the brain and spinal cord
Microglia
Play an immune function in the CNS
When activated can phagocytose
Oligodendrocytes
Myelinate SEVERAL axons
Astrocytes
Most abundant type of glia
Help recycle neurotransmitters
Pick up glucose from blood and turn it into lactic acid and pass it on to neurons which can use it to metabolize aerobically
How does myelin affect the speed of action of an AP
Faster bc ions enter or leave the cell only at the nodes of Ranvier. The AP therefore jumps for node to node
Frontal lobe
Controls voluntary movement
Higher intellectual processes
Somatosensory cortex
Integrates cutaneous (from skin) and propioceptive (about self) info from muscles, tendons, and joint receptors then communicates this processed info to the primary motor cortex from where voluntary muscles are controlled
Pre central gyrus
Producing and coordinating movement
Limbic system
Emotional drives
Pineal gland
Secretes the hormone melatonin which regulates sleep-wake cycles
Thalamus
The gateway to the cerebral cortex bc it serves as a relay center for all sensory info(except olfactory) coming into the cortex
Hypothalamus
Main visceral control center
Regulates autonomic processes like body temp and food and water intake
Itself a giant, regulates the pituitary gland(the master gland) that in turn regulates endocrine glands throughout the body
Heart of the limbic system
Midbrain
Has
Substantia nigra: project to basal nuclei and are the ones that die in Parkinson’s
Ventral tegmental area: project to several areas of the limbic system and involved in behavioral reward and drug addictions
Medulla
Viral respiratory centers
Regulate muscles of our ribs responsible for breathing(so we don’t stop)
Has vital centers that regulate autonomic control of the heart and blood vessels
Reflex arc
Receptor
Sensory neuron
Interneurons
Motor neuron
Effector
Reflex
Unconscious motor response to a sensory stimulus
Monosynaptic reflex
Involves only a sensory and motor neuron(knee jerk reflex)
Polysynaptic reflex
May or may not involve the brain
Spinal reflex
involve more than one synapse
an example is the withdrawal reflex of the hand from a painful stimulus (such as fire)
Cranial reflex
mediated by pathways in the cranial nerves and brain; examples are the blinking and swallowing reflexes
Sympathetic preganglionic neurons
Arise in T1-L2
Paravertebral (sympathetic)
Make up the sympathetic chain of ganglia and are parallel w the vertebrae
Collateral (sympathetic)
Closer to the effector organ
Adrenal medulla (sympathetic)
Acts as a collateral ganglion too
Adrenal medulla (parasympathetic)
Derived from the neural crest (nervous tissue)
Nervous function
Secretes hormones into the blood, so it’s effector organs are found throughout the body
Terminal ganglia (parasympathetic)
Very close or within the effector organ
postganglionic neurotransmitters
Sympathetic: NE both
Parasympathetic: ACh (excitatory)
Adrenal medulla(into blood): E but also some NE both
Cocaine and amphetamines
Sympathomimetic (mimic sympathetic system)
Inhibit NE reuptake by MAO
Beta blockers
Sympathetic
Block b1
Treat hypertension
Albuterol
Sympathetic
Stimulates B2
Treat asthma opens up airways
Atropine
Parasympathetic
Blocks mAChR
Dilate pupils during eye exams
A1
Vasoconstriction in viscera and skin
B1
Increased heart rate and contractility
B2
Dilation of bronchioles and blood vessels
Hormones
Help regulate body metabolism, growth, and reproduction
What organs secrete hormones?
Heart
Liver
Kidneys
White adipose tissue
Hypothalamus
Where are target cells?
In the blood
T4 and T3
T4 is a prehormone
Within the target cell, an iodine is removed converting it to T3 the active form
Insulin
Binds to a tyrosine kinase receptor. Ligand binding causes the receptor to autophosphorylate . Now active, the receptor starts phosphorylating other substrates
Cortisol
Helps with recovery from acute stress( illness)
Fascicles
Bundles of muscle cells
Motor unit
The smallest functional unit of muscle contraction
Neuromuscular junction
Innervates muscle contraction
Sarcomere
From z disc to z disc
The contractile unit of the cell
Made of thick and thin filaments
Thin: actin
Thick: myosin
Increasing the voltage after you can see a muscle twitch will cause even more muscle fibers to contract and therefore a stronger what?
Grades muscle contraction
Maximal contraction
All muscle fibers contract
Stimulus 7
Complete tetanus
When you’re at a high enough frequency that the muscle has less time to relax or doesn’t relax at all
Fatigue
When the muscle can no longer maintain contraction
Vo2 max or max rate of O2 consumption
You hit this at some point as you make ATP aerobically during moderate or heavy exercise
Oxygen debt
When you breath heavily during moderate/heavy exercise into to pay this back
Anaerobic threshold
Before you hit your VO2 max, usually you’re at 50-70% of your max, your muscles start fermenting glucose from glycogen stores
This is known as..
Slow twitch fibers
Slower contraction
Their ATPase isoform is slower
Fast twitch fibers
Contract quickly bc of a faster ATPase isoform
Fibers fatigue quickly bc they can’t metabolize aerobically but they do store lots of glycogen to metabolize anaerobically
Albumin
Maintains osmotic pressure
Hemoglobin
Carry O2 and CO2 gases
Immunoglobulin
Antibodies made by the immune system
Help during a sickness
Fibrin
Needed for blood clotting
A polymer that reinforces the plug and completes the clotting process
AV node
Smaller than the contractile cells and less effiicient in their transfer of the depolarization. delay for ~100mSec. delay allows atria to complete their contraction prior to the contraction of the ventricles.
Bundle of His
Electrical connection between the two regions of the heart (atria and ventricles)
SA node
heart’s natural main pacemaker
consists of a cluster of cells that are situated in the upper part of the wall of the right atrium (the right upper chamber of the heart). The electrical impulses are generated there.
also called the sinus node
Bundle branches
offshoots of the bundle of His in the heart’s ventricle. They
play an integral role in the electrical conduction system of the heart by transmitting cardiac action potentials from the bundle of His to the Purkinje fibers
Purkinje fibers
function is to send nerve impulses to the cells in the ventricles of the heart and cause them to contract and pump blood either to the lungs or the rest of the body.
P wave
Atria depolarize
QRS complex
Ventricles depolarize
T wave
Ventricles repolarize
Arteries
Carry blood away from the heart
Veins
Carry blood toward the heart
What causes the AV valves to close?
The atria contract to pump remaining blood into ventricles.
The higher the volume in the ventricles and thus higher pressure closes the valves shut
AV valves
Prevent backflow into atria when ventricles contract
What causes the semilunar valves to shut?
The ventricles contract to pump remaining blood.
The higher the volume and pressure in the arteries closes the valves shut
Semilunar valves
Prevent backflow into the ventricles when the ventricles relax
Lymphatic circulation
The lymph travels through lymphatic vessels and then bugger lymphatic ducts that propel the lymph back to the heart, where it rejoins blood at the level of the right and left subclavian valves
On the way there the WBCs in the lymph nodes screen lymph for pathogens
Stroke volume
The ejection fraction is about 60% of the end diastolic volume
The higher the end diastolic volume the higher the contractility thus higher stroke volume
Nervous system can extrinsically regulate stroke volume by increasing contractility. Contractile myocardiocytes receive sympathetic inner atom
Factors that increase venous pressure or volume increase venous return which increase EDV
The higher the pre-load (EDV) the higher the stroke volume
The after load can decrease stroke volume
Higher blood volume increases stroke volume, the body regulates blood volume as a way we regulate cardiac output
Blood resistance
Longer vessel=more viscous blood
Smaller radius vessel=higher resistance
Ln/ r4
Myogenic control
Resistance vessels vasodilator to increase perfusion (blood flow) if pressure is low
Or vasoconstrict to prevent the vessel from rupturing if pressure goes up
Innate immunity
Innate meaning were born with it and it’s nonspecific in that it goes after everything that is non-self
Adaptive immunity
It is adaptive (learned from exposure to specific pathogen) and it is specific (attacks specific pathogens) and it is mediated by lymphocytes
External defenses
Skin:serves as a physical barrier and secretes lysozymes
Digestive tract:gastric acid kill pathogens and beneficial colon bacteria compete to outnumber pathogenic bacteria
Genitourinary tract:urine and vaginal pH are slightly acidic to kill pathogens
Respiratory tract: epithelial cells have Cilia and secrete mucus your push pathogens up and out of the tract through nose and mouth
Internal defenses
Phagocytosis: cells that help fight infection
Interferons: family of protein, some of which are made by virus infected cells to warn other cells of impending viral attack
Endogenous pyrogen: molecules secreted by WBCs in response to bacterial toxins, cause fever that speed up recovery
Complement: enhance he immune system
Inflammation: innate response to harmful stimuli like pathogens or damaged cells
Humoral or antibody mediated
Secrete antibodies, humoral or antibody mediated, attack invaders outside of the cell, attack bacteria and some viruses from a distance
Cell mediated
Attack inside the cell
Virus infected, fungus, cancerous, organ transplant
Direct cell to cell combat
Primary response
Immune response that occurs when naive B or T cells are activated
Secondary response
When the memory cells are activated Memory cells also divide faster and are longer lived They are more effective IgM primary IgG secondary
Passive immunity
the short-term immunity that results from the introduction of antibodies from another person or animal.
Active immunity
the immunity that results from the production of antibodies by the immune system in response to the presence of an antigen.
Ventilation
Mechanical process of inhaling and exhaling
O2
2% dissolved in plasma
98% transported bound to hemoglobin as oxyhemoglobin
CO2
10% dissolved in plasma
20% bound to hemoglobin as carbaminohemoglobin
70% reacts chemically with water to form carbonic acid which becomes bicarbonate ion
Loading
Loading of O2 onto hemoglobin to form oxyhemoglobin
Unloading
Refers to unloading of O2 from hemoglobin to form deoxyhemoglobin
At tissues an increase in pCO2 and decrease in pO2 in blood favor…
Unloading
At lungs an increase in pO2 and decrease in pCO2 in blood plasma favor
Loading
Ph decrease
Hyperventilating
Ph basic
Hypoventilation
Function of the kidneys
Volume (pressure)
pH
Wastes
Electrolytes
Nephrons
Filter blood then modify the filtrate producing urine that is drained into the ureter
Ureter
Transport urine to the urinary bladder where it’s stored until micurition
Glomerulus
Blood is filtered by this and modified down the rest of the nephron and urine is collected by the collecting duct
ADH
Regulates high blood osmolality
Osmoreceptors sense this and makes an antidiuretic hormone, target cells in collecting ducts make more aquaporin channels to increase water reabsorption (so you retain water bringing osmolality back down to its set point
Aldosterone
Low blood volume but normal osmolality
Aldosterone tells kidneys to reabsorb salt and when salt is reabsorbed water follows via osmosis
Granular cells sense low blood flow in afferent arteriole which stimulates them to secrete renin into the blood (mascula densa cells are what tell granular cells to do this)
ANP
When blood volume (pressure) is high
Stretch receptors in left atrium stretch more which causes…
The heart to tell the brain to tell the kidneys to decrease ADH secretion
The LA of the heart to secrets ANP which tells kidneys to extreme Na+ (therefore water too)
How do kidneys regulate alkalosis?
Less HCO3 and more H+
Reabsorb less HCO3 and secrete less H+
How do kidneys regulate acidosis?
More HCO3 and less H+
Reabsorb more HCO3 and secrete more H+
Organs part of GI tract
Oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anal canal, anus
Accessory organs
Teeth, tongue, salivary glands, liver, gallbladder, pancreas
Digests starch
Salivary amylase, pancreatic amylase, brush border enzymes
Small intestine
Digest proteins
Duodenum
Fat digestion
Gallbladder
Stores and concentrates bile made by liver
Liver
Makes bile
Detoxifies blood
Regulates level of fuel molecules in blood
Makes plasma proteins
Exocrine portion of the pancreas
Secrete pancreatic juice
How are testes and ovaries determined?
TDF
Leptin
A hormone secreted by adipocytes is required for the onset of puberty
Exercise may inhibit it
More active slimmer girls start puberty later
What processes do FSH and LH secretions stimulate in puberty ?
Tells gonads to start gametogenesis
Spermatogenesis: production of sperm
Oogenesis: production of oocytes or eggs
When and where does spermatogenesis happen?
seminiferous tubules
At puberty
Spermatogonium
cell produced at an early stage in the formation of spermatozoa, formed in the wall of a seminiferous tubule and giving rise by mitosis to spermatocytes.
Primary and secondary spermatocyte
Primary spermatocytes are diploid (2N) cells containing 46 chromosomes.
After Meiosis I, two secondary spermatocytes are formed. Secondary spermatocytes are haploid (N) cells that contain 23 chromosomes.
Spermatid
an immature male sex cell formed from a spermatocyte that can develop into a spermatozoon without further division
Spermatozoon
the mature motile male sex cell of an animal, by which the ovum is fertilized, typically having a compact head and one or more long flagella for swimming.
Spermatogenesis
is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, motile spermatozoa. The spermatid is a more or less circular cell containing a nucleus, Golgi apparatus, centriole and mitochondria.
What are the 4 categories of action that testosterone and it’s androgen derivatives mediate?
Sex determination
Spermatogenesis
Secondary sex characteristics
Anabolic effects
Ovarian cycle
Refers to what happens in the ovaries every month after the onset of puberty
Follicular phase
FSH follicle stimulating hormone stimulates growth of some primary follicles which become secondary follicles
Secrete estrogen
Days 1-14
Ovulation
Ovulation is the release of egg from the ovaries. In humans, this event occurs when the de Graaf’s follicles rupture and release the secondary oocyte ovarian cells.
Day 14
Luteal phase
occurs after ovulation (when your ovaries release an egg) and before your period starts. During this time, the lining of your uterus normally gets thicker to prepare for a possible pregnancy.
Secretes estrogen and progesterone which causes it to thicken
Oogonium
46 chromosomes
Primary oocyte
46 chromosomes
In primary and secondary follicles
secondary oocyte
23 chromosomes
In Graffian follicle
Polar body
each of the small cells that bud off from an oocyte at the two meiotic divisions and do not develop into ova.
Zygote
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
