TEAS

The cell membrane (plasma membrane) is a phospholipid bilayer that:

• Controls what enters and exits the cell

• Has a fluid mosaic structure (proteins embedded in lipids)

• Contains channel proteins for transport

• Is selectively permeable (allows some substances through, not others)

membrane transport

Type	Requires Energy?	Description
Passive diffusion	No	Molecules move from high to low concentration
Facilitated diffusion	No	Uses proteins to help molecules cross
Osmosis	No	Water moves across membrane
Active transport	Yes (ATP)	Moves against concentration gradient

common mistakes to avoid (cells)

• Confusing mitochondria and chloroplasts: Mitochondria = animal cells; chloroplasts = plant cells (for photosynthesis)

• Forgetting ribosomes aren't membrane-bound: They're organelles but don't have membranes

• Mixing up rough and smooth ER: Rough = ribosomes = proteins; Smooth = no ribosomes = lipids

• Thinking the cell wall is in human cells: Cell walls are in plants, bacteria, and fungi — not human cells

TEAS tip: If a question mentions "against the concentration gradient,"

that's always active transport. Always.

Interphase (90% of cell cycle)

Phase	What Happens
G1 (Gap 1)	Cell grows; normal functions
S (Synthesis)	DNA replicates (copies itself)
G2 (Gap 2)	Cell prepares for division

M Phase (Mitotic Phase)

Actual division occurs: Mitosis + Cytokinesis

pro tips (cell cycle)

• Interphase is NOT part of mitosis — it's the preparation phase

• Mitosis = identical; Meiosis = unique — key distinction

• Metaphase = Middle alignment — easy to remember

• After meiosis, cells have HALF the DNA — important for sexual reproduction

• On the TEAS: Focus on the phases of mitosis and the difference between mitosis/meiosis

• Forgetting cytokinesis: Mitosis divides the nucleus; cytokinesis divides the cytoplasm

• Mitosis produces 2 identical daughter cells from one parent cell. Meiosis produces 4 genetically unique cells through two rounds of division.

During which phase of meiosis do homologous chromosomes separate?

Homologous chromosomes separate during Anaphase I. Sister chromatids separate during Anaphase II.

Crossing over occurs during which phase of meiosis?

prophase 1

inheritance patterns

Autosomal Dominant

• One copy of dominant allele = trait expressed

• Examples: Huntington's disease, achondroplasia

• If one parent has it, 50% chance offspring will have it

Autosomal Recessive

• Need TWO copies of recessive allele

• Examples: Cystic fibrosis, sickle cell anemia

• Carriers (Bb) don't show the trait but can pass it on

X-Linked (Sex-Linked)

• Gene is on the X chromosome

• Males (XY) more often affected (only need one copy)

• Examples: Hemophilia, color blindness

• Carrier mothers can pass to sons

• Probability mistakes: Each child is an independent event (25% doesn't mean 1 in 4 children will definitely have it)

genetic disorders (Autosomal Dominant)

Disorder	Notes
Huntington's disease	Late onset, neurological
Marfan syndrome	Affects connective tissue
Achondroplasia	Form of dwarfism

genetic disorders (Autosomal Recessive)

Disorder	Notes
Cystic fibrosis	Affects lungs, digestive system
Sickle cell anemia	Abnormal hemoglobin
PKU	Can't metabolize phenylalanine
Tay-Sachs	Neurological, fatal in childhood

genetic disorders (X-Linked Recessive)

Disorder	Notes
Hemophilia	Blood doesn't clot properly
Color blindness	Can't distinguish certain colors
Duchenne muscular dystrophy	Progressive muscle weakness

genotype interpretation

Genotype	Type	Phenotype
BB	Homozygous dominant	Dominant
Bb	Heterozygous	Dominant
bb	Homozygous recessive	Recessive

Cross Outcomes

Cross	Offspring Phenotypes
BB × BB	100% dominant
BB × Bb	100% dominant
BB × bb	100% dominant (all Bb)
Bb × Bb	75% dominant, 25% recessive
Bb × bb	50% dominant, 50% recessive
bb × bb	100% recessive

DNA protein synthesis

Step 1: Transcription (DNA → RNA)

• Occurs in the nucleus

• DNA is "read" to make messenger RNA (mRNA)

• mRNA is a copy of the gene's instructions

Step 2: Translation (RNA → Protein)

• Occurs at ribosomes (in cytoplasm)

• mRNA is "translated" into a chain of amino acids

• Amino acid chain folds into a protein

key players: DNA protein synthesis

Molecule	Role
DNA	Original instructions (stays in nucleus)
mRNA	Messenger; carries code from DNA to ribosome
tRNA	Transfer; brings amino acids to ribosome
rRNA	Ribosomal; part of ribosome structure
Ribosome	Where translation happens

the genetic code

• DNA is read in groups of 3 bases called codons

• Each codon codes for one amino acid

• 64 codons total → 20 amino acids (some redundancy)

Important Codons:

• AUG = Start codon (also codes for methionine)

• UAA, UAG, UGA = Stop codons (end translation)

Example 3: Following the Process

Question: Where does transcription occur? Where does translation occur?

Step 1 — Think about what each process needs.

Transcription makes a copy of the DNA. DNA lives in the nucleus and never leaves (it's the master copy — too valuable to send out). So transcription has to happen in the nucleus, where the DNA is. The mRNA copy can then leave.

Translation turns that mRNA into protein. Translation happens at ribosomes. Ribosomes are out in the cytoplasm (or on the rough ER). So that's where translation happens.

Step 2 — Lock in the answers.

• Transcription: Nucleus (DNA → mRNA)

• Translation: Ribosome in cytoplasm (mRNA → Protein)

Answer: Transcription = Nucleus. Translation = Ribosome (cytoplasm).

mutation

A mutation is a change in the DNA sequence.

Type	What Happens	Effect
Substitution	One base replaced	May change one amino acid
Insertion	Base added	Frameshift — shifts reading
Deletion	Base removed	Frameshift — shifts reading

common mistakes to avoid

• Forgetting RNA uses U instead of T: DNA: A-T-G-C; RNA: A-U-G-C

• Confusing transcription and translation: Transcription = DNA→RNA; Translation = RNA→Protein

• Location errors: Transcription in nucleus; Translation at ribosomes

• Base pairing errors: A-T and G-C only (never A-G or T-C)

Unsaturated fats are a type of lipid macromolecule that contains double bonds in their fatty acid chains. Which statement about unsaturated lipids is correct?

they are typically liquid at room temp

macromolecules

Lipids- fatty acids and glycerol

Carbohydrates- monosaccharides (glucose and fructose)

Proteins- amino acids (not fatty acids)

Nucleic acids- nucleotides (genetic information; sugar+phosphate+base)

Functions

lipids: long term energy, membranes, steroid horomones

carbs: quick energy, storage (glycogen), cell structure

proteins: enzymes, hormones, antibodies, transport structure (muscles)

nucleic acids: stores genes (DNA), makes proteins (RNA), energy carrier (ATP)

macromolecules

Lipids provide long-term energy storage and are used to form steroid hormones (such as those made from cholesterol). Carbohydrates are for quick energy, proteins serve as enzymes and structure, and nucleic acids store genetic information.

memory trick

"CPLNK" — Carbs, Proteins, Lipids, Nucleic acids are the Key molecules

What they're made of:

• Carbs = "saccharides" (sugars)

• Proteins = "amino acids" (there are 20)

• Lipids = "fatty acids" (fats and oils)

• Nucleic acids = "nucleotides" (DNA and RNA)

carbohydrates

Function: Quick energy source; structural support

Types:

Type	Size	Examples
Monosaccharides	1 sugar	Glucose, fructose, galactose
Disaccharides	2 sugars	Sucrose, lactose, maltose
Polysaccharides	Many sugars	Starch, glycogen, cellulose

Key Facts:

• Glucose = primary energy source for cells

• Glycogen = storage form in humans (liver, muscles)

• Starch = storage form in plants

• Cellulose = plant fiber (we can't digest it)

Chemical formula: (CH₂O)ₙ — "hydrate of carbon"

proteins

Function: Structure, enzymes, transport, immunity, movement

Structure Levels:

Level	Description
Primary	Amino acid sequence (like a chain)
Secondary	Local folding (helix, sheet)
Tertiary	3D shape of one chain
Quaternary	Multiple chains together

Key Facts:

• Made of 20 different amino acids

• Amino acids linked by peptide bonds

• Enzymes are proteins that speed up reactions

• Hemoglobin = protein that carries oxygen in blood

• Antibodies = proteins of the immune system

• Shape determines function — denatured proteins don't work

lipids

Function: Long-term energy storage, cell membranes, hormones, insulation

Types:

Type	Examples	Function
Triglycerides	Fats, oils	Energy storage
Phospholipids	Cell membranes	Structure
Steroids	Cholesterol, hormones	Signaling, membranes

Key Facts:

• Saturated fats = no double bonds (solid at room temp, "bad" fats)

• Unsaturated fats = has double bonds (liquid at room temp, "good" fats)

• Phospholipids make up the cell membrane (hydrophilic head, hydrophobic tails)

• Cholesterol is needed for cell membranes and making hormones

• Lipids are hydrophobic (don't mix with water)

nucleic acids

Function: Store and transmit genetic information

Types:

Type	Location	Function
DNA	Nucleus	Stores genetic code
RNA	Nucleus/cytoplasm	Carries out genetic instructions

Structure:

• Made of nucleotides

• Each nucleotide = sugar + phosphate + base

• Bases: A, T (U in RNA), G, C

Clinical Connection

Example 3: Clinical Connection

Question: Why do trans fats increase heart disease risk?

Step 1 — Know what trans fats are. Normal unsaturated fats (like olive oil) are liquid at room temperature and considered "healthy." Trans fats are artificially modified fats where hydrogen is added to make them solid and shelf-stable (like margarine or partially hydrogenated oils). They look chemically similar to unsaturated fats but behave worse.

Step 2 — Explain the mechanism. Trans fats increase LDL cholesterol (LDL = "bad" — think L for Lousy) and decrease HDL cholesterol (HDL = "good" — think H for Healthy). High LDL causes cholesterol plaques to build up inside artery walls, narrowing them. This is called atherosclerosis. Narrowed arteries → reduced blood flow → heart attack or stroke risk.

Step 3 — Connect to nursing. When you educate patients on heart-healthy diets, trans fats are on the "avoid" list. They were largely banned from commercial food production in the US, but patients may still eat them in processed foods.

Answer: Trans fats raise LDL ("bad") cholesterol and lower HDL ("good") cholesterol, promoting plaque buildup in arteries and increasing cardiovascular disease risk.

common mistakes to avoid

• Confusing starch and glycogen: Starch = plants; Glycogen = animals

• Thinking all fats are bad: Unsaturated fats and cholesterol serve important functions

• Forgetting enzymes are proteins: Many test questions ask about this

• Mixing up monosaccharide names: Glucose is most important for the TEAS

Cardiovacsular System Memory trick for blood flow

Blood flow through the heart: "Toilet Paper My Ass"

• T – Tricuspid valve

• P – Pulmonic valve

• M – Mitral valve

• A – Aortic valve [1]

Superior/Inferior Vena Cava → Right Atrium → Right Ventricle → Pulmonary Artery → Lungs → Pulmonary Veins → Left Atrium → Left Ventricle → Aorta → Body

Arteries = Away (from heart) Veins = Venture back (to heart)

Blood flow pathway

Pulmonary Circuit (Heart ↔ Lungs)

Right side of heart → Lungs → Left side of heart

• Picks up oxygen, drops off CO₂

Systemic Circuit (Heart ↔ Body)

Left side of heart → Body → Right side of heart

• Delivers oxygen, picks up CO₂

blood components

Component	Function	% of Blood
Plasma	Liquid; carries nutrients, waste, proteins	~55%
Red Blood Cells (RBCs)	Carry oxygen (hemoglobin)	~45%
White Blood Cells (WBCs)	Fight infection	<1%
Platelets	Blood clotting	<1%

cardiac cycle & electrical conduction

Electrical Pathway:

1. SA Node (pacemaker) → initiates heartbeat

2. AV Node → delays signal briefly

3. Bundle of His → carries signal to ventricles

4. Purkinje fibers → spread signal through ventricles

Terms:

• Systole: Contraction (pumping)

• Diastole: Relaxation (filling)

• Stroke volume: Blood pumped per beat

• Cardiac output: Blood pumped per minute (HR × SV)

common mistakes

• Thinking all arteries carry oxygenated blood: Pulmonary arteries carry deoxygenated blood

• Confusing tricuspid and mitral: Tricuspid = right side; Mitral = left side

• Blood flow direction errors: Blood flows from atria → ventricles, never backward (valves prevent this)

Respiratory system

Nose/Mouth → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli → Lungs (gas exchange)

Upper respiratory tract

Structure	Function
Nose/Nasal cavity	Warms, moistens, filters air
Pharynx (throat)	Passageway for air and food
Larynx (voice box)	Contains vocal cords; protects airway
Epiglottis	Flap that covers trachea during swallowing

lower respiratory tract

Structure	Function
Trachea (windpipe)	Carries air to bronchi
Bronchi	Two branches from trachea to each lung
Bronchioles	Smaller branches within lungs
Alveoli	Tiny air sacs where gas exchange occurs
Lungs	Right lung (3 lobes); Left lung (2 lobes)

respiratory volumes

Term	Definition	Average
Tidal volume	Normal breath volume	~500 mL
Vital capacity	Max air exhaled after max inhalation	~4,800 mL
Residual volume	Air remaining after forceful exhale	~1,200 mL
Total lung capacity	Max air lungs can hold	~6,000 mL

nervous system

Two Main Divisions:

Division	Components	Function
Central Nervous System (CNS)	Brain + Spinal cord	Processing center
Peripheral Nervous System (PNS)	Nerves throughout body	Connects CNS to body

memory trick

CNS = "Central Station" — Brain and spinal cord, the main hub

PNS = "Peripheral Pathways" — All the nerves branching out

Neuron parts: "Neurons Deliver Action To" = Dendrite → Axon → Terminal

neuron structure

Part	Function
Cell body (soma)	Contains nucleus; metabolic center
Dendrites	Receive signals (input)
Axon	Carries signal away from cell body (output)
Myelin sheath	Insulates axon; speeds transmission
Axon terminals	Release neurotransmitters
Synapse	Gap between neurons

Signal Pathway:

Dendrites → Cell body → Axon → Axon terminals → (Synapse) → Next neuron

PNS

Somatic Nervous System

• Voluntary control

• Controls skeletal muscles

• "I decide to move my arm"

Autonomic Nervous System

• Involuntary control

• Controls internal organs, glands

• "I don't think about my heartbeat"

Autonomic Divisions:

Division	Function	Response
Sympathetic	"Fight or flight"	Increases HR, dilates pupils, inhibits digestion
Parasympathetic	"Rest and digest"	Decreases HR, constricts pupils, promotes digestion

Memory:

• Sympathetic = Stress response

• Parasympathetic = Peace and rest

CNS

Brain Regions

Region	Function
Cerebrum	Thinking, memory, voluntary movement, senses
Cerebellum	Balance, coordination, fine motor control
Brainstem	Vital functions (breathing, heart rate), reflexes
Hypothalamus	Homeostasis, hormones, temperature, hunger
Thalamus	Relay station for sensory information

Cerebral Lobes

Lobe	Location	Function
Frontal	Front	Reasoning, planning, movement, speech
Parietal	Top middle	Sensory processing, spatial awareness
Temporal	Sides	Hearing, memory, language comprehension
Occipital	Back	Vision

neurotransmitters

Neurotransmitter	Function
Acetylcholine	Muscle contraction, memory
Dopamine	Pleasure, reward, movement
Serotonin	Mood, sleep, appetite
GABA	Inhibitory; calming effect
Norepinephrine	Alertness, fight-or-flight

Which organ is considered both an endocrine and exocrine gland?

The pancreas has endocrine (insulin/glucagon) and exocrine (digestive enzymes) functions.

Digestive system

The digestive system breaks down food into nutrients the body can absorb and use for energy, growth, and repair.

Two Types of Digestion:

Type	Description	Examples
Mechanical	Physical breakdown	Chewing, churning
Chemical	Enzyme breakdown	Saliva, stomach acid, bile

accessory organs

Organ	Produces	Function
Salivary glands	Saliva (amylase)	Begins starch digestion
Liver	Bile	Emulsifies (breaks up) fats
Gallbladder	Stores bile	Releases bile into small intestine
Pancreas	Enzymes + bicarbonate	Digests all nutrients; neutralizes acid

enzymes and digestion

Nutrient	Enzyme	Location	Product
Carbs (starch)	Amylase	Mouth, small intestine	Simple sugars
Proteins	Pepsin, trypsin	Stomach, small intestine	Amino acids
Fats	Lipase	Small intestine	Fatty acids + glycerol

• Bile is NOT an enzyme — it emulsifies fat (breaks into smaller droplets) to help lipase work.

• Amylase = carbs; Pepsin/Trypsin = proteins; Lipase = fats

small intestine (main absorption site)

Three Sections:

1. Duodenum — Receives chyme, bile, pancreatic juice; most chemical digestion

2. Jejunum — Primary absorption of nutrients

3. Ileum — Absorbs B12 and bile salts

Absorption Structures:

• Villi — Finger-like projections that increase surface area

• Microvilli — Tiny projections on villi (brush border)

• Huge surface area = efficient absorption

large intestine

Section	Function
Cecum	Receives material from small intestine
Colon	Absorbs water and electrolytes
Rectum	Stores feces
Anus	Eliminates feces

what breaks down fat?

Example 2: What breaks down fat?

Step 1 — Know the two-step process for fat digestion. Fat is a problem in digestion because fat and water don't mix (think of oil in water — it just blobs together). For the enzyme to work on fat, the fat droplets need to be broken into smaller pieces first.

Step 2 — Identify the emulsifier. Bile (made by the liver, stored in the gallbladder) acts like dish soap — it breaks large fat globs into smaller droplets. This process is called emulsification. Bile is NOT an enzyme — it doesn't chemically break down fat. It just makes fat more accessible for the enzyme that comes next.

Step 3 — Identify the enzyme. Once fat is emulsified into small droplets, lipase (from the pancreas) does the actual chemical breakdown of fat into fatty acids and glycerol — the absorbable form.

Answer: Lipase (the enzyme that chemically digests fat) working with bile (the emulsifier that breaks fat into smaller droplets first).

💡 Key distinction: Bile emulsifies (physical breakdown). Lipase digests (chemical breakdown). The TEAS loves testing the difference between these two.

what does the liver produce?

Example 3: What does the liver produce?

Step 1 — Know the liver's role. The liver is one of the body's most versatile organs — it processes nutrients from the GI tract, detoxifies drugs and toxins, and produces important proteins. For digestion specifically, its contribution is bile.

Step 2 — Trace bile's path. Liver makes bile → bile travels down the bile duct → stored in the gallbladder → when you eat fatty food, the gallbladder squeezes → bile is released into the duodenum (first section of small intestine) to emulsify fat.

Step 3 — Distinguish liver vs. gallbladder. The liver PRODUCES bile. The gallbladder STORES it. This is a common TEAS trick.

Answer: Bile — The liver produces bile, which is stored in the gallbladder and released into the small intestine to help digest fat.

skeletal system

Key Facts:

• Adults have 206 bones

• Babies have ~270 (some fuse together)

• Largest bone: Femur (thigh)

• Smallest bone: Stapes (ear)

• Memory: "Tendons attach muscles To bone; Ligaments Link bones"

types of bones

Type	Shape	Examples
Long	Longer than wide	Femur, humerus, phalanges
Short	Cube-like	Carpals (wrist), tarsals (ankle)
Flat	Thin, flat	Skull, ribs, scapula
Irregular	Complex shapes	Vertebrae, facial bones

bone structure

Part	Description
Compact bone	Dense outer layer
Spongy bone	Porous inner layer; contains marrow
Periosteum	Outer membrane; blood vessels, nerves
Bone marrow	Red (makes blood cells) or yellow (fat storage)

Endocrine system

The endocrine system uses hormones (chemical messengers) to regulate body functions. Unlike the nervous system (fast, electrical), the endocrine system is slower but longer-lasting.

Key Characteristics:

• Hormones travel through blood to target organs

• Effects are slower but longer-lasting than nervous system

• Works to maintain homeostasis

memory trick

Major Glands Top to Bottom: "PHAT POP"

Pineal Hypothalamus Anterior/posterior pituitary Thyroid/Parathyroid

Pancreas Ovaries/testes Adrenals

---

Brain

Hypothalamus (Brain)

• Role: Links nervous and endocrine systems

• Controls the pituitary gland

• "Master regulator of the master gland"

Pituitary Gland (Brain)

• "Master gland" — controls other glands

• Growth hormone (GH): Growth and metabolism

• TSH: Stimulates thyroid

• ACTH: Stimulates adrenal cortex

• FSH/LH: Reproductive hormones

• ADH: Water retention (from posterior pituitary)

• Oxytocin: Labor contractions, bonding

Neck

Thyroid Gland (Neck)

Hormone	Function
T3 & T4	Metabolism rate, energy
Calcitonin	Lowers blood calcium

• Hyperthyroidism: Too much → fast metabolism, weight loss, anxiety

• Hypothyroidism: Too little → slow metabolism, weight gain, fatigue

Parathyroid Glands (Behind Thyroid)

Hormone	Function
PTH (Parathyroid hormone)	Raises blood calcium

Memory: PTH Pulls calcium into blood; Calcitonin Calms it down

Kidneys (adrenal glands)

Part	Hormones	Function
Cortex	Cortisol, Aldosterone	Stress response, salt/water balance
Medulla	Epinephrine, Norepinephrine	Fight-or-flight response

Cortisol: "Stress hormone" — raises blood sugar, suppresses immune system

Example 3: Fight-or-Flight

Question: Which gland releases epinephrine during stress?

Step 1 — Know the adrenal gland's two parts. The adrenal glands sit on top of the kidneys (ad = near, renal = kidney). Each gland has two distinct regions with completely different functions:

• Adrenal cortex (outer layer) = produces cortisol (the long-term stress hormone) and aldosterone (sodium/water balance). These are steroid hormones.

• Adrenal medulla (inner core) = produces epinephrine (adrenaline) and norepinephrine. These are catecholamines that cause the immediate fight-or-flight response.

Step 2 — Apply to the question. Epinephrine (also called adrenaline) is the instant stress response hormone — heart pounds, pupils dilate, you feel that surge of energy. That's the medulla.

Answer: Adrenal medulla — Releases epinephrine (adrenaline) for the immediate fight-or-flight stress response.

pancreas (abdomen)

Hormone	Produced By	Function
Insulin	Beta cells	Lowers blood sugar
Glucagon	Alpha cells	Raises blood sugar

Diabetes: Insulin deficiency or resistance → high blood sugar

Gonads (reproductive)

Gland	Hormone	Function
Ovaries	Estrogen, Progesterone	Female characteristics, reproduction
Testes	Testosterone	Male characteristics, sperm production

feedback loops

Most hormones are regulated by negative feedback:

1. Hormone level rises

2. Gland stops producing

3. Level drops

4. Gland starts producing again

Example: Blood glucose rises → Insulin released → Glucose drops → Insulin release stops

mistakes to avoid

• Confusing insulin and glucagon: Insulin LOWERS blood sugar

• Thyroid hyper/hypo mix-up: Hyper = too much = fast metabolism

• Forgetting hypothalamus controls pituitary: Hypothalamus is the "master of the master"

• Adrenal cortex vs. medulla: Cortex = cortisol; Medulla = adrenaline

The master gland is:

• A) Hypothalamus

• B) Thyroid

• C) Pituitary

• D) Adrenal

Full walkthrough:

Step 1 — Know the chain of command. The hypothalamus controls the pituitary, which controls many other glands. The pituitary is called the "master gland" because it controls so many others. But the hypothalamus is the "master of the master."

Step 2 — Apply to the question. The question asks for the "master gland" — that's the pituitary.

• A) Hypothalamus — The hypothalamus is actually above the pituitary in the chain of command, but it's called the "master regulator" or "master of the master gland" — not the master gland itself. ✗

• B) Thyroid — The thyroid regulates metabolism, but it's controlled by the pituitary (via TSH). It's a subordinate gland, not the master. ✗

• C) Pituitary — Correct. The pituitary gland produces hormones that control the thyroid (TSH), adrenals (ACTH), reproductive glands (FSH/LH), and more. It's the central commander of the endocrine system. ✓

• D) Adrenal — The adrenal glands produce cortisol and adrenaline, but they're controlled by the pituitary (via ACTH). Not the master. ✗

Answer: C) Pituitary

Immune system

The immune system defends the body against pathogens (bacteria, viruses, fungi, parasites) and abnormal cells (cancer).

Two Main Divisions:

Type	Response Time	Specificity	Memory
Innate (Non-specific)	Immediate	General	No
Adaptive (Specific)	Days	Targeted	Yes

memory trick

Innate = "Instant" defense — already there, general protection Adaptive = "Adapts" to specific threats — takes time but remembers

Types of White Blood Cells: "Never Let Monkeys Eat Bananas" Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils

innate (non specific) immunity

First line of defense — works against ALL pathogens:

Physical Barriers:

• Skin — Physical barrier

• Mucous membranes — Trap pathogens

• Cilia — Sweep debris out of airways

• Stomach acid — Kills ingested pathogens

Cellular Defenses:

Cell Type	Function
Neutrophils	First responders; phagocytosis (eat pathogens)
Macrophages	Larger phagocytes; present antigens
Natural Killer cells	Kill infected/cancer cells

Other Responses:

• Inflammation — Redness, heat, swelling, pain (brings immune cells)

• Fever — Raises body temperature to inhibit pathogen growth

adaptive (specific) immunity

Targeted defense — takes time but has memory:

Two Types:

Type	Mediated By	Target
Humoral (Antibody-mediated)	B cells → Antibodies	Extracellular pathogens
Cell-mediated	T cells	Intracellular pathogens, cancer

Key Players:

Cell	Function
B cells	Produce antibodies; memory cells
T helper cells	Coordinate immune response (CD4+)
T cytotoxic cells	Kill infected cells directly (CD8+)
Memory cells	Remember past pathogens for faster response

Antibodies (Immunoglobulins):

• Proteins that recognize specific antigens

• Antigen = substance that triggers immune response

• Lock-and-key: Each antibody matches ONE antigen

active vs passive

Type	How Acquired	Duration	Example
Active Natural	Getting sick	Long-lasting	Having chickenpox
Active Artificial	Vaccine	Long-lasting	Flu shot
Passive Natural	Mother to baby	Temporary	Breast milk antibodies
Passive Artificial	Injection	Temporary	Immunoglobulin shot

Active = your body makes antibodies (memory)

Passive = you receive antibodies (no memory)

signs of infection

Sign	Cause
Redness	Increased blood flow
Heat	Increased blood flow
Swelling	Fluid accumulation
Pain	Nerve stimulation
Fever	Systemic response

Urinary system

Main Functions:

1. Filter blood — Remove waste products

2. Regulate fluid balance — Control water retention/excretion

3. Regulate electrolytes — Sodium, potassium, calcium balance

4. Regulate pH — Maintain acid-base balance

5. Produce hormones — Erythropoietin (RBC production), renin (blood pressure)

memory trick

Urinary System Order: "Kids Usually Urinate Beautifully"

Kidneys → Ureters → Urinary bladder → Urethra

Nephron Parts: "Go Bowman, Pass Lightly Down Collecting" Glomerulus → Bowman's → Proximal tubule → Loop of Henle → Distal tubule → Collecting duct

kidney structure

Kidney Structure:

Part	Description
Cortex	Outer layer; contains glomeruli
Medulla	Inner layer; contains loops of Henle
Renal pelvis	Collects urine; connects to ureter
Nephron	Functional unit (about 1 million per kidney)

nephron

The nephron is the functional unit where urine is actually produced.

Parts and Functions:

Part	Function
Glomerulus	Filters blood (like a sieve)
Bowman's capsule	Catches filtrate
Proximal tubule	Reabsorbs nutrients, water, ions
Loop of Henle	Concentrates urine; water reabsorption
Distal tubule	Fine-tuning; hormone-regulated
Collecting duct	Final concentration; collects urine

Three Processes:

Process	What Happens	Where
Filtration	Blood filtered; small molecules pass	Glomerulus
Reabsorption	Good stuff returned to blood	Tubules
Secretion	Waste added to filtrate	Tubules

urine formation

1. Filtration: Blood pressure forces water and small molecules through glomerulus

2. Reabsorption: 99% of filtrate is reabsorbed (water, glucose, amino acids, ions)

3. Secretion: Additional waste (H⁺, K⁺, drugs) added to urine

4. Excretion: Urine sent to bladder and eliminated

Daily production: ~180 L filtered → ~1-2 L urine (99% reabsorbed!)

horomones affecting kidneys

Hormone	Source	Effect
ADH	Pituitary	↑ Water reabsorption (less urine)
Aldosterone	Adrenal	↑ Sodium reabsorption (water follows)
ANP	Heart	↑ Sodium excretion (↓ blood pressure)