Final Exam #2

Osteoblasts

• Function: Build new bone matrix by secreting collagen and minerals.

• Importance: Essential for bone growth, healing, and remodeling.

• Other Facts: Found on bone surfaces; become osteocytes when trapped in matrix.

• Quick Tip: “Blasts Build” — think of them as bone construction workers.

Ligament

• Function: Connects bone to bone; stabilizes joints.

• Importance: Prevents excessive movement and injury.

• Other Facts: Made of dense regular connective tissue; poor blood supply = slow healing.

• Quick Tip: “Ligament = Link bones.”

Epiphyseal Plate

• Function: Site of longitudinal bone growth during childhood/adolescence.

• Importance: Determines future height and bone length.

• Other Facts: Located between epiphysis and diaphysis of long bones; becomes epiphyseal line after puberty.

• Quick Tip: “Growth plate = growing space.”

Blood Calcium Levels

• Function: Supports nerve signaling, muscle contraction, and bone strength.

• Importance: Must stay within a narrow range for survival.

• Other Facts: Regulated by PTH (raises) and calcitonin (lowers); stored in bones.

• Quick Tip: “Calcium = calm nerves + strong bones.”

Spongy Bone

• Function: Reduces bone weight and absorbs shock.

• Importance: Houses red marrow for blood cell production.

• Other Facts: Found in epiphyses and flat bones; made of trabeculae.

• Quick Tip: “Spongy = shock absorber + blood maker.”

Compact Bone

• Function: Provides strength and protection.

• Importance: Supports body weight and resists stress.

• Other Facts: Dense outer layer of bones; made of osteons.

• Quick Tip: “Compact = cortex = strong shell.”

Thyroid 

• Function: Regulate metabolism, heart rate, tempature, brain development, and growth.

• Importance: Crucial for energy balance and development.

• Other Facts:

  • It makes hormones (T3 & T4) that control metabolism — how the body uses energy.

• Quick Tip: Think of the thyroid as your body’s “energy thermostat” — it speeds up or slows down processes.

Pineal Gland

• Function: Secretes melatonin to regulate sleep-wake cycles.

• Importance: Controls circadian rhythm.

• Other Facts: Located deep in the brain near the thalamus.

• Quick Tip: “Pineal = PM hormone.”

Insulin vs Glucagon

🩸 Insulin

• Released by: Pancreas (beta cells).

• Function: Lowers blood glucose.

• How:

  • Released when blood sugar is high (after eating).

  • Helps cells absorb glucose for energy.

  • Stores extra glucose as glycogen in liver & muscles.

🩸 Glucagon

• Released by: Pancreas (alpha cells).

• Function: Raises blood glucose.

• How:

  • Released when blood sugar is low (fasting).

  • Signals liver to break down glycogen → glucose.

  • Glucose is released into blood.

⚡ Quick Tip

• Insulin = “store sugar” (after meals).

• Glucagon = “release sugar” (between meals/fasting).

👉 Easy memory: Insulin IN → glucose into cells. Glucagon GONE → glucose released into blood.

Fight or Flight Hormones

Epinephrine (Adrenaline)

• Made by: Adrenal medulla

• Role: Immediate “boost”

  • Increases heart rate, blood pressure, breathing.

  • Mobilizes glucose for quick energy.

  • Sharpens reflexes and physical readiness.

Norepinephrine (Noradrenaline)

• Made by: Adrenal medulla

• Role: Heightened awareness

  • Constricts blood vessels → raises blood pressure.

  • Keeps you alert, focused, and responsive to surroundings.

Cortisol

• Made by: Adrenal cortex (not medulla — this is the key correction).

• Role: Longer‑term stress support

  • Maintains blood glucose by releasing stored energy.

  • Pauses digestion, immunity, and other to focus on survival

  • Provides “backup fuel” for endurance under stress.

📌 Main takeaway:

• Epinephrine + norepinephrine = fast, immediate fight‑or‑flight response (adrenal medulla).

• Cortisol = slower, sustained stress support (adrenal cortex).

Pancreas

• Function: Regulates blood sugar via insulin and glucagon; aids digestion with enzyme secretion.

• Importance: Critical for glucose homeostasis and nutrient absorption.

• Other Facts: Dual-function gland (endocrine + exocrine); located behind the stomach.

• Quick Tip: “Pancreas = sugar switch + digestive helper.”

ADH & Aldosterone

• Function:

  • ADH: Retains water by acting on kidneys.

  • Aldosterone: Retains sodium, which pulls water with it.

• Importance: Maintain blood pressure and fluid balance.

• Other Facts: ADH from hypothalamus/pituitary; Aldosterone from adrenal cortex.

• Quick Tip: “ADH = Aqua hold, Aldo = Salt saver.”

ADH

• Function: Helps kidneys reabsorb water → reduces urine output.

• Importance: Prevents dehydration, keeps blood pressure and fluid balance stable.

• Other facts:

  • Made in hypothalamus, released by posterior pituitary.

  • Also called vasopressin.

  • Works mainly on kidney tubules.

• Quick tip: ADH = “Adds H₂O” back to the body.

Aldosterone

• Function: Keeps sodium (Na⁺), gets rid of potassium (K⁺).

• Importance: Raises blood pressure, balances salt and water.

• Other facts: Made in adrenal gland (cortex).

• Quick tip: Aldosterone = “Adds Na⁺” → water follows → ↑ BP.

White matter

• Function: Transmits signals quickly across brain and spinal cord.

• Importance: Enables fast communication between brain regions.

• Other Facts: Made of myelinated axons; deeper in brain, outer in spinal cord.

  • made up mainly of myelinated axons — nerve fibers wrapped in a fatty covering called myelin. The myelin gives white matter its pale color and allows electrical signals to travel quickly and efficiently through the nervous system.

• Quick Tip: “White = wires.”

Afferent vs Efferent Neurons

• Function:

  • Afferent: Carry sensory info to CNS.

  • Efferent: Carry motor commands from CNS.

• Importance: Coordinate input and output for body control.

• Other Facts: Afferent = dorsal root; Efferent = ventral root.

• Quick Tip: “Afferent Arrives, Efferent Exits.”

Axons & Synaptic Knobs

Axon:

• Long fiber that carries electrical signals (action potentials) away from the cell body.

• Think of it as the “wire” transmitting the impulse.

Synaptic knob (axon terminal):

• End of the axon.

• Releases neurotransmitters (chemical messengers) into the synaptic cleft.

• These neurotransmitters cross to the next neuron (or muscle/gland) and trigger a response.

Main message:

• Axon = electrical signal highway.

• Synaptic knob = chemical messenger release point.

Importance: Enable neuron-to-neuron communication.

• Other Facts: Axons may be myelinated; knobs are at axon terminals.

• Easy memory: Axon passes it down, knob passes it on.

Autonomic Nervous System

• Function: Controls involuntary functions (heart rate, digestion, breathing).

• Importance: Keeps body running without conscious effort.

• Other Facts: Includes sympathetic and parasympathetic branches.

• Quick Tip: “Auto = automatic body control.”

Sympathetic vs Parasympathetic

• Function:

  • Sympathetic: Activates fight-or-flight.

  • Parasympathetic: Promotes rest-and-digest.

• Importance: Balance stress and recovery.

• Other Facts: Sympathetic = thoracolumbar; Parasympathetic = craniosacral.

• Quick Tip: “Symp = speed, Para = peace.”

Medulla and Cerebellum

• Function:

  • Medulla: Controls vital signs (breathing, heart rate).

  • Cerebellum: Coordinates movement and balance.

• Importance: Essential for survival and smooth motion.

• Other Facts: Both located in hindbrain; medulla = brainstem, cerebellum = posterior.

• Quick Tip: “Medulla = monitor, Cerebellum = coordination.”

Oculomotor Nerve (CN III)

• Function: Controls most eye movements, eyelid lifting, and pupil constriction.

• Importance: Lets you track objects, open your eyes, and adjust to light.

• Other facts:

  • It’s the 3rd cranial nerve.

  • Works with CN IV (trochlear) and CN VI (abducens) for full eye movement.

  • Damage → double vision, drooping eyelid (ptosis), or pupil problems.

• Quick tip: Oculomotor = “Moves the eye & more.”

Olfactory (CN I)

• Function: Sense of smell.

• Importance: Detects odors → linked to taste and memory.

• Other facts: First cranial nerve; damage can cause loss of smell (anosmia).

• Quick tip: Olfactory = “Odor finder.”

Vestibulocochlear Nerve (CN VIII)

• Function: Hearing (cochlear) + balance (vestibular).

• Importance: Lets you hear sounds and stay upright.

• Other facts: Eighth cranial nerve; damage can cause hearing loss, dizziness, vertigo.

• Quick tip: Vestibulocochlear = “Volume + Balance.”

Afferent

• Function: Carry signals into the CNS (brain/spinal cord).

• Importance: Bring sensory info (touch, pain, vision, sound).

  • Sensory signals travel through afferent fibers

• Other facts: Think “incoming messages.”

• Quick tip: Afferent = “Arrive” at CNS.

Efferent

• Function: Carry signals out from the CNS to muscles/glands.

• Importance: Control movement and responses (motor output).

  • Motor signals carry through efferent fibers

• Other facts: Think “outgoing commands.”

• Quick tip: Efferent = “Exit” the CNS.

Track of a sensory and motor neuron path when a sensory receptor is activated by a stimulus nail 

1: afferent
2: ascending
3: brain
4: descending
5: efferent
6: muscle contracts 

Primary Motor & Sensory Cortex

• Function:

  • Motor Cortex: Controls voluntary movement.

  • Sensory Cortex: Processes touch, temperature, pain.

• Importance: Enables body control and sensory awareness.

• Other Facts:

  • Primary Motor located in Frontal lobe

  • Sensory Cortex located in Parietal lobe

• Quick Tip: “Motor = motion, Sensory = sensation.”

Photoreceptors

• Function: Detect light and convert it to neural signals.

• Importance: Enable vision.

• Other Facts:

  • Rods = dim light, peripheral vision.

  • Cones = color and sharp detail.

  • Located in retina.

• Quick Tip: “Rods = night, Cones = color.”

Phalanges (Digits)

• Function: Allow fine motor control and grasping.

• Importance: Essential for hand and foot movement.

• Other Facts: 14 per hand/foot (proximal, middle, distal); thumbs/big toes lack middle phalanx.

  • Thumb has two

  • Rest of fingers have 3

• Quick Tip: “Phalanges = finger bones.”

Tailbone (Coccyx)

• Function: Provides attachment for ligaments, tendons, and pelvic floor muscles.

• Importance: Helps support sitting posture and balance.

• Other facts:

  • Small, triangular bone at the very end of the spine.

  • Made of 3–5 fused vertebrae.

  • Can be painful if injured (coccydynia).

• Quick tip: Coccyx = “Tiny end bone” → supports sitting.

Olecranon Fossa

• Function: Receives olecranon process during elbow extension.

• Importance: Allows full arm straightening.

• Other Facts: Located on posterior distal humerus.

  • articulates with the olecranon process of the ulna

• Quick Tip: “Olecranon = elbow socket.”

Cribriform Plate

• Function: Allows olfactory nerves to pass from nose to brain.

• Importance: Enables sense of smell.

• Other Facts: Part of ethmoid bone; perforated structure.

• Quick Tip: Think of it like a strainer: the little holes let smell signals travel up into the brain.

Central canal of Osteons

• Function: Carries blood vessels and nerves through compact bone.

• Importance: Supplies nutrients and removes waste → keeps bone cells alive.

• Other facts:

  • Found at the center of each osteon (the structural unit of compact bone).

  • Surrounded by concentric rings of bone tissue (lamellae).

• Quick tip: Central canal = “Bone’s highway” → blood & nerves run through.

Short Bones

• Function: Provide support and stability with little movement.

• Importance: Help absorb shock and distribute forces.

• Other facts:

  • Cube‑shaped, about equal length and width.

  • Found mostly in wrists and ankles.

• Examples:

  • Carpals (wrist bones)

  • Tarsals (ankle bones)

• Quick tip: Short bones = “Small cubes for support.”

Irregular Bones

• Function: Protect nervous tissue, provide anchor points for muscles, and support body structure.

• Importance: Their complex shapes fit special roles (not long, short, or flat).

• Other facts:

  • Odd shapes, don’t fit into other bone categories.

  • Often have projections, curves, or holes.

• Examples:

  • Vertebrae (spinal bones)

  • Sacrum

  • Mandible (jaw bone)

• Quick tip: Irregular = “Odd shapes for special jobs.”

Flat Bones

• Function: Protect internal organs + provide broad surfaces for muscle attachment.

• Importance: Strong but thin → shield vital structures.

• Other facts:

  • Usually curved, flat, and thin.

  • Made of spongy bone sandwiched between compact bone.

• Examples:

  • Skull bones (frontal, parietal, occipital)

  • Sternum (breastbone)

  • Ribs

  • Scapula (shoulder blade)

• Quick tip: Flat bones = “Protective plates.”

Osteoclast

• Function: Break down bone tissue, releasing calcium into the blood.

• Importance: Critical for bone remodeling and calcium homeostasis.

• Other Facts: Large, multinucleated cells; found on bone surfaces.

• Quick Tip: “Clasts Crush.”

Endosteum

• Function: Inner lining of bone; contains osteoblasts and osteoclasts.

• Importance: Key in bone growth, repair, and remodeling.

• Other Facts: Lines medullary cavity and canals of osteons.

• Quick Tip: “Endo = inside lining.”

Osteons

• Function: Structural units of compact bone; provide strength and nutrient delivery.

• Importance: Organize bone into concentric rings for durability.

• Other Facts: Each osteon has a central canal with blood vessels/nerves.

• Quick Tip: “Osteon = bone donut.”

SAM Pathway

1. Stressor detected

   • The hypothalamus in the brain senses danger or stress.

2. Sympathetic nervous system activated

   • Hypothalamus sends signals down the sympathetic nerves.

3. Adrenal medulla stimulated

   • The sympathetic nerves directly stimulate the adrenal medulla (inner part of adrenal glands).

4. Hormone release

   • Adrenaline (epinephrine) and noradrenaline (norepinephrine) are secreted into the bloodstream.

5. Body-wide effects

   • Heart rate ↑

   • Blood pressure ↑

   • Breathing rate ↑ (bronchioles dilate)

   • Glucose released from liver for energy

   • Digestion ↓ (energy diverted to muscles)

⚡ Quick Tip:

• SAM = Sympathetic → Adrenal Medulla → Adrenaline surge.

• Activates fight-or-flight response.

• Think: “Sprint Away Mechanism” → fast, short‑term stress response.

Gonad

• Function:

  • Ovaries: Estrogen, progesterone.

  • Testes: Testosterone.

• Importance: Control reproduction, secondary sex characteristics.

• Other Facts: Regulated by pituitary hormones (LH, FSH).

• Quick Tip: “Gonads = gender hormones.”

Pituitary Gland Hormone

Anterior Pituitary:

• GH: Growth of bones, muscles, metabolism

• TSH: Stimulates thyroid

• ACTH: Stimulates adrenal cortex (cortisol)

• FSH: Egg & sperm production

• LH: Ovulation & testosterone

• PRL: Milk production

Posterior Pituitary:

• ADH: Water reabsorption, fluid balance

• Oxytocin: Labor contractions, milk release

⚡ Quick Tip:

• Anterior = Makes hormones

• Posterior = Stores & releases hypothalamus hormones

Thymus Hormone

• Thymosin: Helps T cells grow and mature → “Immune coach.”

• Thymopoietin: Guides T cells to become specialized → “Trainer for identity.”

• Thymulin: Fine‑tunes T cell function (needs zinc) → “Immune tuner.”

📌 Memory trick: Thymus = school for T cells

• Coach = Thymosin

• Teacher = Thymopoietin

• Principal = Thymulin

ACTH 

• Function: Stimulates adrenal cortex to release cortisol.

• Importance: Helps body respond to stress, regulates metabolism and blood pressure.

• Other facts: Made in anterior pituitary, controlled by hypothalamus (CRH).

  • A type of pituitary gland hormone

• Quick tip: ACTH = “Adrenal Cortex Trigger Hormone.”

ADH

• Function: Promotes water reabsorption in the kidneys → reduces urine output.

• Importance: Helps maintain blood pressure and fluid balance.

• Other facts: Made in the hypothalamus, stored and released by the posterior pituitary.

  • A type of pituitary gland hormone

• Quick tip: ADH = “Always Decreases H2O loss.”

Hypothalamus

• Function: Regulates hunger, thirst, temperature, circadian rhythm, and pituitary gland.

• Importance: Maintains homeostasis.

• Other Facts: Located below thalamus; links nervous and endocrine systems.

• Quick Tip: “Hypothalamus = homeostasis hub.”

Hormones

• Function: Chemical messengers that regulate body functions.

• Importance: Coordinate growth, metabolism, reproduction, and stress.

• Other Facts: Travel via blood; act on target cells with receptors.

• Quick Tip: “Hormones = body’s text messages.”

Adrenaline

• Function: Increases heart rate, blood pressure, and energy.

• Importance: Key in fight-or-flight response.

• Other Facts: Secreted by adrenal medulla.

• Quick Tip: “Adrenaline = action fuel.”

Oxytocin

• Function: Stimulates uterine contractions, milk letdown, and bonding.

• Importance: Vital in childbirth and social connection.

• Other Facts: Produced in hypothalamus, released by pituitary.

• Quick Tip: “Oxytocin = cuddle hormone.”

LH

• Function:

  • Triggers ovulation in females

  • stimulates testosterone in males.

• Importance: Essential for fertility and reproduction.

• Other Facts: Secreted by anterior pituitary.

• Quick Tip: “LH = love hormone.”

Type I Diabetes

• Function issue: The pancreas cannot produce insulin because immune cells destroy the insulin‑producing beta cells.

• Importance: Without insulin, glucose cannot enter cells → blood sugar stays high.

• Other facts:

  • Usually develops in childhood or adolescence.

  • Requires lifelong insulin therapy.

  • Autoimmune condition.

• Quick tip: Type 1 = “No insulin made.” → Hyposecretion.

Type II Diabetes

• Function issue: The pancreas makes insulin, but the body’s cells don’t respond properly (insulin resistance).

• Importance: Glucose cannot enter cells efficiently → blood sugar stays high.

• Other facts:

  • Often linked to lifestyle factors (diet, weight, activity).

  • More common in adults, but rising in children too.

  • May be managed with lifestyle changes, oral meds, or insulin if needed.

• Quick tip: Type II = “Cells ignore insulin.” → Hyposensitivity.

Hormones that regulate blood calcium

• Parathyroid Hormone (PTH): Raises blood calcium by pulling calcium from bone and increasing absorption.

• Calcitonin: Lowers blood calcium by storing calcium in bone.

• Vitamin D (Calcitriol): Helps absorb calcium from food in the intestines.

Quick tip:

• PTH = Pulls calcium Higher

• Calcitonin = Calcium in bone

• Vitamin D = Dietary calcium booster

Hydrophilic Hormones

• Definition: Water‑loving, cannot cross cell membrane.

• Action: Bind to surface receptors → use second messengers (like cAMP).

• Examples: Insulin, epinephrine, peptide hormones.

• Effect: Fast, short‑term response.

• Quick tip: Hydrophilic = “Surface signalers.”

Hydrophobic Hormones

• Definition: Water‑fearing, lipid‑soluble, cross cell membrane easily.

• Action: Bind to intracellular receptors → change gene expression.

• Examples: Steroids (cortisol, estrogen, testosterone), thyroid hormones.

• Effect: Slow, long‑lasting response.

• Quick tip: Hydrophobic = “Gene regulators.”

Pituitary gland

• Function: Master gland that controls growth, metabolism, reproduction, stress, and water balance.

• Importance: Directs other endocrine glands (thyroid, adrenal, gonads).

• Other facts: Has two parts — anterior (makes hormones) and posterior (stores/releases hypothalamus hormones).

• Quick tip: Pituitary = “Boss gland.”

Temporal Lobe

• Function: Processes sound, language, and memory.

• Importance: Essential for communication and recognition.

• Other Facts: Located on sides of brain; houses auditory cortex.

• Quick Tip: “Temporal = tunes + talk.”

Cochlea

• Function: Converts sound waves into electrical signals.

• Importance: Enables hearing.

• Other Facts: Spiral-shaped structure in inner ear; contains hair cells.

• Quick Tip: “Cochlea = sound converter.”

Fovea Centrails and Occipital Lobe

• Function:

  • Fovea Centralis: Sharpest vision, high cone density.

  • Occipital Lobe: Processes visual information.

• Importance: Together enable clear, detailed vision.

• Other Facts: Fovea in retina; occipital lobe at back of brain.

• Quick Tip: “Fovea = focus, Occipital = optic processor.”

Proprioceptors

• Function: Specialized receptors that detect stretch, tension, and joint position.

• Importance: Provide feedback to the nervous system to adjust movements in real time.

• Found in:

  • Muscle spindles → in muscles, sense stretch.

  • Golgi tendon organs → in tendons, sense tension.

  • Joint receptors → in ligaments/capsules, sense position.

• Quick tip: Proprioceptors = “Sensors for body awareness.”

Proprioception

• Function: Sense of body position, movement, and balance without needing to look.

• Importance: Essential for coordination, posture, and smooth movement.

• Other facts: Sometimes called the “sixth sense”; lets you touch your nose with eyes closed.

• Quick tip: Proprioception = “Body’s GPS.”