Cell Organelles & Processes

• Cell Organelles: Structures within a cell with specific functions.
• Nucleus: Contains DNA and controls gene expression.
• Ribosomes synthesize proteins and are either free in the cytoplasm or membrane-bound on the rough ER.
• Rough ER: modifies proteins and contains ribosomes.
• Smooth ER: synthesizes lipids and aids in detoxification.
• Golgi Apparatus: modifes, sorts, and packages proteins.
• Lysosomes contain digestive enzymes for waste breakdown.
• Peroxisomes: aid in detoxification and fatty acid breakdown.
• Mitochondria: create ATP through cellular respiration.

Protein Synthesis & Transport

• DNA is transcribed into mRNA in the nucleus.
• Ribosomes translate mRNA into protein.
• In the rough ER proteins are folded and modified.
• The golgi apparatus sorts and packages proteins.
• Vesicles transport proteins to final locations like the membrane, for secretion or to lysosomes.

Plasma Membrane Structure

• A phospholipid bilayer has hydrophilic heads facing outward and hydrophobic tails facing inward.
• Being semi-permeable it allows only selective molecules to pass through.
• Hydrophilic refers to water-loving properties.
• Hydrophobic refers to water-fearing properties.

Membrane Transport

• Passive transport requires no energy, moves down the concentration gradient.
• Simple diffusion is direct and moves small, nonpolar molecules across the membrane. Facilitated diffusion uses carrier or channel proteins to transport molecules.
• Osmosis involves movement of water across a semipermeable membrane.
• Active transport requires ATP and moves against the concentration gradient.
• Primary active transport uses ATP directly.
• Secondary active transport indirectly uses ion gradients to move molecules.

Osmosis & Tonicity

• Osmosis is water moving from a low to high solute concentration.
• An Isotonic solution sees no net water movement, allowing the cell to maintains its shape.
• A Hypotonic solution sees water enter the cell, causing it to swell and potentially burst.
• A Hypertonic solution sees water exit the cell, causing it to shrink.

Na+-K+ Pump Mechanism

• It is an active transport mechanism moving 3 Na+ out and 2 K+ in against their concentration gradients.
• ATP is used to maintain resting membrane potential.
• Crucial to nerve impulses and muscle contraction.

Vesicular Transport

• Endocytosis brings substances into the cell, including Phagocytosis (large particles), Pinocytosis (fluids), and Receptor-mediated Endocytosis (specific molecules).
• The process of Exocytosis expels substances from the cell via vesicles.

ATP in Secondary Active Transport

• Primary active transport (e.g., Na+-K+ pump) creates a gradient which the secondary transport uses to move molecules without directly using ATP.
• An example is the Na+-glucose symporter that moves glucose into the cell using the Na+ gradient.

Summary of Cell Functions

• Cells contain specialized organelles.
• The plasma membrane regulates molecular movement through passive or active transport.
• Osmosis and tonicity affect cell shape.
• The Na+-K+ pump maintains ion balance.
• Vesicular transport moves large molecules.
• Secondary active transport indirectly uses ATP through ion gradients.

Divisions of the Nervous System

• The central nervous system (CNS) houses the brain and spinal cord for integration.
• The Peripheral nervous system (PNS) includes afferent (sensory) and efferent (motor) neurons.
• Somatic Nervous System (SNS) controls voluntary movements.
• Autonomic Nervous System (ANS) controls involuntary actions.

Neuron Classification by Function

• Sensory (afferent) neurons carry signals to the CNS.
• Motor (efferent) neurons transmit signals from the CNS to muscles or glands.
• Interneurons connect sensory and motor neurons within the CNS.

Neuron Structure & Myelination

• Signals are received by dendrites and processed by the cell body (soma).
• Signals are transmitted by the axon.
• The myelin sheath insulates axons for faster transmission.

Resting Membrane Potential (RMP)

• The electrical potential difference across a neuron membrane is ~ -70mV.
• Crucial for nerve impulse transmission.
• Managed by the Na+-K+ pump maintaining high Na+ outside and high K+ inside.
• K+ leaks out, creating a negative interior charge, helping to establish negative RMP.

Depolarization vs. Hyperpolarization

• During depolarization, the membrane potential becomes more positive as Na+ enters.
• During hyperpolarization, the membrane potential becomes more negative as K+ exits or Cl- enters.

Graded Potentials

• Graded potentials are characteristics of local membrance with varying magnitude, and decay over distance.
• Can be either excitatory or inhibitory.
• Action potentials are "all-or-nothing", and do not decay at strength.

Action Potential (AP) Stages

• Resting State sees all channels closed at -70mV.
• During Depolarization, Na+ channels open, where Na+ enters and potential becomes positive.
• Repolarization sees K+ channels open in order to allow K+ to exit, returning potential to negative.
• There is a Hyperpolarization: Excess K+ exits before stabilization

Refractory Periods

• During the Absolute Refractory Period no new AP can occur as Na+ channels are inactive.
• The Relative Refractory Period sees that an AP can occur if stimulus is strong enough as K+ channels closing.

Synaptic Transmission

• An AP reaches axon terminal triggering Ca2+ channels to open and neurotransmitter release.
• The neurotransmitter binds to receptors on the post-synaptic neuron leading to Excitatory (EPSP) or Inhibitory (IPSP) response.
• EPSP’s depolarize and increase AP likelihood.
• IPSP’s hyperpolarize and decrease AP likelihood.

Summation Types

• Spatial Summation involves multiple signals from different locations.
• Temporal Summation involves repeated signals from one neuron.

Sympathetic vs. Parasympathetic Division (ANS)

• The Sympathetic (Fight-or-Flight) system increases HR, BP, and energy use releasing ACh and norepinephrine.
• The Parasympathetic (Rest-and-Digest) system decreases HR, BP, and increases digestion releasing ACh.

Neurotransmitters & Receptors

• Preganglionic Neurons release ACh.
• Ganglionic Neurons include:
• Sympathetic: NE to adrenergic receptors.
• Parasympathetic: ACh to muscarinic receptors.

Nervous System Summary

• Consists of the central and peripheral systems, which are subsequently broken into sensory motor and autonomic levels.
• Neurons use action potentials and synaptic transmission to relay signals.
• The Na+-K+ is vital to neuronal activity being possible.
• Transmission happens via neurotransmitter release and is dependent on the potentials of the post synaptic regions.
• Summation is in charge of if an AP occurs.
• The ANS has subdivisions for fight or flight or rest and digest.

Regions of the Cerebral Cortex & Functions

• The Frontal Lobe controls voluntary actions such as movement, planning, and speech.
• Sensory information is sensed and processed by the Parietal Lobe.
• The Occipital Lobe is in charge of all vision related activities.
• Functions related to hearing, memory, and language occur in the Temporal Lobe.

Major Divisions of the Brain & Functions

• The Cerebrum handles cognition, processing, and movment.
• Relay and homeostasis happens in the Diencephalon
• The Brainstem controls automatic things like heart rate.
• The Cerebellum coordinates movement and balance.

Spinal Cord

• Function: Relays information between the brain and the body; involved in reflexes.
• Structure:
• Gray Matter: Inner region containing neurons and synapses.
• White Matter: Outer region containing myelinated axons for fast signal transmission.

CNS Coverings & Cerebrospinal Fluid (CSF)

• Meninges: Three protective layers include the Dura, Arachnoid and Pia Maters.
• CSF Functions: Cushions the brain, removes waste, and circulates nutrients.

Peripheral Nervous System (PNS) Structure & Function

• It has somatic for movement and autonomic for regulation.
• There are 31 spinal and 12 cranial nerves.

Parasympathetic vs. Sympathetic Nervous System

• Sympathetic increases heart rate, dilates pupils, inhibits digestion.
• Parasympathetic decreases heart rate, constricts pupils, stimulates digestion.

Peripheral Nerve Structure & Spinal vs. Cranial Nerves

• Peripheral Nerve Layers:
• Epineurium: Outer conective tissue covering.
• Perineurium: covers axon bundles.
• Endoneurium: Connective tissue axons.
• Spinal Nerves: Transmit everything..
• Cranial Nerves: Only transmit the types of signals for their specific locations.

Reflex Arc Components

• Receptor: Detects the stimulus.
• Sensory Neuron: Sends the signal.
• Integration Center: Processes the signal.
• Motor Neuron: Issues command.
• Effector: Is the target and responds to the intial signal.

Muscle Spindles & Stretch Reflex

• Detects changes in muscle length.
• Stretch Reflex prevents overstretching.

Stretch Reflex vs. Tendon Reflex

• Stretch Reflex maintains muscle tone and posture (e.g., knee-jerk reflex).
• Tendon Reflex prevents muscle damage by relaxing the muscle when tension is excessive.

Pupillary & Vestibulo-Ocular Reflexes

• Pupillary Reflex: Controls pupil size in response to light.
• Vestibulo-Ocular Reflex: Stabilizes vision by adjusting eye movement based on head position.

Summary of the Nervous and Skeletal Systems

• Regions in the Cortex do different high level things.
• Subdivisions of the brain and different jobs.
• CNS consists of things used for signal transfers and protection.
• PNS is for regulation and movement.
• You have nerves that quickly respond to signals.
• There are sympathetic and parasympathetic functions which serve for both high and low level actions.
• Skeletons support, protect, move and store.

Bone Classifications & Examples

• Long Bones: Femur.
• Short Bones: Carpals.
• Flat Bones: Scapula.
• Irregular Bones: Vertebrae.
• Sesamoid Bones: Patella.

Long Bone Structure

• Epiphysis: Ends of the bone, contains spongy bone and red marrow.
• Diaphysis: Shaft, compact bone surrounding the medullary cavity.
• Periosteum: Outer membrane, site of bone growth and repair.
• Medullary Cavity: Contains yellow marrow (fat storage).
• Endosteum: Inner lining of the medullary cavity.

Vertebral Column Regions

• Spinal bones are segmented.
• Cervical (7)
• Thoracic (12)
• Lumbar (5)
• Sacrum (5, fused)
• Coccyx (4, fused)

Comparison of Vertebrae

• Cervical: Small body, transverse foramen, bifid spinous process.
• Thoracic: Medium body, costal facets for rib articulation.
• Lumbar: Large body, thick spinous process.

Pelvic Bones & Differences by Sex

• Ilium, Ischium, Pubis
• Male pelvis: Narrow, heart-shaped inlet, smaller pubic arch.
• Female pelvis: Wider, oval inlet, larger pubic arch for childbirth.

Bones of the Lower Limb

• Femur: is in the thigh.
• Tibia (weight-bearing), Fibula in the leg.
• Tarsals, Metatarsals, Phalanges in the feet.
• (Upper Limb equivalent: Humerus, Radius/Ulna, Carpals, Metacarpals, Phalanges)

Joint Movements

• Flexion/Extension: Bending/straightening.
• Abduction/Adduction: Moving away/toward midline.
• Plantarflexion/Dorsiflexion: Pointing toes up/down.
• Pronation/Supination: Rotating palm down/up.
• Protraction/Retraction: Forward/backward movement.
• Inversion/Eversion: Sole of foot inward/outward.

Joint Classification

• Structural:
• Fibrous: No movement (e.g., sutures of skull).
• Cartilaginous: Slight movement (e.g., intervertebral discs).
• Synovial: Freely movable (e.g., knee, shoulder).
• Functional:
• Synarthrosis: No movement.
• Amphiarthrosis: Limited movement.
• Diarthrosis: Freely movable.

Synovial Joint Stability Factors

1. Shape of articulating surfaces.
2. Ligament and capsule strength.
3. Muscle tone and surrounding tissues.

Skeletal Muscle Functions

1. Movement.
2. Posture maintenance.
3. Joint stabilization.
4. Heat production.

Connective Tissue Layers of Skeletal Muscle

1. Epimysium: Covers full muscle.
2. Perimysium: Around muscle fascicles.
3. Endomysium: Around individual fibers.

Parallel vs. Pennate Muscles

• Parallel: Fibers run in one direction (ex. Sartorius), for greater movement.
• Pennate: Fibers are angled (ex. Deltoid), for more force.

Patella Function & Type

• Lever to help tendon.
• Is an exampl of a sesamoid bone.

Quadriceps Muscles

1. Rectus Femoris.
2. Vastus Lateralis.
3. Vastus Medialis.
4. Vastus Intermedius.

Muscles Inserting into Achilles Tendon

1. Gastrocnemius.
2. Soleus.
3. Plantaris (deepest).

Key systems

• Bones provide structure, movement, and protection and classify bones into five different types with separate functions.
• There are joints that connect and support the skeletal system, being classified based on structure (fibrous, cartilaginous, synovial) and function
• Functions of skeletal muscles are to move, posturize, and generate heat.
• Muscle layout helps with both power and movement.
• Quadriceps give control of your legs.
• The main leg muscles connect to the Achilles tendon.

Cardiovascular System Components

• The pulmonary and systemic systems are the 2 main routes.
• Blood goes through both routes by use of the heart and blood vessels.
• Blood carries nutrients, gases and wastes.

Heart Anatomy & Blood Flow

• Chambers: Right atrium, right ventricle, left atrium, left ventricle.
• Atrioventricular (AV) Valves separate and provide flow between right and left.
• Flow must follow steps to get to the lungs into the atrium into the aorta.

Heart Valve Mechanics & Sounds

• Lub (S1) happens when AV valves close during systole.
• Dub (S2) is semilunar valves closing during diastole.

Blood Vessel Structure & Comparison

• Arteries: Thick, high, send blood to the body.
• Veins: Thin. low, return blood.
• Capillaries: Very thin for movement of gases.

Major Arteries from the Aorta

• Blood leaves the ascending aorta into the coronaries.
• It branches along the aortic arch into subclavian and carotids.
• Blood leaves the descending aorta into the branches.

Arterial Pulses & Veins

• Check pulse at the Carotid, Brachial, Radial, Femoral, Popliteal, Dorsalis Pedis.
• Veins: Same naming as arteries, some exceptions.

Cardiac Muscle Structure & Function

• Gap junctions are present for the hearts elctrical functions.
• Discs coordinate functions.

Electrical Activity of the Heart

• Autorythmic cells in the SA and AV nodes can autogenerate.
• Conduction happens as a signal: SA Node → AV Node → Bundle of His → Purkinje Fibers.

Cardiac Cycle & ECG

• 5 Steps:
• Atrial Systole.
• IsovolumetricContraction.
• VentricularEjection.
• IsovolumetricRelaxation.
• Ventricular Filling.
• The ECG tells you what area of the heart to focus on in terms of diagnosis
• Waveform tells you which part is at risk

ECG Measurement & Interpretation

• There are Bipolar (I, II, III) and unipolar areas with different leads.
• ECG Pathologies:
• Arrhythmias, Ischemia, Myocardial infarction, Hypertrophy.

Blood Pressure & Regulation

• Mean Arterial Pressure (MAP): is essential for blood flow.
• Heart Rate Regulation:
• Sympathetic (HR): Norepinephrine on ẞ1 receptors.
• Parasympathetic (HR): Acetylcholine on muscarinic receptors.
• The stroke must be strong but not overloading.
• Resistance is critical to blood movement so adjust where its needed.
• You can check levels via baroreceptors.
• BP Pathologies: Hypertension (Chronic high BP), Hypotension (Abnormally low BP).

Summary of Key Systems

• The heart carries blood through distinct functions, each needing different components to function.
• Signals are created to guide pathway regulation.
• Vessel properties provide help and restriction in blood movements.
• Blood flow needs to maintain homestasis.
• There are common disease that stop this from happening.