Human Body Systems Review Flashcards

Anatomical Language and Positional Reference

Anatomical Position: This refers to the standard position humans are in when healthcare professionals use directional and regional terms. The human is standing upright, feet flat on the floor and slightly apart, facing forward, with arms at the sides and palms facing forward.
Anterior and Posterior: * Anterior (Ventral) refers to the front part of a human, which includes the face and the abdominal region. * Posterior (Dorsal) refers to the back part of a human, which includes the shoulder blades and the heels.
Superior and Inferior: * Superior refers to a structure being higher up on the body or closer to the head. * Inferior refers to a structure being lower on the body or closer to the feet.
Medial and Lateral: * Medial refers to a structure being closer to the midline of the body. * Lateral refers to a structure being further away from the midline of the body.
Proximal and Distal (Appendages): * Proximal refers to a point on an appendage (arm or leg) that is closer to the point of attachment to the trunk. * Distal refers to a point further away from the trunk or point of attachment.
Superficial and Deep: * Superficial refers to a structure closer to the surface of the skin. * Deep refers to a structure that is further within the body, away from the surface.
Dorsal and Ventral (Spinal vs. Abdominal): * Dorsal refers to the spinal side of the body. * Ventral refers to the abdominal side of the body.

Regional Anatomy and Terminology

Head and Neck: * Cephalic: Related to the head. * Orbital: Related to the eye. * Buccal: Related to the cheek area. * Oral: Related to the mouth. * Nasal: Related to the nose. * Occipital: Related to the back of the head. * Cervical: Related to the neck.
Trunk and Torso: * Thoracic: Related to the chest cavity. * Sternal: Related to the sternum (the chest bone between the ribs). * Abdominal: Related to the tummy/stomach area. * Umbilical: Related to the belly button. * Pelvic: Related to the pelvis. * Inguinal: Related to the groin area. * Axillary: Related to the armpit. * Coxal: Related to the hip/upper part of the pelvis you can feel. * Lumbar: Related to the lower back. * Sacral: Related to the tailbone area. * Vertebral: Related to the spine. * Scapular: Related to the shoulder blade.
Upper Appendages: * Brachial: Related to the upper arm. * Antecubital: Related to the inside of the elbow (often where blood is drawn). * Olecranal: Related to the back of the elbow. * Carpal: Related to the hands/wrists. * Digital: Related to the fingers or toes.
Lower Appendages: * Femoral: Related to the thigh. * Patellar: Related to the front of the knee. * Popliteal: Related to the back of the knee. * Tarsal: Related to the feet/ankle area. * Calcaneal: Related to the heel of the foot. * Gluteal: Related to the booty/buttocks area.

Body Organization and Structural Planes

Body Planes: * Coronal (Frontal) Plane: Divides the body into anterior (front) and posterior (back) portions. * Sagittal Plane: Divides the body into left and right portions. * Median (Midsagittal) Plane: A sagittal plane that lies exactly on the midline. * Transverse Plane: Divides the body into superior (top) and inferior (bottom) portions.
Body Cavities: * Cranial: Houses the brain. * Vertebral: Houses the spinal cord. * Dorsal: Comprises the cranial and vertebral cavities. * Thoracic: Houses the heart and lungs. * Abdominal: Houses digestive organs. * Pelvic: Houses reproductive and urinary organs. * Abdominopelvic: Comprises the abdominal and pelvic cavities. * Ventral: Comprises the thoracic and abdominopelvic cavities.
Levels of Organization: Cells work together to form tissues; tissues work together to form organs; organs work together to form organ systems; organ systems together make an organism.

Histology: The Four Human Tissue Types

Nervous Tissue: Composed primarily of neurons; functions to receive, interpret, and respond to signals internally and externally.
Epithelial Tissue: Lines the outer surfaces of all organs and blood vessels; acts as a protective barrier and is involved in secretion/absorption.
Muscle Tissue: Main function is to contract. There are three subtypes: * Skeletal: Striated and voluntary. * Smooth: Non-striated and involuntary (e.g., in the gut). * Cardiac: Striated and involuntary (specific to the heart).
Connective Tissue: Supports and protects the body. It holds organs in place, attaches muscle to bone, links bones at joints, and provides elasticity. Adipose (fat) is a specialized type of connective tissue.

The Skeletal System and Bone Physiology

Four Types of Bones (by Shape): 1. Long Bones: Examples include the femur and humerus. 2. Short Bones: Examples include carpals and tarsals. 3. Flat Bones: Examples include the sternum and scapula. 4. Irregular Bones: Examples include the vertebrae and mandible.
Anatomy of a Bone: * Epiphysis: The rounded end of a long bone. * Metaphysis: The narrow portion of a long bone between the epiphysis and the diaphysis. * Diaphysis: The main shaft or midsection of a long bone. * Spongy Bone: Porous bone tissue typically found in the epiphyses. * Compact Bone: Dense bone tissue forming the outer shell. * Periosteum: The membrane covering the outer surface of the bone. * Medullary Cavity: The central cavity of the bone shaft where marrow is stored. * Yellow Bone Marrow: Marrow found in the medullary cavity, consisting mostly of fat.
Specific Bone Locations: * Skull: Frontal bone, Parietal bone, Occipital bone, Temporal bone, Sphenoid, Zygomatic (cheek), Mandible (lower jaw), Maxilla (upper jaw). * Upper Body: Clavicle (collarbone), Scapula (shoulder blade), Rib cage, Sternum, Vertebral column. * Arm/Hand: Humerus, Radius (thumb side), Ulna (pinky side), Carpals (wrist), Metacarpals (palm), Phalanges (fingers). * Lower Body: Pelvic girdle, Femur (thigh), Patella (kneecap), Tibia (shin), Fibula (calf), Tarsals (ankle), Metatarsals (foot bridge), Phalanges (toes).
Bone Cells: * Osteoblasts: Cells responsible for building up bone tissue. * Osteoclasts: Cells responsible for breaking down bone tissue to release minerals or remodel bone. * Equilibrium: An excess of either osteoblasts or osteoclasts results in weakened bones.

Bone Fracture Repair and Imaging Technologies

Four Stages of Fracture Repair: 1. Hematoma Formation: Blood vessels rupture, and a blood-filled swelling (clot) forms. 2. Fibrocartilaginous Callus Formation: Cartilage and collagen fibers bridge the break. 3. Bony Callus Formation: Spongy bone replaces the fibrocartilage. 4. Bone Remodeling: The bony callus is remodeled to resemble the original bone structure.
Fracture Treatment Methods: * Plating: Use of metal plates and screws on the surface of the bone to hold fragments together. * Nailing: Use of an intramedullary rod placed inside the medullary cavity to stabilize a long bone fracture.
Types of Fractures: * Transverse: A break straight across the bone. * Spiral: A break that twists around the bone, often from torque. * Impact (Comminuted): A break where the bone is crushed into several pieces.
Diagnostic Imaging: * X-ray scans: Provide a $2D$ image of the interior, primarily for hard tissues like bone. * MRI (Magnetic Resonance Imaging): Does not use radiation; provides high detail of fine soft tissue. * CT (Computed Tomography) scans: Creates images of internal structures such as tendons, muscles, joints, blood vessels, and internal organs.

The Muscular System and Muscle Physiology

Muscle Types: * Skeletal Muscle: Striated and voluntary. * Smooth Muscle: Non-striated and involuntary. * Cardiac Muscle: Striated and involuntary.
Anatomical Structures: * Epimysium: Outer layer of connective tissue surrounding the whole muscle. * Perimysium: Connective tissue surrounding a fascicle. * Endomysium: Connective tissue surrounding each individual muscle cell. * Fascicle: A bundle of muscle cells. * Myofibril: Thread-like structures within a muscle cell made of actin and myosin. * Tendon: Connective tissue attaching muscle to bone.
Muscle Attachments: * Origin: The attachment point that does not move during contraction. * Insertion: The attachment point that does move during contraction.
6 Muscle Rules: These rules govern how muscles function (e.g., muscles must have at least two attachments, they must cross at least one joint, they always pull and never push, etc.).

Joint Classification and Range of Motion

Joint Categories: 1. Fibrous (Fixed): Joints that are primarily made of collagen and offer no movement. 2. Cartilaginous: Joints primarily made of hyaline cartilage that allow for limited movement. 3. Synovial (Moveable): Joints containing synovial fluid to reduce friction, allowing for significant movement.
Range of Motion (ROM) Terms: * Rotation: Pivot movement around a single axis. * Circumduction: Circular movement of a limb at the far end. * Abduction: Moving a limb away from the midline. * Adduction: Moving a limb toward the midline. * Depression: Downward movement of a body part. * Elevation: Upward movement of a body part. * Flexion: Decreasing the angle between bones. * Extension: Increasing the angle between bones. * Plantar Flexion: Pointing the toes downward. * Dorsiflexion: Pointing the toes upward toward the shin.
Clinical Tools: A Goniometer is used to measure the specific angle of a joint's range of motion. Properly assessing ROM helps track physical therapy progress.
Knee Anatomy and Injuries: * Structures: Femur, Tibia, Fibula, Patella, ACL (Anterior Cruciate Ligament), PCL (Posterior Cruciate Ligament), MCL (Medial Collateral Ligament), LCL (Lateral Collateral Ligament). * Diagnostic Tests: * Anterior Drawer: Tests for ACL injury. * Posterior Drawer: Tests for PCL injury. * Valgus Stress: Tests for MCL injury. * Varus Stress: Tests for LCL injury.
Joint Alignment: * Valgus Motion: Occurs when knees are tilted in and toes point out (knock-kneed). * Varus Motion: Occurs when knees are bent outwards (bow-legged).

The Nervous System: Central and Peripheral Divisions

Central Nervous System (CNS): Consists of the brain and spinal cord; acts as the primary control center.
Peripheral Nervous System (PNS): Consists of all the nerves outside the brain and spinal cord; connects the CNS to limbs and organs.
Brain Regions: * Cerebrum: The largest part, divided into four lobes. * Cerebellum: Located under the cerebrum; coordinates muscle control and balance. * Brainstem: Consists of the medulla oblongata, pons, and midbrain; regulates autonomic functions like breathing, blood pressure, and sleep cycles.
Cortical Structures: * Gyri: The ridges seen on the surface of the brain. * Sulci: The valleys or grooves between the ridges.
Lobe Functions: * Frontal Lobe: Behavior, personality, planning, voluntary movement, mood, social interaction, attention. * Temporal Lobe: Processing smell and sound, language understanding. * Parietal Lobe: Sensing touch, temperature, pressure, pain; spatial processing. * Occipital Lobe: Visual perception.
Internal Brain Structures: * Thalamus: Center for pain perception. * Corpus Callosum: Facilitates communication between the two hemispheres. * Hypothalamus: Coordinates the autonomic nervous system, pituitary gland, body temperature, thirst, and hunger. * Hippocampus: Involved in long-term memory formation.

Neuronal Structures and Impulses

Glial Cells: Specialized cells that provide protection and maintain homeostasis for neurons.
Neuron Anatomy: Includes dendrites (receive signals), cell membrane, nucleus, cell body (soma), axon (transmits signals), Myelin sheath (insulates axon), Schwann cells (make myelin), nodes of Ranvier (gaps in myelin), and axon terminals (release neurotransmitters).
Neuron Types: * Sensory Neurons: Send signals toward the brain. * Interneurons: Process signals within the brain and spinal cord. * Motor Neurons: Send signals from the brain to muscles for action.
Action Potential and Ion Transport: * Sodium-Potassium Pump: Uses ATP to move $3\,Na^+$ ions out of the cell and $2\,K^+$ ions into the cell. * Resting Membrane Potential: Typically $-70\,mV$ . * Depolarization: Sodium channels open; Sodium enters the cell. * Repolarization: Potassium channels open; Potassium exits the cell while Sodium channels close.
Reflex vs. Reaction: A reflex is an involuntary, nearly instantaneous movement in response to a stimulus (bypass the brain for speed), whereas a reaction is a voluntary, conscious response processed by the brain.

Neurotransmitters and Neuropharmacology

Essential Neurotransmitters: * Acetylcholine: Functions in muscle contraction, learning, and memory. * Dopamine: Involved in pleasure, motivation, mood, attention, and movement. * GABA: The primary inhibitory neurotransmitter in the brain. * Glutamate: The primary excitatory neurotransmitter in the brain. * Epinephrine/Norepinephrine: Responsible for the fight-or-flight response. * Serotonin: Regulates mood, sleep, and digestion.
Pharmacological Mechanisms: * Agonist: Binds to a receptor and activates it to produce a response. * Antagonist: Binds to a receptor and blocks the activation of that receptor. * Inverse Agonist: Binds to the same receptor as an agonist but exerts the opposite pharmacological effect. * Reuptake Inhibitor: Blocks the reabsorption of a neurotransmitter into the synapse, increasing its concentration.

The Endocrine System and Hormonal Regulation

Mechanisms: The endocrine system uses chemical signals called hormones that travel through the bloodstream and bind to target receptors on glands or organs.
Selected Glands and Functions: * Hypothalamus: Controls the pituitary gland; affects metabolism and thirst. * Pituitary Gland: Master gland governing growth, reproduction, lactation, and water balance. * Pineal Gland: Regulates sleep/wake cycles via melatonin. * Thyroid Gland: Controls growth, development, and metabolism. * Thymus: Produces white blood cells (T-cells) until puberty. * Adrenal Gland: Manages stress response, metabolism, and blood pressure. * Pancreas: Regulates blood sugar, appetite, and stomach acids. * Ovaries: Produce estrogen and progesterone; facilitate female reproduction. * Testes: Produce testosterone; facilitate male reproduction.
Blood Sugar Dynamics: * High Blood Sugar: The pancreas releases insulin; cells take up glucose and the liver converts excess to glycogen. * Low Blood Sugar: The pancreas releases glucagon; the liver breaks down glycogen to release glucose back into the blood.
Diabetes Mellitus: * Type 1: An autoimmune condition where the body cannot produce insulin. * Type 2: A condition where cells become resistant to insulin or the body doesn't produce enough.

The Cardiovascular System: Heart Anatomy and Conduction

Valves: The role of valves is to ensure unidirectional blood flow and prevent backflow within the heart chambers.
Coronary Circulation: * Coronary Arteries: Provide oxygenated blood to the heart muscle itself. * Left Coronary Artery: Supplies the left side of the heart muscle. * Left Anterior Descending (LAD): Supplies the front of the left side of the heart. * Circumflex Artery: Supplies the outer side and back of the heart. * Right Coronary Artery (RCA): Supplies the right ventricle and right atrium.
Conduction System: * Mechanism: SA Node (Pacemaker) -> AV Node -> Bundle of His -> Purkinje Fibers. * Arrhythmia: A condition characterized by an irregular heartbeat or abnormal electrical conduction.

Blood Pressure and Cardiac Dynamics

Measurement Phases: * Systolic Pressure: Pressure in the arteries when the heart contracts (systole) to pump blood. * Diastolic Pressure: Pressure in the arteries when the heart is at rest (diastole), filling with blood. * Sphygmomanometer: The medical tool used for manual blood pressure measurement.
Blood Pressure Categories ( $mm\,Hg$ ): * Normal: Less than $120$ systolic AND less than $80$ diastolic. * Elevated: $120-129$ systolic AND less then $80$ diastolic. * Hypertension Stage 1: Diastolic between $80-89$ . * Hypertension Stage 2: Systolic $140$ or higher. * Hypertensive Crisis: Diastolic higher than $120$ .
Pulse Points: Major points include Carotid (neck), Radial (wrist), Brachial (arm), and Femoral (groin).
Hemodynamic Formulas: * Cardiac Output ( $CO$ ): The volume of blood pumped by both ventricles in one minute ( $units: mL/min$ or $L/min$ ). * Heart Rate ( $HR$ ): Count of heart beats in one minute ( $bpm$ ). * Stroke Volume ( $SV$ ): Amount of blood pumped per beat; average is stable at $75\,mL/beat$ . * Equation: $CO = HR \times SV$ (e.g., if $HR = 185\,bpm$ , $CO = 185 \times 75 = 13,875\,mL/min$ ).

Cardiovascular Pathology and Circulation

ABI (Ankle-Brachial Index): Calculated by dividing systolic pressure in the ankle by systolic pressure in the arm.
Peripheral Artery Disease (PAD): * Characterized by a narrowing of blood flow to the extremities. * Increases risk for heart attack and stroke. * Symptoms: Pain while walking, changes in skin temperature. * Advanced result: Critical limb ischemia (complete blockage).
Atherosclerosis: The buildup of plaque (fats, cholesterol) in blood vessels, which commonly leads to PAD.

The Respiratory System and Pulmonary Function

Anatomical Structures: Nasal cavity, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi (main, secondary, tertiary), bronchioles, alveoli (site of gas exchange), and diaphragm.
Pulmonary Assessments: * Spirometry: A common test to assess lung volume and air flow. * FEV1 (Forced Expiratory Volume in 1 second): The maximum air volume forcefully exhaled in the first second of a breath. * Diagnostic Threshold: Any FEV1 value under $80\%$ could indicate an airway obstruction.
Pathologies: * Asthma: Causes inflammation and narrowing of the airways. * Pulmonary Edema: A condition caused by excess fluid in the lungs, making breathing difficult.

Immunity, Pathology, and Skin Physiology

Blood Chemistry and Lipids: * Red Blood Cells (RBCs): Transport oxygen via hemoglobin. * LDL (Low-Density Lipoprotein): Transports cholesterol to cells; "bad" cholesterol. * HDL (High-Density Lipoprotein): Transports excess cholesterol to the liver; "good" cholesterol. * Triglycerides: Fats in the blood; levels above $150\,mg/dL$ are linked to heart disease.
Agents of Disease: Bacteria, Viruses, Fungi, Protozoa, Helminths, and Prions.
Skin Layers: Epidermis (outer), Dermis (middle containing oil glands and hair follicles), Subcutaneous fatty tissue (bottom insulation).
Sepsis Progression: An extreme response to infection progressing through inflammation, severe sepsis, and septic shock.
Sepsis TIME Protocol: * T: Temperature (higher or lower than normal). * I: Infection (signs/symptoms of infection). * M: Mental decline (confused/sleepy). * E: Extremely ill (“I feel like I might die”).

The Lymphatic System and Immunological Defense

Definitions and Anatomy: * Lymph: The fluid circulating through the lymphatic system. * Lymph Nodes: Bean-shaped organs distributed along vessels that filter and destroy pathogens. They contains white blood cells, nutrients, bacteria, and dead cells. * Vessels: Afferent (carry unfiltered lymph IN) and Efferent (carry filtered lymph OUT).
Immune Responses: * Innate Immunity: Nonspecific defense mechanisms (skin, mucus, fever, inflammation). * Acquired Immunity: Specific immunity developed after exposure to a pathogen or via vaccination (involves antibodies).
Infection Stages: * Prodromal: The beginning stage of illness when general symptoms develop. * Convalesce: The period of recovery as you begin to get better.

Viral Reproduction and Transmission

Steps of Viral Reproduction: 1. Attachment: Virus attaches to target cell receptor. 2. Entry: Virus enters the cell. 3. Uncoating: Viral capsid is removed, exposing genetic material. 4. Replication: Cell machinery copies the viral genome. 5. Assembly: New viral particles are put together. 6. Maturation: Structural changes occur to make the virus infectious. 7. Release: New viruses exit the host cell.
Transmission Models: * Direct: Physical contact (touching, kissing) or droplet spread (sneezing directly on someone). * Indirect: Airborne (lingering in air), vector-borne (insects), or vehicle-borne (contaminated objects/food/water).

Special Senses: Anatomy and Physiology of the Eye

Anatomy: Cornea (protective front), Pupil (opening), Iris (color part/muscle), Lens (focuses light), Aqueous humor (front fluid), Vitreous humor (rear gel), Retina (receptor layer), Optic Nerve (sends signal to brain), Sclera (white of eye), Tapetum (reflective layer in animals; not humans).
Physiological Process: When light hits the retina, it triggers chemical and electrical impulses that are sent via the optic nerve to the occipital lobe of the brain.
Subconjunctival Hemorrhage: A broken blood vessel beneath the clear surface of the eye (conjunctiva).

The Urinary System and Renal Function

Structures: Kidneys (filtration), Ureters (transport to bladder), Urinary Bladder (storage), Urethra (evacuation).
Renal Mechanisms: * GFR (Glomerular Filtration Rate): Measure of how rapidly blood is cleansed of metabolic wastes and how well homeostasis is maintained. * Tubular Reabsorption: Moving substances from the filtrate back into the blood. * Tubular Secretion: Moving substances from the blood into the filtrate (urine).
Kidney Disorders: * CKD (Chronic Kidney Disease): Gradual loss of kidney function over time. * PKD (Polycystic Kidney Disease): Inherited disorder (Autosomal Dominant/Recessive) characterized by fluid-filled cysts in both kidneys. Symptoms include blood in urine, high blood pressure, and abdominal pain.
Urinalysis Components: Physical (color/clarity), Chemical (using dipsticks for pH, glucose, etc.), and Microscopic (looking for cells or crystals).

The Digestive System and Human Nutrition

Types of Digestion: Mechanical (physical breakdown like chewing) and Chemical (enzymatic breakdown).
Digestion Pathway: * Oral Cavity: Saliva (containing enzymes) and tongue shape food into a bolus. * Stomach: Releases HCl and enzymes; food becomes a liquid/paste called chyme. * Small Intestine: Three sections: Duodenum, Jejunum, Ileum. Most water and nutrients are absorbed here. * Accessory Organs: The Liver produces bile; the Pancreas produces enzymes; both are released into the duodenum.
Clinical Procedures and Tools: * J-tube: A feeding tube inserted into the jejunum. * G-tube: A feeding tube inserted into the stomach. * Ostomy: A surgical opening (stoma) that allows stool to exit the body into a bag. * Diagnostics: Endoscopy (upper digestive view), Colonoscopy (lower digestive view), and Biopsy (tissue sampling).
Gut Microbiome: The community of microorganisms living in the digestive tract.
The Four Macromolecules: 1. Carbohydrates: Primary energy source. 2. Lipids: Fats for long-term energy and cell membranes. 3. Proteins: Built from amino acids; used for structure and enzymes. 4. Nucleic Acids: DNA and RNA; carry genetic information.