HBS Final Exam Notes

Anatomical Terminology

• Anterior: Front
• Posterior: Back
• Superior: Higher
• Inferior: Lower
• Medial: Midline
• Lateral: Away from the midline
• Proximal: Close
• Distal: Far
• Superficial: Skin level/close to skin level
• Deep: Further within than skin level
• Dorsal: Spinal (back)
• Ventral: Abdominal (front)
• Axial: Main axis of the body (head, neck, and trunk)
• Appendicular: All appendages attached to the axis

Levels of Organization

• Cells → Tissues → Organs → Organ Systems → Organism

Tissue Types

• Nervous Tissue:
  • Makes up nerves, spinal cord, and brain.
  • Composed of neuron cells that receive, interpret, and respond to signals.
• Connective Tissue:
  • Supports and connects all tissue types.
  • Includes adipose tissue (fat).
• Epithelial Tissue:
  • Made of epithelial cells aligned in sheets.
  • Lines the outer surface of all organs, blood vessels, and human skin.
• Muscular Tissue:
  • Skeletal (voluntary)
  • Smooth (involuntary) - found on inner walls of all organs
  • Cardiac (involuntary) - found in walls of the heart

Bone Tissue

• Compact Bone Tissue
• Adipose Tissue: Stores body fat with adipocytes (fat cells).
• Skeletal Muscle Tissue: Also striated.
• Flat Bone:
  • Layer of spongy bone between two thin layers of compact bone.
  • Marrow without a marrow cavity.
  • Example: Left parietal and sternum.
• Long Bone:
  • Shaft and two ends.
  • Thick outside layer with marrow cavity.
  • Ends are spongy.
  • Example: Humerus and femur.
• Irregular Bones:
  • Thin layers of spongy bone surrounded by compact bone.
  • Example: Thoracic vertebrae and mandible.
• Short Bones:
  • Cube-shaped with equal horizontal & vertical measurements.
  • Mostly spongy with thin outside layer of compact bone.
  • Example: Carpal and patellae.
• Osteoblasts: Cells that help build bones.
• Osteoclasts: Cells that break down bones.
• Excess of either cells can result in weak bones.

Bone Fracture Repair

• Hematoma Formation:
  • Broken blood vessels swell to form a mass (hematoma) between broken pieces.
  • Kills injured cells by reducing blood supply.
• Fibrocartilage Callus Formation:
  • New capillaries form in clotted blood in damaged area.
  • Fibrocartilage callus forms to close gap.
• Bony Callus Formation:
  • Fibrocartilage callus is gradually replaced with a spongy bone callus.
  • Osteoclasts and osteoblasts appear.
• Bone Remodeling:
  • Callus remodeled with osteoblasts and osteoclasts.
  • Bone heals over next few weeks/months.

Bone Fracture Treatments

• Cast: External brace to support bone remodeling; usually for children or minor adult fractures.
• External Fixation: Minimally invasive short-term fixation during emergency situations; likely to lead to infection.
• Intramedullary Nailing: Bone marrow removed from medullary canal; common in broken long bones where medullary canal is easy to navigate.
• Intramedullary Plating: Relatively large opening used to align metal plate with broken bone.

Types of Fractures

• Spiral Fracture: Cockscrew-esque appearance fracturing all the way around the bone (”complete fracture”).
• Impact/Comminuted Fracture: Multiple fractures.
• Transverse Fracture: Straight across the bone.
• Oblique Fracture: Diagonal.
• Greenstick: Occurs when the bone bends so that only one side fractures; occurs in children who have more flexible bones.
• Compression Fracture: Spinal.

Muscle Structure and Function

• Tendon: Attaches skeletal muscle tissue to bones.
• Epimysium: Outermost layer of connective tissue surrounding skeletal muscle.
• Perimysium: Connective tissue surrounding bundles of fascicles.
• Endomysium: Separates single cell fibers from one another.
• Fascicle: Individual bundles of muscle fibers.
• Myofibril: Basic contracting units within muscle fibers.

Muscle Rules

• Must have two attachments and must cross at at least 1 joint
• Muscles always pull and get shorter
• The attachment that moves is known as the insertion and the stationary attachment is the origin

Muscle Movement

• Muscles that decrease the angle between ventral surfaces of the body are known as flexors.
• Muscles that increase the angle between ventral surfaces of the body are known as extensors.
• Muscles work in opposing pairs.
• Muscle striations point to the attachments and show the direction of the motion.

Brain Regions and Functions

• Cerebellum: Area of brain underneath the cerebrum, muscle control and balance.
• Brain Stem: Medulla oblongata, pons, and midbrain. Breathing, blood pressure regulation, sleeping, and waking.
• Hypothalamus: Coordinates nervous system, pituitary gland activity, body temperature, thirst, hunger, homeostasis, sleep, and emotion.
• Thalamus: Relays sensory information, center for pain perception.
• Corpus Callosum: Bundle of nerve fibers that communicates between the hemispheres.
• Pituitary Gland: Produces hormones & activates hormone production in other glands.
• Central Nervous System: Brain and spinal cord.
• Peripheral Nervous System: Nerves beyond brain and spinal cord.
• Cerebrum: Contains all 4 brain lobes

Brain Lobes and Functions

• Frontal Lobe: Behavior, personality, voluntary muscle movements, planning, mood, emotions, social interaction, attention.
• Parietal Lobe: Sensing touch, temperature, pressure, and pain. Spatial processing, language, long term memory.
• Occipital Lobe: Visual perception, some forms of visual short-term memory.
• Temporal: Processes smell and sound, linguistic recognition, visual memories.

Neuron Structure

• Axon: Long nerve cell process conducting impulses away from cell body.
• Dendrites: Branching protoplasmic processes that conduct impulses toward cell body.
• Cell Membrane: Membrane surrounding cytoplasms of all cells.
• Nucleus: Contains genetic material (chromosomes) for cell development and protein synthesis (for cell survival).
• Cell Body (Soma): Central part of the neuron, contains nucleus, main component of gray matter.
• Sensory Neurons: Send signals to the brain.
• Interneurons: Send signals within the brain.
• Motor Neurons: Send signals to muscles.

Neuron Components

• Nodes of Ranvier: Gaps between myelin sheaths on axon of the neuron, allows ion to diffuse.
• Myelin Sheath: Insulating layer (sheath) around nerves, made of protein & fatty substances. allows for electrical signal transmission.
• Schwann Cells: Cells that produce myelin sheaths.
• Axon Terminals: Endings of axons that change electrical impulses or action potentials in a neuron into chemical messages in form of neurotransmitters.

Endocrine Glands and Hormones

• Insulin:
  • Secreted by pancreas.
  • Essential to metabolism of carbs and glucose regulation.
• Glucagon:
  • Secreted by pancreatic endocrine cells.
  • Raises blood glucose levels, antagonistic to insulin.
• Pineal Gland:
  • Regulates sleep.
  • Secretes melatonin (sleep hormone).
• Thyroid Gland:
  • Major role in growth/development of body & metabolism.
• Thymus:
  • Makes white blood cells until puberty.
  • Releases hormones.
• Adrenal Glands:
  • Releases hormones that help to regulate body’s response to stress, metabolism, blood pressure, and immune system.
• Pancreas:
  • Creates enzymes to break down sugars, and fats, and hormones that regulate blood sugar.
  • Appetite, stomach acid, and stomach emptying.
• Testis:
  • Produces sperm.
  • Testosterone, which helps in the development of muscle, deep voices, and body hair.
• Ovaries:
  • Produces estrogen and progesterone, to regulate reproduction and menstruation.
• Liver:
  • Stores glucose from food as glycogen
• Type 1 Diabetes:
  • Pancreases doesn’t produce insulin, due to immune system attacking cells in pancreas.
• Type 2 Diabetes:
  • Pancreatic insulin output decreases and body becomes resistant to insulin.

Cardiovascular System

• Pulmonary Veins: Vessels that bring oxygenated blood to the heart.
• Left Coronary Artery: Supplies blood to left side of heart.
• Right Coronary Artery: Supplies blood to right ventricle, atrium.
• Sinoatrial Node: Generates an electrical signal that causes upper heart chambers (atria) to contract.
• Atrioventricular Node: Controls passage of electrical signal from atria to ventricles.
• Bundle of His: Extends from AV node, receives electric signal from AV node to carry to the purkinje fibers.
• Purkinje Fibers: Carry electrical impulses to ventricles, runs through the intraventricular system.
• Arteries: Distributes oxygen rich blood throughout body.
• Veins: Carries oxygen-depleted blood to heart.
• Capillaries: Facilitate exchange of blood and oxygen with tissue.
• Systolic Pressure: Pressure in the arteries when heart contracts to push blood through the body.
• Diastolic Pressure: Pressure in the arteries when the heart is at rest in order to allow chambers to fill with blood.

Blood Vessel Locations

• Carotid: Neck
• Jugular: Neck
• Subclavian: By shoulder
• Axillary: By shoulder
• Brachial: Bicep
• Aorta: Top of heart
• Radial: Lateral wrist
• Ulnar: Medial wrist
• Brachiocephalic: Branching off aorta on the left
• Descending Aorta: Runs down behind heart from aorta
• Iliac: Crotch
• Femoral: Thigh
• Popliteal: Knee
• Cephalic: Lateral brachial
• Basilic: Medial forearm

Blood Pressure Categories

• Values are in mmHg.
• Normal: Systolic less than 120 and Diastolic less than 80
• Elevated: Systolic 120-129 and Diastolic less than 80
• Hypertension (Stage 1): Systolic 130-139 or Diastolic 80-89
• Hypertension (Stage 2): Systolic 140 or higher or Diastolic 90 or higher
• Hypertensive Crisis: Systolic higher than 180 and/or Diastolic higher than 120

Factors Influencing Blood Pressure

• Aging (vessels naturally thicken & stiffen)
• Genetic family history
• Unhealthy food especially salty food
• Alcohol
• Caffeine
• Lack of exercise
• Lack of sleep
• Stress
• Recreational drugs
• Antidepressants
• Decongestants
• Birth control
• Aspirin/ibuprofen
• Kidney disease
• Obesity
• Thyroid problems
• Other medical & lifestyle related factors

Cardiac Output

• How much blood pumped by both ventricles in one minute (mL/minute)
• Cardiac Output = Heart Rate \times Stroke Volume
• Heart Rate: amount of heart beats in a minute (bpm)
• Stroke Volume: amount of blood pumped out of heart per beat. avg = 75 mL/beat

Peripheral Artery Disease (PAD)

• Loss of blood flow to the extremities, increasing risk of blood clots.
• Results in pain while walking and/or a change in skin tone.
• Could cause the complete block of blood flow to a limb (critical limb ischemia).
• Atherosclerosis: Buildup of plaque in blood vessels, commonly causes PAD.

Heart Conduction System Steps

1. SA node initiates an electrical signal.
2. Signal spreads across both atria.
3. Signal reaches AV node.
4. Signal travels down the bundle of His.
5. Signal splits into left and right branches of bundle of His.
6. Signal spreads through Purkinje fibers.

Lung Volumes

• Tidal Volume (TV): 500 mL, volume of air breathed in/out without conscious effort.
• Inspiratory Reserve Volume (IRV): 3,100 mL, additional volume that can be inhaled with maximum effort.
• Expiratory Reserve Volume (ERV): 1,200 mL, additional volume that can be forcibly exhaled.
• Residual Volume (RV): 1,200 mL, volume of air that remains in lungs after maximum exhalation, under normal conditions the lungs are never completely empty.
• Vital Capacity (VC): Total volume that can be exhaled after maximum inhalation (TV + IRV + ERV)

Pathogens

• Prions:
  • Nonliving submicroscopic proteins that infect through consumption of tainted meat, treatment with contaminated medical equipment, or receiving corneas/organs from infected donors.
  • Causes normal brain proteins to fold abnormally.
  • Example: Mad cow’s disease.
• Viruses:
  • Non-living microscopic agents made of an outer protein shell (capsid) and DNA/RNA.
  • Infection depends on type but can occur through exposure to infected individuals or contaminated surfaces.
  • Example: Influenza.
• Bacteria:
  • Living, microscopic, unicellular organisms.
  • Infection varies but can include through wound infection, sexual contact, or flora imbalance.
  • Invades cells, causes tissue damage, and produces harmful toxins.
  • Example: Tuberculosis.
• Protists:
  • Living microscopic single-celled organisms.
  • Infection through ingestion of infected food/water.
  • Occupy digestive tract, blood, and/or organs to deprive body of essential nutrients.
• Helminths:
  • Living multicellular eukaryotic worms.
  • Infection either occurs through contaminated food/water or by bug bite.
  • Deprives host of essential nutrients and causes tissue/organ damage.
  • Example: Tapeworm.

Burns

• 1st Degree Burns: Epidermis.
• 2nd Degree Burns: Epidermis & dermis.
• 3rd Degree Burns: Entirely destroys epidermis & dermis, may effect underlying bones and tissues.

Immunity

• Innate Immunity: Non-specific mechanisms of defense that almost everyone has. Tears, nasal mucus, digestive enzymes, phagocytes, stomach acid, skin.
• Acquired Immunity: Developed immunity from past exposure when T-cells preserve information about antigens and corresponding antibodies.
  • Active: Acquired through infection and recovery or through vaccine.
  • Passive: Acquired through mother’s placenta during breastfeeding.
• Prodromal Symptoms: Early signs of disease onset.
• Convalesce: Health gradually recovering after sickness.
• Sepsis: Immune system overreacts causing an inflammation, leading to severe sepsis and septic shock when left untreated.

Infection Control

• TIME: High or low temperature, signs of infections (swollen lymph nodes), signs of mental decline, extreme illness.
• Plaque Assay: Method to measure viral load. Infected sample is serially diluted and inoculated, or placed in host cell culture
• Direct Infection: Physical contact with source or large respiratory inhalation
• Indirect Infection:
  • Airborne particles
  • Living objects like bugs carry agent from one source to another.
  • Nonliving contaminated objects (food, water, surfaces).

Eye Structure

• Pupil: Lets light into eye.
• Cornea: Controls entry of light.
• Aqueous Humor: Maintains ocular pressure.
• Iris: Controls size of pupil to determine light.
• Lens: Absorbs, focuses, and directs light toward retina.
• Retina: Senses light and sends signal to optic nerve.
• Sclera: Maintains eye’s shape & serves as protective layer.
• Tapetum: Provide retinal cells w/ 2nd opportunity for paton-photoreceptor stimulation, enhancing visual sensitivity at lower light levels.
• Vitreous Humor: Provides nutrients to eye & helps maintain eye shape.
• Blind Spot: Where optic nerve leaves eye, no photoreceptors.
• Optic Nerve: Carry sensory visual information to brain from retina.

Eye Conditions

• Subconjunctival Hemorrhage: Bright red patch in white of eye. Conjunctiva (thin layer around sclera), which serves to protect eye by creating tears & provide protective layer, has small blood vessels that can break and bleed near its surface (bulbar conjunctiva), creating a hemorrhage.

Urinary System

• Kidneys: Bean shaped organs that filter blood, regulate fluid volumes, and produce urine.
• Ureter: Transfer urine from kidney to bladder.
• Bladder: Hollow organ that collects urine and expands/deflates.
• Urethra: Tube that carries urine from bladder to outside of body. Longer in males.
• Glomerular Filtration Rates: Represents how rapidly the blood is cleansed of metabolic wastes, how effectively the kidneys carry out both tubular reabsorption and secretion, and how well the kidneys maintain homeostasis.
• Filtration: Blood is processed to remove all waste, which is then converted into urine.
• Reabsorption: Movement of substances from tubular fluid of nephron back into blood.
• Secretion: Movement of substance from blood into tubular fluid.

Polycystic Kidney Disease

• Inherited disorder, may be caused by spontaneous mutation of the PKD gene. Autosomal dominant PKD or autosomal recessive PKD.
• Characterized by fluid filled cysts in both kidneys that may block blood vessels and urine-producing tubes within the kidney.
• May lead to kidney failure after a few decades.
• Symptoms include blood in urine, painful urination, pain in back or abdomen, or high blood pressure.

Algorithms in Medicine

• Procedure used to solve problems.
• Clinical algorithms help in the development of treatment plans, diagnosis, and test result interpretations.
• Consider factors like age, race, gender, medical history, and genetics.
• Criticized for indicating biased data groups. For example, historical documents of heart attack symptoms are focused primarily on how symptoms appear in men, body mass index (BMI) lacks specificity, and GFR was only originally based on data from white men. Race as a consideration has been challenged as playing a major role in medical racism

Dialysis

• Process of removing waste from blood for somebody with kidney disease (since obviously their kidney can’t do that for them).

Digestion

• Mechanical Digestion: Physical break down of food by teeth, organs, and muscles.
• Chemical Digestion: Chemical breakdown of food by digestive enzymes and acids.
• Small Intestine: Duodenum, jejumun, ileum.

Ostomy

• Surgical procedure to transfer waste out of body, necessary of part of the urinary or digestive tract has been removed.
• Bag attaches to colon through the stoma attached to the skin.
• Gastrostomy tube (g tube) and jejunostomy tube (j tube) provide nutrients for people who can’t eat or digest normally

Endoscopy

• Methods to look inside a digestive system.
• Colonoscopy: Endoscope enters through anus and passes through.
• Biopsy: Poly (cell growth) or tissue is removed by biopsy forceps (tweezers) through endoscope for later testing.
• Upper Endoscopy: Endoscope enters through oral cavity and goes through pharynx, esophagus, stomach, to beginning of duodenum pancreas rectum and colon.

Colon Polyps

• Small growth in lining of colon or large intestine, caused by a change in normal cell growth

Acid Reflux

• Involuntary release of stomach acid into esophagus, throat, and mouth.
• Can cause tooth decay, esophagus sores, and discomfort.
• Frequent acid reflux is called gastroesophagal reflux disease (GERD).

Peptic Ulcers

• (PUD), ulcers or sores in stomach lining. either gastric ulcers (stomach) or duodenal ulcers (duodenum).
• Caused by bacterial infection, pain relievers, or anti-inflammatory drugs.

Crohn’s Disease

• Chronic inflammatory bowel disease.
• Common in small or large intestine.
• Causes tissue damage.
• Characterized by thick intestine wall, cobblestone appearance, and stricture.

Whipple’s Disease

• Bacterial infection in the lining of the small intestine and villi (projections in intestinal wall that absorb nutrients)

Gut Microbiome

• The balance of microbes that play a vital role in digestion

Immune Response Indicators in Diseased Tissue

• Lymphoid aggregates (clusters of b-cells, t- cells, and supporting cells).
• Lipid filled histiocytes (type of immune cell which works to remove dead cells in recovery).
• Lymphocytes (white blood cells, appearing as dark purple or bluish nuclei).

Biomolecules

• Carbohydrates: Provide energy, store energy, structured component of all cells ex: glucose, fructose
• Protein: Drives cellular reactions, provides defense, builds structures, transports materials, coordinates cellular activities, and movement ex: amino acids and polypeptides
• Lipids: Stores energy, constructs cellular membranes, and signals cells ex: glycerol and fatty acid chains
• Nucleic Acids (DNA/RNA): Stores & transmits genetic information, not a source of energy for cells ex: nucleotides