Human Body and Microbial Science

Directional Term Superior

Toward the head or upper part of the body

Direction Term Inferior

Toward the feet or lower part of the body

Directional Term Anterior

Toward or at the front of the body

Directional Term: Posterior

Toward or at the back of the body

Directional Term Medial

Toward the midline of the body

Directional Term Lateral

Away from the midline of the body

Directional Term Proximal

Closer to the point of attachment or trunk

Directional Term Distal

Farther from the point of attachment or trunk

Directional Term Superficial

Toward or on the body's surface

Directional Term Deep

Away from the surface; internal

Directional Term Ventral

Toward the front/belly side (often interchangeable with anterior)

Directional Term Dorsal

Toward the back side (often interchangeable with posterior)

Directional Term Cranial

Toward the head

Directional Term Caudal

Toward the tail or lower trunk

Directional Term: Ipsilateral

On the same side of the body

Directional Term Contralateral

On the opposite side of the body

Directional Term Intermediate

Between a more medial and a more lateral structure

Directional Term Unilateral

Pertaining to or affecting one side of the body

Directional Term: Bilateral

Pertaining to or affecting both sides of the body

Directional Term: Palmar

Pertaining to the palm of the hand

Directional Term: Planter

Pertaining to the sole of the foot

Define the term anatomy

The study of the structure of the human body

Define the term physiology

The study of the functions of the human body

Midsagittal plane

Divides the body vertically into equal left and right halves down the exact midline

Parasagittal plane

Divides the body vertically into unequal left and right sides (off-center)

Transverse plane

Divides the body horizontally into superior (top) and inferior (bottom) portions

Frontal plane

Divides the body vertically into anterior (front) and posterior (back) portions

Oblique plane

Cuts through the body or organ at an angle (diagonal) between horizontal and vertical

Cranial cavity

Located inside the skull; protects the head controls - Brain

Vertebral canal / cavity

Runs down the back within the spine; houses the nervous pathway. - spinal cord

Thoracic cavity

Chest area enclosed by the ribs; contains major cardiovascular and respiratory organs. - Heart, lungs, trachea, esophagus, aorta

Abdominal cavity

Main region below the diaphragm containing digestive organs.- Stomach, liver, pancreas, spleen, kidneys, small intestine, most of the large intestine

Pelvic cavity

Lower basin of the trunk enclosed by pelvic bones.- Urinary bladder, rectum, internal reproductive organs (uterus, ovaries, prostate)

Define Homeostasis

The maintenance of a stable internal body environment within narrow physiological limits despite continuous internal or external changes.

Define Set Point (Homeostasis)

The ideal target value or normal physiological range for a body variable (e.g., 37°C for body temperature, 7.35-7.45 for blood pH).

Define Stimulus (Homeostasis)

A change in the internal or external environment that moves a physiological variable away from its set point.

Define Receptor (Sensor) (Homeostasis)

A cellular structure or organ that detects a stimulus (change in variable) and sends input signals to the control center.

Define Control Center (Homeostasis)

The structure (typically the brain/hypothalamus) that receives input, compares it to the set point, and determines the body's output response.

Define Effector (Homeostasis)

A muscle, gland, or organ that receives output from the control center and carries out the physiological action to restore balance.

Define Negative Feedback Loop (Homeostasis)

A primary homeostatic control mechanism where the body's response reverses or opposes the initial change to return to the set point.

Define Positive Feedback Loop (Homeostasis)

A mechanism that amplifies or reinforces the initial change, moving the variable further from normal until a specific endpoint is reached (e.g., childbirth contractions, blood clotting).

Define Vasodilation (Homeostasis)

Widening of skin blood vessels when body temperature is high to allow heat to radiate out through the skin.

Define Vasoconstriction (Homeostasis)

Narrowing of skin blood vessels when body temperature is low to retain heat in the core of the body.

Define Thermoregulation - Response to High Temp (Homeostasis)

Hypothalamus triggers vasodilation (heat radiation) and sweating (evaporative cooling) to reduce core temperature.

Define Thermoregulation - Response to Low Temp (Homeostasis)

Hypothalamus triggers vasoconstriction (heat preservation) and shivering (skeletal muscle contraction to generate heat).

Blood Glucose - High Response (Post-Meal) (Homeostasis)

Pancreas releases insulin, prompting body cells to take up glucose and the liver to store excess glucose as glycogen.

Blood Glucose - Low Response (Fasting) (Homeostasis)

Pancreas releases glucagon, prompting the liver to break down stored glycogen into glucose and release it into the bloodstream.

Osmoregulation - Response to Dehydration (Homeostasis)

Hypothalamus signals thirst and release of ADH (Antidiuretic Hormone) from the pituitary gland, instructing kidneys to reabsorb water and produce concentrated urine.

Blood Pressure - High Response (Homeostasis)

Baroreceptors (pressure sensors) signal the control center to slow heart rate and dilate blood vessels, lowering blood pressure back to normal.

Infectious Agent (Chain of Infection)

The pathogen (microorganism) that causes the disease, such as bacteria, viruses, fungi, or parasites.

Reservoir (Chain of Infection)

The habitat or environment where the pathogen lives, survives, and multiplies (e.g., humans, animals, soil, water, surfaces).

Portal of Exit (Chain of Infection)

The pathway by which the pathogen leaves the reservoir/host (e.g., respiratory tract, blood, open wounds, bodily fluids).

Mode of Transmission (Chain of Infection)

The method by which the pathogen travels from the reservoir to a new host (e.g., direct contact, droplets, airborne, vectors, contaminated objects).

Portal of Entry (Chain of Infection)

The site or opening through which the pathogen enters the new susceptible host (e.g., broken skin, mucous membranes, respiratory tract, gastrointestinal tract).

Suseptible Host (Chain of Infection)

An individual who lacks immunity or resistance to the pathogen, making them vulnerable to infection (e.g., elderly, immunocompromised, unvaccinated).

Standard Precautions (Definition)

Designed to prevent transmission of all infectious agents. It represents a standard of care to be used routinely for all patients regardless of perceived or known infection risk factors.

Why Standard Precautions are Important

Helps to decrease the risk of transmission of microbes from recognized & unrecognized sources of infection in hospitals.

Key Safety Measure 1: Hand Hygiene

Performing hand hygiene (handwashing or hand rub) to prevent the spread of infectious agents.

Key Safety Measure 2: PPE

Personal Protective Equipment (such as gloves, gowns, masks, and eye protection) used to protect healthcare workers from exposure.

Key Safety Measure 3: Cleaning & Decontamination

Cleaning and decontamination of equipment and environmental surfaces to eliminate pathogens.

Key Safety Measure 4: Safe Handling of Blood & Body Fluid Spillage

Safe handling and cleanup of blood and bodily fluid spillage to prevent exposure and contamination.

Key Safety Measure 5: Safe Handling & Disposal of Waste

Safe handling and disposal of clinical and hazardous waste to protect staff and patients from contamination.

Genus Name

The first name; always capitalized and italicized (e.g., Escherichia).

Species Name

The second name; always lowercase and italicized (e.g., coli).

Binomial Rules

Type in italics or underline if handwritten (e.g., E. coli).

Prokaryotes (bacterium) vs. Eukaryotes: Nucleus

Prokaryotes (bacterium): DNA is NOT enclosed within a membrane.

Eukaryotes: DNA IS enclosed in a nuclear membrane.

Prokaryotes (bacterium) vs. Eukaryotes: DNA Structure

Prokaryotes (bacterium): DNA is a single continuous loop.

Eukaryotes: DNA is found in multiple chromosomes.

Prokaryotes (bacterium) vs. Eukaryotes: Organelles

Prokaryotes (bacterium): NO membrane-bound cell organelles.

Eukaryotes: HAS membrane-bound organelles.

Prokaryotes (bacterium) vs. Eukaryotes: Reproduction

Prokaryotes (bacterium): Reproduce by binary fission.

Eukaryotes: Reproduce by mitosis (except sex cells).

Pathogenic (Harmful) Bacteria

Disease-causing microorganisms.

Example: Clostridium tetani, Streptococcus pneumoniae.

Beneficial Bacteria

Assists with various body processes and prevents infection by pathogens.

Example: Lactobacillus acidophilus.

Opportunistic Bacteria

Microbes that are potentially harmful and can cause disease under certain conditions.

Example: E. coli (in urinary tract).

Chromosome (bacterial cell)

Structure: Single continuous loop of DNA (no membrane/true nucleus).

Function: Contains all the genetic info for metabolism and reproduction.

Flagellum (Bacterial Cell)

Structure: Long, tail-like projection.

Function: Assists in attachment to surfaces and helps with locomotion.

Endospore (bacterial cell)

Structure: Specialized dormant resting cell formed within the cell membrane.

Function: Allows survival in unfavorable conditions.

Why can't antibiotics treat the common cold or flu?

Because they are caused by viruses. Antibiotics are effective against bacteria (prokaryotes) only.

Why does antibiotic resistance make antibiotics ineffective?

Bacteria grow and mutate rapidly. Wide antibiotic use allows resistant strains to survive, rendering antibiotics ineffective against them.

What is the main limitation in replacing ineffective antibiotics?

New, effective antibiotics are extremely hard to find and develop.

two measures to reduce the problem of antibiotic resistance

To not prescribe them for viral infections, better infection control to decrease the need

Yeast

Unicellular and reproduces by budding

Mould

Multicellular and reproduces by spores

Fungi

Is eukaryotic, non-photosynthetic organisms with chitin cell walls that absorb nutrients and generally reproduce via spores.

Superficial Fungal Infection

Occurs outside of the body.

Example: Inner toes / feet.

Systemic Fungal Infection

Affects tissues and organs deep within the body.

Example: Lungs.

Opportunistic Fungal Infection

Fungal infections caused by fungi that are normally harmless.

Cell type of Protozoa?

Eukaryote cells

Most common structure/environment of Protozoa?

Unicellular free-living microorganisms found in soil/water or as parasites

How are Protozoa classified?

By the way they move (means of locomotion)

Flagella function and description

Whip like tail that propels the cell

Cilia function and description

Small hair like structures that beat rhythmically to propel the cell

Pseudopodia (“false foot”) function and description

Projections formed from cell membrane filled with cytoplasm, extends and pulls the

Non-motile, parasitic protozoan group example?

Plasmodium

3 human protozoan diseases and key traits?

1. Malaria, 2. Giardiasis, 3. Toxoplasmosis

Label #1 on enveloped virus diagram?

Capsomere

Label #2 on enveloped virus diagram?

Nucleic acid

Label #3 on enveloped virus diagram?

Envelope

Label #4 on enveloped virus diagram?

Spikes

Are viruses cellular? How do they replicate?

Acellular (without a cell), require host cell to replicate (obligate intracellular parasites)

What is a virus host cell specificity?

Host-cell specific (infect cells of one particular species only)

5 steps of virus replication in order?

1. Attachment

2. Entry and uncoating

3. Replication

4. Assembly

5. Release