bios 251 exam 1

BIOS 251 Overview

Introduction to the course content and expectations.
- Syllabus, Schedule, and Due Dates: Key information regarding course structure and timelines.
- Canvas: Online platform for course materials and submissions.
- Edapt: Supplementary tools and resources for learning.
- Lab: Details regarding practical laboratory sessions.

Anatomy: The study of the STRUCTURE of body parts and their relationships to one another.
- Gross Anatomy: Study of structures visible to the naked eye.
- Microscopic Anatomy: Study of structures that require magnification to be seen.
- Developmental Anatomy: Study of the changes in body structures from conception to adulthood.
Physiology: The study of the FUNCTION of body parts.
Relationship: Structure and function are closely related; their interaction is crucial for maintaining life.

The human body comprises eleven systems:

Defined as the “Starting Position” for anatomical reference.
- Characteristics of the position:
- Individual stands erect, facing forward.
- Arms are at the sides with palms facing forward.
- Feet are flat on the floor.

Term	Meaning	Examples of Usage
Ventral	Toward the front or belly	The aorta is ventral to the vertebral column.
Dorsal	Toward the back or spine	The vertebral column is dorsal to the aorta.
Anterior	Toward the ventral side	The sternum is anterior to the heart.
Posterior	Toward the dorsal side	The esophagus is posterior to the trachea.
Cephalic	Toward the head or superior end	The brain develops from the cephalic end of the neural tube.
Rostral	Toward the forehead or nose	The forebrain is rostral to the brainstem.
Caudal	Toward the tail or inferior end	The spinal cord is caudal to the brain.
Superior	Above	The heart is superior to the diaphragm.
Inferior	Below	The liver is inferior to the diaphragm.
Medial	Toward the median plane	The heart is medial to the lungs.
Lateral	Away from the median plane	The eyes are lateral to the nose.
Proximal	Closer to the point of attachment or origin	The elbow is proximal to the wrist.
Distal	Farther from the point of attachment or origin	The fingernails are at the distal ends of the fingers.
Ipsilateral	On the same side of the body (right or left)	The liver is ipsilateral to the appendix.
Contralateral	On opposite sides of the body (right and left)	The spleen is contralateral to the liver.
Superficial	Closer to the body surface	The skin is superficial to the muscles.
Deep	Farther from the body surface	The bones are deep to the muscles.

Planes: Imaginary flat surfaces that divide the body:
- Sagittal Plane: Divides body into right and left sides.
- Midsagittal Plane: Divides into equal right and left sides.
- Parasagittal Plane: Divides into unequal right and left sides.
- Frontal Plane: Divides the body into anterior (front) and posterior (back) sections.
- Transverse (Cross Section): Divides the body into superior (upper) and inferior (lower) parts.
- Oblique Section: Cuts made diagonally.

Dorsal Cavity: Protects the nervous system; divided into:
- Cranial Cavity: Encloses the brain within the skull.
- Vertebral Cavity: Runs within the vertebral column and encases the spinal cord.
Ventral Cavity: Houses internal organs (viscera); divided into:
- Thoracic Cavity
- Abdominopelvic Cavity

Thin, double-layered membranes covering thoracic and abdominal cavities, lining the walls.
- Parietal Membrane: Lines the cavity.
- Visceral Membrane: Covers the organs.
Function: Reduces friction between organs and the cavity walls.
Serous Fluid: Lies between the parietal and visceral membranes.

Humans exhibit slight anatomical variations; over 90% of anatomical structures conform to textbook standards.
- Potential variations include:
- Misplacement of nerves or blood vessels.
- Absence of small muscles.
Aging Process: Characterized by a gradual decline in the body's ability to maintain homeostasis.

Variables: Changes in body conditions trigger regulatory responses.
Components of Homeostasis:
- Sensor (Receptor): Monitors the internal environment and responds to changes (stimuli).
- Control Center: Sets the acceptable range (set point) for regulation.
- Target (Effector): Responds to stimuli to bring conditions back to homeostasis.
This interaction is referred to as a Feedback Loop.

Regulated Variable: A variable that is detected via sensors and requires stabilization within an acceptable range.
Controlled Variable: Non-regulated; cannot be changed by the system and lacks a corresponding sensor.
Set Point: The average, acceptable value for a regulated variable, where homeostatic mechanisms work to stabilize values.

Most common regulatory mechanism for homeostasis.
Action: Reduces or counters the original stimulus causing the imbalance.
Function: Causes the variable to change in the opposite direction of the original change, ultimately restoring homeostasis.
Examples: Body temperature, blood glucose levels, blood volume/pH/composition.

The effector's response amplifies the initial change or stimulus.
Action: Enhances the original stimulus.
Examples: Childbirth, blood clotting, protein digestion, generation of nerve signals.

Disruption of homeostasis can lead to disease, disorder, or death.
Influencing factors include:
- Genetic makeup
- Environmental conditions (air quality)
- Nutritional influence (diet)
- Psychological state (thought patterns, stress).