AN ORIENTATION TO THE HUMAN BODY

Human Biology

• It is the structural, functional, behavioral basis of the human organisms’ ability to adapt to and survive in its environment.

NECESSARY LIFE FUNCTIONS

• Maintain boundaries –

• Movement

• Process of metabolism

• Maintain homeostasis

• Reproduction

• Responsiveness/irritability

• Growth

TRUE FOR:

• Unicellular• Made up of one cell• Example – ameba, • Maintain boundaries –

cell membrane

• Multicellular• Made up of many cells• Example – humans• Maintain boundaries –

skin• Must maintain

homeostasis for single cell as well as for organism

Survival Needs

• Nutrients

• Oxygen

• water

• body temperature

• Appropriate atmospheric pressure

ORGANIZATION OF HUMAN BODY

• Cell• Tissues• Organ• Organ system• Organism• Population• Community• Ecosystem/biome• biosphere

FEEDBACK SYSTEM

• Feedback system is a cycle of events in which the status of a body condition is continually monitored, evaluated, changed, remonitored, reevaluated continuously.

HOMEOSTATIC CONTROL MECHANISMS

• Receptor

• Control center

• Effector

MAINTAINING HOMEOSTASIS

• Negative feedback system

• Positive feedback system

HOMEOSTATIC IMBALANCE

• Most diseases are a result of disturbances in the body’s homeostasis

• Efficiency decreases with age

LANGUAGE OF ANATOMY

Provides ways to accurately describe the body

ANATOMY

• Study of structure and shape of the body and body parts and their relationship to each other

• Gross anatomy – study of large observable structures

• Microscopic anatomy – study of structures that require a microscope to been seen

PHYSIOLOGY

• Study of how the body and its parts function.

Structure determines function.

Governing rule in anatomy

Terms

• Disorder• Disease• Symptom• Signs• Pathology• Epidemiology• Pharmacology• diagnosis

• Infectious disease• Pathogens• Local disease• Systemic disease

ANATOMICAL POSITION

• Standard position

• Basis for directional terms

DIRECTIONAL TERMS

• Explain exact location of 1 body structure in relation to another.

REGIONAL TERMS

• Anterior body landmarks – toward / at front of body

• Posterior body landmarks – toward / at back of body

BODY PLANES AND SECTIONS

• Imaginary line through the body wall or organ

•

Three sections

• Sagittal section

• Frontal (coronal) plane

• Transverse sections (cross-section)

BODY CAVITIES

TWO MAIN CAVITIES

1. Dorsal Cavity

2. Ventral Cavity

Dorsal cavity

2 divisions that are continuous with each other

1. Cranial – space for brain

2. Spinal cavity – space for spinal cord

Foramen magnum – opening at base of brain

allows for spinal cord to connect with brain

Ventral cavity

• 1. Thoracic cavity – separated from rest of ventral cavity by diaphragm

surrounded by ribs houses heart, lungs2. Abdominopelvic a. abdominal – superior cavity houses stomach, liver, intestinesb. Pelvic – inferior cavity houses reproductive organs, bladder, rectum

9 regions of abdominopelvic

• Right hypochondriac region• Left hypochondriac region• Right lumbar region• Left lumbar region• Right iliac region• Left iliac region• Epigastric region• Umbilical region• Hypogastric region

CRANIAL CAVITIES

• Sphenodial sinus

• Frontal sinus

• Orbital cavity

• Nasal cavity

• Oral cavity

• Middle ear cavity

• Cranial cavity

Medical imaging

• Bombards the body with energy to reveal structures of internal organs, and chemical processes of body

X-RAY

• Oldest

• Visualize hard bony structures

• Locate abnormally dense structures such as tumors and TB nodules

ULTRASOUND

• Sonography

• Equipment is inexpensive

• Uses high frequency sound waves

• So far, no harmful effects on living tissue

• Determines fetal age, position: locating placenta.

CT SCAN

• Computer tomography

• Confines its beam to a thin slice of tissue

• Like a refined version of X-ray

• Eliminated exploratory surgery

• Patient is moved through a doughnut shaped CT machine – tube rotates around bed

PET

• Positron-emission tomography

• it sends images about metabolic processes

• Insights into brain activity (mental illness, Alzheimer’s disease, epilepsy)

• Uses radioisotopes

MRI

• Magnetic resonance imaging• Uses magnetic fields 3,000 to 60,000 times

stronger than the earth’s• Bones do not show up thus they do not interfere

with viewing soft tissue behind bone• Good at picking up degenerative diseases – ex MS• Very expensive