Body Systems

Anatomy

Study of the structure of the body and the relationships of body parts

Physiology

Study of how the body and its organs function

Pathophysiology

Study of how disease or injury alters normal body function

Homeostasis

The body's ability to maintain a stable internal environment despite external changes

Anatomical Position

Standard reference position: standing upright, facing forward, arms at sides, palms forward

Anterior/Ventral

Toward the front of the body

Posterior/Dorsal

Toward the back of the body

Superior

Toward the head or upper part of the body

Inferior

Toward the feet or lower part of the body

Proximal

Closer to the trunk or point of attachment

Distal

Farther from the trunk or point of attachment

Medial

Toward the midline of the body

Lateral

Away from the midline of the body

Abduction

Movement away from the midline of the body

Adduction

Movement toward the midline of the body

Extension

Straightening a joint, increasing the angle between bones

Flexion

Bending a joint, decreasing the angle between bones

Supine

Lying flat on the back, face up

Prone

Lying flat on the abdomen, face down

Fowler Position

Seated position with the upper body elevated, often used to ease breathing

Recovery Position

Position lying on the side to help maintain an open airway

Tripod Position

Seated position leaning forward with arms supporting the upper body to improve breathing

Nasopharynx

Upper part of the pharynx behind the nose; passageway for air

Oropharynx

Middle part of the pharynx behind the mouth; passageway for food and air

Epiglottis

Leaf-shaped flap that covers the trachea during swallowing to prevent aspiration

Carina

Point where the trachea divides into the right and left main bronchi

Alveoli

Tiny air sacs in the lungs where gas exchange occurs

Surfactant

Substance lining the alveoli that reduces surface tension and prevents collapse

Tidal Volume

Amount of air inhaled or exhaled during a normal breath

Residual Volume

Amount of air remaining in the lungs after maximum exhalation

Minute Volume

Total amount of air moved in and out of the lungs in one minute (tidal volume × respiratory rate)

Dead Space

Air that occupies the respiratory passages and does not participate in gas exchange

External Respiration

Exchange of oxygen and carbon dioxide between the alveoli and blood

Internal Respiration

Exchange of oxygen and carbon dioxide between blood and body cells

Cellular Respiration

Process by which cells use oxygen to produce energy from nutrients

CO2 Drive

Stimulation to breathe primarily caused by elevated carbon dioxide levels

Hypoxic Drive

Stimulation to breathe primarily caused by low oxygen levels in certain chronic respiratory patients

FBAO

Partial or complete blockage of the airway by a foreign object

Cardiovascular System

Body system consisting of the heart and blood vessels that circulates blood

Endocardium

Inner lining of the heart chambers

Myocardium

Thick muscular middle layer of the heart responsible for pumping blood

Epicardium

Outer layer of the heart wall

Pericardium

Double-layered sac surrounding and protecting the heart

Atria

Two upper chambers of the heart that receive blood

Ventricles

Two lower chambers of the heart that pump blood

SA Node

Natural pacemaker located in the right atrium that initiates the heartbeat

AV Junction

Area between the atria and ventricles that delays and transmits electrical impulses

Bundle of His

Electrical conduction pathway that carries impulses from the AV junction to the ventricles

Cardiac Output

Amount of blood pumped by the heart in one minute (heart rate × stroke volume)

Preload

Degree of stretch of the heart muscle before contraction; related to blood returning to the heart

Afterload

Resistance the heart must overcome to pump blood into circulation

SVR

Resistance offered by the body's blood vessels to blood flow

Systolic Pressure

Maximum pressure in the arteries during ventricular contraction

Diastolic Pressure

Minimum pressure in the arteries during ventricular relaxation

Perfusion

Adequate delivery of oxygen and nutrients to body tissues

Hypoperfusion/Shock

Inadequate tissue perfusion resulting in insufficient oxygen delivery

Plasma

Liquid portion of blood that carries cells, nutrients, hormones, and waste products

Erythrocyte

Red blood cell responsible for transporting oxygen and carbon dioxide

Leukocytes

White blood cells responsible for fighting infection and disease

Platelets

Blood cell fragments involved in clotting and bleeding control

ATP

Primary energy molecule used by cells

Aerobic Metabolism

Process of producing ATP using oxygen

Anaerobic Metabolism

Process of producing ATP without oxygen, resulting in lactic acid formation

CNS

Brain and spinal cord; control center of the body

PNS

All nerves outside the brain and spinal cord

Cerebrum

Largest part of the brain responsible for thought, memory, sensation, and voluntary movement

Cerebellum

Part of the brain responsible for coordination, balance, and posture

Brain Stem

Part of the brain controlling vital functions such as breathing, heart rate, and blood pressure

CSF

Clear fluid surrounding and protecting the brain and spinal cord

Somatic PNS

Division of the PNS controlling voluntary skeletal muscle movement and sensory input

ANS

Division of the PNS controlling involuntary body functions

Sympathetic ANS

Division of the ANS responsible for the "fight-or-flight" response

Parasympathetic ANS

Division of the ANS responsible for the "rest-and-digest" response

Frontal Bone

Bone forming the forehead and upper eye sockets

Parietal Bone

Paired bones forming the sides and roof of the skull

Occipital Bone

Bone forming the back and base of the skull

Temporal Bone

Paired bones on the sides of the skull containing the ears

Maxillae

Paired upper jaw bones that hold the upper teeth

Mandible

Lower jaw bone; only movable bone of the skull

Zygomatic Bone

Cheekbones that form part of the eye sockets

Nasal Bones

Bones forming the bridge of the nose

Smooth Muscle

Involuntary muscle found in organs and blood vessels

Skeletal Muscle

Voluntary muscle attached to bones that produces body movement

Cardiac Muscle

Specialized involuntary muscle found only in the heart