Topographic Anatomy, Circulatory, Respiratory, and Nervous System Overview

Topographic anatomy

Surface structures that guide EMT to internal features

Coronal (frontal) plane

Divides the body front/back

Sagittal (lateral) plane

Divides the body left/right

Midsagittal (midline) plane

Divides the body into equal left and right halves

Transverse (axial) plane

Divides the body top/bottom

Tissue

Cells that share a common function form tissue

Organ

Groups of tissue that perform similar jobs form organs

Body systems

Organs with similar functions work together to comprise body systems

Skeletal system

Serves many functions including providing structural support

Red marrow

Produces red blood cells

Joints

Where two bones meet

Ball-and-socket joint

Allows rotation and bending

Hinge joint

Motion restricted to flexion and extension

Axial skeleton

Includes skull, facial bones, thoracic cage, and vertebral column

Spinal column

Composed of 33 bones (vertebrae) divided into five sections

Thoracic cavity

Contains heart, lungs, esophagus, and great vessels

Appendicular skeleton

Includes upper and lower extremities

Pelvic girdle

Consists of two coxae (hip bones), sacrum, and coccyx

Muscle

A form of tissue that facilitates movement

Skeletal muscle

Attaches to bones and is under voluntary control

Smooth muscle

Found within blood vessels and intestines, involuntary

Cardiac muscle

Found only within the heart, involuntary

Upper airway

Includes pharynx, larynx, and vocal cords

Trachea

Located at the bottom of the pharynx

Lower airway

Includes thyroid cartilage, cricoid cartilage, and bronchi

Alveoli

Allow for gas exchange (oxygen and carbon dioxide)

Ventilation

Movement of air between lungs and environment

Respiration

Exchange of oxygen and carbon dioxide in alveoli and tissues

Diffusion

Passive process in which molecules move from higher to lower concentration

Minute ventilation

Amount of air that moves in and out of the lungs in 1 minute

Heart

Receives blood from the aorta and pumps it through the body

Stroke volume (SV)

Amount of blood moved by one beat

Cardiac output (CO)

Amount of blood moved in 1 minute

CO formula

HR × SV = CO

Aorta

Main artery leaving left side of heart

Aorta function

Carries freshly oxygenated blood to body

Pulmonary artery

Carries oxygen-depleted blood to the lungs

Arteries

Branch into smaller arteries and then into arterioles

Arterioles

Branch into smaller vessels until they connect to capillaries

Capillaries

Connect at one end with arterioles and at other with venules

Veins

Return oxygen-depleted blood to the heart

Superior vena cava

Carries blood returning from head, neck, shoulders, and upper extremities

Inferior vena cava

Carries blood from the abdomen, pelvis, and lower extremities

Systemic vascular resistance

Resistance to blood flow in the systemic circulation

Blood composition

Red blood cells (erythrocytes), white blood cells (leukocytes), platelets, plasma (liquid)

Spleen

Filters blood and is frequently injured from blunt trauma

Blood pressure

Pressure that blood exerts against the walls of arteries

Systole

When left ventricle contracts, it pumps blood from ventricle into aorta

Diastole

When muscle of the ventricle relaxes, ventricle fills with blood

Blood pressure readings

Measured with a blood pressure cuff (sphygmomanometer)

Systolic blood pressure

High point of wave

Diastolic blood pressure

Low point of wave

Perfusion

Circulation of blood in organ or tissue in adequate amounts to meet the needs of cells

Hypoperfusion (shock)

Inadequate blood supply to organs, tissues, and cells

Clotting (coagulation)

Process that prevents blood loss from damaged vessels

Sympathetic nervous system

Sends commands to adrenal glands to secrete epinephrine and norepinephrine

Parasympathetic nervous system

Causes the heart rate to slow and beat more weakly

Baroreceptors

Sense pressure in the blood vessels and allow the brain to maintain perfusion

Cerebrum

Largest part of the brain responsible for higher brain function

Cerebellum

Controls balance, muscle coordination, and posture

Brainstem

Controls body functions necessary for life, including cardiac and respiratory functions

Cerebrospinal fluid

Cushions and protects the brain and spinal cord

Spinal cord

Extension of the brainstem that transmits messages between brain and body

Peripheral Nervous System

Includes somatic nervous system and autonomic nervous system

Epidermis

Superficial layer of skin

Dermis

Deeper layer of skin

Subcutaneous tissue

Lies beneath skin, fat that insulates and serves as energy reservoir

Mucous membranes

Cover inner surface of openings to the body

Gastrointestinal system

Contains major organs of digestion and excretion

Kidneys and pancreas

Lie behind abdominal cavity (retroperitoneal)

Lymphatic system

Composed of spleen, lymph nodes, lymph, lymph vessels, thymus gland, and other components

Urinary system

Controls discharge of certain waste materials filtered from blood by kidneys

Male reproductive system

Consists of testicles, epididymis, vasa deferentia, prostate gland, seminal vesicles, penis

Female reproductive system

Consists of ovaries, fallopian tubes, uterus, cervix, vagina

Aerobic metabolism

Uses oxygen to turn nutrients into chemical energy

Anaerobic metabolism

Occurs when oxygen is limited

Respiratory compromise

Inability of the body to move gas effectively

Hypoxia

Deficiency in the amount of oxygen reaching the tissues

Hypercapnia

Excess carbon dioxide in the bloodstream

Shock

Occurs when organs and tissue do not receive enough oxygen

Effects of inadequate perfusion

Level of oxygen supplied to tissues falls, leading to anaerobic metabolism and severe metabolic acidosis