Chapter 7

Anatomy and Physiology

Introduction

• Anatomy is the study of the structure and makeup of the organism.− Gross anatomy: organs and locations in the

body− Microscopic anatomy: visible through

microscope

• Physiology examines the processes and functions of the body.

The Planes of the Body

• Anatomic planes− Imaginary lines

dividing the body− Coronal plane− Transverse plane− Sagittal plane

• Midsagittal plane− Cross section− Longitudinal

section

Directional Terms

• Needed to discuss:−Where an injury is

located−How pain radiates

Movement and Positional Terms

• Range of motion− Full distance a joint

can be moved

• Flexion− Brings distal point

of extremity toward trunk

• Extension− Returns flexion to

anatomic position

• Abduction− Moves extremity

away from midline

• Adduction− Moves extremity

toward midline

• Hyperflexion− Flexed to or

beyond normal range of motion

Movement and Positional Terms

• Hyperextension− Extended to or

beyond normal range of motion

• Supination− Turning palms

upward

• Pronation− Turning palms

downward

• Internal rotation− Turning extremity

toward midline

• External rotation− Turning extremity

away from midline

Other Directional Terms

• Abdomen is divided into:− Right upper

quadrant− Left upper

quadrant− Right lower

quadrant− Left lower

quadrant

Anatomic Positions

• Prone− Lying face down

• Supine− Lying face up

• Trendelenburg position− Supine with feet

higher than head

• Shock position− Head and torso

supine, lower extremities elevated

• Fowler position− Sitting up with

knees bent

Anatomic Positions

• Recovery position− Lying on side, bottom arm

extended straight with head lying on it

− Top knee is bent, angling body slightly toward floor

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The Skeletal System: Physiology

• Bones protect internal organs.• With muscles, bones enable movement.• Bone stores minerals.

− Particularly calcium• Plays role in forming blood cells, platelets

The Musculoskeletal System: Anatomy

• Musculoskeletal system− Provides body’s form, upright posture, movement− Musculoskeletal refers to bones and voluntary

muscles of the body.− Protects vital internal organs

The Circulatory System: Anatomy

• Also called cardiovascular system− Completely closed

• Two circuits:− Systemic circulation in body− Pulmonary circulation in lungs

The Heart

• Four chambers:− Two atria − Two ventricles− Each side of the heart contains one atrium and

one ventricle.

• Atria receive blood returned to heart.• Ventricles pump blood out of heart.

Blood Flow Within the Heart

• Deoxygenated blood returns to the right atrium via superior vena cava and inferior vena cava.

• Freshly oxygenated blood returns to the left atrium through pulmonary veins.

Blood Flow Within the Heart

• Blood flows through mitral valve into the left ventricle.

• Left ventricle pumps oxygenated blood into aorta, and then to entire body

The Cardiac Cycle

• Process that creates the pumping of the heart

• Systole− Contraction of ventricular mass− Pumping of blood into systemic circulation

• Diastole− Relaxation phase of cycle

The Vascular System

• Arteries carry blood away from the heart.• Veins carry blood back to the heart.• Arteries branch into arterioles.• Arterioles divide into capillaries.• Capillaries enlarge to form venules.• Venules merge to form veins.

The Nervous System: Anatomy and Physiology

• Perhaps most complex organ system • Includes brain, spinal cord, and nerves• Responsible for fundamental functions

The Nervous System: Anatomy and Physiology

• Divided into: − Central nervous system− Peripheral nervous system

• Somatic nervous system regulates voluntary activities.

• Autonomic nervous system (ANS) controls involuntary activities.

The Central Nervous System

• Brain− Controlling organ

of body− Main components

• Cerebrum• Cerebellum• Brainstem

(midbrain, pons, medulla oblongata)

The Central Nervous System

• Spinal cord − Extension of

brainstem− Carries

information to and from brain

− Contains connections between sensory and motor nerves

The Peripheral Nervous System

• Divisions:− Somatic nervous system

• Controls voluntary muscles− Autonomic nervous system

• Sympathetic nervous system• Parasympathetic nervous system

The Peripheral Nervous System

• Sensory nerves carry information from body to CNS

• Motor nerves carry information from CNS to muscles

• Cranial nerves (12 pairs) arise from the base of the brain.

The Peripheral Nervous System

• Spinal nerves (31 pairs) carry information to and from the CNS from a portion of the body.

• Nerve plexuses form when nerves exit the spinal cord and follow similar tracts.

Physiology of Sensation

• Ability to gather and process information about the body and the external environment is important− Generated and transmitted by sensory

receptors− Message is processed and:

• Brought to conscious thought• Generates an automatic response (reflex)• Discarded as unimportant

General Senses

• Monitored by receptors in different tissues− Nociceptors monitor pain.− Mechanoreceptors monitor physical properties.− Proprioceptors track position in space.− Baroreceptors measure changes in pressure.− Chemoreceptors measure chemicals in the

body.

Special Senses

• Sense of taste− Taste receptors respond to sweet, salty, sour,

and bitter

Special Senses

• Sense of smell− Upper

nasal cavity contains olfactory receptors

Special Senses

• Sense of sight− Eyeball is the source of information the brain

processes into pictures− Image is brought into focus by altering shape

and thickness of the lens• Distortion of the lens causes difficulty focusing on

an object.

Special Senses

Special Senses

• Sense of hearing− External ear

collects sounds into the ear canal

− Sound waves travel through the ear canal to the tympanic membrane or eardrum.

Special Senses

• Sense of balance− Vestibular system is contained within the inner

ear.• Composed of fluid-filled sacs (otoliths) and fluid-

filled passageways (semicircular canals)• Structures are used by the CNS to collect

information about movement and orientation.

The Digestive System: Anatomy

• Digestion: breakdown of foods and the absorption of nutrients

• Alimentary canal includes:− Mouth − Pharynx− Esophagus− Stomach− Small intestine− Large intestine− Rectum− Anus

The Digestive System: Anatomy

• Walls of alimentary canal consists of:− Mucosa (carries out secretion and absorption)− Submucosa (carries away absorbed materials)− Muscular layer (provides movement of tube)− Serosa (protects underlying tissues)

The Digestive System: Anatomy

The Digestive System: Anatomy

• Accessory organs of alimentary canal include:− Teeth− Tongue− Salivary glands− Liver− Gallbladder− Pancreas

The Abdomen

• Right upper quadrant (RUQ): liver, gallbladder, some of colon and small intestine

• Left upper quadrant (LUQ): stomach, spleen, some of colon and small intestine

• Right lower quadrant (RLQ): cecum, ascending colon, appendix

• Left lower quadrant (LLQ): descending and sigmoid parts of colon

The Abdomen

The Digestive System: Physiology

• Functions of the digestive system:− Ingestion− Mechanical processing− Digestion− Secretion− Absorption− Excretion

The Digestive System: Physiology

• In succession, different secretions (primarily enzymes) are added to food by:− Salivary glands− Stomach− Liver− Pancreas− Small intestine

The Digestive System: Physiology

• Converts food into basic sugars, fatty acids, amino acids− These products cross wall of intestine and travel

through portal vein to liver− Liver further processes and stores or transports

to heart − Circulatory system then nourishes all cells

The Endocrine System: Anatomy and Physiology

• Made up of glands located throughout body− Remove,

concentrate, or alter materials from blood

− Secrete them back into body

The Endocrine System: Anatomy and Physiology

• Glands secrete proteins called hormones.− Regulate mood, growth and development,

tissue function, metabolism, sexual development

− Steroid hormone diffuses through cell membrane

− Nonsteroidal hormone binds to receptors in cell membrane

The Urinary System: Anatomy and Physiology

• Controls discharge of waste filtered from blood by kidneys

• Functions− Controls fluid balance in body− Filters and eliminates wastes− Controls pH balance

The Urinary System: Anatomy and Physiology

• Components− Kidneys− Ureters− Urinary bladder− Urethra

• Waste products are constantly filtered from the blood to form urine.

The Urinary System: Anatomy and Physiology

• Functions of the kidneys:− Reabsorb water as it passes through the

system− Secrete erythropoietin− Help activate vitamin D− Help maintain blood volume and pressure