Chapter 6 – The Human Body

Topographic anatomy – Study of anatomy based on regions and divisions of the body.

Anatomical position – Patient facing you, arms at side, with palms facing forward.

v  Planes of the body

Ø  Frontal (coronal) plane: divides body into front/back sections

Ø  Transverse (axial) plane: divides body into top/bottom sections

Ø  Sagittal (lateral) plane: divides body into left/right sections

v  Skeletal System – 206 bones of the body
FUNCT: Gives body shape, allows for movement, protects organs, stores calcium, helps created blood cells.

Ø  Axial Skeleton

o   Skull

§  Cranium (6 bones)

·       Occipital bone

·       Temporal bones

·       Parietal bones

·       Frontal bone

§  Face (14 bones)

·       Maxilla (Upper jaw)

·       Zygomatic bone (cheek bones)

·       Mandible (lower jaw)

·       Orbitals (eye sockets – formed by zygomas, maxillae, and frontal bones)

·       Nasal bones

o   Spinal column (33 bones vertebrae)
Vertebrae are connected by ligaments w/ intervertebral disks between each one.

§  Cervical (neck) – 7 bones

§  Thoracic (upper back) – 12 bones

§  Lumbar (lower back) – 5 bones

§  Sacrum (back of pelvis) – 5 bones fused together

§  Coccyx (tailbone) – 4 bones fused together

o   Thorax
Thoracic cavity has heart, lungs, esophagus, and major veins + arteries

§  12 thoracic vertebrae

§  12 pairs of ribs

§  Midline of chest is sternum
Upper border of sternum forms sternal notch

·       Manubrium

·       Body

·       Xiphoid process

Ø  Appendicular Skeleton

o   Upper extremities (from shoulder to finger tips)

§  Shoulder Girdle

·       Clavicle

·       Scapula

·       Humerus (supporting bone of arm)

§  Arm

·       Humerus

·       Forearm

o   Radius – On side w/ thumb

o   Ulna – Little finger (pinky) side

§  Wrist and hand

·       Carpal bones – 8 bones of wrist

·       Metacarpals – 5 bones that form palm of hand

·       Phalanges – 5 bones of finger

o   Pelvis

§  Sacrum

§  2 pelvic bones (3 parts)

·       Ilium

·       Ischium

·       Pubis
Left & right pubis join by pubic symphysis

§  Acetabulum – where leg connects to ilium, ischium and pubic

o   Lower extremities

§  Femur (thigh)

·       Two projections for major muscles

o   Greater trochanter (Lateral/superior)

o   Lesser trochanter (Medical/inferior)

§  Knee

·       Connects upper and lower leg

·       Patella (knee cap)

§  Tibia (shin bone)

·       Lies anterior of the leg (easy to palpate)

§  Fibula

·       Lies posterior of the leg

§  Ankle

·       Hinge joint

·       Allows flexion & extension of foot

·       Talus + tibia + fibula

§  Foot

·       Tarsals – 7 bones

o   Talus (part of ankle)

o   Calcaneus (heel)

o   Navicular

o   Cuboid

o   Medial Cuneiform

o   Intermediate Cuneiform

o   Lateral Cuneiform

·       Metatarsals – 5 bones

·       Phalanges – 15 bones/foot

o   2 bones for large toe

o   3 bones for smaller toes

§  Distal

§  Middle

§  Proximal

v  Muscular System
FUNCT: Form, upright posture, movement, protects organs.

Ø  Skeletal

§  Voluntary muscle

§  Contraction & relaxation allows for movement

§  Most muscles work on a agonist-antagonist principle.

Ø  Smooth

§  Blood vessels and intestines

Ø  Cardiac

§  Only found in heart

v  Joints of the Body

Ø  Occur wherever bones come in contact.

Ø  Symphysis – A joint w/ slight, limited motion in which the bone ends are held together by fibrous tissue,

Ø  Synovial joints – Joint ends held together by fibrous sac called joint capsule.

Ø  Ball-and-socket joint

Ø  Hinge joint

v  Respiratory System
FUNCT: Breathing (respiration)

Ø  Upper respiratory tract

§  Nose

§  Mouth (oral cavity)

§  Tongue

§  Jaw (mandible)

§  Pharynx

·       Nasopharynx

·       Oropharynx

·       Laryngopharynx – above trachea and esophagus

§  Epiglottis

·       Thin, flap that prevents food and liquid from entering trachea

§  Esophagus

·       Posterior to trachea

·       Carries food to the stomach

§  Larynx (Voice box) - Dividing line between upper and lower respiratory tract

·       Thyroid cartilage (adam’s apple)

¨     Anterior part of larynx

¨     Sound created as air is forced past vocal chords

·       Cricoid cartilage

·       Cricothyroid membrane – area for emergency airways

·       Trachea

¨     Ends at carina

¨     Divides into R & L bronchi

Ø  Lower respiratory tract

§  Bronchi

§  Lungs
Held in place by: Trachea, arteries & veins, Pulmonary ligaments
Right lung – 3 lobes            Left lung – 2 lobes

·       Bronchioles

·       Alveoli – allow for gas exchange (CO₂ and O₂)

·       Pleura – Layer of smooth, glistening tissue that covers each lung and lines chest cavity.

¨     Pleural cavity – Space between lung and pleura

Ø  Physiology of Lungs

§  FUNCT: To provide body with oxygen and eliminate carbon dioxide.

§  Ventilation vs respiration (2 independent functions of respiratory system)

·       Respiration

¨     Exchange of oxygen and carbon dioxide in alveoli and tissues of the body.

¨     Diffusion: Passive process of molecules moving from [high] to [low].

¨     Muscles involved:

Ø  Diaphragm

Ø  Intercostal muscles

Ø  Cervical muscles

Ø  Abdominal muscles

Ø  Pectoral muscles

¨     Brain stem controls breathing by monitoring CO2 or O2 arterial levels.

Ø  Medulla oblongata in brain stem sense pH changes (CO2 acidosis) in CS fluid and signals diaphragm.

§  Medulla oblongata – keeps us breathing w/o thinking about it.

Ø  Hypoxic drive – monitoring O2 levels, less sensitive and powerful.

·       Ventilation

¨     Simple movement of air into and out of the lungs.

¨     Requires chest rise and fall

¨     Air volume in respiratory system terms:

Ø  Tidal volume – amount of air regularly moved into/out of lungs during single breath.

Ø  Inspiratory reserve volume – deepest breath you can take after a normal breath.

Ø  Expiratory reserve volume – Maximum amount of air possible to forcibly breath out.

Ø  Residual volume – Gas that remains in lungs to keep the airways open.

Ø  Dead space – Portion of respiratory system w/ little to no gas exchange.

¨     Minute volume = respiratory rate (RR) * tidal volume

¨     Always eval the amount of air being moved w/ each breath

§  Normal Breathing classified as:

·       Normal rate & depth (tidal volume)

·       Regular rhythm

·       Clear, audible breath sounds on both sides of chest

·       Regular rise & fall movement on both sides of chest

·       Movement of abdomen

§  Inadequate breathing patterns:

·       Labored breathing

¨     Requiring effort and use of accessory muscles

¨     Slower/faster breathing than usual

·       Muscle retractions

¨     Above clavicles

¨     Between ribs

¨     Below rib cage

·       Pale/cyanotic skin

·       Cool, damp skin

·       Patient in tripod position

·       Agonal gasps

Ø  Diseases of the Respiratory System

§  Hypoxia

§  Hypercarbia

§  Shock

v  Circulatory System

Ø  FUNCT: Complex arrangement of connected tubes (arties, arterioles, capillaries, venules, and veins) that transport blood through the body.

Ø  Two circuits:

§  Systemic circulation (body) – carries O2 rich blood from left ventricle to rest of body and back to the heart’s right atrium.

§  Pulmonary circulation – carries O2 poor blood from right ventricle to lungs and back.

Ø  Heart

§  Muscular organ ~ the size of an adult’s fist

§  Center of circulation between two different circuits.

§  Right side of the heart receives blood from veins of the body.

·       Blood enters from superior and inferior vena cava into the R. atrium.

·       R. ventricle contracts à Blood flows into pulmonary artery & pulmonary circulation.

§  Left side of heart receives blood from pulmonary circuit

·       Blood returns to the left atrium

·       L. ventricle contracts à Blood flows through aorta to rest of body.

§  Valves prevent blood from flowing backwards to the rest of the body.

§  Normal HR ~ 60 – 100

·       Stroke volume (SV) – amount of blood moved by one beat.

·       Cardiac output (CO) – amount of blood moved in 1 minute.

¨     CO = HR * SV

¨     ~ 1 min, body’s entire blood volume (5 – 6L) circulated through all the vessels of the body.

§  Electrical conduction of the heart

·       Network of specialized tissue

·       Mechanical contraction linked to 2 electrical process:

¨     Depolarization – electrical charges on surface of muscle cell change from (+) à (-)

¨     Repolarization – muscle cell returns to resting state (+) charge restored.

·       Sinoatrial node à Atrioventricular node à Bundle of His à Purkinje fibers

Ø  Veins IN. Arteries OUT.

§  Arteries

·       Important arteries of note in the body organs

¨     Aorta – Main artery leaving left side of the heart (Carries oxygenated blood)

Ø  Coronary artery – supplies heart

Ø  Carotid artery – supplies head

Ø  Hepatic artery – supply liver

Ø  Renal artery – supply kidney

Ø  Mesenteric arteries – supply digestive system

¨     Pulmonary artery

§  Capillaries

·       Tiny blood vessels connecting arterioles and venules

·       Contact of blood with cells of tissues.

·       Oxygen and nutrients diffuse.

§  Veins

·       Return O2 depleted blood to heart.

·       Blood moves from capillaries to venules to veins.

·       Important veins of note:

¨     Superior vena cava – Returns blood from head, neck, shoulders, and upper extremities.

¨     Inferior vena cava – Returns blood from abdomen, pelvis, and lower extremities.

Ø  Spleen

§  Solid organ under rib cage in Upper Left abdomen

§  Filters worn out RBCs, foreign substances, and bacteria from blood.

v  Circulatory system Physiology

Ø  Blood Function

§  Perfusion

§  O2 transportation

§  CO2 transporation

§  Transportation of wastes

§  Clotting (coagulation)

Ø  Blood pressure (BP) – pressure blood exerts against the walls of arteries.

§  Systole: Pressure against the vessels when L. ventricle of heart contracts.

§  Diastole: Pressure against the vessels when ventricles relax.

§  Measured through blood pressure cuff (sphygonomanometer)

Ø  Normal circulation in adults

§  Automatically adjusted

§  Perfusion – Circulation of blood in an organ in adequate amounts to meet current needs of cell.

Ø  Inadequate circulation in adults

§  While the system can adjust to compensate for small blood loss à vessel constriction/heart pumping more radically.

§  Large loss of blood causes shock

·       Shock – State of not enough blood reaching the organs and tissues of the body.

§  Mean arterial pressure = (HR * SV) * systemic vascular resistance à MAP = (HR*SV)*SVR

v  Nervous system effect on Cardiovascular system

Ø  Sympathetic nervous system à fight/flight response

§  Adrenal glands are stimulated to release epinephrine (adrenaline) and norepinephrine (noradrenaline) – (stimulates heart & blood vessels)

·       Epinephrine and norepinephrine are class of organic molecules called catecholamines.

·       Catecholamines target beta-adrenergic receptors à causing HR increase, and bronchial dilation.

Ø  Parasympathetic nervous system à rest and digest

§  Causes HR to slow and beat more weakly.

v  Nervous System

Ø  Central Nervous System

§  Components:

·       Brain

¨     Cerebrum

Ø  Largest part of brain

Ø  4 types of lobes

§  FUNCT: controls activities on opposite side of the body.

§  Frontal

§  Parietal

§  Temporal

§  Occipital

¨     Cerebellum

Ø  FUNCT: Coordinates body movements

¨     Brain Stem

Ø  FUNCT: Controls body functions necessary for life such as cardiac and respiratory functions.

Ø  3 areas:

§  Midbrain

§  Pons

§  Medulla oblongata

·       Spinal cord

¨     Made up of nerve fibers (neurons) extending from cells of the brain that join together below brain stem to form spinal cord.

¨     Transmits messages between brain and body

¨     Encased within spinal canal.

¨     Cerebrospinal fluid (CSF) – cushions brain & spinal cord

Ø  Peripheral Nervous System

§  Nerves outside the brain and spinal cord that link the CNS to various organs of the body

§  Forms cable of nerve fibers that link CNS with different organs of the body.

·       Somatic Nervous System (voluntary)

¨     Transmit signals from brain to voluntary muscles

Ø  Walking, talking, writing

·       Autonomic Nervous System (involuntary)

¨     Controls involuntary actions necessary for basic body functions

Ø  Digestion dilation, constriction of blood vessels, and sweating

¨     Further divides into 2 areas:

Ø  Sympathetic nervous system – fight/flight

Ø  Parasympathetic nervous system – rest/digest

§  Has 2 types of nerves:

·       Sensory nerves – carries info from body to CNS

·       Motor nerves – carries info from brain to muscles

¨     Each muscle has its own motor nerve.

¨     Electrical impulses carried down the spinal cord cause the muscles to contract.

v  Integumentary System (skin)

Ø  FUNCT: Protects body in environment, regulates body temperature, transmit info from environment to brain.

Ø  Epidermis

§  Come Lets Get Sun Burned

§  Stratum Corneum

§  Stratum Lucidum

§  Stratum Granulosum

§  Stratum Spinosum

§  Stratum Basale

Ø  Dermis

v  Digestive System

Ø  Processes food that nourishes the individual cells of the body.

Ø  Components:

§  Abdomen – Major orangs of digestion and excretion

·       Right upper quadrant (RUQ)

¨     Liver

¨     Gallbladder

¨     Portion of Colon

·       Left upper quadrant (LUQ)

¨     Stomach

¨     Spleen

¨     Portion of Colon

·       Right lower quadrant (RLQ)

¨     Two portions of colon

Ø  Cecum

Ø  Ascending colon

·       Left lower quadrant (LLQ)

¨     Two portions of colon

Ø  Descending colon

Ø  Sigmoid Colon

v  Lymphatic System

Ø  Spleen

Ø  Lymph nodes

Ø  Lymph

Ø  Lymph vessels

Ø  Thymus gland

Ø  Etc.

v  Endocrine System

Ø  Adrenal

Ø  Ovary

Ø  Parathyroid

Ø  Pituitary

Ø  Testes

Ø  Thyroid

v  Urinary System

Ø  Kidneys

Ø  Ureters

Ø  Bladder

Ø  Urethra

v  Reproductive System (genital system)

Ø  Male

§  Testicles

§  Epididymis

§  Vasa deferentia

§  Prostate gland

§  Seminal vesicles

§  Penis

Ø  Female

§  Ovaries

§  Fallopian tubes

§  Uterus

§  Cervix

Vagina