Human Anatomy

Anatomical Terminology

• Anatomy - The branch of science dealing with the study of the structure of the body

• Subdivisions of Anatomy

  • Cytology - Examines specific cells

  • Histology - study of tissues

  • Regional - studies specific body regions

  • Systemic - examines specific organ systems

  • Pathology - Studies changes associated with diseases

  • Gross - studies anatomical features observable with a naked eye

  • Topographical - studies layering structure of anatomical regions

• Anatomical Position - Body is erect, or in standing posture, with the arms at the sides and palms turned forward; head and feet pointed forward; feet are aligned at the toe and slightly set apart

• Directional Terminology

  • Superior - Toward the top of the head

  • Anterior - Before or in front of; refers to the front side

  • Medial - Pertaining to the middle or towards the median

  • Inferior - Beneath, lower; the undersurface of things

  • Posterior - Behind or in the back of (remember the megan thee stallion song)

  • Lateral - pertaining to the side of the body; away from the medial plane

  • Proximal - Nearest to the point of attachment of a limb to the trunk of the body

  • Distal - farther away from the point of attachment of from the trunk

  • Internal - within the body

  • External - pertaining to the exterior

  • Parietal - pertaining to, forming, the wall of a cavity

  • Visceral - pertaining to the internal organs contained within a cavity (think of the viscera bag)

  • Peripheral - located at, pertaining to, the outer surface of the body

  • Central - situated at or pertaining to a center or center point

  • Supine - Body is lying face upward

  • Prone - body is lying face down

  • Perpendicular - at right angles to another surface

  • Superficial - pertaining to or situated near the surface of the body or body part

  • Deep - below the surface, or toward the central part of a structure

• Body Planes

  • Bilateral Symmetry - the medial line along the middle of the body divides the body into to similar halves

  • Section - a cut of the body being divided by an imaginary flat plane

    • Sagittal - vertical plane, divides the body into right and left halves

    • Transverse - horizontal plane dividing the body into upper and lower halves

    • Midsagittal - sagittal plane that divides the body into equal right and left halves

    • Frontal - vertical plane dividing the body into front and back

Levels of Organization

• Systems - A group of organs arranged for the performance of a specific function

• Organs - A group of several different kinds of tissues arranged in ways that allow them to act as a unit to perform a special function

• Tissues - an organization of many cells that act together to perform a common function

  • Epithelial - Tissue lining the body surfaces

  • Connective - tissue that provides structural and functional support

  • Muscular - tissues that shorten and contracts to create movement

  • Nervous - tissues that make up the nervous system

• Cells - basic building blocks of all living organisms

• Accessory (Auxiliary) structure - applied to lesser structure that resembles a similar organ in structure and function, such as the accessory pancreatic duct

Body Walls and Cavities

• Body Walls - Surround a cavity

• Body Cavities - Opens spaces that contain internal organs

  • Dorsal Cavities - House organs of the central nervous system

    • Cranial Cavity - space inside the skull that contains the brain

    • Spinal Cavity - Space inside the vertebral column containing the spinal cord

  • Ventral (Thoracic) Cavities - Anterior Cavity separated by the diaphragm

    • Mediastinum - midsection of the thoracic cavity

    • Pleural - contains the lungs

    • Pericardial - contains the heart

  • Abdominopelvic Cavity - Lower anterior cavity

    • Abdominal - Contains the liver, gallbladder, stomach, spleen, pancreas, small intestine, and parts of the large intestine

    • Pelvic - contains lower colon, rectum, urinary bladder and reproductive organs

Body Regions

• Head and Neck (Cervical) - Head is divided into the cranium and face

• Trunk - Divided into the thorax, abdomen, and pelvis

• Upper Extremities - Arms and pectoral girdle

• Lower Extremities - legs and pelvic girdle

Integumentary System

Dermatology – the study of skin
Integumentary – relating to the outer surface of a structure, i.e. the skin and its components
Overview

• Integument is made up of the skin and the connective tissues beneath it

• Skin is a cutaneous membrane that forms a sheetlike covering

• A layer of fat beneath the skin supplies nutrients, cushions the body, and connects skin to muscle and deeper layers (hypodermis or subcutaneous tissue)

Functions

• Protection – first line of defense against microbes and other hazards

• Temperature – sweat secretions, blood vessel dilation, and contraction

• Excretion – sweat & evaporation

• Vitamin D synthesis – via exposure to UV light

• Sense organ activity – nerve endings send signals to the brain

  • Layers of the Skin
    Epidermis – outermost layer of the skin

    • 5 tightly packed layers
      • Outermost layer – stratum corneum
      • Dermis + epidermis meet at dermal-epidermal junction
      • Melanocytes produce melanin in the deepest layer of the epidermis

    • Dermis – deeper layer of the skin
      • Made up of mostly connective tissue
      • Contains lots of blood vessels
      • Collagen and other fibers help to keep the skin elastic and strong
      • Contains two main layers

    • Hypodermis – the deepest layer of the skin

    • Stores energy and connects the dermis to the muscles and bones
      • Mostly adipose tissue
      • contains nerves, blood vessels, and lymphatic vessels

• Accessory structures

  • Hair

    • Hair stems from pocket-like structures called follicles

    • Lips, Palms, and Soles are completely hairless

    • Arrector pili are tiny involuntary muscles

  • Nails

    • The nail body is the visible non-living portion

    • The cuticle hides root

    • Lunula is a crescent-shaped portion near the root end

• Glands - a secretory organs or structure that can manufacture a secretion

• Sudoriferos glands are sweat glands

  • Eccrine glands are distributed around the entire body

    • Secrete sweat

  • Apocrine glands are found in the axilla and around the genitals

    • Secrete a thicker solution

• Sebaceous glands are sebum glands (think of ear cheese)

  • Secrete sebum
    • Sebum is an oil that lubricates hair and skin
    • Present anywhere that hair grows
    • Attached to hair follicles

Skeletal System

• Functions as the internal framework, protection, movement, and hematopoiesis

• 206 bones

  • Skull - 22 bones + 6 ear ossicles

    • Cranial Bones (8)

      • Frontal

      • Parietal - 2

      • Occipital

      • Temporal - 2

      • Sphenoid

      • Ethmoid

    • Facial Bone - 14

      • Nasal -2

      • Lacrimal - 2

      • Zygomatic - 2

      • Palatine - 2

      • Maxilla - 2

      • Vomer - 1

      • Inferior nasal conchae - 2

      • Mandible

  • Hyoid Bone

  • Vertebrae - 26

    • Cervical - 7

      • C1-C7

    • Thoratic - 12

      • T1 - T12

    • Lumbar - 5

      • L1 - L5

    • Sacrum - 1

  • Sternum

  • Ribs - 24

    • 14 true ribs - connect directly to the sternum

    • 10 false “floating” ribs

  • Upper extremities - Pectoral girdle - 64 bones

  • Lower extremities - Pelvic girdle - 62 bones

• Axial skeleton - 80 bones - composes the skull, vertebrae, thorax, and Hyoid bone: central structure to which the appendicular skeleton is attached

• Appendicular - 126 bones - make up the pectoral girdle, upper extremities, pelvic girdle, and lower extremities

  • Clavicle - 2

  • Scapula - 2

  • Humerus - 2

  • Ulna - 2

  • Radius - 2

  • Carpals - 16

  • Metacarpals - 10

  • Phalanges (hands) - 28

  • Os Coxae - 2

  • Femur - 2

  • Patella - 2

  • Tibia - 2

  • Fibula - 2

  • Tarsals - 14

  • Metatarsals - 10

  • Phalanges - 28

• Bursae - fluid-filled cushions to reduce friction for joints

• Ossification - the process of bone formation

• Compact Bone - an outer, harder layer of bone

• Cancellous bone - inner porous bone

Terminology - Joints

• Articulation – the connection between two or more bones; a joint

• Joint – the connection between two bones; an articulation

• Sutural – relating to the line of union in an immovable articulation, such as between the cranial bones

• Symphysis – a joint in which the bones are connected by fibrocartilage, e.g., the pubic symphysis

Terminology – bone features

• Condyle – a curved protuberance at the end of a bone forming part of an articulation

• Epicondyle – protuberance on or above a condyle of a long bone

• Eminence – a prominence or projection, i.e., of a bone

• Foramen – a hole in a bone

• Fossa – a shallow depression

• Meatus – a passage or opening through a bone

• Protuberance – an anatomic landmark that appears as a blunt projection, like a knob

Terminology – specific structures

• Carotid canal – the canal or passageway in the temporal bone through which the internal carotid artery passes

• External auditory meatus – the lateral, outer opening of the ear or auditory canal

• Mandibular fossa – the depression in the temporal bone into which the condyle of the mandible fits

• Pubic symphysis – the slightly movable junction of the anterior portion of the os coxae

• Zygomatic – pertaining to the cheek bone

Terminology – other terms

• Conchae – ridges in the walls of the nasal cavity

• Fontanel – a temporarily unossified area on the surface of the cranium of an infant

• Ossicles – any small bone, e.g., the three bones of the middle ear

• Malleolus – bony prominence on either side of the ankle

• Prominence (bony prominence) – area where bone is close to the surface of the skin (superficial)

• Sesamoid bone – bone shaped like a sesame seed; a bone embedded in a tendon. The patella is the largest of these

• Sinus - a paranasal cavity within a bone; dilated channel for venous blood

Tissue Types

• Cancellous (spongy) bone is porous bone tissue on the inside of bones

• Bone marrow which contains stem cells and produces blood cells

• Compact bone is the outer layer of bone that is hard and dense

  • Contains osteocytes, or bone cells, in tiny spaces called lacunae

• Cartilage is flexible but firm connective tissue that helps to provide structure and support

Functions of bone

• Support – provides body’s internal framework

• Protection – of inner tissues and organs

• Movement – muscles are anchored to bones

• Storage – blood calcium

• Hematopoiesis – process of blood cell formation

Types of bones

• Long bones (i.e. humerus)

• Short bones (i.e. carpals)

• Irregular bones (i.e. vertebrae)

• Sesamoid bones (i.e. patella)

• Sutural bones (i.e. cranial bones)

Appendicular Skeleton

• Appendicular - 126 bones - make up the pectoral girdle, upper extremities, pelvic girdle, and lower extremities

  • Clavicle - 2

  • Scapula - 2

  • Humerus - 2

  • Ulna - 2

  • Radius - 2

  • Carpals - 16

  • Metacarpals - 10

  • Phalanges (hands) - 28

  • Os Coxae - 2

  • Femur - 2

  • Patella - 2

  • Tibia - 2

  • Fibula - 2

  • Tarsals - 14

  • Metatarsals - 10

  • Phalanges - 28

• Pectoral Girdle

  • Collarbone/Clavicle

  • Scapula - Shoulder blade bone

    • Acromion - bony process that extends laterally from the superior and posterior portion of the scapula

    • Coracoid process - bony process that extends laterally from the superior and anterior portion of the scapula

    • Glenoid cavity (fossa) - a depression in the lateral portion of the scapula where the humerus joins the scapula

• Humerus

  • Long proximal bone of the arm

  • Attached to the scapula at the proximal end

  • Attached to the radius and ulna at the distal end

  • head of the humerus articulates with the scapula (at the glenoid cavity)

  • Radius and ulna articulate at the lateral and medial condyles/epicondyles

  • Features:

    • Lateral, distal condyle is the capitulum and it articulates with the radius

    • Medial, distal condyle is the trochlea and it articulates with the ulna

• Ulna

  • Medial forearm bone

    • Features

      • Olecranon process – eminence at the proximal, posterior end of the ulna

      • Styloid process – eminence on the distal end of the ulna

• Radius

  • Lateral forearm bone

    • Features:

      • Styloid process – eminence on the distal end of the radius

• Carpals

  • Bones that make up the wrists

  • 16 total

  • 8 on each side

• Metacarpals

  • Bones that make up the palms

  • 10 total

  • 5 on each side

• Phalanges

  • Bones of the fingers

  • 28 total

  • 14 on each side

The Lower Appendicular Skeleton (62 bones)

• Summary

  • Os coxae (2)

  • Femur (2)

  • Patella (2)

  • Tibia (2)

  • Fibula (2)

  • Tarsals (14)

  • Metatarsals (10)

  • Phalanges (28)
    

• The Pelvic Girdle (2 bones)

  • Summary

  • Os coxae (2)
    

• Os coxae

  • Hip or pelvic bones

  • Features & Divisions:

    • Ilium – superior region

    • Iliac crest – superior anterior border of the ilium

      • Anterior superior iliac spine – anterior portion of the iliac crest

      • Ischium – inferior, posterior region

      • Pubis – inferior, anterior portion

      • Acetabulum – articulation point for femur
        

• The Lower Extremities (60 bones)

  • Summary

    • Femur (2)

    • Patella (2)

    • Tibia (2)

    • Fibula (2)

    • Tarsals (14)

    • Metatarsals (10)

    • Phalanges (28)
      

• Femur

  • Thigh bone

  • Features:
    • Head – ball shaped joint that articulates with the os coxae at the acetabulum
    • Condyles articulate with the tibia and fibula at the distal end
    • Epicondyles sit above the condyles and attach to the muscles and ligaments of the knee joint
    

• Patella

  • Knee bone or kneecap

• Tibia

  • Weight-bearing medial distal leg bone

  • “Shinbone”

  • Slightly anterior to the fibula

    • Features:
      • Medial malleolus – rounded projection at the inferior end of the medial tibia that articulates with the
      talus (ankle bone)

• Fibula

  • Non-weight bearing lateral distal leg bone

    • Features:
      • Lateral malleolus – rounded projection at the inferior end of the fibula that articulates with the talus
      (ankle bone)

• Tarsals

  • Bones of the heel, ankle, and posterior foot

  • 14 total

  • 7 on each side

  • Talus – superior tarsal bone (ankle bone)

  • Calcaneus – heel bone

    • Sits under talus

• Metatarsals

  • Bones of the foot

  • 10 total

  • 5 on each side

• Phalanges

  • Bones of the toes

  • 28 total

• Arthrology

• Arthrology – the study of joints

• Joint – the connection between two bones; an articulation

  • Three types of joints – immovable, slightly movable, and freely movable

    • Synarthrosis (pl. synarthroses) – immovable joint

      • Connected by fibrous tissue

      • include the cranial sutures (fontanels) and sternocostal joint

    • Amphiarthrosis (pl. amphiarthroses) – slightly movable joint

      • Generally held together by cartilage

      • Examples include the pubic symphysis, sacroiliac articulation, and intervertebral joints

    • Diarthroses (pl. diarthroses) – freely movable joint

      • Sometimes called a synovial joint

      • Connected by cartilage in a cavity containing fluid (synovial fluid)

      • Synovial fluid allows for the bones to move appropriately together

      • Examples include the shoulder, elbow, and wrist

Respiratory System

• Respiratory – referring to the organ system that carries out gas exchange, e.g., inhalation and exhalation

• Overview - “Blanket” terminology

  • Lobes – well–defined parts of an organ separated by boundaries

  • Septum – a wall dividing two cavities
    

• Functions

  • Gas exchange between oxygen and carbon dioxide

  • Oxygenation of the cells of the body

  • Removal of waste products

  • Filtration, warming, and humidifying of air breathed in

  • Some respiratory organs also function in speech and smell
    

• Internal vs. external respiration

  • Internal respiration is the exchange of carbon dioxide and oxygen on a microscopic level

  • External respiration is the process of breathing (inhalation + exhalation)
    

• The Nasal Cavity

  • Nasal cavities are the structures located within the nose within the second “third” of the face on the anterior
    aspect

  • Nasal septum – the partition that divides the nasal cavities

  • Begins the process of respiration

  • Floor of the nasal cavity is formed by the hard palate

  • Nasal bones form the anterior superior part of the cavity

  • Cribriform plate of the ethmoid bone forms the superior posterior portion

• Nares

  • Nares – openings of the nose, as in the nostrils (anterior nares), and/or posterior nares

  • Anterior nares are the “nostrils”

  • Posterior nares open into the nasopharynx

• Nasal conchae

  • Conchae – ridges in the walls of the nasal cavity

  • Contained in the lateral walls

  • Three nasal conchae total – superior, middle, and inferior

  • Function is to increase surface area which helps to humidify and warm air

• Paranasal sinuses

  • Sinus – a paranasal cavity within a bone

  • Function in humidifying and warming air and also act as a biological barrier to bacteria or other foreign substances

    • Frontal sinuses

    • Maxillary sinuses

    • Sphenoid sinuses

    • Ethmoid sinuses

• The Pharynx

  • The pharynx (throat) is a muscular tube that connects the nasal cavity to the larynx

  • Also functions in the digestive system

  • Divided into three portions:

  • Divisions:

    • Nasopharynx – superior portion of the pharynx located behind the nasal cavity

    • Oropharynx – middle portion of the pharynx located behind the mouth

    • Laryngopharynx – inferior portion of the pharynx continuing into the larynx anteriorly

• The Larynx

  • The larynx is a hollow, fibro–muscular and cartilaginous structure connecting the pharynx to the trachea

  • Anterior to the esophagus

  • Lined with epithelial tissue that is slightly different above and below the vocal cords

  • Thyroid cartilage is the largest cartilage of the larynx and sits below the hyoid bone

• Vocal cords

  • Larynx contains the vocal cords, which are fibrous bands that function in voice and sound production

  • Epiglottis is the structure that closes during swallowing to prevent food from entering the respiratory
    tract

  • Glottis is the space between the vocal cords
    

• The Trachea

  • The trachea is a fibrocartilaginous, muscular tube that functions in transporting oxygen into and out of the lungs

    • Posterior section is made of muscle tissue

    • Anterior portion is C–shaped rings of cartilage

    • Lined with epithelial tissue

• The Bronchi

  • Bronchi are fibromuscular, cartilaginous tubes leading from the trachea into the lungs

  • Lined with epithelial tissue

  • Primary bronchi lead into smaller secondary bronchi

  • Secondary bronchi branch into bronchioles

  • Bronchioles eventually lead to alveoli within the lungs

• Alveoli

  • Alveoli are small air sacs at the end of the bronchial tree that function in gas exchange between oxygen and carbon dioxide

  • Surrounded by a network of blood capillaries that lead back to the pulmonary artery

  • Respiratory membrane on the alveoli is very thin so that blood cells can pass through the capillaries

• Alveolar process

  • Inhalation occurs

  • Oxygen makes its way into the alveoli

  • Oxygen enters the blood stream

  • Exhalation occurs

  • Carbon dioxide leaves the red blood cells and enter the alveoli

  • Carbon dioxide is exhaled

• The Lungs

  • The lungs are spongy organs in the thoracic cavity that function in inhalation and exhalation on a gross scale and gas exchange between carbon dioxide and oxygen on a microscopic scale

  • R lung is larger than the left and has three lobes

  • L lung has two lobes

  • Lobes are divided by grooves called fissures

  • Sections of the lungs may be referred to as bronchopulmonary segments

• Lung anatomy

  • Superior, narrow portion is the apex

  • Broad, inferior portion is the base

  • Pulmonary artery, pulmonary veins, and bronchi enter the lungs at the hilum

  • Pleura is the membrane surrounding each lung

  • Visceral pleura adheres directly to the lung