Anatomy Exam 2

Skull

22 bones total

• 8 cranial, 14 facial

Vertebral column

vertebrae, sacrum, coccyx

Thoracic column

ribs & sternum

Pectoral girdle

clavicle & scapula

Upper limb

arm, forearm, wrist/hand

Pelvic girdle

pelvic bones & sacrum

• functions to support the upper limb, attachment site for many muscles

Lower limb

thigh, leg, ankle/foot

Sternal end of clavicle

articulates with manubrium at the sternum

• forms sternoclavicular joint

Acromial end of clavicle

articulates with the acromion

• forms acromioclavicular join

Three edges of scapula

medial, lateral, superior

Three points of scapula

superior, inferior, lateral

Three pelvic bones

Ilium, ischium, and pubis

• fused during childhood

Pelvis

pelvic bones, sacrum, and coccyx

Pelvic inlet

defines the boundary between the greater and lesser pelvis

Femur

largest and strongest bone in body

• head articulates with the acetabulum, and this forms the hip joint

Fovea capitis

pit in the center of the head where a ligament from the acetabulum attaches to stabilize the joint

What is the weakest part of the femur which is fracture prone?

the neck

What does the patella articulate with?

patellar surface

Where do the tibia and fibula articulate?

distal and proximal tibiofibular joint

• united by interosseous membrane

What is more commonly fractured in ankle injuries?

the fibula because it is thinner and therefore weaker

• stabilizes the ankle joint

What are the three arches of the foot?

transverse, medial longitudinal, and lateral longitudinal

Functions of bone

protection, mineral storage, acid-base homeostasis, movement, and support

What occurs in yellow bone marrow?

fat storage

What occurs in red bone marrow?

hematopoiesis

• blood cell formation

Long bones

longer than they are wide, surface covered in periosteum

• ex: humerus

What composes short, flat, irregular, and sesamoid bones?

two layers of compact bone surrounding a layer of spongy bone

• periosteum is above compact

What does bone (osseous) tissue consist of?

mainly ECM with cells scattered throughout

Extracellular matrix

65% inorganic matrix

• calcium salts + phosphorus salts = hydroxyapatite crystals

• 35% organic matrix (osteoid)

• Mainly collagen

Hydroxyapatite crystals

make bones able to resist compression

Dipole

spongy bone

Periosteum

composed of dense irregular collagenous CT richly supplied with blood vessels and nerves

• attached to underlying bone by perforating fibers

Short bones

about as long as they are wide, cube shaped

• ex: carpals

Flat

thin and broad

• ex: sternum

Sesamoid bones

small relatively flat, oval-shaped bones in tendons

• ex: patella

Irregular bones

outside of all other categories

• ex: vertebrae

Osteoblasts

build bone and carry out bone deposition

• derived from osteogenic cells → osteocytes

• in inner periosteum and endosteum

Osteocytes

maintains bone

• located in lacuna

Osteoclasts

break down bone and participates in bone reposition

• in shallow depressions on the internal and external surface of bone

Compact bone

contains osteons, lacunae, and central canal

• covered in periosteum

Central canal

surrounds blood vessels and nerves that supply the osteon

Lacunae

small cavities located between lamellae that house osteocytes

• connected via canaliculi

Spongy bone

a non-weight bearing bone which means it is not a dense structure

• forms protective framework for bone marrow

• located in inner portions of bone

Trabeculae

branching structure of bone

• contains concentric lamellae

Process of ossification

primary bone (immature) -> reabsorbed by osteoclasts -> replaced by secondary bone (mature)

Intramembranous ossification

occurs during fetal development

• inner spongy bone forms before the outer compact bone

• many flat bones, skull, clavicle

Endochondral ossification

most occurs during development, some finishes in childhood

• built on a hyaline cartilage model

• all bones below the head excluding clavicles

Longitudinal growth

growth in length

• long bones

Appositional growth

growth in width

• all bones

Testosterone (in relation to bone growth)

increases appositional bone growth and mitosis at epiphyseal plate

• why males are taller

Estrogen (in relation to bone growth)

increases longitudinal bone growth, inhibits osteoclasts, and accelerates closure of epiphyseal plate

Vitamin D

aids in calcium ion absorption

Calcium

bone deposition

Parathyroid hormone

increases blood calcium concentration when it gets low

Calcitonin

decreases blood calcium level when concentration gets high

Functions of connective tissue

connecting (connect structures in body), binding (tissue layers together), support (bone and cartilage support weight of body), protection (bone tissue protects internal organs), and transport (blood)

Loose connective tissue

support, protection, and houses blood vessels supply for epidermis

• located deep in the epidermis, walls of hollow organs, and membranes lining body cavities

Dense irregular connective tissue

strength and resistance to stress in all three planes

• found in deepest layer of skin and around joints/organs

Dense regular collagenous connective tissue

strength and resistance to stress in one plane (parallel collagen fibers)

• found in tendons and ligaments

Dense regular elastic connective tissue

allows tissue to stretch and recoil

• found in large blood vessels and certain ligaments

Reticular connective tissue

forms internal structure of many organs and supports smaller vessels/nerves

• found in lymph nodes, spleen, bone marrow, liver, basement membrane, and around vessels/nerves

Adipose connective tissue

warmth, insulation, shock absorption, protection, and major energy reserve in body

• deep to the skin and surrounds heart/abdominal organs

hyaline cartilage

fibrocartilage

elastic cartilage

Osseous (bone) tissue

Blood tissue

skeletal

• striated, voluntary, multinucleated, with nuclei near the outer edges

• attached to skeleton

smooth muscle tissue

• no striations, involuntary, flattened cells, with single ovoid nucleus in center of cells

cardiac muscle

• striations, involuntary, with intercalated discs

• in heart

nervous tissue

• neurons and neuroglial cells

• in brain, spinal cord, and nerves

Neuroglial cells

anchors neurons and blood vessels in place, monitors extracellular composition, increases rate of impulse transmission, and circulates surrounding fluid of brain and spinal cord

Neurons

generate, conduct, and receive information in the form of nerve impulses

Epithelial tissue

protection for underlying tissue, immune defense against pathogens, secretion, transport into other tissues, and sensation

Components of epithelial tissue

consist of closely packed cells joined by tight junctions and desmosomes

• basement membrane holds basal lamina, reticular lamina, and ECM

Simple epithelium

often found lining hollow organs and surfaces where substances must be diffused or transported

Paracellular transport

substance passing through narrow space between the cells

Transcellular transport

substance entering and diffusing through one cell through cytosol

Simple squamous epithelium

barrier that gases and fluid exchange, produces serous fluid

• lines lungs, ventral cavities, blood vessels, and kidney

Simple cuboidal epithelium

absorption and secretion

• lines kidney, lower respiratory, thyroid, salivary, and mammary glands

Pseudostratified columnar epithelium

secretes mucus and propels it with ciliary motion

• lines trachea, nasal cavity, parts of urethra

Simple columnar epithelium

absorption, secretion, and propulsion of egg through uterine tube

• lines pancreatic duct

Nonkeratinized stratified squamous epithelium

protection from mechanical stress and microorganisms

• found in vagina, anal canal, mouth, pharynx, larynx, and esophagus

• very flat cells

Keratinized stratified squamous epithelium

protection from mechanical stresses and microorganisms, as well as prevent water loss through skin

• found in epidermis

• apical cells dead and flaky

Stratified cuboidal epithelium

absorption and secretion

• found in ducts of sweat glands

Stratified columnar epithelium

protection as well as secretion and absorption

• found in ducts of certain glands, conjunctiva, and parts of male urethra

Transitional epithelium

protection and gives tissues distensibility

• found in ureter, urethra, and urinary bladder

Exocrine glands

release secretions to apical surface via ducts

Unicellular exocrine gland

single cell, most common is a goblet cell which secretes mucus

Multicellular exocrine gland

composed of clusters of secretory cells

• can be either tibular, acinar, or tubuloacinar

• simple: don’t branch

• compound: branch

Endocrine glands

secrete products directly into bloodstream and which facilitates longer-action and communicates further

Merocrine secretion

package products into secretory vesicles for release by exocytosis

• salivary and sweat glands

Holocrine secretion

cells accumulate their product in cytosol and product is not released until cell ruptures and dies

• sebaceous glands

Apocrine secretion

portions of cytoplasm pinched off with product being secreted

• lipid droplet secretion in lactating mammary glands

Regeneration

damaged tissue is replaced with same tissue during healing, function of tissue is completely restored

• epithelial, connective tissue (except cartilage), and smooth muscle tissue

Fibrosis

damaged tissue is replaced with fibrous connective tissue during healing, function is not regained and results in formation of scar tissue

• cardiac muscle, skeletal, and cartilage CT

How does nervous tissue repair?

undergoes mitosis and divides, replaced by neuroglial cells to produce scar if neurons damaged, if cell body damaged it may undergo regeneration

Cutaneous membrane

epidermis (keratinized stratified squamous) and dermis (loose connective/dense irregular)

Loose connective tissue below cutaneous

hypodermis, superficial fascia, and subcutaneous tissue

• anchor skin to muscle and bone

Functions of integumentary system

protection, sensation, thermoregulation, excretion, and vitamin D synthesis

Superficial layer of dermis

papillary layer composed of loose connective tissue