anatomy lecture 1

anatomy

branch of biology concerned with the study of the structure of organisms and their parts

physiology

study of how the body functions, homeostatic mechanisms

4 levels of protein structures

primary structure, secondary structure, tertiary structure

cytology

study of cells

histology

study of tissues

gross anatomy

surface anatomy of superficial anatomical markings and relationship, clinical anatomy changes during illnesses, surgical anatomy landmarks for surgery

synapomorphies

shared derived traits, all members of a group have that trait

i.e. dorsal hollow nerve cord, notochord, post anal tail

molecular composition of human body

66% water, 3% carbs, 10% lipids, 20% proteins

levels of organization

cell, tissue, organ, organ system, organism

characteristics of life

order, regulation, growth and differentiation (hypertrophy and hyperplasia), energy processing, response to environment, reproduction, evolutionary adaptation

anabolism

synthesis of complex molecules

catabolism

breakdown of complex molecules

absorption

process of bringing material into the body

respiration

absorption, transport, use of oxygen

excretion

removal of waste, co2, excess ions

anatomical position

standing with feet flat on the floor, hands are at the side, palms forward (supine is laying up prone is lying down)

serous membranes

provide lubrication to organs

serous membranes in pleural cavity

visceral pleura: contact with lungs

parietal pleura: lines cavity

serous membranes in pericardial cavity

visceral layer of serous pericardium: contact with the heart

parietal layer of serous pericardium: lines cavity

serous membranes in peritoneal cavity

visceral peritoneum: contact with abdominal organs

parietal peritoneum: lines cavity

mesenteries double the sheet of peritoneum

cell theory

base in the hierarchy of biological organization, organizational level at which the properties of life emerge

all organisms are composed of cells (unicellular and multicellular)

all cells come from preexisting cells

cells share similar characteristics

all cells enclosed by a membrane, regulates the passage of materials between the inside of the cells and surroundings, every cell and its surroundings, every cell uses DNA for its genetic information

two types of cells

gametes (sperm and oocyte) somatic (body cells)

non membrane organelles

microvilli, free ribosomes, centriole, centrosome, fixed ribosomes, cytoskeleton, plasma membrane

membraneous organelles

secretory vesicles, mitochondrion, Golgi apparatus, peroxisome, nucleus, nucleoplasm, chromatin, nuclear pores, nucleolus, nuclear envelope, rough ER, smooth ER, lysosome, cytosol

membranes

phospholipids are the main structural components of membranes, hydrophilic head and two hydrophobic tails

plasma membrane

cell to cell communication, structural support, adhesion, regulates exchange with extracellular fluid, physical barrier, senses extracellular stimuli

phospholipids, proteins, glycoproteins, sterols

cytosol

higher concentration of K+ ions and lower concentration of Na+ compares to ECF

intracellular negative charge, extracellular is positive

high concentration of proteins

small quantity of carbs

large reserve of amino acids and lipids

cytoskeleton

microfilaments, actin and inner edge of the cell

intermediate filaments

anchor organelles, throughout cell, transport materials

microtubules

move organelles, cell movement, essential for mitosis, form centrioles cilia and flagella

microvilli

increase SA, churn ECF, microfilament support

ribosomes

free ribosomes float in cytoplasm, attached ribosomes are on ER, synthesis protein using RNA template

mitochondria

site of ATP synthesis and oxidative phosphorylation

nucleus

nuclear envelope, nuclear pores, nucleoplasm, nucleoli makes ribosomes, chromatin loose coils of chromosomes

endoplasmic reticulum

synthesis, storage, transport, detox

endoplasmic reticulum: folds of cisternae

rough endoplasmic reticulum, consists of attached ribosomes and stores and synth. proteins

smooth endoplasmic reticulum, synth lipids and steroids and carbs

embryology

formation of tissues

primary tissue types

epithelial, muscular, connective, neural

epithelial tissue

no intercellular space, polarity, exposed apical surface, attached basal surface, apical basal surfaces are structurally and functionally different, avascular, sheets and layers, regeneration

functions of epithelial tissue

provides physical protection, controls permeability, sensory cells, produces secretions

apical surface structures

microvilli, short and can move and increases surface area

stereocilia, long and rigid

cilia, long and can move substances over apical surface

maintaining epithelium

intercellular connections to give epithelium strength and stability, gap junctions, binds cells to basal lamina, must be replaced frequently due to exposure

2 types of layering

simple epithelium, one layer of cells to protected internal compartments

stratified, two layers

3 shapes of epithelial cells

squamous (flat), cuboid (cube), columnar (longer than wide)

squamous epithelium

simple: lining body cavities, lining heart and blood vessels and alveoli, reduces friction and controls vessel permeability

stratified: orifice and surface of skin, provides physical protection against abrasion

cuboid epithelium

simple: thyroid glands and renal tubules, secretion and absorption

stratified: lumen and secretion and absorption

columnar

simple: stomach and abdominal organs, high secretion and absorption

stratified: pharynx epiglottis anus mammarly, high activity areas and protection

pseudostratified ciliated columnar epithelium

lining of trachea, protects and secretes

transitional epithelium

renal pelvis ureters and bladder “stretchy”

secretory sheet

types of exocrine (serous mucous)

mixed endocrine glands

multicellular glands, mixed serous mucous, glandular tissue mix of duct cells and gland cells simple has no branching

embryonic connective tissue

specialized cells, extracellular protein fibers, ground substance

matrix

extracellular component of protein fibers & “ground substance” (fluid portion) – Matrix of bone is calcified

functions of connective tissue

Establishing body’s structural framework

–Transport fluid & dissolved materials

– Protect organs

– Support, surround, & connect other tissues

– Store energy – Defend body from microorganisms

connective tissue proper

matrix of loose fibers and dense fibers

fluid connective tissue

watery matrix of dissolved proteins

supporting connective tissue

dense matrix of fibers and may have insoluble calcium salts

collagen fibers

high tensile strength tendons and ligaments

reticular fibres

structural mesh within organs

elastic fibers

protein called elastin, rubbery and lines vasculature

ground substance

thick syrupy consistency mix of proteins and carbs

areolar tissue

stuffing of the body, cushions organs and provides support but allows for independent movement

adipose tissues

padding white fat is energy storage brown fat is thermogenesis

reticular tissue

structural sponge, matrix is stiffest of loose CT

dense regular and irregular connective tissue

regular: ligamens tendons aponeuroses high tensile strength

irregular: organ sheath

elastic tissue

rubbery, springy and resilient

FCT matrix: watery mixture of dissolved protein

Blood: moves via cardiovascular system

• Erythrocytes (red blood cells): gas transport

• Leukocytes (white blood cells): immune function

• Thrombocytes (platelets): blood clotting

• Plasma: matrix Lymph: moves via lymphatic system

• Monitors for signs of infection; mainly lymphocytes (T & B cells), but some phagocytic cells

cartilage: contains chondrocytes

Gel matrix made of chondroitin sulfate

• Cells reside in lacunae

• Avascular

• Have a fibrous perichondrium – Cellular layer: maintenance – Fibrous layer: connection to other structures • Most cartilage cannot repair severe damage

hyaline cartilage

between ribs and bones of sternum, tracheal rings, costal cartilage, joints, supportive

elastic cartilage

ears!

fibrous cartilage

firmest and strongest, resists compression and prevents bone to bone contact

bone

Most external bone surfaces are covered with periosteum

• Internal bone surface covered in endosteum

• Osteocytes in lacunae

• Lamellae (matrix): mix of collagen fibers & calcium salts

muscle tissue

cytoplasm=sarcoplasm

cell membrane=sarcolemma

neural tissue

Two types

• Neuroglia: supporting cells of neural tissue; can divide

• Neurons: specialized to conduct electrical signals (action potential) – Longest cells in body – Incapable of cell reproduction – Dendrite: receives stimuli – Axon: transmits a signal; action potential

epidermis

Cell types

• Keratinocytes – Most common cell – Produce keratin

• Melanocytes – Pigment cells – Produce melanin

• Merkel cells – Sensory cells; touch

• Langerhans cells – Wandering macrophages

stratum basic

Melanocytes • Merkel cells: touch sensors • Basal cells: become keratinocytes

stratum spinous

Keratinocytes • Melanocytes • Langerhans: trigger immune response

stratum granulosum

Last layer where cells have nuclei

• Keratinocytes @ this level start making: – Keratin – Keratohyalin

• Callus formation

stratum lucid

Thick skin has Stratum lucidum

• Stacks of dead cells

• High amounts of keratin

• Cells lack organelles & nuclei

stratum corner

Dead cells • Sebaceous & sweat glands maintain these cells

melanin

brown, yellowbrown, black

• Produced by melanocytes

• Synthesized & stored in melanosome

• Melanosome enter keratinocytes

• Melanocyte density is stable, type & amount melanin under genetic control

• Moles: overgrowth of melanocytes

• Albino: DN produce melanin

dermis

Reticular layer

• Dense irregular connective tissue

• Hair follicles

• Sweat glands

• Sebaceous glands Papillary layer

• Loose connective tissue

• Dermal papillae

• Capillaries

• Axons of neurons

• Attachment to Epidermis

tension lines

Collagen & elastic fibers organized in a parallel pattern

• Collagen fibers provide tensile strength

• Elastic fibers allow skin to stretch & recoil

• Stretch marks: reticular fibers break – Due to pregnancy or weight gain – Skin DN recoil, wrinkles & creases

blood vessels

Cutaneous plexus: main arteries & veins

• Subpapillary plexus: Smaller blood vessels

• Blood flow regulated – Thermoregulation – flow to other tissues of body

nerve fibers

controls blood flow to skin, adjusts gland secretion rates, monitors sensory receptors

receptors

tactile corpuscles, light tough

Ruffini corpuscles, stretch receptors

lamellar corpuscles, deep pressure and vibration

hair consists of

Hair shaft: nonliving, visible portion of hair

– Medulla: soft keratin

– Cortex: hard keratin

– Cuticle: outer layer

• Hair root: portion of hair in follicle being formed; anchors hair

• Hair follicle: organs that form hair

• Hair papilla: nerve & blood supply; supports matrix

• Hair matrix: basal cells that divide to become hair

types of hair

Vellus: covers most of body; lacks a medulla

• Terminal: head, eyebrows, eyelashes

• Hair Color – More melanin creates darker hair – Decreased production results in gray hair – White hair: Lack of melanin in hair shaft – Influenced by: Genetics / Hormones / Enviro. factors

• Hair shape: based on follicle shape

sebaceous glands

make sebum – Sebum: lipid mixture – Lubricate epidermis & hair – Antimicrobial properties – No glands on palms & soles – High concentrations on forehead, face, & upper back – If ducts become blocked:

• Acne may occur

• Furuncles may develop

sebaceous follicles

large sebaceous glands, no hair

holocrine secretion

Eccrine (merocrine) sweat glands

Found all over body

• High concentrations on palms & soles

• Sweat – Thermoregulation – Some waste excretion

• Salts

• Nitrogen waste

• Some metabolites – Antimicrobial activity

• Eccrine secretion

apocrine gland s

active at puberty

• High density in armpit & areola

• Produce an odorous secretion

• Secretions can contain pheromones – mother/offspring bonding – kin recognition

• Eccrine secretion

skeletal system

Skeleton – Axial: skull, spine, thoracic cavity – Appendicular: limbs, pectoral girdle, pelvic girdle

• Cartilage

• Ligaments

Osseous tissue

Matrix of bone consists of:
– Hydroxyapatite crystals: mainly calcium phosphate (and calcium hydroxide) will resist compression, but inflexible
• Calcium phosphate makes up \~2/3 of bone mass
– Collagen fibers
• Make up \~1/3 of bone mass
• Contribute to tensile strength of bones • Imparts limited flexibility to matrix
• Bone cells
– Contribute only \~2 percent of bone mass

mature bone

Osteocytes: maintains matrix
• Osteoblasts: produces matrix
• Osteoprogenitor cells: produce osteoblasts • Osteoclasts: break down matrix

Osteocytes: mature bone cells

Maintain protein & mineral content of matrix
• Controls release & deposition of Ca2+ in/out of bone
• Lacunae: depressions where osteocytes reside
• Lamella: osteocytes matrix

Osteoblasts

Osteoblasts: Immature bone cells Found on inner & outer surfaces of bones Produce osteoid: organic mix dumped into matrix Osteogenesis: new bone formation via calcification of osteoid leading to ossification •

Canaliculi: small channels from osteocytes to bone capillaries

Osteoprogenitor cells: bone system cells

Innermost layer of periosteum & inner lining of endosteum

• Differentiate to form new osteoblasts

• Involved in repair of bones after a fracture

Osteoclasts

Multinucleated cells,

Osteolysis: secrete HCL dissolving bones causing release Ca2+ and PO43- into blood