Anatomy and physiology exam

Anatomy

Describes the structures of the body

• what are they made of

• where are they located

• associated structures

Physiology

Studies:

• functions of anatomical structures

• individual and cooperative functions

Organisation of the human body

Chemical level->cellular level-> tissue level->organ systems->organism

Basic and major tissues

• Epithelial tissue

• Connective tissue

• Muscular tissue

• Nervous tissue

Epithelial tissue

Surface lining of the skin(epidermis), also on outside surface of organs

Connective tissue

Dermis and fat, muscle sheath and tendons, bone, cartlidge and ligament, fibrous coats of vessels, fascia and septa, fibrous sheaths of nerves

Muscular tissue

Skeletal muscle fibres, smooth muscle coats of hollow viscera and vessels, cardiac muscle

Nervous tissue

Nerve cells, nerve fibres in a peripheral nerve, brain and spinal chord

Basic systems

• Somatic systems

• Visceral systems

• Supply systems

Somatic systems and what systems it includes

• Body walls, limbs, skin, skeletal muscles, bones and joints, walls of body cavaties

• Somatic nerve supply

• Includes:

-Skeletal system

-Articular system

-Muscular system

-Integumental system

Visceral systems and what systems it includes

• Organs, glands and tubes with smooth muscle

• Contents of body cavities including visceral layer of serous membrane

• Visceral nerve supply(autonomic nervous system)

• Visceral vascular supply

• Includes:

-Cardiovascular and respiratory system

-Digestive system

-Urinary system

-Reproductive system

Supply systems

Includes:

-Nervous system

-Arterial system

-Venous system

-Lymphatic system

Planes of reference

• Coronal plane- vertical plane that divides body into front and back sections

• Sagittal plane- vertical plane that divides body into left and right sections

• Transverse plane- horizontal plane that divides body into top and bottom sections

Terms of relationships

• Superior- higher up or nearer to the head than another structure

• Anterior- toward the front or on the front surface of the body

• Inferior- lower or below another structure relative to the standard anatomical position

• Posterior- toward the back or nearer to the back surface of the body

• Lateral- away from the midline (median plane) of the body

• Medial- toward the midline or middle of the body

Terms of movement

• Flexion- bend

• Extension- in relation to joint angles

• Abduction/adduction- in relation to midline

• Internal(medial)/external(lateral) rotation

Terms of comparison

• Proximal(closer to the origin)/distal

• Superficial(closer to the skin)/deep

• External(outer)/internal(inner)

Major body cavaties

• Dorsal

• Thoracic

• Abdominopelvic

11 major human organ systems

• Integumentary

• Skeletal

• Muscular

• Nervous

• Endocrine

• Cardiovascular

• Lymphatic

• Respiratory

• Digestive

• Urinary

• Reproductive

Slow(negative)feedback process

Works for most systems by reducing the difference between current state and desired state

Rapid(positive) feedback control

Works by building the current state until the system prevent further damage

Atoms

• Atoms join together to form different chemicals

• Chemical characteristics determine physiology at molecular and cellular levels

Subatomic particles

Protons

• Positive charge, 1 mass unit

Neutrons

• Neutral, 1 mass unit

Electrons

• Negative charge, low mass

• Electrons in the electron cloud determine the reactivity of an atom

• Electron cloud contains shells, or energy levels, that can hold a limited number of electrons

Molecule

Two or more atoms joined by strong bonds

Compound

Two or more atoms of different elements joined by strong or weak bon

Chemical bonds

• Ionic bonds

• Covalent bonds

• Hydrogen bonds

Ionic bonds

Attractions between cations (positive ions) and anions(negative ions)

• One atom(the electron donor) loses one or more electrons and becomes a cation

• Another atom(the electron acceptor) gains those same electrons and becomes an anion

Covalent bonds

Strong bonds involving shared electrons

• One electron is donated by each atom to make the pair of electrons

• Sharing one pair = single covalent bond

• Sharing two pairs = double covalent bond

• Sharing three pairs = triple covalent bond

Hydrogen bonds

Weak polar bonds between adjacent molecules based on electrical attractions

Involve attractions between a slight positive charge and a slight negative charge

Decomposition reaction(catabolism)

Breaks chemical bonds

AB -> A+B

E.g., Hydrolysis reaction AB + H₂O -> AH + BOH

Synthesis reaction (anabolism)

Forms chemical bonds

A+B -> AB

E.g., Dehydration synthesis(condensation) reaction AH + BOH -> AB + H₂O

Role of enzymes in metabolism

Act as biological catalysts that accelerate chemical reactions in metabolism by lowering the required activation energy

Inorganic compounds

Carbon dioxide, oxygen, water, and inorganic acids, bases and salts

Organic compounds

Molecules containing carbon and hydrogen

Carbohydrates, proteins, lipids, and nucleic acids

Water

Accounts for two thirds of total body weight

Produces solutions

• A solution consists of a solvent or liquid and solutes

Universal solvent- many molecules are water soluble

Water serves as a reactant in some reactions

High heat capacity

Lubrication to moisten and reduce friction

pH

The negative logarithm of the hydrogen ion concentration of a solution in moles per litre

Plasma membrane structure

Phospholipid bilayer

• Hydrophilic heads-face outwards on both sides, toward watery environments

• Hydrophobic fatty-acid tails-inside membrane

• Barrier to ions and water-soluble compounds

Plasma membrane functions

Separates cytoplasm from the extracellular fluid

Regulation of exchange with the environment

• Ions and nutrients enter

• Wastes eliminated and cellular products released

Sensitivity to the environment

• Extracellular fluid composition and chemical signals

Anchors cells and tissues

Organelles of a typical cell

Endoplasmic reticulum

Golgi apparatus

Lysosomes

Peroxisomes

Mitochondria

Nucleus

Ribosomes

Endoplasmic reticulum

Network of membranes that play a key role in the synthesis of proteins and lipids.

Helps transport materials within the cell and ensures that cells function smoothly.

Two forms of ER:

• Rough ER - ribosomes attached and helps fold and modify new proteins. It prepares them for transport within or out of the cell via the Golgi apparatus.

• Smooth ER - lacks ribosomes and is involved in lipid synthesis and detoxification. It detoxifies by helping drugs and toxins dissolve better in water so they can be cleared from the body.

Golgi apparatus

Modifies, sorts and packages proteins and lipids for transport

Lysosomes

Waste disposal system of animal cells. They contain digestive enzymes that break down (or lyse) excess or old cell parts, food particles and invading viruses or bacteria.

They help cells stay healthy by recycling cellular components and keeping the cell clean

Peroxisomes

Act as metabolic microbodies that handle oxidation reactions and cellular detoxification

Mitochondria

Produces energy through cellular respiration, which involves converting glucose and oxygen into adenosine triphosphate (ATP)

Mitochondria have a double membrane, with the inner membrane folded into structures called cristae. The high level of folding provides more surface area for respiration, allowing the mitochondria to generate more ATP. The space inside the cristae is called the matrix.

Contain their own DNA. This allows them to replicate independently within the cell and adapt to increased energy needs

Nucleus

Manages gene expression, cell growth and replication, and houses the cell's genetic material in the form of deoxyribonucleic acid, or DNA. DNA is organised into chromatin, a complex made of DNA and proteins.

Within the nucleus is the nucleolus, a dense area where ribosomal ribonucleic acid (rRNA) is found. The nucleolus provides the blueprints for making and assembling ribosomes.

A double membrane called the nuclear envelope surrounds the nucleus. It has pores (holes) that regulate the movement of molecules in and out of the nucleus.

Just like the cell has cytoplasm, the nucleus contains a similar gel-like substance called nucleoplasm

Ribosomes

Read the genetic instructions from messenger RNA (mRNA) and assemble proteins from amino acids.

Not membrane-bound. They can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum.

Genetic code

Translates sequences of nucleotide bases (A, C, G, and U/T) into the amino acid sequences that build and run all living cells

Cellular diffusion

Movement of particles from high to low concentration(along the gradient)

Passive process- requires no energy

Osmosis

Diffusion of water across a selectively permeable membrane

Water molecules diffuse across a membrane toward the solution with more solutes

Osmolarity(osmotic concentration)- total solute concentration in a solution

Tonicity- describes how a solution affects cells

•Depends on the nature of the solutes

•Isotonic solution-

• Does not cause osmotic flow

• A cell in this solution stays the same size and shape

•Hypotonic solution-

• Lower solute concentration than the cell

• A cell in this solution gains water and may rupture(hemolysis)

•Hypertonic solution-

• Higher solute concentration than the cell

• A cell in this solution loses water and shrinks(crenation)

Carrier mediated transport

• Facilitated diffusion

• Active transport

Facilitated diffusion

Passive

Carrier proteins transport molecules too large to fit through channel proteins(glucose, amino acids)

• Molecule binds to receptor site on carrier protein

• Protein changes shape, molecule passes through

• Receptor site is specific to certain molecules

Active transport

Active transport proteins move substrates against concentration gradients

Requires energy, e.g., ATP

• Ions pumps move ions (Na+, K+, Ca2+, Mg2+)

• Exchange pumps move two ions in opposite directions at the same time

Primary active transport

Secondary active transport

Vesicular transport

Primary active transport

Carrier mediated

Pumping solutes against a concentration gradient using ATP

Sodium-potassium exchange pump

One ATP powers the movement of three sodium ions (Na+) out, and two potassium ions (K+) in

Secondary active transport

Carrier mediated

ATP is required to establish a concentration gradient of one substance in order to passively transport another

E.g., NA+ concentration gradient drives glucose transport into cells

ATP is used to pump NA+ back out

Vesicular transport

For proteins and large macromolecules that are too big to pass directly through lipid bilayers and the cell packages them into these transport containers

• Endocytosis (Into the cell): The plasma membrane folds inward (invaginates) to engulf external materials, fluids, or particles, pinching off to form an intracellular vesicle

• Exocytosis (Out of the cell): Intracellular vesicles travel to the plasma membrane, fuse with it, and release their cargo (such as hormones, neurotransmitters, or enzymes) into the extracellular space

Epithelial tissue role

1. Provide physical protection

2. Control permeability

3. Provide sensation

4. Produce specialized secretions

Connective tissue role

• Establishing a structural framework for the body

• Transporting fluids and dissolved materials

• Protecting delicate organs

• Supporting, surrounding, and interconnecting other types of tissue

• Storing energy reserved, especially triglycerides

• Defending the body from invading microorganisms

Muscle tissue role

Specialised for contraction

Nervous tissue role and structure

Specialized for conducting electrical impulses

Built from neurons and neuroglia

Classification of epithelia

Based on shape

• Squamous- thin and flat

• Cuboidal-square shaped

• Columnar- tall, slender rectangles

Based on layers

• Simple epithelium- single layer of cells

• Stratified epithelium- several layers of cells

• Pseudostratified epithelium- appears multi-layered because cell nuclei are at different levels, but all cells actually attach to the basement membrane

• Transitional Epithelium- type of stratified tissue that stretches and changes shape as the underlying organ expands

Glandular epithelia

Glands are collections of epithelial cells that produce secretions

Endocrine glands

• Release hormones that enter bloodstream

• No ducts

Exocrine glands

• Produce exocrine secretions

• Discharge secretions through ducts onto epithelial surfaces

Main categories of connective tissue

Connective tissue proper

Supporting connective tissues

Fluid connective tissue

Connective tissue proper

Connect and protect

Categories:

Loose connective tissue

• More ground substance, fewer fibres

Dense connective tissue

• More fibres, less ground substance

Supporting connective tissues

Cartilage and bone support the rest of the body

Fluid connective tissue

Distinctive collections of cells in a fluid matrix

Blood

• Formed elements and plasma

• Blood vessels

Lymph

• Interstitial fluid entering the lymphatic vessels

Types of fascia and their roles

• Superficial Fascia: The outermost layer under the skin, contains loose connective tissue and fat cells to cushion structures and allow the skin to glide

• Deep Fascia: A dense, fibrous layer that wraps around muscles, bones, nerves, and blood vessels, often forming tough compartments in the limbs

• Visceral Fascia: The layers that suspend and wrap internal organs within the chest and abdomen

• Parietal Fascia: The membranes that line the walls of body cavities.

Cartilage

Matrix is a firm gel containing chondroitin sulfate

providing flexible structural support, absorbing mechanical shocks, and creating a smooth, low-friction surface for joint movement

Bone

For weight support

Calcified(made rigid by calcium salts)

Resists shattering(flexible collagen fibres)

Osteocytes lie in lacunae

• Arranged around central canals within matrix

• Small channels through matrix (canaliculi) allow for exchange of materials with blood

Periosteum covers bone

• Fibrous (outer) and cellular (inner) layers

Types of muscle tissue

Skeletal muscle

Cardiac muscle

Smooth muscle

Skeletal muscle

Large muscles responsible for body movement

Consists of long, thin cells called muscle fibers

Cells do not divide

New fibers are produced by divisions of myosatellite cells

Striated voluntary muscle

Cardiac muscle

Found in the heart

Cells form branching networks connected at intercalated discs

Regulated by pacemaker cells

Striated involuntary muscle

Smooth muscle

Found in walls of hollow, contracting organs

Cells are small and spindle shaped

   • Can divide and regenerate

Nonstriated involuntary muscle

Neuron structure

Cell body

       • Contains the nucleus and nucleolus

Dendrites

       • Short branches extending from the cell body

       • Receive incoming signals

Axon (nerve fiber)

       • Long, thin extension of the cell body

       • Carries outgoing electrical signals to their destination

Epidermis

Stratified squamous epithelium

Avascular

Nutrients and oxygen diffuse from capillaries in the dermis

Dermis

Anchors epidermal accesory structures

Contains:

• Outer papillary layer

• Deeper reticular layer

Papillary layer

Consists of areolar tissue

Contains capillaries, lymphatic vessels, and sensory neurons

Features dermal papillae that project between epidermal ridges

Reticular layer

Consists of dense irregular connective tissue

Contains collagen and elastic fibres

Contains all cells of connective tissue proper

Structures and functions of the subcutaneous layer

Deepest layer of the skin

• Adipose Tissue (Fat Cells): Composed mainly of adipocytes grouped into lobules, which store energy as body fat

• Connective Tissue: A loose meshwork of collagen and elastin fibers that binds the dermis to underlying fascia, muscles, and bones.

• Blood and Lymphatic Vessels: A rich vascular network that supplies nutrients and oxygen to the skin and helps regulate body temperature

• Nerves and Sensory Receptors: Nerve endings pass through this layer, transmitting touch, pressure, and pain signals.

• Cellular Components: Contains fibroblasts, macrophages, and fat-storing cells.

• Appendages and Structures: May house the deepest portions of certain hair follicles, sweat glands, and bursae in specific areas of the body

Melanin

Pigment in the epidermis that influences skin colour

Red-yellow or brown-black pigment

Dark-skinned people have large, numerous melanosomes

Carotene

Pigment in the epidermis that influences skin colour

Orange-yellow pigment

Blood flow and oxygenation influence on skin colour

Hemoglobin is bright red when bound to oxygen

• When blood vessels dilate from heat, skin reddens

• When blood flow to skin decreases, skin pales

Hemoglobin turns dark red when oxygen is released

• Extreme cold, heart failure, severe asthma can cause cyanosis(bluish skin)

Hair follicle

Produces hair

Structural basis for hair texture and colour

Texture

• Medulla - contains a flexible soft keratin

• Cortex - contains thick layers of hard keratin, which give hair its stiffness

• Cuticle - thin and rough and contains hard keratin

Colour

• Melanin - eumelanin gives hair brown and black shades. High amounts of result in black or brown hair and lower amounts lead to blonde hair. Pheomelanin gives hair red, orange, and yellow hues. Higher amounts produce red, auburn, or strawberry-blonde hair

Exocrine glands in the skin

Sebaceous glands

• Discharge lipid secretion(sebum) into hair follicles

Sweat glands

• Apocrine sweat glands - secrete products into hair follicles, produces sticky and cloudy secretions which cause odors

• Eccrine sweat glands - discharge directly onto skin surface, secretions are 99% water plus salt, etc

Mammary glands

• Produce milk

Ceruminous glands

• Produce cerumen (earwax)

Nail structure

Nail body

• Visible portion of the nail

• Cover the nail bed

Sides of nails

• Lie in lateral nail grooves

• Surrounded by lateral nail folds

Hyponychium

• Skin beneath the distal free edge of the nail

Nail production

Occurs in an epidermal fold called the nail root

• The visible nail emerges from the under part of the nail root, known as the eponychium(cuticle)

• Near the root, blood vessels are obscured producing a pale lunula

Repair of the integument following an injury

1. Bleeding, swelling and pain occur

2. Mast cells trigger inflammatory response

3. A scab stabilises and protects the area

4. Macrophages clean the area

5. Fibroblasts and endothelial cells divide, producing granulation tissue

Affects of aging on skin

Epidermis thins

Number of dendritic cells decreases

Vitamin D3 production declines

Melanocyte and glandular activities decline

Blood supply to dermis is reduced

Function of hair follicles declines

Dermis thins and elastic fiber network shrinks

Sex specific hair and body fat distribution fades

Repair rate slows

Major functions of the skeletal system

Support

Storage of minerals and lipids

Blood cell production

Protection

Leverage

Classification of bones by shape

Sutural bones

Irregular bones

Short bones

Flat bones

Long bones

Sesamoid bones

Sutural bones

Small, flat, oddly shaped

Found between flat bones of skull

Range in size from a grain of sand to a quarter

Borders are like pieces of jigsaw puzzle

Irregular bones

Complex shapes with short, flat, notched or ridged surfaces

E.g., vertabrae that form the spinal column, bones of the pelvis

Short bones

Boxlike

E.g., carpal bones, tarsal bones

Flat bones

Thin, parallel surfaces

Form the roof of the skull, the sternum, the ribs and the scapulae

Long bones shape and structure

Long and slender

Located in the arm and forearm, thigh and leg, palms, soles, fingers, and toes

Structure:

Diaphysis

• Wall of compact bone

• Central space called medullary cavity

Epiphysis

• Spongy bone

Metaphysis

• Where diaphysis and epiphysis meet

E.g., femur

Sesamoid bones

Small, round and flat

Found near joints of knees, hands, and feet

Compact bone structure

Osteon (functional unit of compact bone)

- Central canal contains blood vessels

- Perforating canals

- Lamellae- layers of bone matrix

• Concentric lamellae surround central canal

• Interstitial lamellae fill spaces between osteons

• Circumferential lamellae are at outer and inner bone surfaces

- Periosteum

• Membrane that covers outside of bones

  – Fibers are interwoven with those of tendons

  – Perforating fibers—fibers that become incorporated into bone tissue

- Endosteum

• Incomplete cellular layer that lines medullary cavity

• Consists of flattened layer of osteogenic cell

Spongy bone structure

Spongy bone lacks osteons

- Matrix forms an open network of trabeculae

• Lacks capillaries and venules

- Red bone marrow fills spaces between trabeculae

• Forms blood cells

• Contains blood vessels that supply nutrients to

osteocytes by diffusion

- Yellow bone marrow

• Found in other sites of spongy bone

• Stores fat

- Endostuem

Compact bone function

Structural support for skeleton

Weight-bearing and strength, especially in long bones

Shields vital internal organs and protects the inner bone marrow and spongy bone

Acts as mechanical levers for body movement

Mineral storage

Spongy bone function

• Reduces skeletal weight

• Absorbs shock and redistributes force

• Acts as a structural "crumple zone" to help protect the brain and prevent the outer bone layers from shattering

• Facilitates Fast Nutrient Exchange and Remodeling

Cell types in bone

Osteogenic cell

Osteoblast

Osteoclast

Osteocyte

Osteogenic cell

Stem cell whose divisions produce osteoblasts

Assist in fracture repai