Anatomy Lecture 1

plasma membrane

the membrane that surrounds the cell

function: control what enters/leaves a cell. Interacts with other cells in environment.

structure: phospholipid bilayer. Separates the cell from the extracellular fluid.

cholesterol: stabilizes membrane fluidity.

proteins: membrane proteins allow material to enter/exit the cell. Also allows for communication between cells.

organelles

membranous (membrane-bound) structures within a cell that carry out particular functions.

survive and maintain homeostasis, and carry out a function

cytosol

the gel-like portion in which the organelles are suspended (floating). Mostly made of water with dissolved ions, nutrients, etc.

cytoplasm

everything between the plasma membrane and the nucleus. Includes cytosol and all organelles.

nucleus

largest organelle, stores DNA and makes RNA (RNA is used to make proteins)

DNA → genetic blueprint on how to built protein

RNA → photocopies

nucleolus

a region within the nucleus that makes ribosomes

mitochondrion (aka mitochondria)

makes ATP (energy for the cell) from glucose

rough endoplasmic reticulum

has ribosomes to make secretory proteins, membrane proteins, and organelle proteins

Golgi apparatus/body/complex

packages proteins into vesicles and sends them to their proper location.

vesicle

1) transport vesicle

2) storage vesicle

3) secretory vesicle

lysosome

storage vesicle containing digestive enzymes (protection from bacteria and get rid of things within the cell we don’t need)

smooth endoplasmic reticulum

-metabolism of carbs & lipids

-stores calcium

-detoxifies harmful substances like drugs, alcohol, etc.

ribosomes

structures that are used to read RNA and make proteins that stay in the cytosol.

cytoskeleton:

1. Microtubules:

2. Intermediate Filaments:

3. Microfilaments:

cytoskeleton: protein fibers that maintain cell shape and are responsible for all movement.

1. Microtubules: maintain cell shape and allow organelles to move within the cell.

2. Intermediate Filaments: provide physical strength to the cell. made of keratin.

3. Microfilaments: allows a cell to move or change shape. made of actin and myosin.

exocrine glands

glands that secret into ducts

exocrine glands

classification of glands based on type of secretion

1. serous glands

2. mucous glands

3. mixed gland

4. oil gland

1. serous glands: (watery secretion) ex. sweat glands

2. mucous glands: (secret mucus) ex. goblet cell (not an exocrine gland)

3. mixed gland: (serous and mucous secretion) ex. salivary glands

4. oil gland: (oil/waxy secretion) ex. sebaceous gland

exocrine glands

Classification of gland based on method of secretion

1. merocrine gland: (exocytosis) ex. most sweat glands, mucus glands

2. apocrine gland: (break off apical PM) ex. mammary gland

3. holocrine gland: (entire cell dissolves) ex. sebaceous glands

1. merocrine gland

-vesicles open onto the surface

-secretory product is discharged from the cell without any further loss of cell substance

-ex. sweat glands

2. apocrine gland

-part of the apical cytoplasm of the cells is lost together with the secretory product

-membrane fuses back together to accumulate secretory product again

-ex. mammary gland

3. holocrine gland

-breakdown & discharge of the entire secretory cell

-only seen in sebaceous glands of the skin

exocrine glands

classification of gland based on structure

1. unicellular gland:

2. multicellular gland:

1. unicellular gland: ex. goblet cell

2. multicellular gland:

a. tubular or alveolar gland

1. simple: ex. sweat gland (simple tubular)

2. compound: ex. mammary gland (compound alveolar)

apoptosis

cell suicide

the cell actively uses its own energy, genes, and proteins to dismantle itself from the inside out.

often because cell is no longer healthy, functional, or safe

benign tumor

non-cancerous mass of abnormal cells that grows slowly, has clear borders, and does not spread to other parts of the body

biopsy

a medical procedure that removes a small sample of cells or tissue from your body so a specialist can examine it under a microscope for disease

cancer

a broad group of more than 100 diseases where abnormal cells grow uncontrollably and can invade nearby tissues or spread to other parts of the body

carcinoma

a type of cancer that starts in the epithelial tissue, which lines your skin, organs, and internal passageways.

main cause is exposure to UV light.

doesnt usually metastasis but should still get checked.

leaky gut syndrome

malignant tumor

a cancerous mass of tissue that grows rapidly, invades nearby healthy tissue, and can spread to other parts of the body.

metastasis

the spread of cancer cells from their original site to other parts of the body to form secondary tumors.

sarcoma

a rare type of cancer that starts in the body's connective tissues, such as bones, muscles, fat, blood vessels, and nerves.

stem cell

the body's raw, unspecialized master cells that can divide to renew themselves and develop into many different specialized cell types and tissues.

Tay-Sachs Disease

-1 of 88 digestive enzymes aren’t functioning

-doesnt properly break down fatty tissues surrounding the brain

-causes brain to not develop properly, seizures, mental retardation, compressed brain

-average death age is 6

Tumor

A tumor is an abnormal mass of tissue that forms when cells grow and divide more than they should, or do not die when they are supposed to

squamous cell carcinoma

-cancer of keratinocytes in squamous cells

-also caused by UV light

melanoma

-cancer of melanocytes

-metastases quickly, very deadly

-ABCDE method (Asymmetry, Boarder, Color, Diameter, Evolving)

cells that must always have oxygen are

1. Neurons (stroke)

2. cardiac muscles (heart attack)

3. kidney cells (kidney failure)

4. liver cells (liver failure)

intercellular junctions

1. tight junction

-close the gap between cells

-prevent things from being absorbed into skin (ex. taking a shower)

2. gap junction

-pass materials from one cell to another

-allow neighboring cells to communicate with each other (all cells within that region are working together)

3. desmosomes

-projections attach to each cells cytoskeleton

-bonding neighboring cells together

cellulite

cellulite is fat

men

-fat cells are crisscrossed series of collagen

women

-fat cells are cube-like structures contained by collagen bands

decubitus ulcer (bed sore)

-epidermis dies

-happens when bed ridden/wheel chair bound

-compresses blood vessels, so no blood flow = no nutrients to stratum base cell (why patients must be rotated every 2-3 hours)

-mats in retail

-dehydration and infection

bone cells:

1. osteoblasts-

2. osteocytes-

3. osteoclasts-

bone cells:

1. osteoblasts- lay down extracellular matrix of bone

2. osteocytes- mature bone cells (located in lacunae) don’t have much of a function within a bone

3. osteoclasts- demineralize bone matrix, release hydrochloric acid to break down extracellular matrix of bone

extracellular matrix

1. hydroxyapatite (tricalcium phosphate) → very strong molecules to resist compressive forces

2. collagen → resist bending and twisting of the bones

1. compact bone:

2. spongy bone:

1. compact bone: tissue where the bone is more dense and more rigid, has units known as osteons

2. spongy bone: the way the projections are allow us to move our body around, doesnt take as much energy, easier since they are lighter, still super strong structure

anatomy of Osteon in Compact Bone

-concentric lamella: bone matrix, calcium crystals (for hardness) & collagen fibers (for flexibility)

**A concentric lamella is what you get when you take that raw bone ECM (concrete mix) and pour it into a specific shape: a neat, microscopic ring

-central canal: very center, contains veins, arteries, nerves

-lacuna: tiny pockets trapped between lamellae

-osteocyte: mature bone cells, not much activity within lacunae

-canaliculi: looks like eyelashes, connect to neighboring lacunae

-interstitial lamella: an irregular, angular shard or fragment of bone extracellular matrix (ECM) found filling the gapsbetweenthe intact, circular osteon pillars in compact bone

They are the structural remnants or "leftovers" of old osteons that were partially broken down, eaten away, and recycled by cells called osteoclasts during the natural process of bone remodeling

Anatomy of a long bone

-medullary cavity: inside is yellow bone marrow (soft tissue made almost entirely of adipocytes (fat cells))

-spongy bone: it provides maximum structural strength while keeping the skeleton light enough for easy movement.

-red marrow: hematopoiesis, the production of all blood cells in the human body (red blood cells, white blood cells, platelets)

-epiphyseal line: where the growth plate was

-periosteum: dense, highly sensitive membrane of connective tissue that covers the entire outer surface of all bones, except at the joints

-articular cartilage: covers the joints of all bones, acts as a self-lubricating, wear-resistant shock absorber

hair follicle

1. arrector pili muscle: tiny, involuntary smooth muscle that connects the hair follicle to the upper layer of the dermis

*when it contracts, it pulls the hair upright, which creates the physical appearance of "goosebumps" on the skin's surface

2. sebaceous gland: secretes oily, waxy sebum to waterproof hair and skin -→ holocrine secretion

3. apocrine gland: a type of sweat gland found primarily in the axillae (underarms), anogenital region, and the areolae of the breasts. Produces a thick, milky fluid that is initially odorless but bacteria make it BO

4. dermal papilla: where blood vessels and nerves interact with hair

trabecula vs endosteum

trabecula: The hard tissue backbone. It is a microscopic, bony strut, beam, or plate of the spongy bone.

endosteum: The soft biological wrap. It is a thin, vascular membrane of connective tissue.