"I swear to god I don't have dead bodies in my basement"

I'm an atheist

Homeostasis

Homeostasis

A condition in which an organism’s internal condition is kept stable despite changes in the outside environment

e: pH balance, temperature, water/sugar in the blood

Cell Theory

1. All living organisms are a compound of cells. They may be unicellular or multicellular.

2. The cell is the basic unit of life

3. All cells arise from preexisting cells.

Levels of Organization in the Human Body

atoms >molecules of life >organelles >cells >tissues > organ systems >organisms

Molecules of life

Carbohydrates (sugars)

Lipids (fats)

proteins (amino acids)

water

vitamins/minerals

Definition of tissue

a group of similar cells that perform the same functions

Tissues

Epithelial

Muscle

Nervous

Connective

How do you hold a microscope?

by its arm and base

Magnification

objective x ocular

Ribosomes

Synthesizes proteins

lysosomes

removes waste

Vacuole

storage for the cell

Cell membrane

covers and protects cells; lets some substances in/out; plants also have cell walls.

Mitochondria

powerhouse of the cell; does cellular respiration to convert glucose to ATP NRG; plants have chloroplasts

Nucleus

contains DNA/ genetic material

Cytoplasm

gel-like fluid fills space between organelles and helps transport material around cell.

Eukaryote

has a membrane bound nucleus

Prokaryote

no nucleus

cancer

a disease when some cells divide uncontrollably

Epithelial

covers and protects body organs

EX: skin, organ lining

Nervous

sends signals/info around body through neutrons

EX: Nervous, cerebrum, cerebellum

Connective

supports and connects parts of the body

EX: ligaments, tendons, blood, bone, fat

Muscle

contracts and relaxes to move the body

a) Skeletal muscle

b) Smooth muscle

c) Cardiac

Skeletal Muscle

moves body; works in pairs to move bones w/ tendons; voluntary; striated; reacts quickly; tires easily

EX: triceps, biceps, quad

Cardiac Muscle

moves blood; found only in the heart; involuntary; striated; react quickly; never tires

Smooth Muscle

Moves organs; involuntary; not striated; react slowly.

EX: diaphragm, digestive systems, stomach, intestines

organ

structure made up of different kinds of tissue

organ system

group of organs working together to carry out major functions

Functions of Skin

1. protections (dead skin cells, proteins)

2. Temperature Control (sweat+dilating blood vessels)(shivering, goosebumps, contracting blood vessels)

3. Gathering information w/ nerve endings

4. Eliminating waste (sweat + H2O and urea)

5. Producing Vitamin D

Epidermis

Dead skin cells rise to the top; new skin cells formed at the bottom of the epi.

Dermis

Living layer; contains sweat glands and oil glands; blood vessels and nerve endings.

Subcutaneous Fat

cushions, protects, controls temp

glands

they make up the endocrine system, release chemical signals directly into the bloodstream.

pore

openings that allow sweat to reach the surface

Three Important Proteins

1. Keratin- sturdy; protective protein.

2. Collagen- gives skin elasticity

3. Melanin- protect skin from UV radiation; gives skin color

Skeleton/ Bones

are made of phosphorus and calcium mineral called apaite

Functions of a Skeleton

1. Structure and support

2. Protection

3. Movement

4. Storage of minerals

Parts of Bone

1. Outer membrane

2. Compact Bone

3. Spongy bone

4. Red Marrow

5. Yellow Marrow

Outer Membrane

covers and protects bone

Compact Bone

hard and dense with blood vessels throughout it

Spongy Bone

lightweight; full of space for marrow

Marrow

a type of soft connective tissue

Red Bone Marrow

soft tissue in marrow produce blood cells

Yellow Bone Marrow

stores fat

Growth Plate

area of rapid growth at end of long bones

Cartilage

Flexible; sturdy; connective tissue found in nose and ears.

Bones meet where?

at joints and are stabilized by ligaments

Type of joints

Immovable and Movable

Movable

1. ball and sockets

   EX: hips, shoulder

2. hinge

   EX: knee

3. pivot

   EX: neck/ vertebrae

4. gliding

   EX: ankle, wrist

How skeletons change as you get older

1. some bones fuse or are lost

   (born with 300 → 200 as adult)

2. Some red marrow is replaced by yellow marrow

3. Growth plates disappear

4. Cartilage in joints can wear away (arthritis)

5. Bones lose mineral density and becomes brittle and break (osteoporosis)