Lecture 2 notes Flashcards
With a light microscope you can mostly see 3 things
1) Plasma membrane
2) Nucleus (DNA region)
3) Cytoplasm
Types of movement through the plasma membrane
Passive movement and Active movement
For passive movement
- Does not require cell energy
- Moves from higher to lower concentration
For active movement
- Uses cell energy (ATP)
- Can move molecules against the gradient
Types of passive movement
-Diffusion
-Osmosis
_Facilitated diffusion
Diffusion is
Simple movement from hight to low concentration
Osmosis is
Movement of water from high to low water concentration
Facilitated diffusion is
Specific molecules attach to proteins and then diffuse
The nucleus is
The control center-houses genetic information (includes nucleolus and chromatin)
The endoplasmic reticulum comes in two ways
Rough and Smooth
Smooth ER
Synthesis of lipids, steroids & few carbohydrates. Stores Ca++
Rough ER
- Presence of ribosomes makes it rough
- Assembly line for proteins
The golgi apparatus
The golgi bodies or apparatus puts on the finishing touches, and packages molecules
There are two types of vesicles
Secretory and transport vesicles
The lysosomes
Arise from the Golgi and carry digestive enzymes to destroy old organelles or pathogens (bacteria or virus)
-suicide organelle
The mitochondria
- Two membranes (outer & a folded inner)
- Have own DNA & can reproduce
- Functions as the cells “powerhouse” converting food materials into molecules of ATP
- ATP is the molecules that supplies energy directly to a cell
- Mitochondrial DNA comes from our mother not father
Ribosomes, the non-membranous organelles are
Responsible for protein synthesis (doesn’t make proteins, just helps).
Could be either stuck on rough ER or free-floating
When a chromosome enters cell division, it has already what and why?
Duplicated, so when it condenses you will see two copies. Each copy is called a chromatid, and each “sister” chromatid is attached at the centromere
We know when a cell is entering mitosis by
Looking through a microscope and see chromosomes
When chromosomes are condensed they are called
Chromatids
The 4 tissues are
1) Epithelial tissue
2) Connective tissue
3) Muscle tissue
4) Nervous tissue
The cell cycle is abbreviated into what
IPMAT
Epithelial tissue is classified by layers & shapes which are
Layers *Simple= one layer of cells *Stratified= more than one layer of cells Shapes *Squamous= Flat shaped cells *Square or cubed= Cuboidal *Rectangular= Columnar
Simple squamous
Lining of blood vessels; lung air sac (alveoli) lining; thin sections kidney tubules
- very thin & delicate lining; moist
- allows diffusion of nutrients, gases & wastes
Stratified squamous
-Skin epidermis
-Keratinized and non-keratinized
keratin is a protein that waterproofs & adds protection
Pseudostratified ciliated columnar
Respiratory tract, parts of the male reproductive tract.
*false illusion of being stratified, but it’s only one cell layer thick
Connective tissue are cells living…?
In a non-living matrix
Connective tissue is composed of
- Cells: various types (i.e. osteocytes, mast cells)
- Intercellular matrix: protein & carbohydrates
- Protein fibers:
- Collagen-most common, thick, strong
- Elastic-farily rare, thin, can stretch & recoil
- Recticular- like collagen but more random
Specialized connective tissue
Cartilage: chondrocytes are the living cells; matrix is protein fibers; cartilage is avascular
3 types of cartilage- Elastic, fibrocartilage, hyaline
Bone
Cell=osteocyte;
Matrix=calcium phosphate + collagen fibers
Two types of bones
Spongy and compact bone
Compact bone=
Unit=osteon
What are the 3 types of muscle tissue?
1) Skeletal muscle
2) Smooth muscle
3) Cardiac muscle
Skeletal muscle
- Body muscles
- Very large fused muscle cells (many peripheral nuclei)
- Striations (bands)
Smooth muscle
- Blood vessels; digestive, respiratory, urinary & reproductive organs
- Spindle-shaped cells with single nuclei. No striations
Cardiac muscle
- Heart muscle; branched, single nuclei
- striations
- intercalated discs
Two types of nervous tissue
1) Neurons: cells that conduct nerve impulses
2) Neuroglia: Cells that support neuron function
What are the 5 functions of the integumentary system
1) Barrier protection: trauma, chemicals, water loss, pathogens, UV radiation, etc.
2) Sense reception: touch, pressure, pain, temperature
3) Excretion: H2O, electrolytes, some drugs
4) Nutritional: Vitamin D converted to Vit. D3 in skin by UV before liver/kidneys can modify it to active form
5) Homeostasis: Body temp. regulation
What are the 3 type of skin layers?
1) Epidermis
2) Dermis
3) Hypodermis
Epidermis
(from ectoderm) 4-5 layers of keratinized stratified squamous epithelium


Dermis
(From mesoderm): areolar & dense irregular connective tissue; blood and nerve supply
Hypodermis
(from mesoderm): areolar & adipose tissue
- also called the subcutaneous layer
- adipose connective tissue
- allows independent movement of skin from underlying structure
- padding
- thermal insulation
Skin color is
Mainly due to melanin a yellow-brown to black pigment produced, stored & released by melanocytes (found in stratum basale). Melanin absorbs UV radiation
Accessory structure: Hair
Provides skull protection, some insulation & delicate touch sensation.
- Epidermal structure that has sunk deep into the dermis.
- The hair papilla (blood supply) is the only dermal structure
- The hair itself is made up of keratin
What causes goose bumps?
Small smooth arrector pili muscles cause “goose bumps” & hairs to stand on end when the body is cold or when frightened
Glandular secretion for merocrine (eccrine)
Most common; secretory cells release vesicles with product by exocytosis (goblet cells, salivary glands, sweat glands)
Glandular secretion for holocrine
Cell death occurs after cells become filled with product and burst; basal cells must continue to undergo cell cycles to replace lysed cells (sebaceous glands)
Glandular secretion for Apocrine
Base of cell with nucleus & Golgi apparatus remain intact but the apical end loses some cytoplasm when product pinches off (mammary glands, prostate)
What are the 2 kinds of sweat glands?
1) Merocrine (eccrine)
2) Apocrine
The merocrine (eccrine) sweat glands are found
Throughout the body (highest #’s on palms & soles); watery sweat; ducts empty onto free skin surface
The apocrine sweat glands are less
Numerous but larger sweat glands are found only in axillae, groin & areolae (nipples). Ducts empty into hair follicles in pubic regions.
Sebaceous glands produce
An oily sebum that provides lubrication for hair, moisture of skin & inhibits bacterial growth
Modified sweat gland in the ear canal
Ceruminous glands
Mammory glands
- Modified “apocrine” sweat gland
- Secretion is apocrine
Accessory structure; Nails
Nail grows from the nail root which lies way under the eponychium (cuticle)
