· Mitosis = “daughter cell” exact replica
· Interphase (G1, S, G2)
· Prophase
· Metaphase
· Anaphase
· Telophase
· Cytokinesis
· Meiosis = “daughter cells” different genetic coding
· Only happens in gametes*
· 1
...
· Mitosis = “daughter cell” exact replica
· Interphase (G1, S, G2)
· Prophase
· Metaphase
· Anaphase
· Telophase
· Cytokinesis
· Meiosis = “daughter cells” different genetic coding
· Only happens in gametes*
· 1
st phase
· chromosomes cross over
· genetic material exchanged
· tetrads of 4 chromatids formed
à Homologous pairs of chromatids are separated and go to different poles
à2 cells go through 2nd cell division
à 4 daughter cells with different sets of chromosomes
· Haploid : contains half genetic material of parent cell
· Zygote- controls cell differentiation
Tissues
à groups of cells
à Muscle, nerve, epithelial, connective
2. Epithelial: (joined together tightly) ex. Skin
3. Connective: (dense, loose, or fatty) ex. Bone tissue, cartilage, tendons, ligaments, fat,
blood, lymph
àProtects & binds body parts
a. Cartilage: cushions & provides structural support
i. Fibrous
b. Blood: transports oxygen to cells & removes waste / ALSO carries hormones &
defends against disease
c. Bone: (hard) produces red blood cells
2. Muscle: Support & move body
a. Smooth
b. Cardiac
c. Skeletal
3. Nervous: ex. Brain, spinal cord, & nerves
a. Neurons- control responses to changes in environment
Organs
à groups of tissues
ex. Heart = muscle tissue in myocardium; connective tissue in blood; nervous tissue for heart
rate; epithelial tissue in membranes
Organ Systems
à groups of organs
1. Integumentary (Exocrine system)
a. Skin
i. Sebaceous glands sweat glands
ii. Hair
iii. Nails
b. Protection
i. Protects body from pathogens
c. Secretion
i. Secrete oil
d. Communication
i. Sensory receptors send info. about pain, touch, pressure, and temperature
LAYERS OF THE SKIN
1. Epidermis
a. Most superficial layer of skin
b. Epithelial cells **Does not contain any blood vessels
c. Stratum basale
i. deepest portion
ii. single layer of cells
iii. keratinized
1. waxy protein waterproofs skin
2. Dermis
a. Mostly connective tissue
b. Blood vessels, sensory receptors, hair follicles, sebaceous
glands, sweat glands
c. Elastin and collagen fibers
3. Subcutaneous layer/ Hypodermis
a. Connective tissue
i. Binds skin to muscle
b. Fat deposits cushion and insulate
TEMPERATURE HOMEOSTASIS
à skin is involved in temperature homeostasis through sweat glands
a. Controlled by negative feedback system
a. Receptor
i. Sensory cells in dermis of skin
b. Control center
i. Hypothalamus
c. Effector
i. Sweat glands, blood vessels, and muscles (shivering)
ii. Evaporation of sweat cools body
iii. Vasodilation of blood vessels release heat into environment to lower
body temperature
SEBACEOUS VS SWEAT GLANDS
a. Both exocrine glands
a. Secrete substances into ducts
i. Through ducts to the surface of the skin
1. Sebaceous glands
a. Holocrine glands
i. Secrete sebum
1. Oily mixture of lipids and proteins
b. Connected to hair follicles and secrete sebum
through hair pore
2. Sweat glands
a. Eccrine or apocrine glands
i. Eccrine glands: not connected to hair
follicles
1. Secrete salty solution
2. Forehead, neck, back
3. Activated by elevated body
temperature
ii. Apocrine glands
1. Secrete oily solution
2. Armpits, groin, palms, soles of feet
3. Activated by stress or anxiety
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