TEAS Science Study Guide
Cell Cycle
• Mitosis = “daughter cell” exact replica
o Interphase (G1, S, G2)
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o Prophase
o Metaphase
o Anaphase
o Telophase
o Cytokinesis
• Meiosis = “daughter cells” different genetic coding
o Only happens in gametes*
o 1st phase
• chromosomes cross over
• genetic material exchanged
• tetrads of 4 chromatids formed
Homologous pairs of chromatids are separated and go to different poles
2 cells go through 2nd cell division
4 daughter cells with different sets of chromosomes
• Haploid : contains half genetic material of parent cell
• Zygote- controls cell differentiation
Tissues
groups of cells
Muscle, nerve, epithelial, connective
1. Epithelial: (joined together tightly) ex. Skin
2. Connective: (dense, loose, or fatty) ex. Bone tissue, cartilage, tendons, ligaments, fat, blood, lymph
Protects & 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
3. Muscle: Support & move body
a. Smooth
b. Cardiac
c. Skeletal
4. Nervous: ex. Brain, spinal cord, & nerves
a. Neurons- control responses to changes in environment
Organs
groups of tissues
ex. Heart = muscle tissue in myocardium; connective tissue in blood; nervous tissue for heart rate; epithelial tissue in membranes
Organ Systems
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
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
2. Respiratory
a. Structure
i. UPPER: Nose, nasal cavity, mouth, pharynx (throat), larynx (voice box)
ii. LOWER: trachea (windpipe), lungs, bronchial tree
iii. Airway: lined with cilia that sweep debris back towards mouth
iv. Lungs: (bronchi & bronchial network ---alveoli)
v. RIGHT LUNG: 3 lobes
vi. LEFT LUNG: 2 lobes
vii. MUSCLES
1. Diaphragm
a. Dome-shaped
b. Separates thoracic & abdominal cavities
2. Intercostal muscles
a. Between ribs
b. Function
i. Supply body w/ oxygen by alveoli
ii. Filters air (warmed, moistened, & filtered before reaching lungs)
iii. Speech (air moves through larynx produces sound trachea
iv. Smell
1. Chemoreceptors (in nasal cavity) respond to chemicals
v. BREATHING PROCESS (controlled by medulla oblongata)
1. Diaphragm & intercostal muscles expand increase size of chest cavity
2. Volume chest cavity increases = pressure inside decreases
3. Outside air (high pressure); Air in lungs (low pressure) air goes in lungs
4. Muscles relax air leaves lungs
3. Cardiovascular
• BLOOD
o Red blood cells
Transport oxygen to cells
Form in bone marrow
o White blood cells
Defend against infection
• Lymphocytes
• Neutrophils
• Monocytes
• Eosinophils
• Basophils
o Platelets
Blood clotting
o Plasma
half blood volume
mostly water/ serves as a solvent
contains plasma proteins, ions, glucose, amino acids, hormones, & dissolved gas
• BLOOD VESSELS
• HEART
o 4 chambers
each half = atrium & ventricle
• AV valve separates halves
o between ventricle & artery leading away from heart
• keep blood moving in single direction
o Cardiac cycle
Atrial contraction = fills ventricles
Ventricular contraction = empties ventricles
1st DIASTOLE PHASE
• Blood flows through superior & inferior venae cavae
• (heart relaxed) atrium tricuspid valve right ventricle
• SA node (pacemaker wall of right atrium) generates signals (carried by Purkinje fibers) to rest of atrium
• Contracts & fills right ventricle w/ blood
• Impulse from SA node transmitted to ventricle through AV node
• Signals the right ventricle to contract & initiate 1st systole phase
1st SYSTOLE PHASE
• Tricuspid valve closes Pulmonary semilunar valve opens
• Blood is pumped out the pulmonary arteries to lungs
2nd DIASTOLE PHASE
• Blood returning from lungs fills left atrium
• SA node triggers mitral valve to open Blood fills left ventricle
2nd SYSTOLE PHASE
• Mitral valve closes Aortic semilunar valve opens
• Left ventricle contracts blood is pumped out of aorta to rest of body
o Types of Circulation
Coronary: Flow of blood to heart
• Coronary arteries aorta (supplying major arteries) enter heart w/ oxygenated blood
• Deoxygenated blood returns to right atrium through cardiac veins (empty into the coronary sinus)
Pulmonary: flow of blood between the heart & lungs
• Deoxygenated blood flows from right ventricle to the lungs through pulmonary arteries
• Oxygenated blood flows back to the left atrium through pulmonary veins
Systemic: flow of blood to entire body
• blood exits left ventricle through aorta branches into the carotid arteries, subclavian arteries, common iliac arteries, & renal artery
• blood returns to heart through jugular veins, subclavian veins, common iliac veins, & renal veins empty into superior & inferior venae cavae
o Portal circulation: flow of blood from digestive system to the liver & then back to the heart
o Renal circulation: flow of blood between the heart & kidneys
o Blood Pressure
fluid pressure generated by the cardiac cycle
Functions by transporting oxygen-poor blood into the lungs & oxygen-rich blood to body tissues
Arteries branch into smaller arterioles which contract & expand based on body signals
Arterioles are where adjustments are made in blood delivery to specific areas based on complex communication from body systems
• Capillary beds: diffusion sites for exchanged between blood and interstitial fluid
o has the thinnest wall of any blood vessel (single layer endothelial cells) [Show Less]