1. What are 4 different types of tissue, give an example of each & their function?
Epithelial tissue: Simple (1 layer) vs. Stratified (1 layer). Squamous (flat), Cuboidal (cube), or Columnar (rectangle). Functions include absorption (intestines), secretion (glands), and protection (skin)
Note: stratified tissue is named after the top layer of cells, regardless of the other layers.
Muscular tissue: Skeletal (striated, voluntary, multi-nucleated), smooth (non-striated, involuntary, elongated nuclei, or cardiac muscle (striated, involuntary, intercalated discs). Functions include movement of an organism and moving something within a tube.
Nervous tissue: Neuron (axon, cell body, and dendrites) and neuroglia (astrocytes, Schwann’s cells, etc). Functions include regulation, control, and coordination of the body along with endocrine system.
Connective tissue: Dense, Loose (elastic fiber CT, cartilage (hyaline cartilage is most common and found on ends of long bones), bone, blood, adipocytes. – Functions include transport (blood), support (bone), energy storage (fat), connection of other tissues, and protection (WBCs).
Note: Collegen fibers are the most abundant protein in connective tissue.
Note: CT is the only tissue that contains dead material (matrix)
Where can the various epithelial tissues be found (including specialized cells)?
Transitional epithelial tissue: innermost layer of ureter
What are the twelve systems?
Nervous, skeletal, muscular, integumentary, cardiovascular, respiratory, digestive (alimentary canal), urinary, reproductive, endocrine, sense organs, and immune
3. What are general characteristics of a nerve bundle?
An accumulation of neurons (axons) held together with connective tissue (fascicles). There is a connective tissue sheath that surrounds all fascicles. The nerve bundle may contain blood vessels. It can contain both myelenated and unmyelanted neurons.
4. Explain the characteristics of a myelinated and unmyelinated neuron?
Unmyelinated: axon is wrapped in a Schwann’s cell one time. Action potentials are slower in unmyelinated neurons.
Myelinated: Single Schwann’s cell wraps around axon numerous times, creating the myelin sheet. The myelin sheeth is non-conductive because it is hydrophobic (phospholipid bilayer). Small areas between Schwann’s cells are called “Nodes of Ranvier” The action potential “jumps” between these nodes during saltatory conduction creating a faster AP than in myelinated neurons.
Note: unmyelinated neurons found in primitive animals like the jellyfish. More advanced animals have a combination of both.
5. What is a neuromuscular junction?
A neuromuscular junction is the synapse between a motor axon and a muscle cell. ACh is released across the synapse to facilitate muscle contraction.
Note: neurons can only connect to muscles, other neurons, or glands
6. What is action potential and its function?
A neuron’s resting membrane potential is -70mV due to high concentration of Na+ outside the cell. When stimulated to threshold level the Na+ gates open allowing Na+ to rush into the cell, quickly raising the charge of the neuron to +40mV. When the charge hits +40mV the Na+ gates become inactivated and the K+ open allowing K+ to flow out of the cell (thereby lowering the charge). This period is known as the refractory period because another action potential cannot occur until it is complete. The entire process takes only a few msecs.
The function is to relay signals and messages throughout the body
7. What happens between a presynaptic neuron and post synaptic neuron?
When an action potential is “initialized” it travels down the entire axon (all or none), as it reaches the end of the axon it allows Ca2+ into the cell, which forces vesicles filled with Acetylcholine to be excreted (the vesicles’ membrane fuses with the cell membrane) into the synapse. Acetylcholine then attaches to ligand-gated ion channels on the post synaptic neuron which causes the Na+ gates to open and Na+ to rush into the cell. If the postsynaptic neuron reaches threshold then it will undergo an action potential and become the presynaptic neuron. Acetylcholine in the synapse is then inactivated by aceytlcholinesterase embedded in the postsynaptic cell membrane, and is reabsorbed into the presynaptic axon knob for “recycling.”
8. Explain reflex arc with an example?
Receptor gets poked -> sensory neuron (presynaptic) to interneuron (postsynaptic) -> interneuron (presynaptic) to motor neuron (postsynaptic) -> motor neuron to skeletal muscle (neuromuscular junction) -> muscle contracts
Hot, sharp, hammer to knee
9. What are parts of brain and spinal cord? Lab material.
Dermis: dense irregular connective tissue (major protein is collagen for elasticity), blood vessels, glands, pigment cells, arrector pili (smooth muscle that controls hair follicles)
Subcutaneous / Hypodermis: adipocytes
Keratinization: only the bottom layer of epidermis is living cells that perform mitosis. As mitosis occurs the cells are displaced upward (away from the dermis). As they are pushed farther away from the dermis they are pushed farther away from blood vessels and die, leaving only the hard protein keratin filling the cells.
12. What are the pigments of skin?
Melanin: black/brown – the most dominant pigment in human skin
Carotenoid: orange in skin
Xanthophores – yellow in skin
Iridophores – camouflage (not in human skin) – contains crystals of guanine or other purine (nitrogenous bases).
Exoskeleton vs endoskeleton AND types of bone development.
Exoskeleton: arthropods – bones on the outside of the body
Endoskeleton: humans – bones on the inside of the body
Intramembraneous development: skull and clavicle – cartilage plates merge to bone (membrane becomes bone)
Endochondral development: rest of body – cartilage (chondrocytes) become bone
13. What is the histology of bone?
Compact bone surrounds bone, spongy bone inner to compact, bone marrow is the soft inside of bone
Compact bone organized into osteons (haversian system)
Central / Haversian canal: contains blood vessels and nerves, run parallel to bone
Perforating / Volksman canal: connect two central canals to eachother
Canaliculi: connect osteocytes to eachother and the central canal
lacuna: “house” that osteocyte resides in
lamella: single ring of osteon
14. Explain the relation between the bone cells and hormones that effect them?
Parathyroid Hormone from the Parathyroid gland increases blood Ca2+ level by activating osteoclasts which breakdown bone
Calcitonin from the thyroid gland decreases blood Ca2+ level by activating osteoblasts who build bone
15. What are the bones in the body and the functions of atlas and axis?
Atlas: 1st bone (floating) in vertebral column – allows head to move front/back
Axis: 2nd bone in vertebral column – allows head to move side/side
Areas of vertebral column: cervical (neck), thoracic (chest), lumbar (back), sacral (beneath back)
Bones are located on slide 39, Pg 626, or phone images
Define: sliding filament model, atrophy, hypertrophy, hyperplasia, creatine phosphate, red muscle, and white muscle.
Sliding filament model: name of theory that describes muscle contraction
Atrophy: death of cells (shrink)
Hypertrophy: increase in size
hyperplasia: increase in number
Creatine phosphate: stores a Phosphate bond for regeneration of ATP from ADP
Red muscle: highly vascularized, has many mitochondria, more numerous than white muscles
White muscle: fast fiber (twitch-fibers)
16. What is the histology of muscle?
Myosin: thick filament, consists of a head and tail
Actin: thin filament, several intertwining circles held together by tropomyosin
Z-Line: point of attachment for actin, center of sarcomere
H-zone: myosin without actin overlap (shrinks during contraction) - light
A-band: entire length of myosin including actin overlap (does not change during contraction) - dark
I-band: actin without myosin overlap (shrinks during contraction) - light
17. How does a muscle fiber contract & relax?
Release of ACh at the NMJ allows opening of Na+ channel on the motor-end plate. This causes an AP in the muscle cells which follows the T-tubules into the myofibers. When the AP reaches the sarcoplasmic reticulum it releases Ca2+ into the sarcoplasm. Ca2+ binds to troponin complex and causes tropomyosin to pull away from myosin binding sites (on actin). Head of myosin attaches to actin, pulls them together, releases, then reattaches and repeats process (50-100 times/sec) pulling the Z-lines toward eachother and causing contraction.
A large amount of ATP is requires for contracting and releasing contraction (every time myosin/actin attach, every time myosin/actin release, Ca2+ pump to remove Ca2+ from sarcoplasm)
45% formed elements: erythrocytes, leukocytes, thrombocytes
Proteins: albumin (osmotic equilibrium), globulins (antibodies – Ig_), fibrinogen (coagulation)
Note: RBCs are most common BY FAR, but only have 120 day life cycle
Note: formed elements are produced by stem cells in the bone marrow.
19. What are different types of white blood cells & their function?
Neutrophil: granulocyte, 2.5x RBC size. First responders, phagocytize small particles. Most common. Three-lobed nucleus
Eosinophil / Acidophil: granulocyte, 2.5x RBC size. Kills parasites and helps control inflammation / allergic reaction. Red granules.
Basophil: granulocyte, 2.5x RBC size. Release heparin and histamine. Least common. Purple granules.
Lymphocyte: agranulocyte, 1x RBC size. Provides humoral immunity. Nucleus is almost whole cell.
Monocyte: agranulocyte, 3x RBC size. Phagocytizes large particles. Big C shaped nucleus.
Granules (lysosomes) are what actually destroy the bacteria/pathogens
Note: natural killer cells function similarly to T-Cells, but are nonspecific and kill sick/unhealthy cells also
20. Explain the structure of an antibody and different types of Ab?
Antibodies look like a Y. the v of the Y are the light chains (4), and the I of the Y are the heavy chains (2). These are connected together by several disulfide bonds.
Each antibody has a constant region (same between all antibodies) which makes up ¾ of the antibody and a variable region (what makes them unique) which makes up the top ½ of the light chains.
There are 5 antibodies which make the acronym DAMAGE – IgD, IgA, IgM, IgG, and IgE.
IgM appears at the site of infection first (along with neutrophils).
An antigen is anything that causes antibody production.
Doctors use antibodies to diagnose patients.
Antibodies produced by B Cells.
21. What is cellular & humoral immune response?
Cellular: no antibodies involved. Nonselective phagocytosis of pathogen, lysosomes destroy bacteria and it is released through exocytosis.
Humoral: Viral antigen connects to antigen-presenting macrophage which releases interleukin to stimulate T-Helper cells. T-helper cells secrete interleukin to stimulate B cells which differentiate into memory cells and plasma cells. Plasma cells secrete the appropriate antibodies which attach to the antigen. After the antibodies attach to the antigen it is engulfed by a phagocytic macrophage and treated similarly to the cellular response.
Note: Plasma cells are made mostly of rough ER because they need to make a lot of proteins (antibodies).
22. Explain the structure of blood vessel? Differences between artery & vein?
Most inner layer of all blood vessels is endothelial tissue (simple squamous epithelium)
Middle layer is smooth muscle (thinner in vein)
Final layer is elastic fiber connective tissue (thinner in vein)
Only veins have valves.
Skeletal muscle movement is required to bring blood from veins back to heart.
23. What is the passage of blood in the heart?
Right atrium -> Right atrioventricular valve -> right ventricle -> pulmonary semilunar valve -> pulmonary artery -> lungs -> pulmonary vein -> left atrium -> left atrioventricular valve -> left ventricle -> aortic semilunar valve -> aorta -> arteries -> arterioles -> capillaries -> venuoles -> veins -> superior or inferior vena cava -> Right atrium
Note: heart is two pumps – pulmonary and systemic
24. What is anatomy of the respiratory system?
Upside down tree – trachea = trunk, bronchioles = branches, alveoli = leaves.
Respiratory tract is ciliated pseudostratified columnar epithelial tissue
Alveoli is simple squamous epithelial tissue
Right lung has 3 lobes, left lung has 2 lobes (to make room for heart)
25. How does respiration occur? What are different pressure of O2 and CO2 in
During inhalation the chest cavity expands causing the pressure within the lungs to drop lower than atm. Pressure, forcing air to rush into the lungs.
During exhalation the chest cavity contracts casuing the pressure within the lungs to increase above atm. Pressure, forcing air to leave the lungs.
blood entering the lungs has high CO2 and low O2, the alveoli has high O2 and low CO2, so they exchange. Oxygenated blood heads to the tissues which have high CO2 and low O2, so they exchange. Then deoxygenated blood returns to the lungs and becomes oxygenated again.
28. What is the passage of food in digestive system?
Passage of food: Mouth -> esophagus -> stomach -> small intestine (duodenum -> jejunum -> ileum) -> large intestine -> anus
Accessory organs: Salivary glands, liver (makes bile), pancreas (secretes buffering agents and enzymes to duodenum), gallbladder (stores bile)
Small intestine is 90% of total absorption, Large instestine is other 10% (mostly water, vitamins, minerals)
Digestion = breaking food down, absorption = nutrients into bloodstream
29. What is peristalsis?
Peristalsis is the involuntary muscular contractions that propel food throughout your GI tract (esophagus, small intestine, large intestine).
The layers of your GI tract are mucosa (stratified squamous epithelial tissue), submucosa (lymph nodes located here), and muscularis (circular, then longitudinal). The two muscle layers work together to move food throughout your system.
Note: the stomach has a third muscle layer under the circular muscles called oblique muscles. The addition of this set of muscles prevents the stomach from performing peristalsis but allows it to “mash up” food in various directions to facilitate in its digestion.
Name various functions of the liver
Makes bile, makes glycogen, detoxifies whatever you eat, filters formed elements, breaks down RBCs (120 days) and WBCs, performs deamination of amino acids, converts ammonia to urea
30.How is food being absorbed in the intestine?
Villi: fingerlike projections in the intestines whose borders are made of simple columnar epithelial tissue. The edge of these membranes fold in and out forming microvilli (brush border) for increased surface area for nutrient absorption.
After complete digestion to the smallest possible molecule nutrients are digested into the villi and taken up by the blood vessels (carbohydrates, amino acids, small and intermediate fatty acids) or the lacteal (large fatty acids)
After the nutrients are absorbed into the blood vessels they are transported to the liver for detoxification, filtration, and distribution through the body. Some molecules are reformed here, and some are stored as glycogen.
What are the various lengths of life for skin cells, RBCs, and cells in the GI tract?
Skin = 2-3 weeks, RBCs = 120 days, GI tract = 2-3 days
31.What is the central pathway of energy metabolism?
32.How is urine and urea being made?
Deamination (the removal of nitrogen from fatty acids) occurs in the liver when during protein breakdown. This produces ammonia, which is extremely toxic to the body. To counteract the effects of ammonia during this process the liver converts ammonia to urea (NH3 + CO2 -> urea). Urea is toxic to the body, but is less toxic than ammonia AND is excreted in the urine.
Note: too much ammonia in blood is an indication of a malfunctioning liver while too much urea in the blood is an indication of a malfunctioning kidney.
Functions of pineal gland and thymus gland?
Pineal gland: biological clock (studied in horses)
thymus gland: puts out T-lymphocytes.
Note: thymus gland shrinks with age, there is a possible link to decreased immune system with age.
33. What are the hormones from posterior pituitary gland and their effect?
ADH: functions to oppose dieresis
Oxytocin: contracts smooth muscle in uterus during childbirth and is involved in continued lactation (after initiation)
Note: these hormones are made in the hypothalamus by neurosecretory cells and stored in the posterior pituitary.
34. What are the hormones from anterior pituitary gland and their effect?
GH (Growth hormone): stimulates general body growth. Needed for basic body functions after initial growth occurs. Note: Released in large quantities during sleep (children).
PRL (Prolactin): initiates milk production by mammary glands
ACTH (adrenocorticotrophic hormone): stimulates adrenal cortex to secrete its hormones
TSH (thyroid-stimulating hormone): stimulates thyroid gland to secrete its hormones
FSH (follicle-stimulating hormone): stimulates sperm production in testes / stimulates egg production in ovaries
LH (Iuteinizing hormore): stimulates testosterone secretion by testes / prepares uterus for implantation of a fertilized ovum
35. What are the functions of thyroid gland?
Controls BMR through release of thyroxin (T4) and controls Ca2+ level in blood through release of calcitonin (stimulation of osteoblasts, Ca in blood increased)
Thyroid gland is made of many follicles (liquid colloid surrounded by follicular cells [simple cuboidal epithelial tissue]). Follicular cells produce Thyroglobulin (a glycoprotein) in the colloid. Iodine (from diet) enters the follicle and allows creation of thyroxin (T4), which exits the follicle and travels through the body increasing BMR.
Note: Lack of Iodine will cause goiter (enlargement of thyroid gland).
36. What are the functions of pancreas and adrenal gland?
Pancreatic islets of langerhans: control blood glucose level through release of insulin and glucagon.
Pancreatic exocrine acini: releases enzymes and buffer to duodenum
Adrenal medulla: releases adrenaline (epinephrine) for fight or flight mechanism (increased heartbeat, respiration, glycogen breakdown, etc). Body can only survive in this state for approximately 5 minutes. Releases noradrenaline (norepinephrine) for rest and digest mechanism (decreased heartbeat, respiration, etc) for countering adrenaline.
Adrenal cortex: Zona glomerulosa secretes aldosterone (activity, sexuality). Zona Fasciculata secretes glucocorticoids (gluconeogenesis). Zona reticularis secretes gonadocorticoids (maintenance/maturation of gonads)
37. How is sugar and calcium level being regulated in our body?
Sugar: When blood sugar is high the islets of langerhans in the pancreas release insulin which facilitates the absorption of glucose into all body cells (specifically liver/muscle). When blood sugar is low the islets of langerhans in the pancreas release glucagon which causes glycogen breakdown in liver/muscle.
Sugar levels should never be over 110mg/dL (diabetic or hyperglycemic) or under 80mg/dL (hypoglycemic) for any reason due to this balance mechanism.
Calcium: When Ca2+ level in the blood is high the thyroid gland releases calcitonin which encourages osteoblasts to build up bone, lowering blood Ca2+. When Ca2+ level in the blood is low the parathyroid gland releases parathyroid hormone which encourages osteoclasts to break down bone, raising blood Ca2+.