Biology 13A – Test 2Lecture Notes

Chapter 5 – Tissues

  1. Epithelial
  2. Makes up linings and coverings of organs and body cavities
  3. Simple – single layer of cells
  4. Squamous – flat and tightly connected. Substances diffuse easily. E.g. lining of lungs (Fig. 5.1)
  5. Cuboidal – cube-shaped. Covers ducts of glands. E.g. kidney ducts (Fig. 5.2)
  6. Columnar – long and tightly connected.
  7. Ciliated – moves substances past surface. E.g. lining of ovarian ducts.
  8. Nonciliated – secretes or absorbs materials. E.g. lining of the digestive tract (Fig. 5.3)
  9. Stratified – contains many layers of cells
  10. Squamous – E.g. oral cavity (Fig. 5.5)
  11. Cuboidal – E.g. salivary glands (Fig. 5.6)
  12. Columnar – E.g. male urethra (Fig. 5.7)
  13. Glandular – specialized for secretion
  14. Exocrine – secretes to open surfaces. E.g. sweat gland (Fig. 5.9)
  15. Endocrine – secretes into tissues or blood. E.g. adrenal gland
  16. Connective
  17. Broad characteristics. Can provide support, protection, store fat, make up blood.
  18. Types
  19. Loose
  20. Areolar – very delicate. Fills in spaces between muscles (Fig. 5.13)
  21. Adipose – large and contains fat (Fig. 5.14)
  22. Reticular – fibrous to form networks to support organs.
  23. Dense – very strong collagenous fibers. Used in tendons and ligaments (Fig. 5.15)
  24. Cartilage
  25. Hyaline – tough collagenous fibers. Used in joints (Fig. 5.16)
  26. Elastic – stretchable. E.g. ears (Fig. 5.17)
  27. Fibrocartilage – used as shock absorbers. E.g. vertebral discs (Fig. 5.18)
  28. Bone – extremely rigid. Osteocytes are bone cells embedded in the bone. Bone grows in concentric circles (Fig. 5.19)
  29. Blood (Fig. 5.20)
  30. Red – carries oxygen
  31. White – immune function
  32. Platelets - clotting
  33. Muscle
  34. For movement
  35. Types
  36. Skeletal – voluntary. Consist of striations (Fig. 5.21)
  37. Smooth – involuntary. No striations. E.g. digestive tract (Fig. 5.22)
  38. Cardiac – involuntary. Has striations. Only found in the heart (Fig. 5.23)
  39. Nervous
  40. For communication
  41. Cell types
  42. Neurons – elongated to carry impulses long distances (Fig. 5.24)
  43. Neuroglial cells – support neurons by providing nutrients.

Chapter 6 – Integumentary System

  1. Skin (Fig. 6.1)
  2. Epidermis (Fig. 6.2)
  3. Made from stratified squamous epithelium
  4. Cells divide and are pushed out where they die and keratinize. Forms a waterproof barrier
  5. Melanocytes exist deeper in layers and produce the skin color pigment, melanin (Fig. 6.3)
  6. Skin cancers are usually derived from this layer, e.g. squamous cell carcinoma, melanoma. (Fig. 6A)
  7. Dermis
  8. Made mostly from dense connective tissue
  9. Blood vessels, nerves, glands, and follicles originate here
  10. Tattoo ink remains here!
  11. Subcutaneous – layer of fat beneath the skin (not considered skin)
  12. Accessory Structures
  13. Nails – epithelial cells containing keratin die and merge with the nail plate (Fig. 6.4)
  14. Hair Follicles
  15. Embedded in dermis.
  16. Similar to nails; hair cells containing keratin die and are pushed outwards. (Fig. 6.5)
  17. Goose bumps are contraction of smooth muscles around follicle
  18. Glands
  19. Sebaceous – oil glands associated with hair follicles. Helps protect hair and make it waterproof
  20. Sweat – secretes water to help cool the body. Some are activated under emotional changes. Mammary glands in females are modified to secrete milk.
  21. Maintenance
  22. Body Temperature Regulation (Fig. 1.7)
  23. If too hot – skin vessels dilate, sweat glands secrete
  24. If too cold – skin vessels constrict, sweat glands do not secrete
  25. Wound Healing
  26. Breaking of skin promotes inflammation
  27. Broken cells release chemicals such as histamine
  28. Histamine causes vessel dilation. This allows more blood to the area and allows healing factors to leak out
  29. Clotting and scabbingcan form
  30. Tissues heal, scarring (new connective tissue in dermis) can form
  31. Scab falls off (if present)
  32. Tattoos are permanent because the ink is embedded in scar tissue which does not move

Chapter 7 – Skeletal System

  1. Bone Structure
  2. Longitudinal structures (Fig. 7.1)
  3. Diaphysis is the shaft
  4. Epiphysis is the end
  5. Cross section structures (Fig. 7.2, 7.3)
  6. Compact bone is dense
  7. Spongy bone has gaps containing red marrow
  8. Medullary cavity contains yellow marrow, nerves, and blood vessels.
  9. Functions
  10. Support – strength of compact and spongy bone
  11. Movement – uses lever system (Fig. 7.7)
  12. Blood Cell Formation – red marrow forms blood cells (yellow is just to store fat)
  13. Storage – minerals are stored and released. Blood and bone calcium levels are regulated (Fig. 7.8)
  14. Bone Repair
  15. There are many types of fractures (Fig. 7A)
  16. Steps in repair of a fracture (Fig. 7B)
  17. Hematoma formation. Fractures result in blood leakage. This area will form a clot (hematoma).
  18. Osteoblasts enter hematoma and begin to build spongy bone. Fibrocartilage is produced.
  19. Bone replaces fibrocartilage.
  20. Osteoclasts remove excess bone
  21. Skeletal Organization
  22. Skull
  23. Cranium – protects the brain. 8 bones that are sutured together (Fig. 7.10)
  24. Facial – for facial movements and jaw movements. 14 bones including one movable lower jaw (Fig. 7.15)
  25. Vertebral Column and Thoracic Cage
  26. Vertebra – circular bones that allow nerves to pass through center. Processes allow attachment of muscles or other bones. (Fig. 7.17-19)
  27. Cervical – the neck
  28. Thoracic – upper back
  29. Lumbar – lower back
  30. Sacrum – fused vertebrae that forms a triangle (Fig. 7.20)
  31. Coccyx – tailbone
  32. Thoracic Cage – protects organs
  33. Ribs – attaches to thoracic vertebrae
  34. Sternum – breastbone that attaches to ribs in front.
  35. Pectoral and Pelvic Girdles
  36. Girdles are circular and allow attachment of limbs
  37. Pectoral – supports upper limbs (Fig. 7.23)
  38. Clavicles – collar bones. Attaches to scapulae.
  39. Scapulae – shoulder blades. Upper limbs attach. Chest and back muscles attach.
  40. Pelvic – supports lower limbs and protects lower organs (Fig. 7.27)
  41. Hip bones along with sacrum and coccyx make up the pelvis
  42. The pelvic cavity is larger than in males.
  43. Upper and lower limbs
  44. Upper
  45. Humerus – the upper arm bone. Attaches to scapula and lower arm bones (Fig. 7.24)
  46. Radius – thumb side of the forearm (Fig. 7.25)
  47. Ulna – pinky side of the forearm.
  48. Hand bones (Fig. 7.26)
  49. Carpal – wrist bones
  50. Metacarpal – palm bones
  51. Phalanges – fingers
  52. Lower
  53. Femur – upper leg bone. Longest in body! Attaches to hip bone and two lower leg bones (Fig. 7.30)
  54. Tibia – big toe side (medial) of lower leg (Fig. 7.31)
  55. Fibula – pinky toe side (lateral)
  56. Foot bones (Fig. 7.32)
  57. Tarsal – ankle bones
  58. Metatarsal – ball of foot
  59. Phalanges – toes
  60. Joints – joins bones together
  61. Fibrous
  62. No or very little movement
  63. Thin layer of dense connective tissue
  64. E.g. suture between skull bones (Fig. 7.34)
  65. Cartilaginous
  66. Allows slight movement. Can absorb shock
  67. Hyaline or fibrocartilage
  68. E.g. intervertebral discs
  69. Synovial
  70. Allows free movement
  71. Complex structure
  72. Joint capsule contains ligaments that connect the bones and synovial membrane that secretes synovial fluid into center (lubricant)
  73. Bone ends are surrounded by hyaline cartilage

Chapter 8 – Muscular System

  1. Skeletal Muscle Structure
  2. Fascia is the covering of the muscle. It extends to form the tendon which attaches to a bone (Fig. 8.1)
  3. Each muscle fiber is a single cell
  4. Striations are from muscle filaments that overlap (Fig. 8.3)
  5. Actin filaments are thin
  6. Myosin filaments are thick
  7. Sarcomere is a functional unit
  8. Neuromuscular junction
  9. Motor neurons attach to motor end plate of muscle (Fig. 8.5)
  10. Space between neuron and muscle is a synapse. Neurotransmitters get released from neuron to tell muscle to contract.
  11. Skeletal Muscle Contraction
  12. Contraction Mechanism
  13. Release of acetylcholine into synaptic cleft activates muscle
  14. Myosin binds actin and pulls towards center (Fig. 8.6)
  15. The pulling requires ATP and involves myosin heads to change shape (Fig. 8.7). Rigor mortis occurs when myosin heads are attached to actin.
  16. Fatigue can occur if lactic acid or heat builds up, especially due to anaerobic respiration (fermentation) (Fig. 8.10)
  17. Muscular Responses
  18. Twitch – a muscle contraction (Fig. 8.11)
  19. Latent period – a delay before the contraction
  20. Contraction – force is exerted
  21. Relaxation – force is released
  22. Combination of twitches (Fig. 8.12)
  23. Summation combines individual twitches with increasing force
  24. Tetanus – sustained contraction. Muscle tone is a form of tetanus.
  25. Major Skeletal Muscles
  26. Facial – very superficial muscles that control facial expressions (Fig. 8.17a)
  27. Mastication – for chewing. Controls jaw movements
  28. Head movement – neck and back muscles allow bending and rotating the head (Fig. 8.17b)
  29. Pectoral girdle – allows shoulders to move forward, back, up, and down. Also allows rotation of arm
  30. Arms, legs, hands, feet – flexors and extensors are opposites. Abductors lift away from body. Rotators rotate. (Fig. 8.20-8.23, 8.25-8.30)
  31. Abdominal wall – can help in exhaling, defecation, urination, vomiting, childbirth.
  32. Pelvic – defecation, urination in males, vaginal contraction in females (Fig. 8.24)

Chapter 9 – Nervous System

  1. Introduction
  2. Nerves send information to and from the brain/spinal cord
  3. The central nervous system (CNS) consists of the brain and spinal cord. Is the main controller. The peripheral nervous system (PNS) connects CNS to other body parts. (Fig. 9.2)
  4. Cell types
  5. Neuroglial cells – several types that support the neurons.
  6. Neurons – carry impulses (Fig. 9.4)
  7. Cell body is the main body of the cell.
  8. Dendrites – pick up signals from other cells.
  9. Axon – long extension that transmits signal.
  10. Covered in myelin sheath that acts as insulation.
  11. The terminus passes signal to the next cell
  12. Nerve Function
  13. The synapse
  14. Junction between two nerve cells (Fig. 9.9)
  15. When impulse reaches synaptic knob, neurotransmitters form in vesicles and are released into synaptic cleft.
  16. Neurotransmitters bind receptors on postsynaptic neuron
  17. Excitatory neurotransmitters – cause nerve transmission
  18. Inhibitory neurotransmitters – block nerve transmission (e.g. dopamine)
  19. Drug Abuse
  20. Cocaine – binds to dopamine reuptake transporters. Dopamine stays for too long in synaptic cleft. Is a CNS stimulant.
  21. Heroin – an “opiate” that binds to opioid receptors. Is a CNS depressant.
  22. LSD (lysergic acid diethylamide) – a hallucinogen that acts as an excitatory neurotransmitter for serotonin receptors.
  23. Neural impulses
  24. Overview (Fig. 9.15)
  25. An axon has positive charges outside of membrane and negative charges inside the membrane.
  26. An action potential begins by letting positive charge in through gates and this triggers adjacent gates to open. Gates behind the action potential close. This causes “the wave”
  27. Sodium (Na) and Potassium (K) control action potentials (Fig. 9.14)
  28. Sodium starts out high outside, low inside. Potassium starts out high inside and low outside.
  29. Sodium rushes in at the “front” of the action potential.
  30. Potassium rushes out at the “back” of the action potential. This restores original charge quickly.
  31. Gates change their shapes (Fig. 9.11).They close and cannot be opened for a brief period (refractory period).
  32. Initiation of the impulse (Fig. 9.13)
  33. Neurotransmitters bind receptors and trigger influx of sodium into cell body.
  34. This triggers sodium gates at beginning of axon to open.
  35. Intensity of impulse is always the same. When “on” it is fully turned on. This is called “all-or-none”.
  36. Parts of the Nervous System
  37. Brain
  38. Cerebrum
  39. Structure
  40. Left and right hemispheres (Fig. 9.27)
  41. 5 lobes (Fig. 9.28)
  42. Functions
  43. Motor – movements
  44. Sensory – all five senses are processed here
  45. Association – link different functions together. Involved in memory, reasoning, judgment, verbal skills, and emotion.
  46. Diencephalon – processes sensory information
  47. Brainstem – connects the cerebrum to the spinal cord. Regulates visceral activities like heart rate, vessel contraction, and breathing.
  48. Cerebellum – helps in coordination, equilibrium, complex muscle movements
  49. Spinal Cord (Fig. 9.23)
  50. Nerve impulse conduction
  51. Ascending tracts allow for sensory information to go to brain (Fig. 9.25)
  52. Descending tracts allow for motor information to be sent out to muscles and glands (Fig. 9.26)
  53. Spinal reflexes
  54. Patellar – “knee jerk”. Only two neurons involved. Important in posture (Fig. 9.19)
  55. Withdrawal – “pullback”. Three neurons involved. Reaction to pain or heat (Fig. 9.20)
  56. Peripheral Nerves
  57. Cranial
  58. Arises from under the brain (Fig. 9.34)
  59. Communicates to head, neck, trunk
  60. Spinal
  61. Originate from spine and travel outwards (Fig. 9.35)
  62. Communicates to limbs, neck, and trunk
  63. Autonomic Nervous System
  64. Part of the PNS that functions without conscious effort.
  65. Types
  66. Sympathetic – active during emergency situations or “fight-or-flight” response.
  67. Parasympathetic – active during normal conditions. Restores body back from sympathetic response
  68. Some examples of activities are changes in heart rate, blood distribution, glucose concentration in blood (Tab. 9.7)