DEH 103: Histology & Embryology

• Deepest
• Cuboidal cells
• Basement membrane
• germinative

• Basement Membrane
• Basal lamina: Produced by epithelum cells (SUPERFICIAL)
• Reticular lamina: produced by connective tissue and is more fibrous (DEEP)

• Supports, cushions the epithelium
• Reinforces the epithelial sheet, helping it resist stretching and tearing forces
• Connects epithelium to the connective tissue and defines the boundary
• Acts as a filtration barrier for both the epithelium and connective tissue

• Basal lamina: supperficial epithelial type tissue
• Reticular lamina: deeper connective type tissue
• Lamina propria: loose connective tissue that underlies the epithelium of mucous membranes.

• Neurons: nerve cells that retrieve and conduct impulses.
• Neuroglia: supporting cells of the nervous system (5-50x more numerous than neurons) protects the nerve cells.

• Dendrite: multiple, receives impulses and conducts them into the cell body
• Cell body: contains neucleus and cytopasm and transfers signal to axon
• Ason: conducts nerve impulses away from the cell body. The impulses terminate into axon terminals.

FYI: axons outside the CNS are insulated by myelin sheeth (product of Schwann cells)

• Loose
• Dense
• Loose with special purpose

• Support
• Repair
• Protection

• Collagen
• Elastic
• Reticular

• Areolar: present when skin is attached to muscle, muscle attached to muscle, or where organs are held together by membranes of connective tissue called fascia (loose connective)
• Adipose: fatty tissue, stores energy and insultates (loose connective with speical propertieis)
• Fibrous: cartilage, bone, and ligaments (dense connective tissue)

• Cartilage: gives support and permits skeletal growth (contain no nerves or blood vessels. (CHRONDROCYTES)
• Bone: supports the body, is mineralized, contains dense fibrous interellular sybstances. (OSTEOCYTES)
• Ligaments & Tendons: attach muscles to bones (FIBROBLASTS)

• Hyaline: most common form, in the nose, tracheal rings, layrnx, bronchi, ends of ribs and artiulating bone surfaces
• Elastic: in the epiglottis, larynx, and ear canal and tube
• Fibrous: bundels of collagen fibers in the vertebral disks and tendons

**All konwn as specialized connective tissue

• Located at the articular surfaces of most freely movable joints.
• It has no nerve supply or blood supply
• It takes longer to heal than bone and is not calcified.
• It is the skeletal system of an embryo

• Interstitial growth: growth deep within the tissue by mitosis of each condyle
• Appositional growth: layered growth on the external surface of cartilage, occurs after injury

• Compact (dense) bone: solid, composed of layers, lamellae, with no interventing soft tissue (outside/bone wall)
• Spongy (concellous) bone: common in developing bone, has trabeculae intervene by marrow spaces. Hollow center of bone.

• Osteocytes: bone cells that are housed in calcified matrix niches called lacunae.
• Osteoblasts: bone formes, that originate from mesenchymal cells.
• Osteoclasts: involved in bone remodeling and repair process (multinucleated)

Periosteum

Endosteum

• Osteocytes: cell of the bone
• Osteoblasts: bone forming cell
• Osteoclasts: absorption and removal of bone

• Conducts O2 to the clles
• Returns CO2 from the cells to the lungs
• Clots to prevent blood loss
• Regulates pH through buffering system

Plasma

• Erythrocytes: RBC, not true cells lack nucli function to cary O2 from the lungs to the tissues and return CO2 from tissue to lungs
• Leukocytes: WBC
• Platelets: function in clot formation stimulates phagocyte action of leukocytes

• Granular (cytoplasmic granules)
  • Neutorphils: involved with defense against pathogenic organisms, enfulf invaders (phagocytosis) 55-65%
  • Eosinophils: function to combat allergic reactions & parasitic infections 1-3%
  • Basophils: contain histamine and heparindigest micoorganisms and fight allergy symptoms 0-0.7%
• Nongranular:
  • Lymphocytes: arise and function in the bone marrow
    • T and B cells active in immune response 20-35%
  • Monocytes: phagocytic macrophages invovled in immune system 3-7%

• Smooth (involuntary) muscles
• Skeletal (striated/voluntary) muscles
• Cardiac (involuntary/striated) muscel

• Characteristics of all three:
  • Covered with epimysium
  • Fibers are covered by perimysium
  • Each muscle fiber is covered with an endomysium
  • Each muscle type contains actin and myosin 2 proteins which change chemical to mechanical energy by clevage of ATP which enable muscle contractions
  • Each type have a full complement of cells during development, only growth is increasing the volume of myoctes (muscle cells)

1. Skin system
2. Neural system
3. Skeletal system
4. Digestive system
5. Respiratory system
6. Vascular system
7. Lymphatic system
8. Muscular system
9. Endocrine system
10. Urinary system
11. Reproductive system
12. Speical senses

Skin system

• Central nervous system (CNS)
• Peripheral nervous system (PNS)

• Afferent (sensory) system: nerves that convey information from muscles and glands to the CNS
• Efferent (motor) system: nerves that convey information from the CNS to the muscles and glands.

Somatic system

• Autonomic system
  • Sympathetic: caries increased activity
  • Parasympathetic: modifies or decreases activity

• Digestive system
  • Oral cavity (salivary digestion)
  • Pharynx, esophagus, and stomach (acids and liquidation)
  • Small intestine (glandular excretions further digestion)
  • Large intestine (absorption and dehydration)

• Nasal passages
• Pharynx
• Trachea
• Bronchi of lungs (cilia lining this sytem help trap dust particles)

• Heart
• Arteries
• Caillaries
• Veins

5-6 liters 60x a minute