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Chapter 4 Organization and Regulation of Body Systems.

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Presentation on theme: "Chapter 4 Organization and Regulation of Body Systems."— Presentation transcript:

1 Chapter 4 Organization and Regulation of Body Systems

2 Points to Ponder What is a tissue? Organ? Organ system? What are the 4 main types of tissue? What do these tissues look like, how do they function and where are they found? What is the integumentary system? How can you prevent skin cancer? What is homeostasis and how is it maintained?

3 What is a tissue? A collection of cells of the same type that perform a common function There are 4 major tissue types in the body: 1.Connective 2.Muscular 3.Nervous 4.Epithelial 4.1 Types of tissues

4 The four tissues of the Body Epithelial Tissue: “covering” –Covers exposed surfaces –Lines internal passageways –Forms glands Connective Tissue: “support” –Fills internal spaces –Provides structure and strength to support other tissues –Transports materials –Stores energy

5 The four tissues of the Body Muscle Tissue: “movement” –Specialized for contraction –Skeletal muscle, heart muscle, and walls of hollow organs Neural Tissue: “control” –Carries electrical signals from 1 part of the body to another

6 1. Connective tissue Binds and supports parts of the body All have specialized cells, ground substance and protein fibers Ground substance is noncellular and ranges from solid to fluid prevents microbe penetration The ground substance and proteins fibers together make up the matrix of the tissue There are three main types of connective tissue: A. fibrous, B. supportive and C. fluid 4.2 Connective tissue connects and supports

7 1. Connective Tissue Protein Fiber types: 1. Collagen fibers: collagen protein -resists force 2. Reticular fibers: collagen protein -branchy, forms framework -framework of an organ 3. Elastic fibers: elastin protein -wavy, flexible - Designed to stretch Figure 4–8

8 3 main types of connective tissue A. Fibrous B. Supportive C. Fluid 4.2 Connective tissue connects and supports

9 Categories of Connective Tissue Proper Loose connective tissue: –more ground substance, less fibers –e.g., fat (adipose tissue) Dense connective tissue: –more fibers, less ground substance –e.g., tendons

10 Loose Connective Tissue Highly vascularized Functions: –Fill space –Cushion & support tissues –Store fat –Feed epithelial layers Three types: 1.Areolar CT 2.Adipose Tissue 3.Reticular Tissue

11 Loose fibrous connective tissue

12 Loose Connective Tissue: Areolar CT

13 Dense Connective Tissue Poorly vascularized Mostly fibers, little ground substance Only fibroblasts Location: –tendons (muscle to bone) –ligaments (bone to bone) –muscle coverings Function: - high strength attachment - stabilize positions

14 Dense Connective Tissue Dense Regular CT

15 B. Supportive Connective Tissues Strong framework and few cells Function: support and shape Mature cells in lacunae Two types: 1. Cartilage: gel-type ground substance for shock absorption and protection 2. Bone: calcified (made rigid by calcium salts, minerals) for weight support

16 B. Supportive connective tissue: Cartilage Cells are in chambers called lacunae Matrix is solid but flexible 3 types are distinguished by types of fibers 1.Hyaline cartilage – fine collagen fibers Location: Nose, ends of long bones and fetal skeleton 2.Elastic cartilage – more elastic fibers than cartilage fibers Location: Outer ear 3.Fibrocartilage – strong collagen fibers Location: Disks between vertebrae 4.2 Connective tissue connects and supports

17 Hyaline Cartilage  Fibro Cartilage  Elastic  Cartilage

18 B. Supportive connective tissue: Bone Highly vascularized Little ground substance Matrix –solid and rigid that is made of collagen and calcium salts Cells: Osteocytes –Located in chambers called lacunae arranged around central canals within matrix –Connected by cytoplasmic extensions that extend through canaliculi Canaliculi: excess blood supply –Canaliculi necessary for nutrient and waste exchange, no diffusion through calcium

19 B. Structures of Bone Osteocytes –Connected by cytoplasmic extensions that extend through canaliculi (small channels through matrix) –Canaliculi necessary for nutrient and waste exchange Figure 4–15 LM X 362 Canaliculi Osteocytes in lacunae Matrix Blood vessels Central canal PERIOSTEUM Fibrous layer Cellular layer

20 B. Supportive connective tissue: Bone Function: –Support & Protection –Levers for movement –Storage of minerals 1.Compact – made of repeating circular units called osteons which contain the hard matrix and living cells and blood vessels Location: Shafts of long bone 2.Spongy – an open, latticework with irregular spaces Location: Ends of long bones 4.2 Connective tissue connects and supports

21 What do bone and cartilage look like? 4.2 Connective tissue connects and supports

22 C. Fluid connective tissue: Blood Made of a fluid matrix called plasma and cellular components that are called formed elements Function: - transport nutrients, wastes and defense cells throughout the body 3 formed elements: 1.Red blood cells – cells that carry oxygen 2.White blood cells – cells that fight infection 3.Platelets – pieces of cells that clot blood 4.2 Connective tissue connects and supports

23 Formed Elements of Blood Erythrocytes (RBCs): carry oxygen Leukocytes (WBCs): defense –Neutrophils, Eosinophils, Basophils, Lymphocytes (B and T cells), Monocytes (Macrophages) Platelets: carry clotting factors Figure 4–12

24 C. Fluid connective tissue: Lymph Matrix is a fluid called lymph White blood cells congregate in this tissue Location: –contained in lymphatic vessels Function: –purify and return fluid to blood 4.2 Connective tissue connects and supports

25 2. Muscle tissue Allows for movement in the body Made of muscle fibers/cells and protein fibers called actin and myosin There are 3 types of muscle tissue in humans: A. Skeletal B. Smooth C. Cardiac 4.3 Muscle tissue moves the body

26 A. Muscle tissue - Skeletal Appearance: long, cylindrical cells, multiple nuclei, striated fibers Location: attached to bone for movement Nature: voluntary movement 4.3 Muscle tissue moves the body

27 B. Muscle tissue – Cardiac Appearance: branched cells with a single nucleus, striations with darker striations called intercalated disks between cells Location: heart Nature: involuntary movement 4.3 Muscle tissue moves the body

28 C. Muscle tissue - Smooth Appearance: spindle-shaped cell with one nucleus, lack striations Location: walls of hollow organs and vessels Nature: involuntary movement 4.3 Muscle tissue moves the body

29 3. Nervous tissue Function –Allows for communication between cells through sensory input, integration of data and motor output Location: –Most in brain and spinal cord: Central Nervous System –2% in Peripheral Nervous System Made of 2 major cell types: A. Neurons B. Neuroglia 4.4 Nervous tissue communicates

30 A. Nervous tissue - neurons Made of dendrites, a cell body and an axon Dendrites carry information toward the cell body Axons carry information towards a cell body 4.4 Nervous tissue communicates

31 Cell Parts of a Neuron Cell body: –contains the nucleus and nucleolus Dendrites: –short branches extending from the cell body –receive incoming signals Axon (nerve fiber): –long, thin extension of the cell body –carries outgoing electrical signals to their destination

32 A. Nervous tissue - neuroglia A collection of cells that support and nourish neurons Outnumber neurons 9:1 Examples are oligodendrocytes, astrocytes and microglia 4.4 Nervous tissue communicates

33 4. Epithelial tissue A groups of cells that form a tight, continuous network Lines body cavities, covers body surfaces and found in glands Cells are anchored by a basement membrane on one side and free on the other side Named after the appearance of cell layers and the shape of the cells There is transitional epithelium that changes in appearance in response to tension 4.5 Epithelial tissue protects

34 Figure 4–1 Free Surface and Attached Surface 1. Apical Surface: exposed to environment, may have: Microvilli: absorption or secretion Cilla: fluid movement 2. Basolateral Surface: attachment to neighboring cells via intercellular connections

35 Classes of Epithelia Based on shape and layers Shape: (all are hexagonal from the top) 1.Squamous: flat, disc shaped nucleus 2.Cuboidal: cube or square, center round nucleus 3.Columnar: tall, basal oval nucleus Table 4–1

36 Layers Simple epithelium: –single layer of cells –Function: absorption, secretion, filtration Stratified epithelium: –2 or more layers of cells –Function: Protection **In stratified, name for apical cell shape**

37 How do we name epithelial tissue? Number of cell layers: Simple: one layer of cells Stratified: more than one layer of cells Pseudostratified: appears to have layers but only has one layer Shape of cell: Cuboidal: cube-shaped Columnar: column-shaped Squamous: flattened 4.5 Epithelial tissue protects

38 Epithelial tissue

39 4.5 Epithelial tissue protects

40 How are cells connected within a tissue? Tight junctions – proteins join and form an impermeable barrier between plasma membranes in a zipper-like fashion Prevents passage of water and solutes Adhesion junctions – cytoskeletal fibers join between cells and have flexibility Gap junctions – a fusion of adjacent plasma membranes with small channels between them that allow small molecules to diffuse –Allow ions to pass –Coordinated contractions in heart muscle 4.6 Cell junction types

41 Cell junctions 4.6 Cell junction types

42 Glandular Epithelia For secretion, makes up glands 1.Endocrine glands: “internally secreting” -secrete into interstital fluid  blood -secretions = hormones -regulate and coordinate activities e.g. pancreas andthyroid 2.Exocrine glands: “externally secreting” -secrete into duct  epithelial surface e.g. digestive enzymes, perspiration, tears, milk, and mucus

43 Exocrine: Types of Secretion 1.Serous Glands: water + enzymes - e.g. parotid salivary gland 2.Mucus Glands: mucin (+water = mucus) - e.g. goblet cell 3.Mixed exocrine glands: (serous + mucus secretion) -e.g. submandibular salivary gland

44 Structure of Multicellular Exocrine Glands Structural classes of exocrine glands Figure 4–7 (1 of 2) Simple Glands = undivided tube shape blind pockets chamberlike

45 Structure of Multicellular Exocrine Glands Figure 4–7 (2 of 2) Compound Glands = Divided tube shaped blind pockets chamberlike

46 Moving from tissue to organs and organ systems An organ is 2 or more tissue types working towards a particular function An organ system is a combination of organs that work together to carry out a particular function 4.7 Integumentary system

47 Body Cavities 4.8 Organ systems

48 Body Cavities Function: –protect organs –permit changes in size and shape of internal organs Two Cavities: 1. Dorsal body cavity: Cranial and Spinal Cavity 2. Ventral body cavity: Thoracic Cavity (heart and lungs) Abdominopelvic Cavity (“guts”- viscera) –Organs enclosed in a cavity are called viscera

49 The Ventral Body Cavity Includes organs of the –Respiratory, cardiovascular, digestive, urinary, and reproductive system Divided by the diaphragm into the thoracic cavity and the abdominopelvic cavity Figure 1–10a

50 Ventral Body Cavity: Abdominal Cavity Also the peritoneal cavity 1.Abdominal Cavity -liver, stomach, spleen, small intestine, and large intestine -Kidneys and pancreas 2.Pelvic Cavity -Inferior large intestine, inferior urinary bladder, and some reproductive organs -Superior urinary bladder, ovaries, and uterus

51 The Body Membranes lining Cavities Mucous membranes –lining of the digestive, respiratory, urinary and reproductive systems Serous membranes –line lungs, heart, abdominal cavity and covers the internal organs; named after their location Pleura: lungs Peritoneum: abdominal cavity and organs Pericardium: heart Synovial membranes –lines the cavities of freely movable joints Meninges – cover the brain and spinal cord 4.8 Organ systems

52 Organ Systems The body is divided into 11 organ systems All organ systems work together Many organs work in more than 1 organ system

53 What are the organ systems of the human body? 4.8 Organ systems

54 What are the organ systems of the human body? 4.8 Organ systems

55 Homeostasis The ability to maintain a relatively constant internal environment in the body The nervous and endocrine systems are key in maintaining homeostasis Changes from the normal tolerance limits results in illness or even death All systems important in maintaining homeostasis 4.9 Homeostasis


57 What are the mechanisms for maintaining homeostasis? Negative feedback Positive feedback 4.9 Homeostasis

58 Negative feedback The primary mechanism for maintaining homeostasis Has two components: sensor control center The output of the system dampens the original stimulus 4.9 Homeostasis

59 Example of negative feedback: Body Temperature

60 Positive feedback A mechanism for increasing the change of the internal environment in one direction An example is the secretion of oxytocin during birth to continually increase uterine contractions Can be harmful such as when a fever is too high and continues to rise 4.9 Homeostasis

61 Homeostasis Requires coordinated efforts of multiple organ systems. Any adjustment made by one physiological system has direct and indirect effects on a variety of other systems. Therefore, the use of homeostasis integrates the human body to allow for the support of life.

62 Structure of the Integument 16% of body mass Composed of: 1.Cutaneous Membrane: 1.Epidermis– Superficial epithelium 2.Dermis – underlying CT with blood supply 2.Accessory Structures: originate in dermis 1.Hair 2.Nails 3.Exocrine Glands Subcutaneous layer –under the skin between the dermis and internal structures where fat is stored

63 Parts of the Integumentary System Figure 5–1

64 Functions of the Integument Protects underlying tissues from infection, exposure and dehydration Excretes salts, water, and organic waste Maintains normal body temp: –conserve and radiate heat Synthesizes Vitamin D3 for calcium metabolism Stores Nutrients and Fat Sensory detection: –Allowing awareness of surroundings –touch, pressure, pain, and temp. Is important for maintaining homeostasis

65 Connections Circulatory system: –blood vessels in the dermis Nervous system: –sensory receptors for pain, touch, and temperature

66 There are two regions of the skin Epidermis Dermis 4.7 Integumentary system

67 The epidermis: The thin, outermost layer of the skin Made of epithelial tissue Cells in the uppermost cells are dead and become filled with keratin thus acting as a waterproof barrier Langerhans cells –a type of white blood cell that help fight pathogens Melanocytes –produce melanin that lend to skin color and protection for UV light Some cells convert cholesterol to vitamin D 4.7 Integumentary system

68 Skin Color Pigment based: epidermal pigments and blood pigments contribute to the color 1.Epidermal Pigmentation 2.Dermal Circulation

69 Skin Color 1.Epidermal Pigmentation A. Carotene: yellow-orange, from diet - converted into Vitamin A - localized to epithelium - functions in normal maintenance of epithelia and photoreceptors - excess accumulates B. Melanin: Brown, from melanocytes - for UV protection

70 1. Epidermal Pigmentation Melanocytes: in stratum basale –Packaged in melanosomes –Transferred to cytoplasm of keratinocytes –Cluster around top side of nucleus –Eventually digested by lysosomes Everyone has ~1000 melanocytes/mm 2 –Pale People: small melansomes –Dark People: larger, greater number of melansomes

71 1. Epidermal Pigmentation Freckles: –Overproduction of melanin form single melanocytes UV exposure: –Some needed for Vitamin D3 production –Excess = damage (DNA mutation) Fibroblasts  altered CT structures –Wrinkles Epidermal cells, melanocytes  cancer –Squamous cell carcinoma –Melanoma

72 What you need to know about skin cancer? 2 of the 3 types that arise in the epidermis: Basal cell carcinoma is the most common yet least deadly form of skin cancer Melanoma is the most deadly form of skin cancer but is the least common What can you do to help prevent this? Stay out of the sun between 10am-3pm Wear protective clothing (tight weave, treated sunglasses, wide-brimmed hat) Use sunscreen with an SPF of at least 15 and protects from UV-A and UV-B rays Don’t use tanning beds 4.7 Integumentary system

73 What might skin cancer look like? 4.7 Integumentary system

74 Skin 2. Dermal Circulation: hemoglobin pigment - Oxygenated blood: - red color, hemoglobin in RBCs, through skin looks pink A) Vasodilation  skin looks more red B) Vasoconstriction  skin looks more pale

75 The Dermis Is located between epidermis and subcutaneous layer Anchors epidermal accessory structures –hair follicles, sweat glands Contains: –All cells of CT proper, accessory organs of integument, blood vessels, lymphatic vessels, nerves, and sensory receptors Has 2 components: –outer papillary layer –deep reticular layer

76 Dermis Papillary layer: –Thin (20%) –Consists: Areolar CT Comprise dermal papillae Capillaries, lymphatics, and sensory neurons –Function: feed epidermis Reticular Layer: –Thick (80%) –Consists: Dense irregular CT Elastic and Collagen fibers –Function: provide strength and flexibility

77 The Hypodermis The subcutaneous layer or hypodermis: –lies below the integument –Not part of cutaneous membrane –Stabilizes position of skin while permitting independent movement of skin and muscles

78 Integumentary Accessory Structures 1.Hair and hair follicles 2.Sebaceous glands 3.Sweat glands 4.Nails: Accessory Structures: –are derived from embryonic epidermis –are located in dermis –project through the skin surface

79 Functions of Hair Function: –Protects and insulates –Guards openings against particles and insects –Is sensitive to very light touch

80 Hair Color red: iron added Range yellow to black due to melanin from melanocytes in hair matrix –Melanin stored in cortex and medulla With age, melanin declines, air pockets in medulla increase = gray or white hair

81 Nails Function: –protect tips from mechanical stress, assist in gripping Consists of dead cells containing hard keratin New nail formed at nail root

82 What are the accessory organs of the skin and why are they important? Includes nails, hair and glands Nails are derived from the epidermis that offer a protective covering Hair follicles are derived from the dermis but hair grows from epidermal cells Oil glands are associated with hair and produce sebum that lubricates hair and skin as well as retards bacterial growth Sweat glands are derived from the dermis and helps to regulate body temperature 4.7 Integumentary system

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