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Ideas to cover

 

  • Animal Tissue
  •  Organs
  • Human organ systems

 

Animal Tissues

 

  • Animal cells are grouped together to form animal tissues
  • Vary in their structure, function, and origin
  •  4 Major types:

– Epithelial tissue

– Connective tissue

– Muscular tissue

– Nervous tissue

 

Animal Tissues – Epithelial

 

  • Cover surfaces (exterior and interior) e.g. skin, blood vessels, esophagus etc.
  • Functions:

– Protective

– Secretion and absorption

  • Can be single layered or multi layered
  •  Regenerative
  • Plasma membrane of cells can be specialized into flagella, cilia, microvilli etc.

 

Animal Tissues – Epithelial

 

  • Different types of epithelial tissues according to number of layers and shape of individual cells making these:

– Simple epithelium: single layer of cells

– Stratified epithelium: two or more layers of cells – Squamous : flattened cells

– Cuboidal: cube shaped cells

– Columnar: vertically elongated

 

Animal Tissues – Epithelial

  • Different types of epithelial tissues according to number of layers and shape of individual cells making these:

– Simple epithelium: single layer of cells

– Stratified epithelium: two or more layers of cells – Squamous : flattened cells

– Cuboidal: cube shaped cells

– Columnar: vertically elongated

 

Animal Tissues – Epithelial

 

 

Animal Tissues – Epithelial

 

 

Animal Tissues – Connective

 

  • Support, connect/bind or separate different types of tissues and organs in the body
  • Consists of:

– Cells:

– Fibres

– Intercellular matrix: fluid, dense, or rigid in accordance with function of tissue

  • E.g. Blood, areolar connective tissue, adipose tissue, compact bone, blood etc.

 

 

Animal Tissues – Muscular tissue

 

  • Consists of elongated cells called muscle fibres
  • Responsible for movement including peristalsis and parturition
  • Also provide supportive function
  • Muscles contain special proteins called contractile proteins: contract and relax to cause movement

 

 

Animal Tissues – Muscular tissue

 

  • Types:

Skeletal (Striated): • Voluntary

  • Show alternate light and dark band(striation)
  • Cells are long cylindrical, unbranched and multinucleate (having multiple nuclei)

– Smooth aka unstriated muscles

  • involuntary, non-striated muscle with tapered ends • E.g. digestive system, urinary tract, blood vessels
  • Long pointed ended uninucleate cells – Cardiac (heart)
  • Involuntary
  • Cells – cylindrical, branched and uninucleate • Have striations

 

 

Animal Tissues – Muscular tissue

 

 

 

Animal Tissues – Nervous

 

  • Ability to initiate and transmit the nerve impulse
  • Found in Brain, spinal cord, nerves • Cells : neurons
  • Several neurons bound together by connective tissue = nerve

 

Organs and Organ Systems

 

  • organ is a group of tissues forming recognizable structures performing specific functions e.g. heart, liver, kidney, stomach etc.
  • An organ system is a group of organs that work together as a biological system to perform one or more functions e.g. digestive system, respiratory system, cardiovascular system etc.

 

Organs and Organ Systems

 

System Function Some organs
Respiratory Breathing: exchange of O2, CO2 nose, mouth, sinus, pharynx, larynx, trachea, bronchi, lungs and diaphragm
Digestive Digestion: breakdown and absorption of nutrients + excretion of waste teeth, tongue, salivary glands, esophagus, stomach,

liver, gall bladder, pancreas, small intestine, large intestine, rectum and anus

Cardiovascular Circulate blood, nutrients, hormones etc. blood, heart, arteries, veins, capillaries
Urinary maintain fluid and electrolyte balance, purify blood and excrete liquid waste kidneys, ureters, bladder and urethra
Integumentary exterior protection of body and thermal regulation skin, hair, exocrine glands, fat, and nails

 

 

Organs and Organ Systems

 

System Function Some organs
Skeletal Structural support and protection, production of blood cells bones, cartilage, ligaments and tendons.
Muscular Movement of body, production of heat skeletal muscles, smooth muscles and cardiac muscle
Endocrine Hormones hypothalamus, pituitary, pineal gland, thyroid, parathyroid and adrenal

glands, ovaries, testes

Lymphatic Return fluids (lymph) to blood stream, aid immune responses, form white blood cells lymph, lymph nodes, lymph vessels, tonsils, spleen, thymus
Nervous Sensing and processing information, controlling body activities brain, spinal cord, nerves, sensory organs
Reproductive Reproduction ovaries, fallopian

tubes, uterus, vagina, penis, testes, vas deferens, seminal vesicles and prostate

 

Human Digestive System

 

  • Biomacromolecules in food can not be directly utilized by our body in original form
  • They need to be broken down and converted into simpler substances
  • Digestion is the process of breaking down of complex biomolecules into simpler form that can be utilized by the body:

– Carbs -> simpler sugars like glucose – Fats -> fatty acids and glycerol

– Proteins -> amino acids

 

 

Human Digestive System

 

  • Stages in food processing:

– Ingestion: taking food into alimentary canal [voluntary]

– Digestion

– Absorption: digested food passes through intestinal wall into blood stream

– Assimilation: absorbed food taken in by body cells and used for energy, growth and repair

– Egestion: elimination of indigestible food waste from the organism

 

Human Digestive System

 

 

Human Digestive System

 

  • Mouth

– Buccal cavity/oral cavity

– Contains teeth, tongue, salivary glands

– Chemical process of digestion starts here

– Saliva contains “salivary amylase” that converts starch into sugar maltose

– Mucus -> helps form “Bolus”

– Mastication -> increases surface available for digestion

 

Human Digestive System

 

  • Tongue presses upward and pushes the “Bolus” to pharynx (common passage for food and air) where “epiglottis” direct the food towards oesophagus [From here actions become involuntary]
  • Travels down oesophagus -> peristalsis -> to stomach

 

Human Digestive System

 

  • Stomach:

– Stores food and breakdown mainly proteins

– Secretes mucous, hydrochloric acid and digestive juices. – Mucous protects inner stomach lining

– HCL -> kills bacteria in food, + reduces pH that is necessary for action of “pepsin”

– Protein [pepsin] -> peptones

– Casein [rennin] -> calcium paracaseinate – Fat [gastric lipase] -> glycerol

– The churned partly digested thick liquid food is called “chyme” -> this passes to small intestine through pyloric sphincter

 

Human Digestive System

 

  • Small intestine:

– The digestive process is completed on partly digested food by pancreatic juices, intestinal juice and bile

– Pancreatic juice:

  • Produced by pancreas and sent to small intestine • Strong digestive action
  • Proteins [trypsin] -> peptones
  • Proteins [chymotrypsin] -> peptides
  • Peptides [carboxy peptidase] -> amino acids • Starch [amylopsin] -> maltose
  • Fats [lipase] -> fatty acid + glycerol

– Bile (alkaline) comes from liver, has no enzyme but contains salts that activate lipase, emulsfiy fats and aid their absorption

– Intestinal juice has similar enzymes to pancreatic juice but lower strength

– Sodium bicarbonate in bile and pancreatic juice reduces acidity – Above reactions occur in duodenum

 

Human Digestive System

 

  • Small intestine [continued]

– After duodenum food goes to “jejunum” and ileum where some absorption starts and digestive enzymes keep on working

  • Peptones + proteoses [Erepsin] -> amino acid • Peptides [Peptidase] -> amino acid
  • Maltose [maltase] -> glucose • Sucrose [sucrase] -> glucose • Lactose [lactase] -> glucose
  • Fats [lipase] -> fatty acids + glycerol – Most absorption occurs in ileum

 

Human Digestive System

 

  • Small intestine [continued]

– After duodenum food goes to “jejunum” and ileum where some absorption starts and digestive enzymes keep on working

  • Peptones+proteoses [Erepsin] -> amino acid • Peptides [Peptidase] -> amino acid
  • Maltose [maltase] -> glucose • Sucrose [sucrase] -> glucose • Lactose [lactase] -> glucose
  • Fats [lipase] -> fatty acids + glycerol – Most absorption occurs in ileum

 

Human Digestive System

 

  • Large intestine:

– The food that could not be broken and absorbed enters large intestine

– Almost no digestion occurs

– Only water and some salt absorption

– Bacterial action produces final waste product -> faeces

 

Human Nervous System

 

  • the part of the human body that coordinates a person’s voluntary and involuntary actions and transmits signals between different parts of the body
  • 2 main parts:

– Central nervous system (CNS)

– Peripheral nervous system (PNS)

  • CNS acts as main switchboard that controls and coordinates the activities of entire nervous system

– Consists of Brain and Spinal cord

 

Human Nervous System

 

  • Brain:

– 3 main divisions:

  • Forebrain: comprises of cerebrum, thalamus and hypothalamus. Processes sensory ino
  • Hindbrain: medulla + cerebellum + pons
  • Midbrain: between above two. Conveys impulses to and fro via the cerebral hemispheres. Contains the “optic lobe” and is particularly concerned with hearing and sight

 

Human Nervous System

 

  • Brain:

– 3 main divisions:

  • Forebrain: comprises of cerebrum, thalamus and hypothalamus. Processes sensory ino
  • Hindbrain: medulla + cerebellum + pons
  • Midbrain: between above two. Conveys impulses to and fro via the cerebral hemispheres. Contains the “optic lobe” and is particularly concerned with visual response
  • Spinal cord -> cable of neurons that extends from the neck down the backbone. The backbone surrounds and protects the spinal cord. It has pathways that carry sensory information to brain and relay command from brain to motor neurons