Human Biology 112 Notes - PDF

‫ﻧﺴﺨﺔ ‪ ١٧‬اﻟﻤﺤﺪﺛﺔ ﻟﻠﻜﺘﺎب‬ ‫ﺍﻟﻜﻠﻴـﺎﺕ ﺍﻟﺼﺤﻴـﺔ‬ ‫‪Human biology 112‬‬ ‫ﺩ‪ /‬ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬ ‫‪@gamal_sharawy‬‬ ‫‪0556806264‬‬  ‫ﻓﻘﻂ ﻻ ﻧﺤﻠﻞ ﺑ ﻌﻬﺎ أو ﻣﺸﺎرﻛﺘﻬﺎ‬ ‫ﻟﻠﻤﺸ ﻛ‬ ‫‪Chapter 14 / Nervous System‬‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬...

‫ﻧﺴﺨﺔ ‪ ١٧‬اﻟﻤﺤﺪﺛﺔ ﻟﻠﻜﺘﺎب‬ ‫ﺍﻟﻜﻠﻴـﺎﺕ ﺍﻟﺼﺤﻴـﺔ‬ ‫‪Human biology 112‬‬ ‫ﺩ‪ /‬ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬ ‫‪@gamal_sharawy‬‬ ‫‪0556806264‬‬  ‫ﻓﻘﻂ ﻻ ﻧﺤﻠﻞ ﺑ ﻌﻬﺎ أو ﻣﺸﺎرﻛﺘﻬﺎ‬ ‫ﻟﻠﻤﺸ ﻛ‬ ‫‪Chapter 14 / Nervous System‬‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ 1  Nervous system: Has two major divisions: A) Central nervous system (CNS): consists of the ________ & spinal cord B) Peripheral nervous system (PNS): consists of nerves  which lie outside the CNS @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Three functions of nervous system 1) receives sensory input: – sensory receptors in skin & other organs  respond to external & internal stimuli  by generating nerve signals that travel via PNS to CNS. 2) CNS performs information processing & integration of sensory input = Summing up 3) CNS generates motor output: – Nerve signals which travel from CNS via PNS to effectors (muscles, glands, & organs.) Nervous tissue: two types of cells A) neurons B) neuroglia  Transmit nerve impulses 2  Support & nourish neurons  Three types:  Greatly outnumber neurons. 1) sensory neurons – takes nerve signals from a sensory receptor to CNS  Neuroglia in the CNS: – with long axon covered by myelin sheath 1) Microglia  phagocytic cells  remove bacteria 2) interneuron & debris and metabolic support – lies entirely within the CNS 2) Astrocytes  Structural support to neurons. – communicate between sensory & motor neurons – with short axon not covered by myelin sheath 3) oligodendrocytes  form myelin sheath in CNS 3) motor neuron  Neuroglia in the PNS: – takes nerve impulses away from CNS to an effector (muscle fiber, organ, or gland). – Schwann cells  form myelin sheath in PNS – with long axon covered by myelin sheath @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Neurons have three structures A) Cell body: – Contains the nucleus, other organelles. B) Dendrites: take signals to the cell body. – Short extensions off cell body that receive signals from sensory receptors or other neurons. C) Axon: conducts nerve signals away from the cell body. – The portion of a neuron that conducts nerve impulses. – Individual axons are termed nerve fibers. – Collectively nerve fibers form a _________. – Axons branch into fine endings called axon terminals. 3 Myelin sheath  Covers only long axons  not short ones  Formed when Schwann cells (PNS) or oligodendrocytes (CNS) wrap around an axon many times.  gives nerve fibers their white appearance & serves as an insulator  Multiple sclerosis (MS): – Gray matter of CNS is gray  because no myelinated axons – When myelin breaks down. – White matter of CNS is white  because myelinated axons. – Neurons can’t transmit information  is important in nerve regeneration within PNS if an axon is  Node of Ranvier: accidentally severed – space (gaps) between myelin sheaths @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Synapse  Synapse – is the region close proximity axon terminals of one neuron & dendrite of cell body of another neuron  Synaptic cleft – a small gap that separates sending neuron from receiving neuron.  Neurotransmitter – Molecules transmits action potentials across a synapse. – Stored in synaptic vesicles in axon terminals. 4 – are more than 100 neurotransmitters. – Ex. Acetylcholine / norepinephrine / dopamine / serotonin / glutamate & GABA  The events at a synapse: – Nerve signals travel along an axon & reach an axon terminal. – Calcium ions enter terminal  stimulate synaptic vesicles to merge with the sending membrane. – Neurotransmitter is released into synaptic cleft & diffuses across to receiving membrane. – There, they bind to receptor proteins. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Excitation & Inhibition – Depending on the type of neurotransmitter, the response of the receiving neuron can be: A) Excitation  occurs if the neurotransmitter such as acetylcholine (ACh) causes sodium gates to open  Sodium ions diffuse into the receiving neuron. B) Inhibition  occurs if a neurotransmitter causes potassium ions to exit the receiving neuron.  Removal of the Neurotransmitter: – After neurotransmitter has initiated a response, it is removed from the synaptic cleft by: A) In some synapses, the receiving membrane contains enzymes that rapidly inactivate the neurotransmitter. (For example, acetylcholinesterase (AChE) enzyme breaks down acetylcholine neurotransmitter.) 5 B) In other synapses, the sending membrane rapidly reabsorbs the neurotransmitter  for repackaging in synaptic vesicles or for molecular breakdown. – The short existence of neurotransmitters at a synapse  prevents continuous stimulation of receiving membranes. – If the neurotransmitter were to linger in cleft  the receiving cell would be unable to respond to a new signal from a different cell.  Sensory receptors  detect changes in the environment.  An interneuron ‫ﺗﻜﻤﻠﺔ‬ – can receive input from sensory neurons & from other interneurons in the CNS. – Sum up signals received from other neurons, then communicate with motor neurons. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Neurotransmitter molecules – Acetylcholine (ACh) and norepinephrine  are active in both the CNS and PNS.  In the PNS, they act at neuromuscular junctions.  In the PNS, ACh excites skeletal muscle but inhibits cardiac muscle.  Norepinephrine generally excites smooth muscle.  In the CNS, norepinephrine is important to dreaming, waking, and mood. – Serotonin is involved in thermoregulation, sleeping, emotions, and perception.  Nerve signals are the electrochemical changes that convey information within the nervous system 6  Resting potential (polarization) – the potential energy of a neuron at rest. – Exists because the plasma membrane is polarized. – there is a more positive charge outside the cell, more negative charge inside.  positively outside caused by potassium ions (K+) diffusing out to join sodium ions.  negative inside because of large, negatively charged proteins & other molecules inside the cell because of their size – It is measured in millivolts (mV). @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Action potential. (Depolarization) – occurs in the axons of neurons – Is the process of conduction of nerve signals – A stimulus activates the neuron and begins the action potential. For example, a stimulus for pain neurons in the skin would be the prick of a sharp pin – Sodium Gates (channels) Open  Na+ rushes into the cell – Depolarization.  the inside of the axon to become positive compared to the outside  charge (polarity) inside axon changes from negative to positive.  Threshold  the minimum voltage that must be reached for an action 7 potential to occur. – Equal to −55 mV @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Repolarization. – Na+ channels close and K+ channels open Immediately after depolarization. – K+ flows out of the cell. – The inside of the cell becomes negative again.  Finally, the sodium–potassium pump completes the action potential. – K+ are returned to the inside of cell and Na+ to outside; resting potential is restored.  Unmyelinated axons: – Action potentials stimulate adjacent parts of the axon membrane to produce an action potential. 8 – Conduction can be slow (1 m/s) because each section of axon must be stimulated.  Myelinated fibers, – action potentials only occur at nodes of Ranvier. – This is called saltatory conduction and is much faster (100 m/s).  Refractory period – the period of time immediately after an action potential during which the axon is unable to conduct another action potential. – This ensures the one-way direction of the signal from the cell body down the length of the axon. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Central Nervous System (CNS)= A) the brain & B) the spinal cord  Receives sensory information & initiates motor control.  Both spinal cord & brain are protected by bone  Spinal cord  is surrounded by vertebrae  Brain  is enclosed by the skull  Both spinal cord & brain are wrapped in membranes known as meninges  Meningitis: infection of the meninges; may be caused by either bacterial or viral pathogens  Cerebrospinal fluid:  Found in spaces between the meninges 9  For cushions & protects the CNS  The brain has four ventricles (chambers) that produce & serve as a reservoir for cerebrospinal fluid  Normally, excess cerebrospinal fluid drains away into cardiovascular system. However, blockages can occur  Lumbar puncture: A small amount of this fluid is withdrawn from around spinal cord for laboratory testing  The CNS is composed of two types of nervous tissue  Gray matter  contains cell bodies & short, nonmyelinated axons.  White matter  contains myelinated axons that run together in bundles called tracts. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ A) Brain (cerebrum / diencephalon / cerebellum / & brain stem) 1) Cerebrum  Also called the telencephalon.  The largest part of the brain.  The last center to receive sensory input & carry out integration before commanding voluntary motor responses  Communicates with & coordinates activities of other parts of brain.  It is surrounded by a thin layer of meninges between it & skull  Composed of two cerebral hemispheres – communicate via corpus callosum, an extensive bridge of nerve tracts. 10 – Each cerebral hemisphere divided into 4 lobes: a) Frontal lobe  the most anterior. b) Parietal lobe  posterior to the frontal lobe. c) Occipital lobe  posterior to parietal lobe. d) Temporal lobe  inferior to frontal & parietal lobes. 2) Diencephalon  includes the hypothalamus / thalamus / pineal gland 3) Cerebellum  under the occipital lobe.  Separated from brain stem by the fourth ventricle.  Maintains posture & balance.  Produces smooth, coordinated, voluntary movements. 4) The brain stem  Contains the midbrain, pons, medulla oblongata. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ B) Spinal cord  extends from the base of brain through a large opening in skull called foramen magnum  Travels in the vertebral canal.  Functions of the spinal cord: – provides a means of communication between brain & peripheral nerves – Acts as a gateway for pain signals. – Motor signals from the brain pass down spinal cord & out to the muscles. – The center for thousands of reflex arcs. – also creates reflex arcs for internal organs. The Peripheral Nervous System (PNS) 11  The PNS contains the nerves: A) Cranial nerves (12 pairs)  arise from brain. B) Spinal nerves (31 pairs)  arise from spinal cord.  Ganglia (singular, ganglion)  collections of nerve cell bodies outside CNS.  Nerves  collections of axons (nerve fibers) outside CNS.  The PNS two divisions: A) Somatic PNS  The nerves serve the skin, skeletal muscles, & tendons. B) Autonomic PNS  regulates cardiac & smooth muscles, organs, & glands. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ B) Automatic Nervous System  divided into: 1) the sympathetic & 2) parasympathetic divisions.  These two systems create opposite responses.  Are involuntary.  Innervate all internal organs 1) Sympathetic division. – Active during emergency situations when you might be required to fight or take flight. – Increases the heartbeat 12 – dilates airways for a ready supply of glucose & oxygen. – Inhibits the digestive & urinary organs 2) Parasympathetic division. – Promotes responses associated with a relaxed state. – Ex. promotes digestion of food – slows heart rate. – Can be called the “rest-and-digest” system @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬ ‫أﺣ ﺎء ‪ ١١٢‬ﻣﺴﺎر ﺻ‬ ‫د‪.‬ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ ‫‪13‬‬ ‫‪@gamal_sharawy‬‬ ‫‪0556806264‬‬ ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﺩ‪/‬ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬  ‫ﻓﻘﻂ ﻻ ﻧﺤﻠﻞ ﺑ ﻌﻬﺎ أو ﻣﺸﺎرﻛﺘﻬﺎ‬ ‫ﻟﻠﻤﺸ ﻛ‬ ‫‪Chapter‬‬ ‫‪16‬‬ ‫‪Endocrine‬‬ ‫‪System‬‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Endocrine system  its organs (endocrine glands) produce chemical signals called hormones  which are involved in regulation of other organs.  works very closely with nervous system to maintain homeostasis in the body Endocrine glands 1) The hypothalamus & pituitary glands: – are in the center of the brain 2) The pituitary gland: 1 – has 2 parts, anterior & posterior. 3) The thyroid gland  is in throat (in neck) 4) the parathyroids are 4 tiny glands / posterior to thyroid 5) The thymus gland  is attached to the heart 6) The 2 adrenal glands  on top of kidney 7) the pancreas  Is endocrine & exocrine gland 8) The testes or ovaries are in the groin @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬ ‫أﺣ ﺎء ‪ ١١٢‬ﻣﺴﺎر ﺻ‬ ‫د‪.‬ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ ‫‪2‬‬ ‫‪@gamal_sharawy‬‬ ‫‪0556806264‬‬ ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﺩ‪/‬ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  The hypothalamus – produces two hormones, ADH & oxytocin, which are stored & secreted by the posterior pituitary. – acts as the link between nervous & endocrine systems  posterior pituitary & anterior pituitary glands are similar in: – Both are controlled by the hypothalamus 3  anterior pituitary gland ‫اﻟﺮﺳﻤﺔ اﻟﺼﻔﺤﺔ اﻟﻘﺎدﻣﺔ‬ – is are controlled by the hypothalamus – connected to hypothalamus via a portal system – produce releasing & inhibiting hormones – produce hormones that control other glands – (FSH) = follicle stimulating hormone – (LH) = luteinizing hormone @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬ ‫أﺣ ﺎء ‪ ١١٢‬ﻣﺴﺎر ﺻ‬ ‫د‪.‬ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ ‫‪4‬‬ ‫‪@gamal_sharawy‬‬ ‫‪0556806264‬‬ ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﺩ‪/‬ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ 5 Endocrine gland Exocrine gland – secrete their products – have ducts and secrete their (hormones) into the bloodstream, products into these ducts. which delivers them throughout – The glands’ products are carried the body to the interior of other organs or outside the body. – ‫ﻛل اﻷﻣﺛﻠﺔ اﻟﺳﺎﺑﻖ ﺷرﺣﮭﺎ ﺑﺎﻟﺟدول واﻟرﺳﻣﺔ‬ – e.g., Glands of digestive system ‫اﻟﺧﺎﺻﺔ ﺑﺎﻟﻐدد‬ (the salivary glands) @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Target cells – certain cells that can respond to a specific hormone of endocrine glands – has a receptor protein for that hormone. – The hormone & receptor protein bind together like a key that fits a lock. Comparison of the Endocrine & Nervous System  both nervous system & endocrine system  The nervous system  might affect homeostasis  regulate activities of other systems  uses neurotransmitters 6  use chemical signals  is faster than the endocrine system   use negative feedback mechanisms  is organized to respond rapidly to stimuli  Endocrine system  Communication depends on nerve signals,  is largely composed of glands. conducted in axons, and  uses hormones neurotransmitters, which cross synapses.  effects are slower, but longer lasting  have an very prolonged  Nervous system is composed of neurons. response to stimuli  useful if the stimulus is an external event  takes time to deliver hormones, & it takes time for cells to respond that endangers our safety  we can move  is organized for a slow but prolonged response quickly to avoid being hurt. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Hormones are chemical signals  Hormones are chemical signals  Hormones are a means of communication between cells, between body parts, and even between individuals.  Most hormones act at a distance from where they are secreted.  hormones affect the metabolism of cells that have receptors to bind them  Hormones have a wide range of effects on target cells. – ex. increases the uptake of particular substances (such as glucose) – ex. alters the target cell’s structure in some way. – ex. influence cell metabolism 7  Local hormones:  affect neighboring cells;  they are not carried elsewhere in the bloodstream.  ex, prostaglandins & growth factors. promote cell division and mitosis promoting pain and inflammation  Pheromones  Chemical signals that influence the behavior of other individuals.  ex, animals rely heavily on pheromones to mark territory and attract a mate.  ex, humans also produce pheromones.  a woman who is menstruating @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Mode of action of peptide & steroid hormones Peptide hormone  do not have ability to cross (enter) plasma membrane of target cell  therefore must interact with a receptor on surface of membrane.  Are peptides / proteins /glycoproteins /modified amino acids.  Ex, Most hormones are peptide hormones.  Ex, growth hormone  Ex, epinephrine hormone binds to a receptor on a muscle cell, it breaks glycogen down to glucose for ATP production. 8 – This occurs in steps: 1) Hormone binds to a receptor protein in the plasma membrane. 2) This leads to activation of an enzyme in receptor protein  that changes ATP to cAMP (cyclic adenosine monophosphate) 3) This activates a protein kinase enzyme in the cell  which activates another enzyme, and so forth  called enzyme cascade 4) many molecules of glycogen are broken down to glucose, which leaves cell & enters blood stream.  The hormone  is called the first messenger  cAMP  is called the second messenger. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Receptors usually in nucleus & sometimes in cytoplasm Steroid hormones  Example of a steroid hormone is aldosterone.  derived from cholesterol  have the same complex of four carbon rings  Produced only from the adrenal cortex / the ovaries /the testes  do not bind to plasma membrane receptors.  Because they are hydrophobic (lipid soluble)  they are able to cross (diffuse) through the plasma membrane.  Inside the nucleus, the hormone–receptor complex binds with DNA and activates certain genes to make mRNA 9  Messenger RNA (mRNA) moves to the ribosomes for protein synthesis  act more slowly than peptide hormones  because it takes more time to synthesize new proteins than to activate enzymes already present in cells.  Their action, however, typically lasts longer  Thyroid hormones belong to a class of molecules called the amines, which act in a similar way as steroid hormones @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Both the nervous system & the endocrine system make use of negative feedback mechanisms:  Example on nervous system: – If the blood pressure falls  sensory receptors signal a control center in the brain  This center sends out nerve signals to the arterial walls  so that they constrict  blood pressure rises  now the sensory receptors are no longer stimulated.  Example on endocrine system: – a rise in blood glucose level  causes the pancreas to release insulin  promotes glucose uptake by the liver, muscles, and other cells of the body.  When the blood glucose level falls  the pancreas no longer secretes insulin. 10 @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ﻓﻘﻂ ﻻ ﻧﺤﻠﻞ ﺑ ﻌﻬﺎ أو ﻣﺸﺎرﻛﺘﻬﺎ‬ ‫ﺴﻠﻢ ﻣﺠﺎﻧﺎ ﻟﻠﻤﺸ ﻛ‬ ‫‪Chapter‬‬ ‫‪17‬‬ ‫‪Reproductive‬‬ ‫‪System‬‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ The Human Life Cycle  Sex cells:  body cells:  Nucleus contains 23  Nucleus contains 46 chromosomes chromosomes = 23 pairs:  Is haploid (1n) each pair contains one  Is gamete (Sperm or egg) from both parents  Is diploid (2n)  When sperm (23 chromosomes) fertilizes egg (23 chromosomes)  1 the new cell, called a zygote (2 N) (diploid) or 46 chromosomes.  Zygote  formed by fusing the egg and sperm.  DNA:  Contains genetic instructions.  Distributed among 46 chromosomes within the nucleus of most body cells. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Mitosis:  Meiosis:  chromosome number stays constant.  the chromosome number is reduced from 46 (diploid or 2n)  cell produces exact copies of itself to 23 (haploid or 1n).  is duplication division  called reduction division  ensures that each new cell has 2 N (46  During production of sex cells (gametes) (Sperm or egg) chromosomes)  Is cell division for the purposes of reproduction.  During growth or cell repair  Takes place in testes (during sperm production) (spermatogenesis)  Takes place in ovaries (during egg production) (oogenesis) 2  Also introduces genetic variation: ensuring that new individual is not an exact copy of either parent.  Requires two successive divisions (meiosis I & meiosis II)  Following meiosis  the haploid cells develop into either sperm (males) or eggs (females).  Without meiosis  chromosome number in each generation would double  cells would no longer be able to function  Sperm are much smaller than eggs. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ The male reproductive system Paired testes (singular, testis)  Are male gonads (primary sex organs).  Produce sperm & male sex hormones  lie outside the abdominal cavity, suspended (rest) within sacs called scrotum  Begin development in the abdominal cavity  then descend into scrotum the last 2 months of fetal development. – If the testes do not descend  sterility (inability to produce offspring) (why) 3  The male reproductive organs  because internal temperature of body is too high to produce viable sperm. – testes  to vas deferens  to seminal vesicle  to prostate gland  to bulbourethral gland  is composed of compartments, called lobules, each of which  urethra  runs down through the penis contains one to three tightly coiled seminiferous tubules – seminiferous tubules  the site of spermatogenesis Scrotum  sac that contains the paired testes.  contains interstitial cells.  regulates temperature of testes: – Lie between the seminiferous tubules. – it holds them closer to or farther away from – Produce the male sex hormones (androgens). The most important of the androgens is testosterone. the body, depending on temperature. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Epididymis  Is a tightly coiled duct lying just outside each testis.  Is ducts where sperm mature, and some sperm are stored  Sperm produced by testes mature within epididymis Vas deferens (ductus deferens)  Conduct & store sperm – it passes sperm into ejaculatory duct, then urethra.  Is a small tube ascends to the seminal vesicle  Each one passes into abdominal cavity 4 Penis Several glands contribute to semen  Organ of sexual intercourse 1) A pair seminal vesicle  also contains urethra of the urinary system 2) a single prostate gland 3) A pair bulbourethral gland (Cowper’s glands)  At the time of ejaculation, sperm leave penis – Their secretion makes the semen gelatinous. in a fluid called semen. Semen (seminal fluid)  Slightly basic pH (about 7.5)  Contains the sugar fructose  which serves as an energy source.  Contains prostaglandins  which cause the uterus to contract  to propel the sperm toward the egg @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Spermatogenesis  produces sperm cells  Occurs in seminiferous tubules in testes  First give spermatids then develop into sperms.  Takes 74 days for development from spermatogonia to sperm.  Steps  a spermatogonium (diploid) undergoes mitosis,  becoming 2 primary spermatocytes (diploid) (2n). 5  Primary spermatocytes divide during meiosis I to form two secondary spermatocytes (haploid) (n).  Secondary spermatocytes divide during meiosis  sperm (spermatozoa): have three parts: II to produce four spermatids.  Head  contains a haploid nucleus covered by a cap  Spermatids mature into sperm (spermatozoa). called acrosome (stores enzymes to penetrate the egg)  Sertoli cells  Middle piece  contains mitochondria to provide energy  support, nourish, and regulate the for the movement of tail process of spermatogenesis.  Tail  is a flagellum @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Hormonal regulation (control) in males  The hypothalamus produces GnRH  which stimulates the anterior pituitary to produce gonadotropic hormones (FSH & LH) A) Follicle-Stimulating Hormone (FSH) – promotes production of sperm in seminiferous tubules B) Luteinizing Hormone (LH) – controls production of testosterone by interstitial cells  Testosterone & inhibin exert negative feedback control over hypothalamus & anterior pituitary  this regulates level of testosterone 6 in blood & production of sperm by testes  Testosterone: (main sex hormone in males).  Essential for normal development & functioning of male sex organs  Brings about & maintains male secondary sex characteristics that develop at puberty 1) Males are generally taller than females 2) Broad shoulders, longer legs relative to trunk length 3) Greater muscular development 4) Hair growth on face, chest, other regions (as back) 5) Deeper voices due to a larger larynx with longer vocal cords 6) Receding hairline, male-pattern baldness 7) The Adam’s apple is usually more prominent in males than in females @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ The female reproductive system & genital tract Ovaries  Are the female gonads.  Produce eggs (ova) (singular, ovum).  Produce female sex hormones (estrogen & progesterone)  Lie in shallow depressions, one on each side of the upper pelvic cavity. Uterine tubes (oviducts)(fallopian tubes) Uterus  Conduct eggs from ovaries to uterus.  Houses developing fetus  Is location of fertilization (zygote formation)  Location of development of embryo & fetus 7  Are not attached to the ovaries  they have fingerlike  thick-walled, muscular organ. projections called fimbriae (singular, fimbria).  at its upper end: join to the uterine tubes  After ovulation  the fimbriae sweep egg into a uterine  at its lower end: the cervix enters the vagina tube.  Endometrium  the lining of the uterus.  Then egg is propelled by ciliary movement toward uterus. Supplies nutrients needed for embryonic & fetal  An egg lives approximately 6 to 24 hours development.  Sperm remain viable for 6 days in uterine tube Cervix  then embryo implantation occurs after several days from  Contains opening to uterus fertilization  Embeds in uterine lining (endometrium)  leads to the vaginal canal @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Vagina  Receives penis during sexual intercourse  serves as birth canal  acts as an exit for menstrual flow  its mucosal lining is folded & can stretch.  reside several different types of bacteria  create an acidic environment.  to prevents growth of pathogenic bacteria  but sperm prefer the basic environment provided by seminal fluid Hormonal regulation (control) in female ovarian cycle  Like male, hypothalamus produces GnRH  which stimulates anterior pituitary  8 to produce gonadotropic hormones (FSH & LH) – FSH  stimulates the follicle  to produce primarily estrogen – LH  stimulates ovulation & formation of the corpus luteum  to produce primarily progesterone.  Estrogen & progesterone  exert negative feedback control over the hypothalamus & anterior pituitary  regulates the relative amounts of estrogen & progesterone in blood  the gonadotropic hormones (FSH & LH)  are present in both males & females @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  Estrogen & progesterone.  Both maintain the sexual organs, such as uterus  Both are also required for breast development  Estrogen  is largely responsible for secondary sex characteristics: – Shape of axillary & pubic hair. – Greater fat accumulation under skin  so females have a more rounded appearance than male  Prolactin  is involved in milk production following pregnancy.  Oxytocin  induces milk letdown when a baby begins to nurse. Placenta Fertilization & Pregnancy  Sustains the developing embryo.  Only one sperm is needed to fertilize egg  form a zygote  Originates from both maternal & 9 fetal tissues.  As zygote travels down the uterine tube to uterus  it begins mitosis  Once it is made of many cells, it is called an embryo.  Where exchange between fetal &  The endometrium is now prepared  to receive the developing embryo. maternal blood occurs.  The embryo implants in endometrial lining several days following  Produces human chorionic fertilization. gonadotropin (HCG)  to maintains  Implantation signals the beginning of a pregnancy. the corpus luteum.  An abortion may be spontaneous (referred to as a miscarriage) or – A pregnancy test detects HCG in induced.  Both end with loss of the embryo or fetus the blood or urine @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ Ovarian Cycle: Nonpregnant 10  Stage 1  a primary follicle contains a primary oocyte & begins producing estrogen.  Stage 2  a primary follicle develops into a secondary follicle that contains a secondary oocyte & continues to produce estrogen & some progesterone.  Stage 3  it is a vesicular follicle (a Graafian) – the fluid-filled cavity enlarges to the point that follicle wall balloons out on the surface of the ovary. @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬  fourth stage  ovulation (vesicular follicle bursts & secondary oocyte is released from the ovary.  At stage 5  The remains of vesicular follicle develop into a corpus luteum (a glandlike structure) – a corpus luteum: releases progesterone & some estrogen.  stage 6 (final)  corpus luteum degenerates (disintegrates) if pregnancy does not occur (if egg is not fertilized) & Menstruation occurs  Oocyte: immature egg; contained within a follicle.  Females are born with 2 million follicles but have only 300,000—400,000 by puberty.  Only 400 ever mature; a female produces only one egg per month during her reproductive years.  As the follicle matures during ovarian cycle  it changes from a primary to a secondary to a vesicular (Graafian) 11  Oogenesis  produces egg cells  A primary oocyte (diploid) undergoes meiosis I  give One secondary Oocyte (haploid) +. first polar body  If the secondary oocyte is fertilized by sperm  undergoes meiosis 2  becomes a zygote + second polar body  The polar body  is simply to hold discarded chromosomes @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ ﻣﺴﺎر ﺻ‬١١٢ ‫أﺣ ﺎء‬ ‫ ﺟﻤﺎل اﻟﺸــﻌﺮاوي‬.‫د‬ ‫ﻫﺬە أﻣ ـ ـ ـ ـ ـ ــﺎﻧﺔ‬ ‫ﻻ ﻧﺤــﻠﻞ ﺑ ﻌﻬـ ــﺎ او ﻣﺸ ــﺎرﻛﺘــﻬﺎ ﺄي وﺳ ﻠﺔ‬ ‫ﺴﻠﻢ ﻣﺠ ـ ــﺎﻧﺎﻟﻠﻤﺸ ـ ﻛ ــﻦ ﻓﻘﻂ‬ The function of reproductive system or genitals or organs  Produces gametes (eggs, sperm): – Males  produce sperm within testes & females  produce eggs within ovaries.  Males: transport sperm in ducts & females transport eggs in uterine tubes to uterus.  Females  also protect & nourish the developing fetus until birth:  The penis  delivers sperm to vagina, which also transports menstrual fluid to exterior & acts as birth canal.  The uterus  allows the fertilized egg to develop within the body.  After birth, the breast  provides nourishment.  The testes & ovaries  produce sex hormones which bring about masculinization or feminization 12  Puberty  The time during which a child becomes a sexually competent adult.  Sexual maturity typically occurs between the ages of 10 and 14 in girls and 12 and 16 in boys.  At the completion of puberty, the individual is capable of producing children. ‫ﺗﻣﻧﯾﺎﺗﻲ ﺑﺎﻟﻧﺟﺎح واﻟﺗﻔوق‬ The end @gamal_sharawy 0556806264 ‫ﻭﺍﺗﺲ ﻭﺗﻴﻠﻴﺠﺮﺍﻡ‬ ‫ﲨﺎﻝ ﺍﻟﺸﻌﺮﺍﻭﻱ‬/‫ﺩ‬  ‫ﻓﻘﻂ ﻻ ﻧﺤﻠﻞ ﺑ ﻌﻬﺎ أو ﻣﺸﺎرﻛﺘﻬﺎ‬ ‫ﺴﻠﻢ ﻣﺠﺎﻧﺎ ﻟﻠﻤﺸ ﻛ‬ Chapter 19 Patterns of Chromosome Inheritance  ‫‪1‬‬ ‫ﺗﯿـﻠﯿﺠـﺮام ‪@gamal_sharawy 0556806264 /‬‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫د‪ /‬ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ ‪ /‬ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬  DNA / Gene / Chromosomes / Chromatin / Chromatids  Nucleus  holds all genetic material to direct all functions (proteins) in body Karyotype  Chromatin  DNA-protein complex / When a cell is not undergoing division  A display of chromosomes  Chromosomes: presents in a cell.  When a cell divides  chromatin condenses to form chromosomes  Staining causes chromosomes to  Has instructions that are contained within genes (composed of DNA) have dark & light cross-bands of  Genes  are the units of heredity that control the cell. varying widths & a computer  Contain proteins  that assist in the organizational structure. uses these, in addition to size & shape, to pair up chromosomes.  Normal body cell of humans  has 46 chromosomes (23 pairs) (diploid) 2  22 pairs  autosomes  found in both males & females.  Any cell in the body except red  One pair  sex chromosomes  contain genes that control gender blood cells (lack a nucleus) can  Male  one X + one Y = Xy Y  contains SRY gene  that causes testes to develop be a source of chromosomes for  Female  two X = XX examination  Replicated or duplicated chromosome  In dividing cells  each chromosome is composed of two identical sister chromatids (contain the same genes) joined at centromere  Pair of homologous duplicated chromosomes  contains four chromatids. @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  Cell cycle Cell cycle:  G1 (Growth 1) (gap 1):  is an orderly process that has two parts: interphase & Mototic phase (cell division)  The begin of interphase of the cell cycle A) Interphase:  occurs before DNA replication  Preparations (cells get ready) for division  cell increases in size, doubles its organelles (such  The cell grows larger  number of organelles as mitochondria, ribosomes, etc.) doubles & chromatin doubles (DNA replication)  accumulates materials needed for DNA synthesis  Three stages:  (G1  _____  G2)  the cell performs its normal function.  Most time of cell cycle is spent in interphase  have G0 phase (is a holding stage outside of cell 3 B) Mitotic stage (M) (cell division)  following interphase cycle) a) mitosis  nuclear division b) cytokinesis  cytoplasm division  S stage:  occurs after G1  includes DNA synthesis (replication)  After S stage  each duplicated chromosome is composed of two sister chromatids @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  S stage ‫ﺗﻜﻤﻠﺔ‬  G2 (Growth 2) (gap 2):  Two sister chromatids:  the final portion of the interphase  are held together at a region called centromere  occurs after DNA replication  are identical DNA (they contain the same genes)  cell synthesizes proteins needed for cell division.  remain holds together until anaphase of mitosis  Ex. proteins of microtubules (that form centromere splits.  sister chromatids separated mitotic spindle fibers) & each one is a chromosome.  Time the cell spends in interphase varies widely:  ex. Some cells (as nerve & muscle cells)  not 4 complete S & G2 phases  they permanently arrested in G1  entered Go state.  ex. embryonic cells spend very little time in G1 & complete cell cycle in a few hours. @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬ ‫)‪a) Mitosis  nuclear division 4 phases (prophaseprometaphasemetaphaseanaphase Telophase‬‬ ‫‪5‬‬ ‫ﺗﯿـﻠﯿﺠـﺮام ‪@gamal_sharawy 0556806264 /‬‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫د‪ /‬ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ ‪ /‬ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬ prophase  Chromatin is condensing into chromosomes  So chromosomes coil & become condensed (are visible.)  Each chromosome is composed of two sister chromatids held together at a centromere  Nucleolus disappears & nuclear envelope fragments  centrosomes have duplicated, & they begin moving toward opposite ends of nucleus  spindle fibers appear Prometaphase  Spindle fibers attach to centromeres  Chromosomes are randomly placed in nucleus. Metaphase 6  The spindle is fully formed.  The chromosomes attached to spindle fibers at their centromeres  line up at metaphase plate  The metaphase plate  is a plane perpendicular to axis of spindle & equidistant from poles Anaphase  Centromeres divide  sister chromatids separate & move toward opposite poles  spindle fibers shorten & causes movement of chromosomes.  Sister chromatids are now called chromosomes.  diploid (2n) number of chromosomes moving toward each pole @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬ ______phase  Begins when chromosomes arrive at the poles.  Chromosomes become indistinct chromatin again.  The spindle disappears.  nucleolus & nuclear envelope reappears.  Characterized by the presence of two daughter nuclei. b) Cytokinesis  Is division (separate) of cytoplasm & organelles into two independent daughter cells.  An indentation called a cleavage furrow passes around the circumference of the cell. 7  Actin filaments form a contractile ring  as ring becomes smaller, the cleavage furrow pinches the cell in half.  each cell becomes enclosed by its own plasma membrane. Mitotic spindles  Centrosome  the microtubule organizing center of the cell.  After centrosome duplicate  they separate & form the poles  where they assemble microtubules that make up mitotic spindle fibers.  Each centrosome  contains a pair of centrioles (short cylinders of microtubules)  Aster  an array of microtubules.  The chromosomes are attached to the spindle fibers at their centromeres. @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  ‫‪Meiosis division‬‬ ‫‪8‬‬ ‫ﺗﯿـﻠﯿﺠـﺮام ‪@gamal_sharawy 0556806264 /‬‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫د‪ /‬ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ ‪ /‬ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬  Mitosis Meiosis I Meiosis II Prophase  Prophase I Prophase II  ‫ﻧﻔس اﻟﺷرح اﻟﺳﺎﺑﻖ‬  Synapsis (chromosome pairing):  are similar to  No crossing over  homologous duplicated chromosomes come together and mitosis except in  No synapsis line up side by side (4 chromatids) meiosis II   No chromosome pairing called homologous because they look alike & carry genes nuclei contain for the same traits haploid number of  Crossing over chromosomes.  an exchange of genetic material between non-sister chromatids of homologous pair. 9  Produces chromatids that are no longer identical Metaphase Metaphase I  individual duplicated  homologous pairs of duplicated chromosome independently chromosomes align at the align at metaphase plate (the equator) = Independent metaphase plate Alignment = independent assortment @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  Anaphase Anaphase I Anaphase II  Centromeres split &  homologous pairs of chromosomes with intact  Centromeres split & sister sister chromatids centromeres separate & moves to opposite chromatids separate & moves separate & moves to poles to opposite poles opposite poles  each chromosome still has 2 chromatids  chromosome number is  chromosome number is reduced.  chromosome number is the the same same  Produce 2 diploid cells  Produce 2 haploid cells  Produce 4 haploid cells (gametes = sperms or eggs) 10  ALL  have the same four stages of nuclear division  The events of meiosis II are like those of mitosis  except that in meiosis II the nuclei are haploid. @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  Mitosis Meiosis  One nuclear division  Two nuclear divisions (Meiosis I & Meiosis II)  One interphase  One interphase  replication occurs once prior to meiosis I  DNA does not replicate during interkinesis (time between meiosis I & meiosis II)  DNA replication takes place only once prior to both meiosis & mitosis  The parent cell is diploid (2n);  The parent cell is diploid (2n) daughter cells = new cells  Produce 2 daughter cells (Diploid) (2n)  Produce 4 daughter cells (haploid) (n)  are genetically identical to each  are not genetically identical to each other or to the parent cell 11 other & to the parent cell  are genetically different to each other or to the parent cell  duplication division  reduction division  one diploid (__n) cell give two diploid  produces ____ daughter _____ploid (___n) nuclei (___n) cells  produces ____ daughter ___ploid cells  produces two ___ploid daughter cells  In humans  diploid number (46 chromosomes) is reduced to haploid (___n) number (23 chromosomes) in gametes (i.e., sperm or egg)  chromosome number is the same  chromosome number reduces from diploid (___n) to haploid (____n) @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  Occurrence of mitosis  Occurrence of meiosis  is more common  occurs only at certain times in the life cycle  occurs in all tissues & times during growth & repair (healing) of sexually reproducing organisms  Creates new cells in developing embryo, fetus, & child.  occurs in reproductive organs (gonads) (sex  when fertilized egg (zygote) starts dividing. organs) (testis or ovary) to produces the  Ensures that every cell is diploid (46 chromosomes) gametes  for replacement of cells in adults.  But abnormal mitosis can lead to cancer  Mitosis & meiosis  have specific differences in occurrence & process. 12  Mitosis is balanced by the process of apoptosis (programmed cell death)  Apoptosis  occurs when cells are no longer needed or have become excessively damaged.  Significance (function) of meiosis. 1) keep the chromosome number constant from generation to generation. 2) genetic recombination (variation)  results from crossing-over and independent alignment of chromosomes  to ensures that offspring will be genetically different from each other and their parents.  Generates the diversity needed to survive in changing conditions @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  Gametogenesis (Spermatogenesis & Oogenesis)  Both:  Produce haploid cells  Produce gametes  Produce sex cells  Occurs by meiosis 13 Spermatogenesis Oogenesis  production of sperm in males  the production of eggs in females  Occurs in testes in seminiferous tubules  Occurs in Ovaries  Produce 4 sperms (spermatozoa)  one egg and two or three polar bodies  All four daughter cells become sperms  starting after puberty & is continual  starting before birth and complete after puberty & stop after menopause @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  300,000 sperm are produced per minute, or over  Ovaries contain many immature follicles  which contain 400 million per day primary oocytes arrested in prophase I  Produce only one egg per month  Primary spermatocyte (diploid) (2n) formed by  primary oocyte (diploid) (2n) formed by mitosis mitosis  Primary spermatocyte divides by meiosis I to  primary oocyte divides by meiosis I into one secondary form two secondary spermatocytes (haploid) (n) Oocyte (haploid) & first polar body  Secondary spermatocytes divide by meiosis II to  secondary Oocyte (egg) begins meiosis II but stops at produce four spermatids metaphase II  not complete it unless a sperm fertilizes it 14  secondary Oocyte leaves ovary (ovulation)  enters a uterine tube  If it is fertilized  complete the second meiotic division to give one egg and second polar body  Spermatids mature into 4 sperm (spermatozoa)  give one egg & two or three polar bodies  Polar bodies  hold discarded (unnecessary) chromosomes. & Not receive cytoplasm keeping most cytoplasm in egg @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  Cell Cycle Control by checkpoints & external factors checkpoints  delay the cell cycle until certain conditions are met  For a cell to reproduce successfully  Failure of the cell cycle control mechanisms may result in unrestricted cell growth, or cancer. A) G1 checkpoint  The integrity of the DNA is also checked.  if the cell cycle passes this checkpoint  the cell is committed to divide.  This occurs by proper growth signals, such as growth factors  If the cell does not pass this checkpoint  it can enter G0 (where it performs normal functions but not divide)  Ex  If DNA is damaged  proteins such as p53  can stop the cycle at G1 checkpoint & place the cell in G0. 15  If the DNA can be repaired  it may reenter the cell cycle;  if not  it may undergo apoptosis. B) G2 checkpoint  Prevents initiation of M stage unless chromosomes are duplicated (replicated)  If DNA is damaged as from exposure to solar (UV) radiation or X-rays  arresting cell cycle  allows time for repairing  so not passed on to daughter cells. C) Mitotic (M) checkpoint.  occurs between metaphase & anaphase  to make sure chromosomes are properly attached to spindle  so distributed accurately to daughter cells @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬ external factors  An external signal (as a hormone or growth factor)  can stimulate a cell to divide.  Ex hormone progesterone stimulates cells lining uterus to prepare implantation of a fertilized egg.  It binds to a receptor in the plasma membrane of a target cell.  Signal is then relayed from the receptor to proteins inside the cell.  Proteins form a pathway called signal transduction pathway  they pass signal from one to the next  The last signal activates genes in the nucleus  expression of these genes may stimulate or inhibit cell cycle.  Genes called proto-oncogenes stimulate the cell cycle & prevent apoptosis.  genes called tumor suppressor genes inhibit the cell cycle & promote apoptosis 16 @gamal_sharawy 0556806264 / ‫ﺗﯿـﻠﯿﺠـﺮام‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫ ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬/‫د‬ ‫ ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬/ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ‬  ‫ﻓﻘﻂ ﻻ ﻧﺤﻠﻞ ﺑ ﻌﻬﺎ أو ﻣﺸﺎرﻛﺘﻬﺎ‬ ‫ﺴﻠﻢ ﻣﺠﺎﻧﺎ ﻟﻠﻤﺸ ﻛ‬ ‫‪Chapter‬‬ ‫‪22‬‬ ‫‪DNA Biology‬‬ ‫‪& Technology‬‬  ‫‪DNA and RNA Structure and Function‬‬ ‫‪1‬‬ ‫ﺗﯿـﻠﯿﺠـﺮام ‪@gamal_sharawy 0556806264 /‬‬ ‫أﺣــــــﯿﺎء & ﻛـﯿﻤﯿــﺎء ﺣﯿــﻮﯾـــــﺔ ﻟﻠﻜﻠﯿــــﺎت اﻟﻄــــﺒﯿﺔ‬ ‫د‪ /‬ﺟﻤـــــﺎل اﻟﺸــــــﻌـﺮاوي‬ ‫ﺗﺴﻠﻢ ﻣﺠﺎﻧﺎ ً ﻟﻠﻤﺸﺘﺮﻛﯿﻦ ‪ /‬ﻻ ﻧﺤﻠﻞ ﺑﯿﻌﮭﺎ أو ﻣﺸﺎرﻛﺘﮭﺎ‬  DNA (deoxyribonucleic acid) RNA (ribonucleic acid) Differences  Found in nucleus & mitochondria (small amount)  May be found throughout the cell  Deoxyribose sugar  ribose sugar  Bases  A, C, G, T  Bases are A, C, G, U  project to inside.  Purines  adenine (A) / guanine (G)  Forms the rungs of the ladder  Pyrimidines  cytosine (C) / uracil (U)  Purine (two rings)  adenine (A) / guanine (G)  Pyrimidines (one ring)  cytosine (C) / thymine (T)  Double-stranded (double helix)  Single-stranded  two strands that spiral (twisted) about each other 2  Transcribed to produce RNA  translated to produce proteins  Is genetic material  Stores genetic information  Assists in the processing of genetic information  Contains genes  Involved in gene regulation Similarities  Are nucleic acids  Composed of nucleotides subunits (monomers)  that made from three subunits: 1) phosphate 2) a pentose sugar 3) a nitrogen-containing base  Four different types of bases  Sugar-phosphate